Sample records for d7-branes elektronische ressource

  1. M5-brane and D-brane scattering amplitudes

    NASA Astrophysics Data System (ADS)

    Heydeman, Matthew; Schwarz, John H.; Wen, Congkao

    2017-12-01

    We present tree-level n-particle on-shell scattering amplitudes of various brane theories with 16 conserved supercharges. These include the world-volume theory of a probe D3-brane or D5-brane in 10D Minkowski spacetime as well as a probe M5-brane in 11D Minkowski spacetime, which describes self interactions of an abelian tensor supermultiplet with 6D (2, 0) supersymmetry. Twistor-string-like formulas are proposed for tree-level scattering amplitudes of all multiplicities for each of these theories. The R symmetry of the D3-brane theory is shown to be SU(4) × U(1), and the U(1) factor implies that its amplitudes are helicity conserving. Each of 6D theories (D5-brane and M5-brane) reduces to the D3-brane theory by dimensional reduction. As special cases of the general M5-brane amplitudes, we present compact formulas for examples involving only the self-dual B field with n = 4, 6, 8.

  2. Highly symmetric D-brane-anti-D-brane effective actions

    NASA Astrophysics Data System (ADS)

    Hatefi, Ehsan

    2017-09-01

    The entire S-matrix elements of four, five and six point functions of D-brane-anti D-brane system are explored. To deal with symmetries of string amplitudes as well as their all order α ' corrections we first address a four point function of one closed string Ramond-Ramond (RR) and two real tachyons on the world volume of brane-anti brane system. We then focus on symmetries of string theory as well as universal tachyon expansion to achieve both string and effective field theory of an RR and three tachyons where the complete algebraic analysis for the whole S-matrix < {V}_{C^{-1}}{V}_{T^{-1}}{V}_{T^0}{V}_{T^0}> was also revealed. Lastly, we employ all the conformal field theory techniques to < {V}_{C^{-1}}{V}_{T^{-1}}{V}_{T^0}{V}_{T^0}{V}_{T^0}> , working out with symmetries of theory and find out the expansion for the amplitude to be able to precisely discover all order singularity structures of D-brane-anti-D-brane effective actions of string theory. Various remarks about the so called generalized Veneziano amplitude and new string couplings are elaborated as well.

  3. T-branes through 3d mirror symmetry

    NASA Astrophysics Data System (ADS)

    Collinucci, Andrés; Giacomelli, Simone; Savelli, Raffaele; Valandro, Roberto

    2016-07-01

    T-branes are exotic bound states of D-branes, characterized by mutually non-commuting vacuum expectation values for the worldvolume scalars. The M/F-theory geometry lifting D6/D7-brane configurations is blind to the T-brane data. In this paper, we make this data manifest, by probing the geometry with an M2-brane. We find that the effect of a T-brane is to deform the membrane worldvolume superpotential with monopole operators, which partially break the three-dimensional flavor symmetry, and reduce super-symmetry from {N} = 4 to {N} = 2. Our main tool is 3d mirror symmetry. Through this language, a very concrete framework is developed for understanding T-branes in M-theory. This leads us to uncover a new class of {N} = 2 quiver gauge theories, whose Higgs branches mimic those of membranes at ADE singularities, but whose Coulomb branches differ from their {N} = 4 counterparts.

  4. Spherical D-brane by tachyon condensation

    NASA Astrophysics Data System (ADS)

    Asakawa, Tsuguhiko; Matsuura, So

    2018-03-01

    We find a novel tachyon condensation which provides a D-brane system with spherical worldvolume in the flat spacetime. The tachyon profile is a deformation of a known D0-brane solution on non-BPS D3-branes in type IIA superstring theory, which realizes a bound state of a spherical D2-brane and a D0-brane. The D0-brane is resolved into the sphere as a U(1) monopole flux of the unit magnetic charge. We show that the system has the correct tension and the RR-coupling. Although the low-energy effective action of the system is the same as that of the dual description of the fuzzy sphere solution of multiple D0-branes, our system cannot be equivalent to the fuzzy sphere. The use of projective modules in describing the tachyon condensation is emphasized.

  5. Microstates of D1-D5(-P) black holes, as interacting D-branes

    NASA Astrophysics Data System (ADS)

    Morita, Takeshi; Shiba, Shotaro

    2015-07-01

    In our previous study (Morita et al., 2014 [1]), we figured out that the thermodynamics of the near extremal black p-branes can be explained as the collective motions of gravitationally interacting elementary p-branes (the p-soup proposal). We test this proposal in the near-extremal D1-D5 and D1-D5-P black holes and show that their thermodynamics also can be explained in a similar fashion, i.e. via the collective motions of the interacting elementary D1-branes and D5-branes (and waves). It may imply that the microscopic origins of these intersecting black branes and the black p-brane are explained in the unified picture. We also argue the relation between the p-soup proposal and the conformal field theory calculations of the D1-D5(-P) black holes in superstring theory.

  6. Formulation of D-brane Dynamics

    NASA Astrophysics Data System (ADS)

    Evans, Thomas

    2012-03-01

    It is the purpose of this paper (within the context of STS rules & guidelines ``research report'') to formulate a statistical-mechanical form of D-brane dynamics. We consider first the path integral formulation of quantum mechanics, and extend this to a path-integral formulation of D-brane mechanics, summing over all the possible path integral sectors of R-R, NS charged states. We then investigate this generalization utilizing a path-integral formulation summing over all the possible path integral sectors of R-R charged states, calculated from the mean probability tree-level amplitude of type I, IIA, and IIB strings, serving as a generalization of all strings described by D-branes. We utilize this generalization to study black holes in regimes where the initial D-brane system is legitimate, and further this generalization to look at information loss near regions of nonlocality on a non-ordinary event horizon. We see here that in these specific regimes, we can calculate a path integral formulation, as describing D0-brane mechanics, tracing the dissipation of entropy throughout the event horizon. This is used to study the information paradox, and to propose a resolution between the phenomena and the correct and expected quantum mechanical description. This is done as our path integral throughout entropy entering the event horizon effectively and correctly encodes the initial state in subtle correlations in the Hawking radiation.

  7. d-Brane Instantons in Type II Orientifolds

    NASA Astrophysics Data System (ADS)

    Blumenhagen, Ralph; Cvetič, Mirjam; Kachru, Shamit; Weigand, Timo

    2009-11-01

    We review recent progress in determining the effects of d-brane instantons in [Formula: see text] supersymmetric compactifications of Type II string theory to four dimensions. We describe the abstract d-brane instanton calculus for holomorphic couplings such as the superpotential, the gauge kinetic function, and higher fermionic F-terms, and we briefly discuss the implications of background fluxes for the instanton sector. We then summarize the concrete consequences of stringy d-brane instantons for the construction of semirealistic models of particle physics or supersymmetry breaking in compact and noncompact geometries.

  8. 5-brane webs for 5d N = 1 G 2 gauge theories

    NASA Astrophysics Data System (ADS)

    Hayashi, Hirotaka; Kim, Sung-Soo; Lee, Kimyeong; Yagi, Futoshi

    2018-03-01

    We propose 5-brane webs for 5d N = 1 G 2 gauge theories. From a Higgsing of the SO(7) gauge theory with a hypermultiplet in the spinor representation, we construct two types of 5-brane web configurations for the pure G 2 gauge theory using an O5-plane or an \\tilde{O5} -plane. Adding flavors to the 5-brane web for the pure G 2 gauge theory is also discussed. Based on the obtained 5-brane webs, we compute the partition functions for the 5d G 2 gauge theories using the recently suggested topological vertex formulation with an O5-plane, and we find agreement with known results.

  9. Finite temperature corrections to tachyon mass in intersecting D-branes

    NASA Astrophysics Data System (ADS)

    Sethi, Varun; Chowdhury, Sudipto Paul; Sarkar, Swarnendu

    2017-04-01

    We continue with the analysis of finite temperature corrections to the Tachyon mass in intersecting branes which was initiated in [1]. In this paper we extend the computation to the case of intersecting D3 branes by considering a setup of two intersecting branes in flat-space background. A holographic model dual to BCS superconductor consisting of intersecting D8 branes in D4 brane background was proposed in [2]. The background considered here is a simplified configuration of this dual model. We compute the one-loop Tachyon amplitude in the Yang-Mills approximation and show that the result is finite. Analyzing the amplitudes further we numerically compute the transition temperature at which the Tachyon becomes massless. The analytic expressions for the one-loop amplitudes obtained here reduce to those for intersecting D1 branes obtained in [1] as well as those for intersecting D2 branes.

  10. Landau-Ginzburg to Calabi-Yau dictionary for D-branes

    NASA Astrophysics Data System (ADS)

    Aspinwall, Paul S.

    2007-08-01

    Based on the work by Orlov (e-print arXiv:math.AG/0503632), we give a precise recipe for mapping between B-type D-branes in a Landau-Ginzburg orbifold model (or Gepner model) and the corresponding large radius Calabi-Yau manifold. The D-branes in Landau-Ginzburg theories correspond to matrix factorizations and the D-branes on the Calabi-Yau manifolds are objects in the derived category. We give several examples including branes on quotient singularities associated with weighted projective spaces. We are able to confirm several conjectures and statements in the literature.

  11. Discrete Torsion, (Anti) de Sitter D4-Brane and Tunneling

    NASA Astrophysics Data System (ADS)

    Singh, Abhishek K.; Pandey, P. K.; Singh, Sunita; Kar, Supriya

    2014-06-01

    We obtain quantum geometries on a vacuum created pair of a (DDbar)3-brane, at a Big Bang singularity, by a local two form on a D4-brane. In fact our analysis is provoked by an established phenomenon leading to a pair creation by a gauge field at a black hole horizon by Stephen Hawking in 1975. Importantly, the five dimensional microscopic black holes are described by an effective non-perturbative curvature underlying a discrete torsion in a second order formalism. In the case for a non-propagating torsion, the effective curvature reduces to Riemannian, which in a low energy limit may describe Einstein vacuum in the formalism. In particular, our analysis suggests that a non-trivial space begin with a hot de Sitter brane-Universe underlying a nucleation of a vacuum pair of (DDbar)-instanton at a Big Bang. A pair of instanton nucleats a D-particle which in turn combines with an anti D-particle to describe a D-string and so on. The nucleation of a pair of higher dimensional pair of brane/anti-brane from a lower dimensional pair may be viewed via an expansion of the brane-Universe upon time. It is in conformity with the conjecture of a branes within a brane presumably in presence of the non-zero modes of two form. Interestingly, we perform a thermal analysis underlying various emergent quantum de Sitter vacua on a D4-brane and argue for the plausible tunneling geometries underlying a thermal equilibrium. It is argued that a de Sitter Schwarzschild undergoes quantum tunneling to an AdS-brane Schwarzschild via Nariai and de Sitter topological black hole.

  12. Teleparallel dark energy in a system of D0-branes

    NASA Astrophysics Data System (ADS)

    Sharma, Umesh Kumar; Sepehri, Alireza; Pradhan, Anirudh

    A new model which allows a non-minimal coupling between gravity and quintessence in the configuration of teleparallel gravity was recently proposed by Geng et al. [“Teleparallel” dark energy, Phys. Lett. B 704 (2011) 384-387] and they named it teleparallel dark energy. Now the main problem which arises is to know what is the source of this dark energy? The answer of this question is given by us in M-theory. This type of dark energy may be produced at three stages in our model. First, one six-dimensional universe is formed by combining and expanding D0-branes. We know that this universe-brane is polarized on two circles and our four-dimensional cosmos and two D1-branes are yielded. At third stage, two D1-branes glued to each other and one D2-brane is formed. This D2 connects our universe with another universe, gives its energy to them and causes the production of dark energy. Thus, the D2-brane is unstable and dissolves in our four-dimensional universes and supplies the needed teleparallel dark energy for expansion. These calculations are extended to M-theory and shown that the amount of teleparallel dark energy which is produced by compactification of universe-branes in M-theory is more than string theory.

  13. 6D thick branes from interacting scalar fields

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dzhunushaliev, Vladimir; Folomeev, Vladimir; Singleton, Douglas

    2008-02-15

    A thick brane in six dimensions is constructed using two scalar fields. The field equations for 6D gravity plus the scalar fields are solved numerically. This thick brane solution shares some features with previously studied analytic solutions, but has the advantage that the energy-momentum tensor which forms the thick brane comes from the scalar fields rather than being put in by hand. Additionally the scalar fields which form the brane also provide a universal, nongravitational trapping mechanism for test fields of various spins.

  14. Linear Sigma Model Toolshed for D-brane Physics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hellerman, Simeon

    Building on earlier work, we construct linear sigma models for strings on curved spaces in the presence of branes. Our models include an extremely general class of brane-worldvolume gauge field configurations. We explain in an accessible manner the mathematical ideas which suggest appropriate worldsheet interactions for generating a given open string background. This construction provides an explanation for the appearance of the derived category in D-brane physic complementary to that of recent work of Douglas.

  15. Extensive numerical study of a D-brane, anti-D-brane system in AdS 5 /CFT 4

    NASA Astrophysics Data System (ADS)

    Hegedűs, Árpád

    2015-04-01

    In this paper the hybrid-NLIE approach of [38] is extended to the ground state of a D-brane anti-D-brane system in AdS/CFT. The hybrid-NLIE equations presented in the paper are finite component alternatives of the previously proposed TBA equations and they admit an appropriate framework for the numerical investigation of the ground state of the problem. Straightforward numerical iterative methods fail to converge, thus new numerical methods are worked out to solve the equations. Our numerical data confirm the previous TBA data. In view of the numerical results the mysterious L = 1 case is also commented in the paper.

  16. AdS5 solutions from M5-branes on Riemann surface and D6-branes sources

    DOE PAGES

    Bah, Ibrahima

    2015-09-24

    Here, we describe the gravity duals of four-dimensional N = 1 superconformal field theories obtained by wrapping M5-branes on a punctured Riemann surface. The internal geometry, normal to the AdS 5 factor, generically preserves two U(1)s, with generators (J +, J –), that are fibered over the Riemann surface. The metric is governed by a single potential that satisfies a version of the Monge-Ampère equation. The spectrum of N = 1 punctures is given by the set of supersymmetric sources of the potential that are localized on the Riemann surface and lead to regular metrics near a puncture. We usemore » this system to study a class of punctures where the geometry near the sources corresponds to M-theory description of D6-branes. These carry a natural (p, q) label associated to the circle dual to the killing vector pJ + + qJ – which shrinks near the source. In the generic case the world volume of the D6-branes is AdS 5 × S 2 and they locally preserve N = 2 supersymmetry. When p = –q, the shrinking circle is dual to a flavor U(1). The metric in this case is non-degenerate only when there are co-dimension one sources obtained by smearing M5-branes that wrap the AdS 5 factor and the circle dual the superconformal R-symmetry. The D6-branes are extended along the AdS 5 and on cups that end on the co-dimension one branes. In the special case when the shrinking circle is dual to the R-symmetry, the D6-branes are extended along the AdS 5 and wrap an auxiliary Riemann surface with an arbitrary genus. When the Riemann surface is compact with constant curvature, the system is governed by a Monge-Ampère equation.« less

  17. D-brane disformal coupling and thermal dark matter

    NASA Astrophysics Data System (ADS)

    Dutta, Bhaskar; Jimenez, Esteban; Zavala, Ivonne

    2017-11-01

    Conformal and disformal couplings between a scalar field and matter occur naturally in general scalar-tensor theories. In D-brane models of cosmology and particle physics, these couplings originate from the D-brane action describing the dynamics of its transverse (the scalar) and longitudinal (matter) fluctuations, which are thus coupled. During the post-inflationary regime and before the onset of big bang nucleosynthesis (BBN), these couplings can modify the expansion rate felt by matter, changing the predictions for the thermal relic abundance of dark matter particles and thus the annihilation rate required to satisfy the dark matter content today. We study the D-brane-like conformal and disformal couplings effect on the expansion rate of the Universe prior to BBN and its impact on the dark matter relic abundance and annihilation rate. For a purely disformal coupling, the expansion rate is always enhanced with respect to the standard one. This gives rise to larger cross sections when compared to the standard thermal prediction for a range of dark matter masses, which will be probed by future experiments. In a D-brane-like scenario, the scale at which the expansion rate enhancement occurs depends on the string coupling and the string scale.

  18. Axionic D3-D7 inflation

    NASA Astrophysics Data System (ADS)

    Burgess, C. P.; Cline, J. M.; Postma, M.

    2009-03-01

    We study the motion of a D3 brane moving within a Type IIB string vacuum compactified to 4D on K3 × T2/Z2 in the presence of D7 and O7 planes. We work within the effective 4D supergravity describing how the mobile D3 interacts with the lightest bulk moduli of the compactification, including the effects of modulus-stabilizing fluxes. We seek inflationary solutions to the resulting equations, performing our search numerically in order to avoid resorting to approximate parameterizations of the low-energy potential. We consider uplifting from D-terms and from the supersymmetry-breaking effects of anti-D3 branes. We find examples of slow-roll inflation (with anti-brane uplifting) with the mobile D3 moving along the toroidal directions, falling towards a D7-O7 stack starting from the antipodal point. The inflaton turns out to be a linear combination of the brane position and the axionic partner of the K3 volume modulus, and the similarity of the potential along the inflaton direction with that of racetrack inflation leads to the prediction ns <= 0.95 for the spectral index. The slow roll is insensitive to most of the features of the effective superpotential, and requires a one-in-104 tuning to ensure that the torus is close to square in shape. We also consider D-term inflation with the D3 close to the attractive D7, but find that for a broad (but not exhaustive) class of parameters the conditions for slow roll tend to destabilize the bulk moduli. In contrast to the axionic case, the best inflationary example of this kind requires the delicate adjustment of potential parameters (much more than the part-per-mille level), and gives inflation only at an inflection point of the potential (and so suffers from additional fine-tuning of initial conditions to avoid an overshoot problem).

  19. Minimal left-right symmetric intersecting D-brane model

    NASA Astrophysics Data System (ADS)

    Anchordoqui, Luis A.; Antoniadis, Ignatios; Goldberg, Haim; Huang, Xing; Lüst, Dieter; Taylor, Tomasz R.

    2017-01-01

    We investigate left-right symmetric extensions of the standard model based on open strings ending on D-branes, with gauge bosons due to strings attached to stacks of D-branes and chiral matter due to strings stretching between intersecting D-branes. The left-handed and right-handed fermions transform as doublets under S p (1 )L and S p (1 )R, and so their masses must be generated by the introduction of Higgs fields in a bifundamental (2 ,2 ) representation under the two S p (1 ) gauge groups. For such D-brane configurations the left-right symmetry must be broken by Higgs fields in the doublet representation of S p (1 )R and therefore Majorana mass terms are suppressed by some higher physics scale. The left-handed and right-handed neutrinos pair up to form Dirac fermions which control the decay widths of the right-handed W' boson to yield comparable branching fractions into dilepton and dijet channels. Using the most recent searches at LHC13 Run II with 2016 data we constrain the (gR,mW') parameter space. Our analysis indicates that independent of the coupling strength gR, gauge bosons with masses mW'≳3.5 TeV are not ruled out. As the LHC is just beginning to probe the TeV scale, significant room for W' discovery remains.

  20. B-branes and supersymmetric quivers in 2d

    NASA Astrophysics Data System (ADS)

    Closset, Cyril; Guo, Jirui; Sharpe, Eric

    2018-02-01

    We study 2d N = (0, 2) supersymmetric quiver gauge theories that describe the low-energy dynamics of D1-branes at Calabi-Yau fourfold (CY4) singularities. On general grounds, the holomorphic sector of these theories — matter content and (classical) superpotential interactions — should be fully captured by the topological B-model on the CY4. By studying a number of examples, we confirm this expectation and flesh out the dictionary between B-brane category and supersymmetric quiver: the matter content of the supersymmetric quiver is encoded in morphisms between B-branes (that is, Ext groups of coherent sheaves), while the superpotential interactions are encoded in the A ∞ algebra satisfied by the morphisms. This provides us with a derivation of the supersymmetric quiver directly from the CY4 geometry. We also suggest a relation between triality of N = (0 ,2) gauge theories and certain mutations of exceptional collections of sheaves. 0d N = 1 supersymmetric quivers, corresponding to D-instantons probing CY5 singularities, can be discussed similarly.

  1. Instantons in Script N = 2 magnetized D-brane worlds

    NASA Astrophysics Data System (ADS)

    Billò, Marco; Frau, Marialuisa; Pesando, Igor; Di Vecchia, Paolo; Lerda, Alberto; Marotta, Raffaele

    2007-10-01

    In a toroidal orbifold of type IIB string theory we study instanton effects in Script N = 2 super Yang-Mills theories engineered with systems of wrapped magnetized D9 branes and Euclidean D5 branes. We analyze the various open string sectors in this brane system and study the 1-loop amplitudes described by annulus diagrams with mixed boundary conditions, explaining their rôle in the stringy instanton calculus. We show in particular that the non-holomorphic terms in these annulus amplitudes precisely reconstruct the appropriate Kähler metric factors that are needed to write the instanton correlators in terms of purely holomorphic variables. We also explicitly derive the correct holomorphic structure of the instanton induced low energy effective action in the Coulomb branch.

  2. Ressources pour les personnes atteintes de démence

    PubMed Central

    Frank, Christopher; Feldman, Sid; Schulz, Mary

    2011-01-01

    Résumé Objectif Résumer les services offerts par la Société Alzheimer et discuter des autres sources de soutien et d’information à la disposition des personnes atteintes de démence. Sources de l’information On a fait une recension dans Ovid MEDLINE à l’aide des expressions dementia, Alzheimer disease, community health services utilization et caregiver stress. Message principal Il a été démontré qu’il est bénéfique aux patients et aux aidants si le diagnostic de la démence est posé tôt dans la maladie. Une consultation auprès de la Société Alzheimer peut aider dans la prise en charge non pharmacologique de la démence au moment du diagnostic et en tout temps durant l’évolution de la maladie. Parmi les services offerts, on peut mentionner des renseignements au sujet de la démence, le soutien aux aidants, la coordination des services communautaires et une grande diversité de ressources écrites à l’intention des patients et des aidants. Là où il est offert, le programme Premier lien peut aider avec l’orientation vers des services en minimisant la nécessité pour les patients ou les aidants de communiquer eux-mêmes avec les filiales locales de la Société. On discute aussi d’autres ressources, y compris les soins de répit et les approches technologiques pour prendre en charge l’errance. Conclusion La Société Alzheimer joue un rôle important dans la prise en charge de la démence et les médecins de famille devraient toujours envisager d’y référer leurs patients au moment du diagnostic, quelle que soit la gravité de l’état. Premier lien, quand il est accessible, peut faciliter le contact avec les services. Des ressources comme les soins de répit et les programmes de jour devraient toujours être considérés lorsqu’ils sont disponibles.

  3. Brane - Anti-Brane Democracy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rajaraman, Arvind

    2003-06-02

    We suggest a duality invariant formula for the entropy and temperature of nonextreme black holes in supersymmetric string theory. The entropy is given in terms of the duality invariant parameter of the deviation from extremality and 56 SU(8) covariant central charges. It interpolates between the entropies of Schwarzschild solution and extremal solutions with various amount of unbroken supersymmetries and therefore serves for classification of black holes in supersymmetric string theories. We introduce the second auxiliary 56 via E(7) symmetric constraint. The symmetric and antisymmetric combinations of these two multiplets are related via moduli to the corresponding two fundamental representations ofmore » E(7): brane and anti-brane ''numbers.'' Using the CPT as well as C symmetry of the entropy formula and duality one can explain the mysterious simplicity of the non-extreme black hole area formula in terms of branes and anti-branes.« less

  4. Holographic entanglement entropy and entanglement thermodynamics of 'black' non-susy D3 brane

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Aranya; Roy, Shibaji

    2018-06-01

    Like BPS D3 brane, the non-supersymmetric (non-susy) D3 brane of type IIB string theory is also known to have a decoupling limit and leads to a non-supersymmetric AdS/CFT correspondence. The throat geometry in this case represents a QFT which is neither conformal nor supersymmetric. The 'black' version of the non-susy D3 brane in the decoupling limit describes a QFT at finite temperature. Here we first compute the entanglement entropy for small subsystem of such QFT from the decoupled geometry of 'black' non-susy D3 brane using holographic technique. Then we study the entanglement thermodynamics for the weakly excited states of this QFT from the asymptotically AdS geometry of the decoupled 'black' non-susy D3 brane. We observe that for small subsystem this background indeed satisfies a first law like relation with a universal (entanglement) temperature inversely proportional to the size of the subsystem and an (entanglement) pressure normal to the entangling surface. Finally we show how the entanglement entropy makes a cross-over to the thermal entropy at high temperature.

  5. Brane Inflation, Solitons and Cosmological Solutions: I

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, P.

    2005-01-25

    In this paper we study various cosmological solutions for a D3/D7 system directly from M-theory with fluxes and M2-branes. In M-theory, these solutions exist only if we incorporate higher derivative corrections from the curvatures as well as G-fluxes. We take these corrections into account and study a number of toy cosmologies, including one with a novel background for the D3/D7 system whose supergravity solution can be completely determined. Our new background preserves all the good properties of the original model and opens up avenues to investigate cosmological effects from wrapped branes and brane-antibrane annihilation, to name a few. We alsomore » discuss in some detail semilocal defects with higher global symmetries, for example exceptional ones, that occur in a slightly different regime of our D3/D7 model. We show that the D3/D7 system does have the required ingredients to realize these configurations as non-topological solitons of the theory. These constructions also allow us to give a physical meaning to the existence of certain underlying homogeneous quaternionic Kahler manifolds.« less

  6. Thick de Sitter brane solutions in higher dimensions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dzhunushaliev, Vladimir; Department of Physics and Microelectronic Engineering, Kyrgyz-Russian Slavic University, Bishkek, Kievskaya Str. 44, 720021, Kyrgyz Republic; Folomeev, Vladimir

    2009-01-15

    We present thick de Sitter brane solutions which are supported by two interacting phantom scalar fields in five-, six-, and seven-dimensional spacetime. It is shown that for all cases regular solutions with anti-de Sitter asymptotic (5D problem) and a flat asymptotic far from the brane (6D and 7D cases) exist. We also discuss the stability of our solutions.

  7. Global embeddings for branes at toric singularities

    NASA Astrophysics Data System (ADS)

    Balasubramanian, Vijay; Berglund, Per; Braun, Volker; García-Etxebarria, Iñaki

    2012-10-01

    We describe how local toric singularities, including the Toric Lego construction, can be embedded in compact Calabi-Yau manifolds. We study in detail the addition of D-branes, including non-compact flavor branes as typically used in semi-realistic model building. The global geometry provides constraints on allowable local models. As an illustration of our discussion we focus on D3 and D7-branes on (the partially resolved) ( dP 0)3 singularity, its embedding in a specific Calabi-Yau manifold as a hypersurface in a toric variety, the related type IIB orientifold compactification, as well as the corresponding F-theory uplift. Our techniques generalize naturally to complete intersections, and to a large class of F-theory backgrounds with singularities.

  8. 1/2-BPS D-branes from covariant open superstring in AdS4 × CP3 background

    NASA Astrophysics Data System (ADS)

    Park, Jaemo; Shin, Hyeonjoon

    2018-05-01

    We consider the open superstring action in the AdS4 × CP 3 background and investigate the suitable boundary conditions for the open superstring describing the 1/2-BPS D-branes by imposing the κ-symmetry of the action. This results in the classification of 1/2-BPS D-branes from covariant open superstring. It is shown that the 1/2-BPS D-brane configurations are restricted considerably by the Kähler structure on CP 3. We just consider D-branes without worldvolume fluxes.

  9. Strings, boundary fermions and coincident D-branes

    NASA Astrophysics Data System (ADS)

    Wulff, Linus

    2007-01-01

    This thesis describes an attempt to write down covariant actions for coincident D-branes using so-called boundary fermions instead of matrices to describe the non-abelian fields. These fermions can be thought of as Chan-Paton degrees of freedom for the open string. It is shown that by gauge-fixing and by suitably quantizing these boundary fermions the non-abelian action that is known, the Myers action, can be reproduced. Furthermore it is shown that under natural assumptions, unlike the Myers action, the action formulated using boundary fermions also posseses kappa-symmetry when formulated on superspace. Another aspect of string theory discussed in this thesis is that of tensionless strings. These are of great interest for example because of their possible relation to higher spin gauge theories via the AdS/CFT-correspondence. The tensionless superstring in a plane wave background, a Penrose limit of the near-horizon geometry of a stack of D3-branes, is considered and compared to the tensile case.

  10. Dualities of deformed N=2 SCFTs from link monodromy on D3-brane states

    NASA Astrophysics Data System (ADS)

    Grassi, Antonella; Halverson, James; Ruehle, Fabian; Shaneson, Julius L.

    2017-09-01

    We study D3-brane theories that are dually described as deformations of two different N=2 superconformal theories with massless monopoles and dyons. These arise at the self-intersection of a seven-brane in F-theory, which cuts out a link on a small three-sphere surrounding the self-intersection. The spectrum is studied by taking small loops in the three-sphere, yielding a link-induced monodromy action on string junction D3-brane states, and subsequently quotienting by the monodromy. This reduces the differing flavor algebras of the N=2 theories to the same flavor algebra, as required by duality, and projects out charged states, yielding an N=1 superconformal theory on the D3-brane. In one, a deformation of a rank one Argyres-Douglas theory retains its SU(2) flavor symmetry and exhibits a charge neutral flavor triplet that is comprised of electron, dyon, and monopole string junctions. From duality we argue that the monodromy projection should also be imposed away from the conformal point, in which case the D3-brane field theory appears to exhibit confinement of electrons, dyons, and monopoles. We will address the mathematical counterparts in a companion paper.

  11. Charged chiral fermions from M5-branes

    NASA Astrophysics Data System (ADS)

    Lambert, Neil; Owen, Miles

    2018-04-01

    We study M5-branes wrapped on a multi-centred Taub-NUT space. Reducing to String Theory on the S 1 fibration leads to D4-branes intersecting with D6-branes. D-braneology shows that there are additional charged chiral fermions from the open strings which stretch between the D4-branes and D6-branes. From the M-theory point of view the appearance of these charged states is mysterious as the M5-branes are wrapped on a smooth manifold. In this paper we show how these states arise in the M5-brane worldvolume theory and argue that are governed by a WZWN-like model where the topological term is five-dimensional.

  12. On D-brane -anti D-brane effective actions and their all order bulk singularity structures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hatefi, Ehsan; Institute for Theoretical Physics, TU Wien,Wiedner Hauptstrasse 8-10/136, A-1040 Vienna

    All four point functions of brane anti brane system including their correct all order α{sup ′} corrections have been addressed. All five point functions of one closed string Ramond-Ramond (RR), two real tachyons and either one gauge field or the scalar field in both symmetric and asymmetric pictures have also been explored. The entire analysis of is carried out. Not only does it fix the vertex operator of RR in asymmetric picture and in higher point functions of string theory amplitudes but also it confirms the fact that there is no issue of picture dependence of the mixed closed RR,more » gauge fields, tachyons and fermion fields in all symmetric or anti symmetric ones. We compute S-matrix in the presence of a transverse scalar field, two real tachyons and that reveals two different kinds of bulk singularity structures, involving an infinite number of u-channel gauge field and (u+s{sup ′}+t{sup ′})-channel scalar bulk poles. In order to produce all those bulk singularity structures, we define various couplings at the level of the effective field theory that involve the mixing term of Chern-Simons coupling (with C-potential field) and a covariant derivative of the scalar field that comes from the pull-back of brane. Eventually we explore their all order α{sup ′} corrections in the presence of brane anti brane system where various remarks will be also pointed out.« less

  13. Fine-tuning with brane-localized flux in 6D supergravity

    NASA Astrophysics Data System (ADS)

    Niedermann, Florian; Schneider, Robert

    2016-02-01

    There are claims in the literature that the cosmological constant problem could be solved in a braneworld model with two large (micron-sized) supersymmetric extra dimensions. The mechanism relies on two basic ingredients: first, the cosmological constant only curves the compact bulk geometry into a rugby shape while the 4D curvature stays flat. Second, a brane-localized flux term is introduced in order to circumvent Weinberg's fine-tuning argument, which otherwise enters here through a backdoor via the flux quantization condition. In this paper, we show that the latter mechanism does not work in the way it was designed: the only localized flux coupling that guarantees a flat on-brane geometry is one which preserves the scale invariance of the bulk theory. Consequently, Weinberg's argument applies, making a fine-tuning necessary again. The only remaining window of opportunity lies within scale invariance breaking brane couplings, for which the tuning could be avoided. Whether the corresponding 4D curvature could be kept under control and in agreement with the observed value will be answered in our companion paper [1].

  14. Brane-World Gravity.

    PubMed

    Maartens, Roy; Koyama, Kazuya

    2010-01-01

    The observable universe could be a 1+3-surface (the "brane") embedded in a 1+3+ d -dimensional spacetime (the "bulk"), with Standard Model particles and fields trapped on the brane while gravity is free to access the bulk. At least one of the d extra spatial dimensions could be very large relative to the Planck scale, which lowers the fundamental gravity scale, possibly even down to the electroweak (∼ TeV) level. This revolutionary picture arises in the framework of recent developments in M theory. The 1+10-dimensional M theory encompasses the known 1+9-dimensional superstring theories, and is widely considered to be a promising potential route to quantum gravity. At low energies, gravity is localized at the brane and general relativity is recovered, but at high energies gravity "leaks" into the bulk, behaving in a truly higher-dimensional way. This introduces significant changes to gravitational dynamics and perturbations, with interesting and potentially testable implications for high-energy astrophysics, black holes, and cosmology. Brane-world models offer a phenomenological way to test some of the novel predictions and corrections to general relativity that are implied by M theory. This review analyzes the geometry, dynamics and perturbations of simple brane-world models for cosmology and astrophysics, mainly focusing on warped 5-dimensional brane-worlds based on the Randall-Sundrum models. We also cover the simplest brane-world models in which 4-dimensional gravity on the brane is modified at low energies - the 5-dimensional Dvali-Gabadadze-Porrati models. Then we discuss co-dimension two branes in 6-dimensional models.

  15. Strong coupling in F-theory and geometrically non-Higgsable seven-branes

    NASA Astrophysics Data System (ADS)

    Halverson, James

    2017-06-01

    Geometrically non-Higgsable seven-branes carry gauge sectors that cannot be broken by complex structure deformation, and there is growing evidence that such configurations are typical in F-theory. We study strongly coupled physics associated with these branes. Axiodilaton profiles are computed using Ramanujan's theories of elliptic functions to alternative bases, showing explicitly that the string coupling is O (1) in the vicinity of the brane; that it sources nilpotent SL (2 , Z) monodromy and therefore the associated brane charges are modular; and that essentially all F-theory compactifications have regions with order one string coupling. It is shown that non-perturbative SU (3) and SU (2) seven-branes are related to weakly coupled counterparts with D7-branes via deformation-induced Hanany-Witten moves on (p , q) string junctions that turn them into fundamental open strings; only the former may exist for generic complex structure. D3-brane near these and the Kodaira type II seven-branes probe Argyres-Douglas theories. The BPS states of slightly deformed theories are shown to be dyonic string junctions.

  16. Standard 4D gravity on a brane in six-dimensional flux compactifications

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Peloso, Marco; Sorbo, Lorenzo; Tasinato, Gianmassimo

    We consider a six-dimensional space-time, in which two of the dimensions are compactified by a flux. Matter can be localized on a codimension one brane coupled to the bulk gauge field and wrapped around an axis of symmetry of the internal space. By studying the linear perturbations around this background, we show that the gravitational interaction between sources on the brane is described by Einstein 4D gravity at large distances. Our model provides a consistent setup for the study of gravity in the rugby (or football) compactification, without having to deal with the complications of a deltalike, codimension two brane.more » To our knowledge, this is the first complete study of gravity in a realistic brane model with two extra dimensions, in which the mechanism of stabilization of the extra space is fully taken into account.« less

  17. D-brane instantons and the effective field theory of flux compactifications

    NASA Astrophysics Data System (ADS)

    Uranga, Angel M.

    2009-01-01

    We provide a description of the effects of fluxes on euclidean D-brane instantons purely in terms of the 4d effective action. The effect corresponds to the dressing of the effective non-perturbative 4d effective vertex with 4d flux superpotential interactions, generated when the moduli fields made massive by the flux are integrated out. The description in terms of effective field theory allows a unified description of non-perturbative effects in all flux compactifications of a given underlying fluxless model, globally in the moduli space of the latter. It also allows us to describe explicitly the effects on D-brane instantons of fluxes with no microscopic description, like non-geometric fluxes. At the more formal level, the description has interesting connections with the bulk-boundary map of open-closed two-dimensional topological string theory, and with the Script N = 1 special geometry.

  18. Brane Physics in M-theory

    NASA Astrophysics Data System (ADS)

    Argurio, Riccardo

    1998-07-01

    The thesis begins with an introduction to M-theory (at a graduate student's level), starting from perturbative string theory and proceeding to dualities, D-branes and finally Matrix theory. The following chapter treats, in a self-contained way, of general classical p-brane solutions. Black and extremal branes are reviewed, along with their semi-classical thermodynamics. We then focus on intersecting extremal branes, the intersection rules being derived both with and without the explicit use of supersymmetry. The last three chapters comprise more advanced aspects of brane physics, such as the dynamics of open branes, the little theories on the world-volume of branes and how the four dimensional Schwarzschild black hole can be mapped to an extremal configuration of branes, thus allowing for a statistical interpretation of its entropy. The original results were already reported in hep-th/9701042, hep-th/9704190, hep-th/9710027 and hep-th/9801053.

  19. Accidental SUSY: enhanced bulk supersymmetry from brane back-reaction

    NASA Astrophysics Data System (ADS)

    Burgess, C. P.; van Nierop, L.; Parameswaran, S.; Salvio, A.; Williams, M.

    2013-02-01

    We compute how bulk loops renormalize both bulk and brane effective interactions for codimension-two branes in 6D gauged chiral supergravity, as functions of the brane tension and brane-localized flux. We do so by explicitly integrating out hyper- and gauge-multiplets in 6D gauged chiral supergravity compactified to 4D on a flux-stabilized 2D rugby-ball geometry, specializing the results of a companion paper, arXiv:1210.3753, to the supersymmetric case. While the brane back-reaction generically breaks supersymmetry, we show that the bulk supersymmetry can be preserved if the amount of brane- localized flux is related in a specific BPS-like way to the brane tension, and verify that the loop corrections to the brane curvature vanish in this special case. In these systems it is the brane-bulk couplings that fix the size of the extra dimensions, and we show that in some circumstances the bulk geometry dynamically adjusts to ensure the supersymmetric BPS-like condition is automatically satisfied. We investigate the robustness of this residual supersymmetry to loops of non-supersymmetric matter on the branes, and show that supersymmetry-breaking effects can enter only through effective brane-bulk interactions involving at least two derivatives. We comment on the relevance of this calculation to proposed applications of codimension-two 6D models to solutions of the hierarchy and cosmological constant problems.

  20. Supersymmetric Localization and Probe Branes in the AdS/CFT correspondence

    NASA Astrophysics Data System (ADS)

    Robinson, Brandon

    In this thesis, a precise, rigorous test of probe brane holography will be constructed. Since its discovery, the AdS/CFT correspondence has provided a window into the strongly coupled dynamics of supersymmetric gauge theories. The ability to include degrees of freedom that provide analogs for the physics of heavy quarks via the probe brane paradigm has further expanded the utility of the duality. The deformation away from a strictly conformal theory by the addition of flavor degrees of freedom induces a Landau pole outside of the 't Hooft limit where Nc → infinity and Nf/Nc " 1, which invites questions about the utility of the probe brane paradigm. Following from the recent application equivariant localization to massive supersymmetric gauge theories on curved backgrounds, a precise question can be formulated to compare, e.g., the free energy of a supersymmetric probe brane embedding and that of the localized dual field theory. This thesis will apply those concepts to the D3/D7 probe brane system dual to Nf N = 2 fundamental hypermultiplets on an S4 and the D3/D5 probe brane system dual to Nf N = 2 fundamental hypermultiplets living on a co-dimension one defect- an equatorial S3 ⊂ S4. In that framework, exact matching to the localization results are found.

  1. "big" Divisor D3/D7 Swiss-Cheese Phenomenology

    NASA Astrophysics Data System (ADS)

    Misra, Aalok

    We review progress made over the past couple of years in the field of Swiss-Cheese Phenomenology involving a mobile spacetime filling D3-brane and stack(s) of fluxed D7-branes wrapping the "big" (as opposed to the "small") divisor in (the orientifold of (a) Swiss-Cheese Calabi-Yau. The topics reviewed include reconciliation of large volume cosmology and phenomenology, evaluation of soft supersymmetry breaking parameters, one-loop RG-flow equations' solutions for scalar masses, obtaining fermionic (possibly first two generations' quarks/leptons) mass scales in the {O}(MeV--GeV)-regime as well as (first two generations') neutrino masses (and their one-loop RG flow) of around an eV. The heavy sparticles and the light fermions indicate the possibility of "split SUSY" large volume scenario.

  2. Towards a systematic construction of realistic D-brane models on a del Pezzo singularity

    NASA Astrophysics Data System (ADS)

    Dolan, Matthew J.; Krippendorf, Sven; Quevedo, Fernando

    2011-10-01

    A systematic approach is followed in order to identify realistic D-brane models at toric del Pezzo singularities. Requiring quark and lepton spectrum and Yukawas from D3 branes and massless hypercharge, we are led to Pati-Salam extensions of the Standard Model. Hierarchies of masses, flavour mixings and control of couplings select higher order del Pezzo singularities, minimising the Higgs sector prefers toric del Pezzos with dP 3 providing the most successful compromise. Then a supersymmetric local string model is presented with the following properties at low energies: (i) the MSSM spectrum plus a local B - L gauge field or additional Higgs fields depending on the breaking pattern, (ii) a realistic hierarchy of quark and lepton masses and (iii) realistic flavour mixing between quark and lepton families with computable CKM and PMNS matrices, and CP violation consistent with observations. In this construction, kinetic terms are diagonal and under calculational control suppressing standard FCNC contributions. Proton decay operators of dimension 4, 5, 6 are suppressed, and gauge couplings can unify depending on the breaking scales from string scales at energies in the range 1012-1016 GeV, consistent with TeV soft-masses from moduli mediated supersymmetry breaking. The GUT scale model corresponds to D3 branes at dP 3 with two copies of the Pati-Salam gauge symmetry SU(4) × SU(2) R × SU(2) L . D-brane instantons generate a non-vanishing μ-term. Right handed sneutrinos can break the B - L symmetry and induce a see-saw mechanism of neutrino masses and R-parity violating operators with observable low-energy implications.

  3. Extended generalized geometry and a DBI-type effective action for branes ending on branes

    NASA Astrophysics Data System (ADS)

    Jurčo, Branislav; Schupp, Peter; Vysoký, Jan

    2014-08-01

    Starting from the Nambu-Goto bosonic membrane action, we develop a geometric description suitable for p-brane backgrounds. With tools of generalized geometry we derive the pertinent generalization of the string open-closed relations to the p-brane case. Nambu-Poisson structures are used in this context to generalize the concept of semi-classical noncommutativity of D-branes governed by a Poisson tensor. We find a natural description of the correspondence of recently proposed commutative and noncommutative versions of an effective action for p-branes ending on a p '-brane. We calculate the power series expansion of the action in background independent gauge. Leading terms in the double scaling limit are given by a generalization of a (semi-classical) matrix model.

  4. Emergence and expansion of cosmic space as due to M0-branes

    NASA Astrophysics Data System (ADS)

    Sepehri, Alireza; Setare, Mohammad Reza; Capozziello, Salvatore

    2015-12-01

    Recently, Padmanabhan (arXiv:1206.4916 [hep-th]) discussed that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region causes the accelerated expansion of the universe. The main question arising is: what is the origin of this inequality between the surface degrees of freedom and the bulk degrees of freedom? We answer this question in M-theory. In our model, first M0-branes are compactified on one circle and N D0-branes are created. Then N D0-branes join each other, grow, and form one D5-branes. Next, the D5-brane is compactified on two circles and our universe's D3-brane, two D1-branes and some extra energies are produced. After that, one of the D1-branes, which is closer to the universe's brane, gives its energy into it, and this leads to an increase in the difference between the numbers of degrees of freedom and the occurring inflation era. With the disappearance of this D1-brane, the number of degrees of freedom of boundary surface and bulk region become equal and inflation ends. At this stage, extra energies that are produced due to the compactification cause an expansion of the universe and deceleration epoch. Finally, another D1-brane dissolves in our universe's brane, leads to an inequality between degrees of freedom, and there occurs a new phase of acceleration.

  5. Ghosts in the self-accelerating brane universe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Koyama, Kazuya; Institute of Cosmology and Gravitation, Portsmouth University, Portsmouth, PO1 2EG

    2005-12-15

    We study the spectrum of gravitational perturbations about a vacuum de Sitter brane with the induced 4D Einstein-Hilbert term, in a 5D Minkowski spacetime (DGP model). We consider solutions that include a self-accelerating universe, where the accelerating expansion of the universe is realized without introducing a cosmological constant on the brane. The mass of the discrete mode for the spin-2 graviton is calculated for various Hr{sub c}, where H is the Hubble parameter and r{sub c} is the crossover scale determined by the ratio between the 5D Newton constant and the 4D Newton constant. We show that, if we introducemore » a positive cosmological constant on the brane (Hr{sub c}>1), the spin-2 graviton has mass in the range 0brane fluctuation mode with mass m{sup 2}=2H{sup 2}. Although the brane fluctuation mode is healthy, the spin-2 graviton has a helicity-0 excitation that is a ghost. If we allow a negative cosmological constant on the brane, the brane fluctuation mode becomes a ghost for 1/21/2. In a self-accelerating universe Hr{sub c}=1, the spin-2 graviton has mass m{sup 2}=2H{sup 2}, which coincides with the mass of the brane fluctuation mode. Then there arises a mixing between the brane fluctuation mode and the spin-2 graviton. We argue that this mixing presumably gives a ghost in the self-accelerating universe by continuity across Hr{sub c}=1, although a careful calculation of the effective action is required to verify this rigorously.« less

  6. Deformation of N = 4 SYM with varying couplings via fluxes and intersecting branes

    NASA Astrophysics Data System (ADS)

    Choi, Jaewang; Fernández-Melgarejo, José J.; Sugimoto, Shigeki

    2018-03-01

    We study deformations of N = 4 supersymmetric Yang-Mills theory with space-time dependent couplings by embedding probe D3-branes in supergravity backgrounds with non-trivial fluxes. The effective action on the world-volume of the D3-branes is analyzed and a map between the deformation parameters and the fluxes is obtained. As an explicit example, we consider D3-branes in a background corresponding to ( p, q) 5-branes intersecting them and show that the effective theory on the D3-branes precisely agrees with the supersymmetric Janus configuration found by Gaiotto and Witten in [1]. D3-branes in an intersecting D3-brane background is also analyzed and the D3-brane effective action reproduces one of the supersymmetric configurations with ISO(1 , 1) × SO(2) × SO(4) symmetry found in our previous paper [2].

  7. Hierarchies from D-brane instantons in globally defined calabi-yau orientifolds

    DOE PAGES

    Cvetič, Mirjam; Weigand, Timo

    2008-06-01

    We construct the first globally consistent semi-realistic Type I string vacua on an elliptically fibered manifold where the zero modes of the Euclidean D1-instanton sector allow for the generation of non-perturbative Majorana masses of an intermediate scale. In another class of global models, a D1-brane instanton can generate a Polonyi-type superpotential breaking supersymmetry at an exponentially suppressed scale.

  8. Brane boxes, anomalies, bending, and tadpoles

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Leigh, R.G.; Rozali, M.

    1999-01-01

    Certain classes of chiral four-dimensional gauge theories may be obtained as the world volume theories of D5-branes are suspended between networks of NS5-branes, the so-called brane box models. In this paper, we derive the stringy consistency conditions placed on these models, and show that they are equivalent to an anomaly cancellation of the gauge theories. We derive these conditions in the orbifold theories which are {ital T} dual to the elliptic brane box models. Specifically, we show that the expression for tadpoles for unphysical twisted Ramond-Ramond 4-form fields in the orbifold theory are proportional to the gauge anomalies of themore » brane box theory. Thus string consistency is equivalent to world volume gauge anomaly cancellation. Furthermore, we find additional cylinder amplitudes which give the {beta} functions of the gauge theory. We show how these correspond to bending of the NS-branes in the brane box theory. {copyright} {ital 1998} {ital The American Physical Society}« less

  9. D-brane solutions under market panic

    NASA Astrophysics Data System (ADS)

    Pincak, Richard

    The relativistic quantum mechanic approach is used to develop stock market dynamics. The relativistic is conceptional here as the meaning of big external volatility or volatility shock on a financial market. We used a differential geometry approach with the parallel transport of prices to obtain a direct shift of the stock price movement. The prices are represented here as electrons with different spin orientation. Up and down orientations of the spin particle are likened here to an increase or a decrease of stock prices. The parallel transport of stock prices is enriched by Riemann curvature, which describes some arbitrage opportunities in the market. To solve the stock-price dynamics, we used the Dirac equation for bispinors on the spherical brane-world. We found out that when a spherical brane is abbreviated to the disk on the equator, we converge to the ideal behavior of financial market where Black-Scholes as well as semi-classical equations are sufficient. Full spherical brane-world scenarios can describe non-equilibrium market behavior where all arbitrage opportunities as well as transaction costs are taken into account. Real application of the model to the option pricing was done. The model developed in this paper brings quantitative different results of option pricing dynamics in the case of nonzero Riemann curvature.

  10. Explicit construction of BRST charge of noncommutative D-brane system

    NASA Astrophysics Data System (ADS)

    Hong, Soon-Tae

    2006-01-01

    In the BRST BFV scheme for noncommutative D-branes with constant NS B-field, introducing ghost degrees of freedom we construct the gauge-fixed Hamiltonian and corresponding effective Lagrangian invariant under nilpotent BRST charge. It is also shown that the presence of auxiliary variables introduced via the improved Dirac formalism plays a crucial role in the construction of the BRST invariant Lagrangian.

  11. Moving branes in the presence of background tachyon fields

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rezaei, Z., E-mail: z.rezaei@aut.ac.ir; Kamani, D., E-mail: kamani@aut.ac.ir

    2011-12-15

    We compute the boundary state associated with a moving Dp-brane in the presence of the open string tachyon field as a background field. The effect of the tachyon condensation on the boundary state is discussed. It leads to a boundary state associated with a lower-dimensional moving D-brane or a stationary instantonic D-brane. The former originates from condensation along the spatial directions and the latter comes from the temporal direction of the D-brane worldvolume. Using the boundary state, we also study the interaction amplitude between two arbitrary Dp{sub 1}- and Dp{sub 2}-branes. The long-range behavior of the amplitude is investigated, demonstratingmore » an obvious deviation from the conventional form, due to the presence of the background tachyon field.« less

  12. Inflation versus collapse in brane matter

    NASA Astrophysics Data System (ADS)

    Zheltukhin, A. A.

    2017-11-01

    Mapping of fundamental branes to their worldsheet (ws) multiplets originating from spontaneous breaking of the Poincaré symmetry is studied. The interaction Lagrangian for fields of the Nambu-Goldstone multiplet is shown to encode R2 gravity on the ws. The power law kp ˜ Tp 3-p 2(p+1) for the SO(D - p - 1) gauge coupling kp as the function of the p-brane tension Tp is assumed. It points to the presence of asymptotic freedom and confinement phases in brane matter. Their connection with collapse and inflation of the branes is discussed.

  13. Dark solitons, D-branes and noncommutative tachyon field theory

    NASA Astrophysics Data System (ADS)

    Giaccari, Stefano; Nian, Jun

    2017-11-01

    In this paper we discuss the boson/vortex duality by mapping the (3+1)D Gross-Pitaevskii theory into an effective string theory in the presence of boundaries. Via the effective string theory, we find the Seiberg-Witten map between the commutative and the noncommutative tachyon field theories, and consequently identify their soliton solutions with D-branes in the effective string theory. We perform various checks of the duality map and the identification of soliton solutions. This new insight between the Gross-Pitaevskii theory and the effective string theory explains the similarity of these two systems at quantitative level.

  14. Five-brane actions in double field theory

    NASA Astrophysics Data System (ADS)

    Blair, Chris D. A.; Musaev, Edvard T.

    2018-03-01

    We construct an action for NSNS 5-branes which is manifestly covariant under O( d, d). This is done by doubling d of the spacetime coordinates which appear in the worldvolume action. By formulating the DBI part of the action in a manner similar to a "gauged sigma model", only half the doubled coordinates genuinely appear. Our approach allows one to describe the full T-duality orbit of the IIB NS5 brane, the IIA KKM and their exotic relations in one formalism. Furthermore, by using ideas from double field theory, our action can be said to describe various aspects of non-geometric five-branes.

  15. Negative branes, supergroups and the signature of spacetime

    NASA Astrophysics Data System (ADS)

    Dijkgraaf, Robbert; Heidenreich, Ben; Jefferson, Patrick; Vafa, Cumrun

    2018-02-01

    We study the realization of supergroup gauge theories using negative branes in string theory. We show that negative branes are intimately connected with the possibility of timelike compactification and exotic spacetime signatures previously studied by Hull. Isolated negative branes dynamically generate a change in spacetime signature near their worldvolumes, and are related by string dualities to a smooth M-theory geometry with closed timelike curves. Using negative D3-branes, we show that SU(0| N) supergroup theories are holographically dual to an exotic variant of type IIB string theory on {dS}_{3,2}× {\\overline{S}}^5 , for which the emergent dimensions are timelike. Using branes, mirror symmetry and Nekrasov's instanton calculus, all of which agree, we derive the Seiberg-Witten curve for N=2 SU( N | M ) gauge theories. Together with our exploration of holography and string dualities for negative branes, this suggests that supergroup gauge theories may be non-perturbatively well-defined objects, though several puzzles remain.

  16. Brane f(R) gravity cosmologies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Balcerzak, Adam; DaPbrowski, Mariusz P.

    2010-06-15

    By the application of the generalized Israel junction conditions we derive cosmological equations for the fourth-order f(R) brane gravity and study their cosmological solutions. We show that there exists a nonstatic solution which describes a four-dimensional de Sitter (dS{sub 4}) brane embedded in a five-dimensional anti-de Sitter (AdS{sub 5}) bulk for a vanishing Weyl tensor contribution. On the other hand, for the case of a nonvanishing Weyl tensor contribution, there exists a static brane solution only. We claim that in order to get some more general nonstatic f(R) brane configurations, one needs to admit a dynamical matter energy-momentum tensor inmore » the bulk rather than just a bulk cosmological constant.« less

  17. Bulk axions, brane back-reaction and fluxes

    NASA Astrophysics Data System (ADS)

    Burgess, C. P.; van Nierop, L.

    2011-02-01

    Extra-dimensional models can involve bulk pseudo-Goldstone bosons (pGBs) whose shift symmetry is explicitly broken only by physics localized on branes. Reliable calculation of their low-energy potential is often difficult because it requires an understanding of the dynamics that stabilizes the geometry of the extra dimensions. Rugby ball solutions provide simple examples of extra-dimensional configurations for which two compact extra dimensions are stabilized in the presence of only positive-tension brane sources. The effects of brane back-reaction can be computed explicitly for these systems, allowing the calculation of the shape of the low-energy pGB potential, V 4 D ( φ), as a function of the perturbing brane properties, as well as the response of both the extra dimensional and on-brane geometries to this stabilization. If the φ-dependence is a small part of the total brane tension a very general analysis is possible, permitting an exploration of how the system responds to frustration when the two branes disagree on what the proper scalar vacuum should be. We show how the low-energy potential is given by the sum of brane tensions (in agreement with common lore) when only the brane tensions couple to φ. We also show how a direct brane coupling to the flux stabilizing the extra dimensions corrects this result in a way that does not simply amount to the contribution of the flux to the brane tensions. The mass of the low-energy pseudo-Goldstone mode is of order m a ˜ ( μ/ F)2 m KK (where μ is the energy scale associated with the brane symmetry breaking and F < M p is the extra-dimensional axion decay constant). In principle this can be larger or smaller than the Kaluza-Klein scale, m KK, but when it is larger axion properties cannot be computed purely within a 4D approximation (as they usually are). We briefly describe several potential applications, including a brane realization of `natural inflation,' and a dynamical mechanism for suppressing the couplings

  18. Intersecting flavor branes

    NASA Astrophysics Data System (ADS)

    Pomoni, Elli; Rastelli, Leonardo

    2012-10-01

    We consider an instance of the AdS/CFT duality where the bulk theory contains an open string tachyon, and study the instability from the viewpoint of the boundary field theory. We focus on the specific example of the AdS5 × S 5 background with two probe D7 branes intersecting at general angles. For generic angles supersymmetry is completely broken and there is an open string tachyon between the branes. The field theory action for this system is obtained by coupling to {N}=4 super Yang-Mills two {N}=2 hyper multiplets in the fundamental representation of the SU( N) gauge group, but with different choices of embedding of the two {N}=2 subalgebras into {N}=4 . On the field theory side we find a one-loop Coleman-Weinberg instability in the effective potential for the fundamental scalars. We identify a mesonic operator as the dual of the open string tachyon. By AdS/CFT, we predict the tachyon mass for small 't Hooft coupling (large bulk curvature) and confirm that it violates the AdS stability bound.

  19. E11, brane dynamics and duality symmetries

    NASA Astrophysics Data System (ADS)

    West, Peter

    2018-05-01

    Following arXiv:hep-th/0412336 we use the nonlinear realisation of the semi-direct product of E11 and its vector representation to construct brane dynamics. The brane moves through a space-time which arises in the nonlinear realisation from the vector representation and it contains the usual embedding coordinates as well as the worldvolume fields. The resulting equations of motion are first order in derivatives and can be thought of as duality relations. Each brane carries the full E11 symmetry and so the Cremmer-Julia duality symmetries. We apply this theory to find the dynamics of the IIA and IIB strings, the M2 and M5 branes, the IIB Dbrane as well as the one and two branes in seven dimensions.

  20. Black hole thermalization, D0 brane dynamics, and emergent spacetime

    NASA Astrophysics Data System (ADS)

    Riggins, Paul; Sahakian, Vatche

    2012-08-01

    When matter falls past the horizon of a large black hole, the expectation from string theory is that the configuration thermalizes and the information in the probe is rather quickly scrambled away. The traditional view of a classical unique spacetime near a black hole horizon conflicts with this picture. The question then arises as to what spacetime does the probe actually see as it crosses a horizon, and how does the background geometry imprint its signature onto the thermal properties of the probe. In this work, we explore these questions through an extensive series of numerical simulations of D0 branes. We determine that the D0 branes quickly settle into an incompressible symmetric state—thermalized within a few oscillations through a process driven entirely by internal nonlinear dynamics. Surprisingly, thermal background fluctuations play no role in this mechanism. Signatures of the background fields in this thermal state arise either through fluxes, i.e. black hole hair; or if the probe expands to the size of the horizon—which we see evidence of. We determine simple scaling relations for the D0 branes’ equilibrium size, time to thermalize, lifetime, and temperature in terms of their number, initial energy, and the background fields. Our results are consistent with the conjecture that black holes are the fastest scramblers as seen by matrix theory.

  1. Running with rugby balls: bulk renormalization of codimension-2 branes

    NASA Astrophysics Data System (ADS)

    Williams, M.; Burgess, C. P.; van Nierop, L.; Salvio, A.

    2013-01-01

    We compute how one-loop bulk effects renormalize both bulk and brane effective interactions for geometries sourced by codimension-two branes. We do so by explicitly integrating out spin-zero, -half and -one particles in 6-dimensional Einstein-Maxwell-Scalar theories compactified to 4 dimensions on a flux-stabilized 2D geometry. (Our methods apply equally well for D dimensions compactified to D - 2 dimensions, although our explicit formulae do not capture all divergences when D > 6.) The renormalization of bulk interactions are independent of the boundary conditions assumed at the brane locations, and reproduce standard heat-kernel calculations. Boundary conditions at any particular brane do affect how bulk loops renormalize this brane's effective action, but not the renormalization of other distant branes. Although we explicitly compute our loops using a rugby ball geometry, because we follow only UV effects our results apply more generally to any geometry containing codimension-two sources with conical singularities. Our results have a variety of uses, including calculating the UV sensitivity of one-loop vacuum energy seen by observers localized on the brane. We show how these one-loop effects combine in a surprising way with bulk back-reaction to give the complete low-energy effective cosmological constant, and comment on the relevance of this calculation to proposed applications of codimension-two 6D models to solutions of the hierarchy and cosmological constant problems.

  2. Weak gravity conjecture as a razor criterium for exotic D-brane instantons

    NASA Astrophysics Data System (ADS)

    Addazi, Andrea

    2017-01-01

    We discuss implications of weak gravity conjecture (WGC) for exotic D-brane instantons. In particular, WGC leads to indirect stringent bounds on non-perturbative superpotentials generated by exotic instantons with many implications for phenomenology: R-parity violating processes, neutrino mass, μ-problem, neutron-antineutron transitions and collider physics.

  3. Deriving all p-brane superalgebras via integrability

    NASA Astrophysics Data System (ADS)

    Grasso, D. T.; McArthur, I. N.

    2018-03-01

    In previous work we demonstrated that the enlarged super-Poincare algebras which underlie p-brane and D-brane actions in superstring theory can be directly determined based on the integrability of supersymmetry transformations assigned to fields appearing in Wess-Zumino terms. In that work we derived p-brane superalgebras for p = 2 and 3. Here we extend our previous results and give a compact expression for superalgebras for all valid p.

  4. Study of Strongly Coupled Systems via Probe Brane Constructions

    NASA Astrophysics Data System (ADS)

    Chang, Han-Chih

    In this thesis, we present our study towards better understanding of the strongly coupled systems with extra matter content in the fundamental representation of some prescribed global symmetry group in the quenched approximation, with the toolkit of holography via a probe brane construction. Specically, for the defect conformal systems, we unearth and quantify the phase trasition diagram, and novel supersymmetric vacua in the top-down model of the D3/D5 probe brane system. For further quantify various non-Fermi quantum liquid phases realized through the holographical probe brane construction, we then propose and verify the method to include the backreaction of entanglement entropy due to the probe branes at the leading order, which can potentially be used to detect topological phase transitions. We will recapitulate the main results of our works, in collaboration with Prof. Andreas Karch, published in the following journals: "Minimal Submanifolds asymptotic to AdS4 xS2 in AdS5xS5', JHEP, vol.1404, p.037, 2014; "The Novel Solutions of Finite-Density D3/D5 Probe Brane System and Their Implications for Stability'', JHEP, vol.1210, p.060, 2014; "Entanglement Entropy for Probe Branes'', JHEP, vol.1401, p.180, 2014.

  5. Towards realistic string vacua from branes at singularities

    NASA Astrophysics Data System (ADS)

    Conlon, Joseph P.; Maharana, Anshuman; Quevedo, Fernando

    2009-05-01

    We report on progress towards constructing string models incorporating both realistic D-brane matter content and moduli stabilisation with dynamical low-scale supersymmetry breaking. The general framework is that of local D-brane models embedded into the LARGE volume approach to moduli stabilisation. We review quiver theories on del Pezzo n (dPn) singularities including both D3 and D7 branes. We provide supersymmetric examples with three quark/lepton families and the gauge symmetries of the Standard, Left-Right Symmetric, Pati-Salam and Trinification models, without unwanted chiral exotics. We describe how the singularity structure leads to family symmetries governing the Yukawa couplings which may give mass hierarchies among the different generations. We outline how these models can be embedded into compact Calabi-Yau compactifications with LARGE volume moduli stabilisation, and state the minimal conditions for this to be possible. We study the general structure of soft supersymmetry breaking. At the singularity all leading order contributions to the soft terms (both gravity- and anomaly-mediation) vanish. We enumerate subleading contributions and estimate their magnitude. We also describe model-independent physical implications of this scenario. These include the masses of anomalous and non-anomalous U(1)'s and the generic existence of a new hyperweak force under which leptons and/or quarks could be charged. We propose that such a gauge boson could be responsible for the ghost muon anomaly recently found at the Tevatron's CDF detector.

  6. Global D-brane models with stabilised moduli and light axions

    NASA Astrophysics Data System (ADS)

    Cicoli, Michele

    2014-03-01

    We review recent attempts to try to combine global issues of string compactifications, like moduli stabilisation, with local issues, like semi-realistic D-brane constructions. We list the main problems encountered, and outline a possible solution which allows globally consistent embeddings of chiral models. We also argue that this stabilisation mechanism leads to an axiverse. We finally illustrate our general claims in a concrete example where the Calabi-Yau manifold is explicitly described by toric geometry.

  7. Fractional-wrapped branes with rotation, linear motion and background fields

    NASA Astrophysics Data System (ADS)

    Maghsoodi, Elham; Kamani, Davoud

    2017-09-01

    We obtain two boundary states corresponding to the two folds of a fractional-wrapped Dp-brane, i.e. the twisted version under the orbifold C2 /Z2 and the untwisted version. The brane has rotation and linear motion, in the presence of the following background fields: the Kalb-Ramond tensor, a U (1) internal gauge potential and a tachyon field. The rotation and linear motion are inside the volume of the brane. The brane lives in the d-dimensional spacetime, with the orbifold-toroidal structure Tn ×R 1 , d - n - 5 ×C2 /Z2 in the twisted sector. Using these boundary states we calculate the interaction amplitude of two parallel fractional Dp-branes with the foregoing setup. Various properties of this amplitude such as the long-range behavior will be analyzed.

  8. Entropy of N=2 black holes and their M-brane description

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Behrndt, K.; Mohaupt, T.

    1997-08-01

    In this paper we discuss the M-brane description for an N=2 black hole. This solution is a result of the compactification of M-5-brane configurations over a Calabi-Yau threefold with arbitrary intersection numbers C{sub ABC}. In analogy with the D-brane description where one counts open string states we count here open M-2-branes which end on the M-5-brane. {copyright} {ital 1997} {ital The American Physical Society}

  9. Criticality for charged black branes

    NASA Astrophysics Data System (ADS)

    Hennigar, Robie A.

    2017-09-01

    We show that the inclusion of higher curvature terms in the gravitational action can lead to phase transitions and critical behaviour for charged black branes. The higher curvature terms considered here belong to the recently constructed generalized quasi-topological class [arXiv:1703.01631], which possess a number of interesting properties, such as being ghost-free on constant curvature backgrounds and non-trivial in four dimensions. We show that critical behaviour is a generic feature of the black branes in all dimensions d ≥ 4, and contextualize the results with a review of the properties of black branes in Lovelock and quasi-topological gravity, where critical behaviour is not possible. These results may have interesting implications for the CFTs dual to this class of theories.

  10. Branes in Extended Spacetime: Brane Worldvolume Theory Based on Duality Symmetry.

    PubMed

    Sakatani, Yuho; Uehara, Shozo

    2016-11-04

    We propose a novel approach to the brane worldvolume theory based on the geometry of extended field theories: double field theory and exceptional field theory. We demonstrate the effectiveness of this approach by showing that one can reproduce the conventional bosonic string and membrane actions, and the M5-brane action in the weak-field approximation. At a glance, the proposed 5-brane action without approximation looks different from the known M5-brane actions, but it is consistent with the known nonlinear self-duality relation, and it may provide a new formulation of a single M5-brane action. Actions for exotic branes are also discussed.

  11. Dual formulation of covariant nonlinear duality-symmetric action of kappa-symmetric D3-brane

    NASA Astrophysics Data System (ADS)

    Vanichchapongjaroen, Pichet

    2018-02-01

    We study the construction of covariant nonlinear duality-symmetric actions in dual formulation. Essentially, the construction is the PST-covariantisation and nonlinearisation of Zwanziger action. The covariantisation made use of three auxiliary scalar fields. Apart from these, the construction proceed in a similar way to that of the standard formulation. For example, the theories can be extended to include interactions with external fields, and that the theories possess two local PST symmetries. We then explicitly demonstrate the construction of covariant nonlinear duality-symmetric actions in dual formulation of DBI theory, and D3-brane. For each of these theories, the twisted selfduality condition obtained from duality-symmetric actions are explicitly shown to match with the duality relation between field strength and its dual from the one-potential actions. Their on-shell actions between the duality-symmetric and the one-potential versions are also shown to match. We also explicitly prove kappa-symmetry of the covariant nonlinear duality-symmetric D3-brane action in dual formulation.

  12. Periodic arrays of M2-branes

    NASA Astrophysics Data System (ADS)

    Jeon, Imtak; Lambert, Neil; Richmond, Paul

    2012-11-01

    We consider periodic arrays of M2-branes in the ABJM model in the spirit of a circle compactification to D2-branes in type IIA string theory. The result is a curious formulation of three-dimensional maximally supersymmetric Yang-Mills theory in terms of fermions, seven transverse scalars, a non-dynamical gauge field and an additional scalar `dual gluon'. Upon further T-duality on a transverse torus we obtain a non-manifest- Lorentz-invariant description of five-dimensional maximally supersymmetric Yang-Mills. Here the additional scalar field can be thought of as the components of a two-form along the torus. This action can be viewed as an M-theory description of M5-branes on {{{T}}^3}.

  13. Holographic butterfly velocities in brane geometry and Einstein-Gauss-Bonnet gravity with matters

    NASA Astrophysics Data System (ADS)

    Huang, Wung-Hong

    2018-03-01

    In the first part of the paper we generalize the butterfly velocity formula to anisotropic spacetime. We apply the formula to evaluate the butterfly velocities in M-branes, D-branes, and strings backgrounds. We show that the butterfly velocities in M2-branes, M5-branes and the intersection M 2 ⊥ M 5 equal to those in fundamental strings, D4-branes and the intersection F 1 ⊥ D 4 backgrounds, respectively. These observations lead us to conjecture that the butterfly velocity is generally invariant under a double-dimensional reduction. In the second part of the paper, we study the butterfly velocity for Einstein-Gauss-Bonnet gravity with arbitrary matter fields. A general formula is obtained. We use this formula to compute the butterfly velocities in different backgrounds and discuss the associated properties.

  14. Super-Lie n-algebra extensions, higher WZW models and super-p-branes with tensor multiplet fields

    NASA Astrophysics Data System (ADS)

    Fiorenza, Domenico; Sati, Hisham; Schreiber, Urs

    2015-12-01

    We formalize higher-dimensional and higher gauge WZW-type sigma-model local prequantum field theory, and discuss its rationalized/perturbative description in (super-)Lie n-algebra homotopy theory (the true home of the "FDA"-language used in the supergravity literature). We show generally how the intersection laws for such higher WZW-type σ-model branes (open brane ending on background brane) are encoded precisely in (super-)L∞-extension theory and how the resulting "extended (super-)space-times" formalize spacetimes containing σ-model brane condensates. As an application we prove in Lie n-algebra homotopy theory that the complete super-p-brane spectrum of superstring/M-theory is realized this way, including the pure σ-model branes (the "old brane scan") but also the branes with tensor multiplet worldvolume fields, notably the D-branes and the M5-brane. For instance the degree-0 piece of the higher symmetry algebra of 11-dimensional (11D) spacetime with an M2-brane condensate turns out to be the "M-theory super-Lie algebra". We also observe that in this formulation there is a simple formal proof of the fact that type IIA spacetime with a D0-brane condensate is the 11D sugra/M-theory spacetime, and of (prequantum) S-duality for type IIB string theory. Finally we give the non-perturbative description of all this by higher WZW-type σ-models on higher super-orbispaces with higher WZW terms in stacky differential cohomology.

  15. Witten Effect and Fractional Charges on the Domain Wall and the D-Brane-Like Dot

    NASA Astrophysics Data System (ADS)

    Kanazawa, I.; Maeda, R.

    2018-04-01

    We have discussed the anomalous excitations such as dyons, Majorana fermions, and quark-like fermions on the domain wall in topological materials and the D-brane-like dot, and the relation to low-energy hadrons in QCD, from the viewpoint of a field-theoretical formula.

  16. D2-brane as the wormhole and the number of the universes

    NASA Astrophysics Data System (ADS)

    Gusin, Paweł

    2016-02-01

    We construct wormhole-like solutions in type IIA string theory. These solutions represent wormholes in four dimensions and are given by the D2-branes within appropriated backgrounds fields. We present the conditions on these fields which lead to the four-dimensional wormholes. In the special case, we show how the particular solution in type IIA theory leads to the dynamic wormhole. We also speculate about the number of universes and the cosmological constant.

  17. Towards multi-field D-brane inflation in a warped throat

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Heng-Yu; Gong, Jinn-Ouk; Koyama, Kazuya

    2010-11-01

    We study the inflationary dynamics in a model of slow-roll inflation in warped throat. Inflation is realized by the motion of a D-brane along the radial direction of the throat, and at later stages instabilities develop in the angular directions. We closely investigate both the single field potential relevant for the slow-roll phase, and the full multi-field one including the angular modes which becomes important at later stages. We study the main features of the instability process, discussing its possible consequences and identifying the vacua towards which the angular modes are driven.

  18. Moduli thermalization and finite temperature effects in "big" divisor large volume D3/ D7 Swiss-cheese compactification

    NASA Astrophysics Data System (ADS)

    Shukla, Pramod

    2011-01-01

    In the context of Type IIB compactified on a large volume Swiss-Cheese orientifold in the presence of a mobile space-time filling D3-brane and stacks of fluxed D7-branes wrapping the "big" divisor Σ B of a Swiss-Cheese Calabi Yau in WCP 4[1, 1, 1, 6, 9], we explore various implications of moduli dynamics and discuss their couplings and decay into MSSM (-like) matter fields early in the history of universe to reach thermal equilibrium. Like finite temperature effects in O'KKLT, we observe that the local minimum of zero-temperature effective scalar potential is stable against any finite temperature corrections (up to two-loops) in large volume scenarios as well. Also we find that moduli are heavy enough to avoid any cosmological moduli problem.

  19. Spacelike brane actions.

    PubMed

    Hashimoto, Koji; Ho, Pei-Ming; Wang, John E

    2003-04-11

    We derive effective actions for "spacelike branes" (S-branes) and find a solution describing the formation of fundamental strings in the rolling tachyon background. The S-brane action is a Dirac-Born-Infeld action for Euclidean world volumes defined in the context of time-dependent tachyon condensation of non-BPS (Bogomol'nyi-Prasad-Sommerfield) branes. It includes gauge fields and, in particular, a scalar field associated with translation along the time direction. We show that the BIon spike solutions constructed in this system correspond to the production of a confined electric flux tube (a fundamental string) at late time of the rolling tachyon.

  20. On the effective field theory of intersecting D3-branes

    NASA Astrophysics Data System (ADS)

    Abbaspur, Reza

    2018-05-01

    We study the effective field theory of two intersecting D3-branes with one common dimension along the lines recently proposed in ref. [1]. We introduce a systematic way of deriving the classical effective action to arbitrary orders in perturbation theory. Using a proper renormalization prescription to handle logarithmic divergencies arising at all orders in the perturbation series, we recover the first order renormalization group equation of ref. [1] plus an infinite set of higher order equations. We show the consistency of the higher order equations with the first order one and hence interpret the first order result as an exact RG flow equation in the classical theory.

  1. Sharp predictions from eternal inflation patches in D-brane inflation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hertog, Thomas; Janssen, Oliver, E-mail: thomas.hertog@fys.kuleuven.be, E-mail: opj202@nyu.edu

    We numerically generate the six-dimensional landscape of D3-brane inflation and identify patches of eternal inflation near sufficiently flat inflection points of the potential. We show that reasonable measures that select patches of eternal inflation in the landscape yield sharp predictions for the spectral properties of primordial perturbations on observable scales. These include a scalar tilt of .936, a running of the scalar tilt −.00103, undetectably small tensors and non-Gaussianity, and no observable spatial curvature. Our results explicitly demonstrate that precision cosmology probes the combination of the statistical properties of the string landscape and the measure implied by the universe's quantummore » state.« less

  2. Asymptotic M5-brane entropy from S-duality

    NASA Astrophysics Data System (ADS)

    Kim, Seok; Nahmgoong, June

    2017-12-01

    We study M5-branes compactified on S 1 from the D0-D4 Witten index in the Coulomb phase. We first show that the prepotential of this index is S-dual, up to a simple anomalous part. This is an extension of the well-known S-duality of the 4d N=4 theory to the 6d (2, 0) theory on finite T 2. Using this anomalous S-duality, we find that the asymptotic free energy scales like N 3 when various temperature-like parameters are large. This shows that the number of 5d Kaluza-Klein fields for light D0-brane bound states is proportional to N 3. We also compute some part of the asymptotic free energy from 6d chiral anomalies, which precisely agrees with our D0-D4 calculus.

  3. Giant graviton interactions and M2-branes ending on multiple M5-branes

    NASA Astrophysics Data System (ADS)

    Hirano, Shinji; Sato, Yuki

    2018-05-01

    We study splitting and joining interactions of giant gravitons with angular momenta N 1/2 ≪ J ≪ N in the type IIB string theory on AdS 5 × S 5 by describing them as instantons in the tiny graviton matrix model introduced by Sheikh-Jabbari. At large J the instanton equation can be mapped to the four-dimensional Laplace equation and the Coulomb potential for m point charges in an n-sheeted Riemann space corresponds to the m-to- n interaction process of giant gravitons. These instantons provide the holographic dual of correlators of all semi-heavy operators and the instanton amplitudes exactly agree with the pp-wave limit of Schur polynomial correlators in N = 4 SYM computed by Corley, Jevicki and Ramgoolam. By making a slight change of variables the same instanton equation is mathematically transformed into the Basu-Harvey equation which describes the system of M2-branes ending on M5-branes. As it turns out, the solutions to the sourceless Laplace equation on an n-sheeted Riemann space correspond to n M5-branes connected by M2-branes and we find general solutions representing M2-branes ending on multiple M5-branes. Among other solutions, the n = 3 case describes an M2-branes junction ending on three M5-branes. The effective theory on the moduli space of our solutions might shed light on the low energy effective theory of multiple M5-branes.

  4. Holographic dark energy in braneworld models with moving branes and the w = -1 crossing

    NASA Astrophysics Data System (ADS)

    Saridakis, E. N.

    2008-04-01

    We apply the bulk holographic dark energy in general 5D two-brane models. We extract the Friedmann equation on the physical brane and we show that in the general moving-brane case the effective 4D holographic dark energy behaves as a quintom for a large parameter-space area of a simple solution subclass. We find that wΛ was larger than -1 in the past while its present value is wΛ0≈-1.05, and the phantom bound wΛ = -1 was crossed at zp≈0.41, a result in agreement with observations. Such a behavior arises naturally, without the inclusion of special fields or potential terms, but a fine-tuning between the 4D Planck mass and the brane tension has to be imposed.

  5. On classical de Sitter and Minkowski solutions with intersecting branes

    NASA Astrophysics Data System (ADS)

    Andriot, David

    2018-03-01

    Motivated by the connection of string theory to cosmology or particle physics, we study solutions of type II supergravities having a four-dimensional de Sitter or Minkowski space-time, with intersecting D p -branes and orientifold O p -planes. Only few such solutions are known, and we aim at a better characterisation. Modulo a few restrictions, we prove that there exists no classical de Sitter solution for any combination of D 3/ O 3 and D 7/ O 7, while we derive interesting constraints for intersecting D 5/ O 5 or D 6/ O 6, or combinations of D 4/ O 4 and D 8/ O 8. Concerning classical Minkowski solutions, we understand some typical features, and propose a solution ansatz. Overall, a central information appears to be the way intersecting D p / O p overlap each other, a point we focus on.

  6. Complex marginal deformations of D3-brane geometries, their Penrose limits and giant gravitons

    NASA Astrophysics Data System (ADS)

    Avramis, Spyros D.; Sfetsos, Konstadinos; Zoakos, Dimitrios

    2007-12-01

    We apply the Lunin-Maldacena construction of gravity duals to β-deformed gauge theories to a class of type IIB backgrounds with U(1 global symmetry, which include the multicenter D3-brane backgrounds dual to the Coulomb branch of N=4 super-Yang-Mills and the rotating D3-brane backgrounds dual to the theory at finite temperature and chemical potential. After a general discussion, we present the full form of the deformed metrics for three special cases, which can be used for the study of various aspects of the marginally-deformed gauge theories. We also construct the Penrose limits of the solutions dual to the Coulomb branch along a certain set of geodesics and, for the resulting PP-wave metrics, we examine the effect of β-deformations on the giant graviton states. We find that giant gravitons exist only up to a critical value of the σ-deformation parameter, are not degenerate in energy with the point graviton, and remain perturbatively stable. Finally, we probe the σ-deformed multicenter solutions by examining the static heavy-quark potential by means of Wilson loops. We find situations that give rise to complete screening as well as linear confinement, with the latter arising is an intriguing way reminiscent of phase transitions in statistical systems.

  7. Gestion des ressources hydriques adaptee aux changements climatiques pour la production optimale d'hydroelectricite. Etude de cas: Bassin versant de la riviere Manicouagan

    NASA Astrophysics Data System (ADS)

    Haguma, Didier

    Il est dorenavant etabli que les changements climatiques auront des repercussions sur les ressources en eau. La situation est preoccupante pour le secteur de production d'energie hydroelectrique, car l'eau constitue le moteur pour generer cette forme d'energie. Il sera important d'adapter les regles de gestion et/ou les installations des systemes hydriques, afin de minimiser les impacts negatifs et/ou pour capitaliser sur les retombees positives que les changements climatiques pourront apporter. Les travaux de la presente recherche s'interessent au developpement d'une methode de gestion des systemes hydriques qui tient compte des projections climatiques pour mieux anticiper les impacts de l'evolution du climat sur la production d'hydroelectricite et d'etablir des strategies d'adaptation aux changements climatiques. Le domaine d'etude est le bassin versant de la riviere Manicouagan situe dans la partie centrale du Quebec. Une nouvelle approche d'optimisation des ressources hydriques dans le contexte des changements climatiques est proposee. L'approche traite le probleme de la saisonnalite et de la non-stationnarite du climat d'une maniere explicite pour representer l'incertitude rattachee a un ensemble des projections climatiques. Cette approche permet d'integrer les projections climatiques dans le probleme d'optimisation des ressources en eau pour une gestion a long terme des systemes hydriques et de developper des strategies d'adaptation de ces systemes aux changements climatiques. Les resultats montrent que les impacts des changements climatiques sur le regime hydrologique du bassin de la riviere Manicouagan seraient le devancement et l'attenuation de la crue printaniere et l'augmentation du volume annuel d'apports. L'adaptation des regles de gestion du systeme hydrique engendrerait une hausse de la production hydroelectrique. Neanmoins, une perte de la performance des installations existantes du systeme hydrique serait observee a cause de l'augmentation des

  8. A realistic intersecting D6-brane model after the first LHC run

    NASA Astrophysics Data System (ADS)

    Li, Tianjun; Nanopoulos, D. V.; Raza, Shabbar; Wang, Xiao-Chuan

    2014-08-01

    With the Higgs boson mass around 125 GeV and the LHC supersymmetry search constraints, we revisit a three-family Pati-Salam model from intersecting D6-branes in Type IIA string theory on the T 6/(ℤ2 × ℤ2) orientifold which has a realistic phenomenology. We systematically scan the parameter space for μ < 0 and μ > 0, and find that the gravitino mass is generically heavier than about 2 TeV for both cases due to the Higgs mass low bound 123 GeV. In particular, we identify a region of parameter space with the electroweak fine-tuning as small as Δ EW ~ 24-32 (3-4%). In the viable parameter space which is consistent with all the current constraints, the mass ranges for gluino, the first two-generation squarks and sleptons are respectively [3, 18] TeV, [3, 16] TeV, and [2, 7] TeV. For the third-generation sfermions, the light stop satisfying 5 σ WMAP bounds via neutralino-stop coannihilation has mass from 0.5 to 1.2 TeV, and the light stau can be as light as 800 GeV. We also show various coannihilation and resonance scenarios through which the observed dark matter relic density is achieved. Interestingly, the certain portions of parameter space has excellent t- b- τ and b- τ Yukawa coupling unification. Three regions of parameter space are highlighted as well where the dominant component of the lightest neutralino is a bino, wino or higgsino. We discuss various scenarios in which such solutions may avoid recent astrophysical bounds in case if they satisfy or above observed relic density bounds. Prospects of finding higgsino-like neutralino in direct and indirect searches are also studied. And we display six tables of benchmark points depicting various interesting features of our model. Note that the lightest neutralino can be heavy up to 2.8 TeV, and there exists a natural region of parameter space from low-energy fine-tuning definition with heavy gluino and first two-generation squarks/sleptons, we point out that the 33 TeV and 100 TeV proton-proton colliders

  9. High-energy effective theory for matter on close Randall-Sundrum branes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rham, Claudia de; Webster, Samuel

    2005-09-15

    Extending the analysis of C. de Rham and S. Webster [Phys. Rev. D 71, 124025 (2005)], we obtain a formal expression for the coupling between brane matter and the radion in a Randall-Sundrum braneworld. This effective theory is correct to all orders in derivatives of the radion in the limit of small brane separation, and, in particular, contains no higher than second derivatives. In the case of cosmological symmetry the theory can be obtained in closed form and reproduces the five-dimensional behavior. Perturbations in the tensor and scalar sectors are then studied. When the branes are moving, the effective Newtonianmore » constant on the brane is shown to depend both on the distance between the branes and on their velocity. In the small-distance limit, we compute the exact dependence between the four-dimensional and the five-dimensional Newtonian constants.« less

  10. Comments on SUSY Inflation Models on the Brane

    NASA Astrophysics Data System (ADS)

    Lee, Lu-Yun; Cheung, Kingman; Lin, Chia-Min

    In this paper we consider a class of inflation models on the brane where the dominant part of the inflaton scalar potential does not depend on the inflaton field value during inflation. In particular, we consider supernatural inflation, its hilltop version, A-term inflation, and supersymmetric (SUSY) D- and F-term hybrid inflation on the brane. We show that the parameter space can be broadened, the inflation scale generally can be lowered, and still possible to have the spectral index ns = 0.96.

  11. Dynamique des ressources naturelles dans le Parc national de Manda: Cartographie et analyse pour le Développement durable

    NASA Astrophysics Data System (ADS)

    Ballah Solkam, Rosalie; Médard, Ndoutorlengar

    2018-05-01

    Au Tchad, le réseau d'aires protégées couvre près de 10,2% de la surface du pays et reste globalement représentatif de toute la diversité des écosystèmes de la région. Cependant, ce réseau n'est pas constitué d'écosystèmes intacts car de nombreuses altérations y ont été apportés (certaines espèces sont déjà au seuil critique d'extinction (Addax, gazelle dama, lamantin), voire ont disparu (Rhinocéros noir et blanc, Oryx)) surtout dans les parcs nationaux. Ce qui nous amène à nous interroger sur la dynamique des ressources naturelles et le degré de conservation du parc national de Manda? Une évaluation de la diversité biologique et des ressources hydrographiques de 1951 à 1999 sur la base de la bibliographie existante, de la carte topographique de 1956, des images satellitaires Landsat 5 et 7 TM et ETM+ de 2 périodes (1986, 1999), complétée par des interviews semi-structurés et des transects sur le terrain, permettra de mieux appréhender la dynamique des ressources et les actions de conservation de la biodiversité réalisées à cet effet. Les résultats montrent une dynamique progressive de la faune de 1951 à 1970, puis une dynamique régressive de 1970 à 1989. Après cette tumultueuse période, un repeuplement du parc s'opère de 1989 à 2002. Par contre, la flore est relativement bien conservée avec quelques cours d'eau, des mares, champs et plantations. Et cela grâce aux multiples projets de conservation de la biodiversité. La promotion de l'écotourisme serait une alternative au développement durable de ce parc.

  12. Gauge field localization on brane worlds

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guerrero, Rommel; Rodriguez, R. Omar; Melfo, Alejandra

    2010-04-15

    We consider the effects of spacetime curvature and brane thickness on the localization of gauge fields on a brane via kinetic terms induced by localized fermions. We find that in a warped geometry with an infinitely thin brane, both the infrared and the ultraviolet behavior of the electromagnetic propagator are affected, providing a more stringent bound on the brane's tension than that coming from the requirement of four-dimensional gravity on the brane. On the other hand, for a thick wall in a flat spacetime, where the fermions are localized by means of a Yukawa coupling, we find that four-dimensional electromagnetismmore » is recovered in a region bounded from above by the same critical distance appearing in the thin case, but also from below by a new scale related to the brane's thickness and the electromagnetic couplings. This imposes very stringent bounds on the brane's thickness which seem to invalidate the localization mechanism for this case.« less

  13. Bulk renormalization and particle spectrum in codimension-two brane worlds

    NASA Astrophysics Data System (ADS)

    Salvio, Alberto

    2013-04-01

    We study the Casimir energy due to bulk loops of matter fields in codimension-two brane worlds and discuss how effective field theory methods allow us to use this result to renormalize the bulk and brane operators. In the calculation we explicitly sum over the Kaluza-Klein (KK) states with a new convenient method, which is based on a combined use of zeta function and dimensional regularization. Among the general class of models we consider we include a supersymmetric example, 6D gauged chiral supergravity. Although much of our discussion is more general, we treat in some detail a class of compactifications, where the extra dimensions parametrize a rugby ball shaped space with size stabilized by a bulk magnetic flux. The rugby ball geometry requires two branes, which can host the Standard Model fields and carry both tension and magnetic flux (of the bulk gauge field), the leading terms in a derivative expansion. The brane properties have an impact on the KK spectrum and therefore on the Casimir energy as well as on the renormalization of the brane operators. A very interesting feature is that when the two branes carry exactly the same amount of flux, one half of the bulk supersymmetries survives after the compactification, even if the brane tensions are large. We also discuss the implications of these calculations for the natural value of the cosmological constant when the bulk has two large extra dimensions and the bulk supersymmetry is partially preserved (or completely broken).

  14. Asymmetric Wormholes via Electrically Charged Lightlike Branes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guendelman, E.; Kaganovich, A.; Nissimov, E.

    2010-06-17

    We consider a self-consistent Einstein-Maxwell-Kalb-Ramond system in the bulk D = 4 space-time interacting with a variable-tension electrically charged lightlike brane. The latter serves both as a material and charge source for gravity and electromagnetism, as well as it dynamically generates a bulk space varying cosmological constant. We find an asymmetric wormhole solution describing two 'universes' with different spherically symmetric black-hole-type geometries connected through a 'throat' occupied by the lightlike brane. The electrically neutral 'left universe' comprises the exterior region of Schwarzschild-de-Sitter (or pure Schwarzschild) space-time above the inner(Schwarzschild-type) horizon, whereas the electrically charged 'right universe' consists of the exteriormore » Reissner-Nordstroem (or Reissner-Nordstroem-de-Sitter) black hole region beyond the outer Reissner-Nordstroem horizon. All physical parameters of the wormhole are uniquely determined by two free parameters - the electric charge and Kalb-Ramond coupling of the lightlike brane.« less

  15. Brane inflation and cosmic string tension in superstring theory

    NASA Astrophysics Data System (ADS)

    Firouzjahi, Hassan; Tye, S.-H. Henry

    2005-03-01

    In a simple reanalysis of the KKLMMT scenario, we argue that the slow roll condition in the D3-overline {D}3 -brane inflationary scenario in superstring theory requires no more than a moderate tuning. The cosmic string tension is very sensitive to the conformal coupling: with less fine-tuning, the cosmic string tension (as well as the ratio of tensor to scalar perturbation mode) increases rapidly and can easily saturate the present observational bound. In a multi-throat brane inflationary scenario, this feature substantially improves the chance of detecting and measuring the properties of the cosmic strings as a window to the superstring theory and our pre-inflationary universe.

  16. Micro-orbits in a many-brane model and deviations from Newton's 1/r^2 law

    NASA Astrophysics Data System (ADS)

    Donini, A.; Marimón, S. G.

    2016-12-01

    We consider a five-dimensional model with geometry M = M_4 × S_1, with compactification radius R. The Standard Model particles are localized on a brane located at y=0, with identical branes localized at different points in the extra dimension. Objects located on our brane can orbit around objects located on a brane at a distance d=y/R, with an orbit and a period significantly different from the standard Newtonian ones. We study the kinematical properties of the orbits, finding that it is possible to distinguish one motion from the other in a large region of the initial conditions parameter space. This is a warm-up to study if a SM-like mass distribution on one (or more) distant brane(s) may represent a possible dark matter candidate. After using the same technique to the study of orbits of objects lying on the same brane (d=0), we apply this method to the detection of generic deviations from the inverse-square Newton law. We propose a possible experimental setup to look for departures from Newtonian motion in the micro-world, finding that an order of magnitude improvement on present bounds can be attained at the 95% CL under reasonable assumptions.

  17. Identification of market trends with string and D2-brane maps

    NASA Astrophysics Data System (ADS)

    Bartoš, Erik; Pinčák, Richard

    2017-08-01

    The multidimensional string objects are introduced as a new alternative for an application of string models for time series forecasting in trading on financial markets. The objects are represented by open string with 2-endpoints and D2-brane, which are continuous enhancement of 1-endpoint open string model. We show how new object properties can change the statistics of the predictors, which makes them the candidates for modeling a wide range of time series systems. String angular momentum is proposed as another tool to analyze the stability of currency rates except the historical volatility. To show the reliability of our approach with application of string models for time series forecasting we present the results of real demo simulations for four currency exchange pairs.

  18. Gerbes, M5-Brane Anomalies and E8 Gauge Theory

    NASA Astrophysics Data System (ADS)

    Aschieri, Paolo; Jurco, Branislav

    2004-10-01

    Abelian gerbes and twisted bundles describe the topology of the NS 3-form gauge field strength H. We review how they have been usefully applied to study and resolve global anomalies in open string theory. Abelian 2-gerbes and twisted nonabelian gerbes describe the topology of the 4-form field strength G of M-theory. We show that twisted nonabelian gerbes are relevant in the study and resolution of global anomalies of multiple coinciding M5-branes. Global anomalies for one M5-brane have been studied by Witten and by Diaconescu, Freed and Moore. The structure and the differential geometry of twisted nonabelian gerbes (i.e. modules for 2-gerbes) is defined and studied. The nonabelian 2-form gauge potential living on multiple coinciding M5-branes arises as curving (curvature) of twisted nonabelian gerbes. The nonabelian group is in general tilde OmegaE8, the central extension of the E8 loop group. The twist is in general necessary to cancel global anomalies due to the nontriviality of the 11-dimensional 4-form field strength G and due to the possible torsion present in the cycles the M5-branes wrap. Our description of M5-branes global anomalies leads to the D4-branes one upon compactification of M-theory to Type IIA theory.

  19. A Deconstruction Lattice Description of the D1/D5 Brane World-Volume Gauge Theory

    DOE PAGES

    Giedt, Joel

    2011-01-01

    I genermore » alize the deconstruction lattice formulation of Endres and Kaplan to two-dimensional super-QCD with eight supercharges, denoted by (4,4), and bifundamental matter. I specialize to a particularly interesting (4,4) gauge theory, with gauge group U ( N c ) × U ( N f ) , and U ( N f ) being weakly gauged. It describes the infrared limit of the D1/D5 brane system, which has been studied extensively as an example of the AdS 3 /CFT 2 correspondence. The construction here preserves two supercharges exactly and has a lattice structure quite similar to that which has previously appeared in the deconstruction approach, that is, site, link, and diagonal fields with both the Bose and Fermi statistics. I remark on possible applications of the lattice theory that would test the AdS 3 /CFT 2 correspondence, particularly one that would exploit the recent worldsheet instanton analysis of Chen and Tong.« less

  20. Isolated Minkowski vacua, and stability analysis for an extended brane in the rugby ball

    NASA Astrophysics Data System (ADS)

    Himmetoǧlu, Burak; Peloso, Marco

    2007-06-01

    We study a recently proposed model, where a codimension one brane is wrapped around the axis of symmetry of an internal two-dimensional space compactified by a flux. This construction is free from the problems which plague delta-like, codimension two branes, where only tension can be present. In contrast, arbitrary fields can be localized on this extended brane, and their gravitational interaction is standard 4d gravity at large distances. In the first part of this work, we study the de Sitter (dS) vacua of the model. The landscape of these vacua is characterized by discrete points labeled by two integer numbers, related to the flux responsible for the compactification and to the current of a brane field. A Minkowski external space emerges only for a special ratio between these two integers, and it is therefore (topologically) isolated from the nearby dS solutions. In the second part, we show that the Minkowski vacua are stable under the most generic axially-symmetric perturbations, and we argue that this is sufficient to ensure the overall stability.

  1. D=10 Chiral Tensionless Super p-BRANES

    NASA Astrophysics Data System (ADS)

    Bozhilov, P.

    We consider a model for tensionless (null) super-p-branes with N chiral supersymmetries in ten-dimensional flat space-time. After establishing the symmetries of the action, we give the general solution of the classical equations of motion in a particular gauge. In the case of a null superstring (p=1) we find the general solution in an arbitrary gauge. Then, using a harmonic superspace approach, the initial algebra of first- and second-class constraints is converted into an algebra of Lorentz-covariant, BFV-irreducible, first-class constraints only. The corresponding BRST charge is as for a first rank dynamical system.

  2. Supersymmetric Janus solutions of dyonic ISO(7)-gauged N = 8 supergravity

    NASA Astrophysics Data System (ADS)

    Suh, Minwoo

    2018-04-01

    We study supersymmetric Janus solutions of dyonic ISO(7)-gauged N = 8 supergravity. We mostly find Janus solutions flowing to 3d N = 8 SYM phase which is the worldvolume theory on D2-branes and non-conformal. There are also solutions flowing from the critical points which are dual to 3d SCFTs from deformations of the D2-brane theory.

  3. Fermion localization on a split brane

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chumbes, A. E. R.; Vasquez, A. E. O.; Hott, M. B.

    2011-05-15

    In this work we analyze the localization of fermions on a brane embedded in five-dimensional, warped and nonwarped, space-time. In both cases we use the same nonlinear theoretical model with a nonpolynomial potential featuring a self-interacting scalar field whose minimum energy solution is a soliton (a kink) which can be continuously deformed into a two-kink. Thus a single brane splits into two branes. The behavior of spin 1/2 fermions wave functions on the split brane depends on the coupling of fermions to the scalar field and on the geometry of the space-time.

  4. Cosmic microwave background radiation anisotropies in brane worlds.

    PubMed

    Koyama, Kazuya

    2003-11-28

    We propose a new formulation to calculate the cosmic microwave background (CMB) spectrum in the Randall-Sundrum two-brane model based on recent progress in solving the bulk geometry using a low energy approximation. The evolution of the anisotropic stress imprinted on the brane by the 5D Weyl tensor is calculated. An impact of the dark radiation perturbation on the CMB spectrum is investigated in a simple model assuming an initially scale-invariant adiabatic perturbation. The dark radiation perturbation induces isocurvature perturbations, but the resultant spectrum can be quite different from the prediction of simple mixtures of adiabatic and isocurvature perturbations due to Weyl anisotropic stress.

  5. Exceptional M-brane sigma models and η-symbols

    NASA Astrophysics Data System (ADS)

    Sakatani, Yuho; Uehara, Shozo

    2018-03-01

    We develop the M-brane actions proposed in Y. Sakatani and S. Uehara, arXiv:1607.04265, by using η-symbols determined in Y. Sakatani and S. Uehara, arXiv:1708.06342. Introducing η-forms that are defined with the η-symbols, we present U-duality-covariant M-brane actions which describe the known brane worldvolume theories for Mp-branes with p=0,2,5. We show that the self-duality relation known in the double sigma model is naturally generalized to M-branes. In particular, for an M5-brane, the self-duality relation is nontrivially realized, where the Hodge star operator is defined with the familiar M5-brane metric while the η-form contains the self-dual three-form field strength. The action for a Kaluza-Klein monopole is also partially reproduced. Moreover, we explain how to treat type IIB branes in our general formalism. As a demonstration, we reproduce the known action for a (p,q)-string.

  6. Induced gravity on intersecting brane worlds. II. Cosmology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Corradini, Olindo; Koyama, Kazuya; Tasinato, Gianmassimo

    2008-12-15

    We explore cosmology of intersecting brane worlds with induced gravity on the branes. We find the cosmological equations that control the evolution of a moving codimension-one brane and a codimension-two brane that sits at the intersection. We study the Friedmann equation at the intersection, finding new contributions from the six-dimensional bulk. These higher dimensional contributions allow us to find new examples of self-accelerating configurations for the codimension-two brane at the intersection and we discuss their features.

  7. Superradiant instabilities of rotating black branes and strings

    NASA Astrophysics Data System (ADS)

    Cardoso, Vitor; Yoshida, Shijun

    2005-07-01

    Black branes and strings are generally unstable against a certain sector of gravitational perturbations. This is known as the Gregory-Laflamme instability. It has been recently argued [1], [2] that there exists another general instability affecting many rotating extended black objects. This instability is in a sense universal, in that it is triggered by any massless field, and not just gravitational perturbations. Here we investigate this novel mechanism in detail. For this instability to work, two ingredients are necessary: (i) an ergo-region, which gives rise to superradiant amplification of waves, and (ii) ``bound'' states in the effective potential governing the evolution of the particular mode under study. We show that the black brane Kerr4×Rp is unstable against this mechanism, and we present numerical results for instability timescales for this case. On the other hand, and quite surprisingly, black branes of the form Kerrd×Rp are all stable against this mechanism for d > 4. This is quite an unexpected result, and it stems from the fact that there are no stable circular orbits in higher dimensional black hole spacetimes, or in a wave picture, that there are no bound states in the effective potential. We also show that it is quite easy to simulate this instability in the laboratory with acoustic black branes.

  8. Carroll limit of non-BPS Dp-brane

    NASA Astrophysics Data System (ADS)

    Klusoň, J.

    2017-05-01

    We find Carroll non-BPS Dp-brane action by performing Carroll limit of a canonical form of unstable Dp-brane action. We analyze different Carroll limits and discuss solutions of the equations of motion of Carroll non-BPS Dp-brane at the tachyon vacuum.

  9. Brane Craft

    NASA Technical Reports Server (NTRS)

    Janson, Siegfried

    2017-01-01

    A Brane Craft is a membrane spacecraft with solar cells, command and control electronics, communications systems, antennas, propulsion systems, attitude and proximity sensors, and shape control actuators as thin film structures manufactured on 10 micron thick plastic sheets. This revolutionary spacecraft design can have a thickness of tens of microns with a surface area of square meters to maximize area-to-mass ratios for exceptionally low-mass spacecraft. Communications satellites, solar power satellites, solar electric propulsion stages, and solar sails can benefit from Brane Craft design. It also enables new missions that require low-mass spacecraft with exceptionally high delta-V. Active removal of orbital debris from Earth orbit is the target application for this study.

  10. Escape of black holes from the brane.

    PubMed

    Flachi, Antonino; Tanaka, Takahiro

    2005-10-14

    TeV-scale gravity theories allow the possibility of producing small black holes at energies that soon will be explored at the CERN LHC or at the Auger observatory. One of the expected signatures is the detection of Hawking radiation that might eventually terminate if the black hole, once perturbed, leaves the brane. Here, we study how the "black hole plus brane" system evolves once the black hole is given an initial velocity that mimics, for instance, the recoil due to the emission of a graviton. The results of our dynamical analysis show that the brane bends around the black hole, suggesting that the black hole eventually escapes into the extra dimensions once two portions of the brane come in contact and reconnect. This gives a dynamical mechanism for the creation of baby branes.

  11. Counting supersymmetric branes

    NASA Astrophysics Data System (ADS)

    Kleinschmidt, Axel

    2011-10-01

    Maximal supergravity solutions are revisited and classified, with particular emphasis on objects of co-dimension at most two. This class of solutions includes branes whose tension scales with xxxx. We present a group theory derivation of the counting of these objects based on the corresponding tensor hierarchies derived from E 11 and discrete T- and U-duality transformations. This provides a rationale for the wrapping rules that were recently discussed for σ ≤ 3 in the literature and extends them. Explicit supergravity solutions that give rise to co-dimension two branes are constructed and analysed.

  12. 3 d printing of 2 d N=(0,2) gauge theories

    NASA Astrophysics Data System (ADS)

    Franco, Sebastián; Hasan, Azeem

    2018-05-01

    We introduce 3 d printing, a new algorithm for generating 2 d N=(0,2) gauge theories on D1-branes probing singular toric Calabi-Yau 4-folds using 4 d N=1 gauge theories on D3-branes probing toric Calabi-Yau 3-folds as starting points. Equivalently, this method produces brane brick models starting from brane tilings. 3 d printing represents a significant improvement with respect to previously available tools, allowing a straightforward determination of gauge theories for geometries that until now could only be tackled using partial resolution. We investigate the interplay between triality, an IR equivalence between different 2 d N=(0,2) gauge theories, and the freedom in 3 d printing given an underlying Calabi-Yau 4-fold. Finally, we present the first discussion of the consistency and reduction of brane brick models.

  13. Equivariant branes and equivariant homological mirror symmetry

    NASA Astrophysics Data System (ADS)

    Ashwinkumar, Meer; Tan, Meng-Chwan

    2018-03-01

    We describe supersymmetric A-branes and B-branes in open N =(2 ,2 ) dynamically gauged nonlinear sigma models (GNLSM), placing emphasis on toric manifold target spaces. For a subset of toric manifolds, these equivariant branes have a mirror description as branes in gauged Landau-Ginzburg models with neutral matter. We then study correlation functions in the topological A-twisted version of the GNLSM and identify their values with open Hamiltonian Gromov-Witten invariants. Supersymmetry breaking can occur in the A-twisted GNLSM due to nonperturbative open symplectic vortices, and we canonically Becchi-Rouet-Stora-Tyutin quantize the mirror theory to analyze this phenomenon.

  14. k-essence in the DGP brane-world cosmology

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bouhmadi-Lopez, Mariam; Chimento, Luis P.

    We analyze a Dvali-Gabadadze-Porrati (DGP) brane filled with a k-essence field and assume the k field evolving linearly with the cosmic time of the brane. We then solve analytically the Friedmann equation and deduce the different behavior of the brane at the low- and the high-energy regimes. The asymptotic behavior can be quite different involving accelerating branes, big bangs, big crunches, big rips, or quiescent singularities. The latter correspond to a type of sudden singularity.

  15. Constraining brane tension using rotation curves of galaxies

    NASA Astrophysics Data System (ADS)

    García-Aspeitia, Miguel A.; Rodríguez-Meza, Mario A.

    2018-04-01

    We present in this work a study of brane theory phenomenology focusing on the brane tension parameter, which is the main observable of the theory. We show the modifications steaming from the presence of branes in the rotation curves of spiral galaxies for three well known dark matter density profiles: Pseudo isothermal, Navarro-Frenk-White and Burkert dark matter density profiles. We estimate the brane tension parameter using a sample of high resolution observed rotation curves of low surface brightness spiral galaxies and a synthetic rotation curve for the three density profiles. Also, the fittings using the brane theory model of the rotation curves are compared with standard Newtonian models. We found that Navarro-Frenk-White model prefers lower values of the brane tension parameter, on the average λ ∼ 0.73 × 10‑3eV4, therefore showing clear brane effects. Burkert case does prefer higher values of the tension parameter, on the average λ ∼ 0.93 eV4 ‑ 46 eV4, i.e., negligible brane effects. Whereas pseudo isothermal is an intermediate case. Due to the low densities found in the galactic medium it is almost impossible to find evidence of the presence of extra dimensions. In this context, we found that our results show weaker bounds to the brane tension values in comparison with other bounds found previously, as the lower value found for dwarf stars composed of a polytropic equation of state, λ ≈ 104 MeV4.

  16. Cosmology from quantum potential in a system of oscillating branes

    NASA Astrophysics Data System (ADS)

    Sepehri, Alireza

    2016-11-01

    Recently, some authors proposed a new mechanism which gets rid of the Big Bang singularity and shows that the age of the universe is infinite. In this paper, we will confirm their results and predict that the universe may expand and contract many N fundamental strings decay to N M0-anti-M0-branes. Then, M0-branes join each other and build a M8-anti-M8 system. This system is unstable, broken and two anti-M4-branes, a compactified M4-brane, a M3-brane in addition to one M0-brane are produced. The M3-brane wraps around the compactified M4-brane and both of them oscillate between two anti-M4-branes. Our universe is located on the M3-brane and interacts with other branes by exchanging the M0-brane and some scalars in transverse directions. By wrapping of M3-brane, the contraction epoch of universe starts and some higher order of derivatives of scalar fields in the relevant action of branes are produced which are responsible for generating the generalized uncertainty principle (GUP). By oscillating the compactified M4-M3-brane and approaching one of anti-M4-branes, one end of M3-brane glues to the anti-M4-brane and other end remains sticking and wrapping around M4-brane. Then, by getting away of the M4-M3 system, M4 rolls, wrapped M3 opens and expansion epoch of universe begins. By closing the M4 to anti-M4, the mass of some scalars become negative and they make a transition to tachyonic phase. To remove these states, M4 rebounds, rolls and M3 wraps around it again. At this stage, expansion branch ends and universe enters a contraction epoch again. This process is repeated many times and universe expands and contracts due to oscillation of branes. We obtain the scale factor of universe in this system and find that its values only at t →-∞ shrinks to zero. Thus, in our method, the Big Bang is replaced by the fundamental string and the age of universe is predicted to be infinite. Also, when tachyonic states disappear at the beginning of expansion branch, some extra

  17. The Einstein equations on the 3-brane world

    NASA Astrophysics Data System (ADS)

    Shiromizu, Tetsuya; Maeda, Kei-Ichi; Sasaki, Misao

    2000-07-01

    We carefully investigate the gravitational equations of the brane world, in which all the matter forces except gravity are confined on the 3-brane in a 5-dimensional spacetime with Z2 symmetry. We derive the effective gravitational equations on the brane, which reduce to the conventional Einstein equations in the low energy limit. From our general argument we conclude that the first Randall-Sundrum-type theory predicts that the brane with a negative tension is an antigravity world and hence should be excluded from the physical point of view. Their second-type theory where the brane has a positive tension provides the correct signature of gravity. In this latter case, if the bulk spacetime is exactly anti-de Sitter spacetime, generically the matter on the brane is required to be spatially homogeneous because of the Bianchi identities. By allowing deviations from anti-de Sitter spacetime in the bulk, the situation will be relaxed and the Bianchi identities give just the relation between the Weyl tensor and the energy momentum tensor. In the present brane world scenario, the effective Einstein equations cease to be valid during an era when the cosmological constant on the brane is not well defined, such as in the case of the matter dominated by the potential energy of the scalar field.

  18. Laplace-Beltrami operator and exact solutions for branes

    NASA Astrophysics Data System (ADS)

    Zheltukhin, A. A.

    2013-02-01

    Proposed is a new approach to finding exact solutions of nonlinear p-brane equations in D-dimensional Minkowski space based on the use of various initial value constraints. It is shown that the constraints Δx→=0 and Δx→=-Λ(t,σr)x→ give two sets of exact solutions.

  19. Brane surgery: energy conditions, traversable wormholes, and voids

    NASA Astrophysics Data System (ADS)

    Barceló1, C.; Visser, M.

    2000-09-01

    Branes are ubiquitous elements of any low-energy limit of string theory. We point out that negative tension branes violate all the standard energy conditions of the higher-dimensional spacetime they are embedded in; this opens the door to very peculiar solutions of the higher-dimensional Einstein equations. Building upon the (/3+1)-dimensional implementation of fundamental string theory, we illustrate the possibilities by considering a toy model consisting of a (/2+1)-dimensional brane propagating through our observable (/3+1)-dimensional universe. Developing a notion of ``brane surgery'', based on the Israel-Lanczos-Sen ``thin shell'' formalism of general relativity, we analyze the dynamics and find traversable wormholes, closed baby universes, voids (holes in the spacetime manifold), and an evasion (not a violation) of both the singularity theorems and the positive mass theorem. These features appear generic to any brane model that permits negative tension branes: This includes the Randall-Sundrum models and their variants.

  20. Holographic cosmology from a system of M2–M5 branes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sepehri, Alireza, E-mail: alireza.sepehri@uk.ac.ir; Research Institute for Astronomy and Astrophysics of Maragha; Faizal, Mir, E-mail: f2mir@uwaterloo.ca

    In this paper, we analyze the holographic cosmology using a M2–M5 brane configuration. In this configuration, a M2-brane will be placed in between a M5-brane and an anti-M5-brane. The M2-brane will act as a channel for energy to flow from an anti-M5-brane to a M5-brane, and this will increase the degrees of freedom on the M5-brane causing inflation. The inflation will end when the M5-brane and anti-M5-brane get separated. However, at a later stage the distance between the M5-brane and the anti-M5-bran can reduce and this will cause the formation of tachyonic states. These tachyonic states will again open amore » bridge between the M5-branes and the anti-M5-branes, which will cause further acceleration of the universe.« less

  1. Towards large volume big divisor D3/D7 " μ-split supersymmetry" and Ricci-flat Swiss-cheese metrics, and dimension-six neutrino mass operators

    NASA Astrophysics Data System (ADS)

    Dhuria, Mansi; Misra, Aalok

    2012-02-01

    We show that it is possible to realize a " μ-split SUSY" scenario (Cheng and Cheng, 2005) [1] in the context of large volume limit of type IIB compactifications on Swiss-cheese Calabi-Yau orientifolds in the presence of a mobile space-time filling D3-brane and a (stack of) D7-brane(s) wrapping the "big" divisor. For this, we investigate the possibility of getting one Higgs to be light while other to be heavy in addition to a heavy higgsino mass parameter. Further, we examine the existence of long lived gluino that manifests one of the major consequences of μ-split SUSY scenario, by computing its decay width as well as lifetime corresponding to the three-body decays of the gluino into either a quark, a squark and a neutralino or a quark, squark and goldstino, as well as two-body decays of the gluino into either a neutralino and a gluon or a goldstino and a gluon. Guided by the geometric Kähler potential for Σ obtained in Misra and Shukla (2010) [2] based on GLSM techniques, and the Donaldson's algorithm (Barun et al., 2008) [3] for obtaining numerically a Ricci-flat metric, we give details of our calculation in Misra and Shukla (2011) [4] pertaining to our proposed metric for the full Swiss-cheese Calabi-Yau (the geometric Kähler potential being needed to be included in the full moduli space Kähler potential in the presence of the mobile space-time filling D3-brane), but for simplicity of calculation, close to the big divisor, which is Ricci-flat in the large volume limit. Also, as an application of the one-loop RG flow solution for the higgsino mass parameter, we show that the contribution to the neutrino masses at the EW scale from dimension-six operators arising from the Kähler potential, is suppressed relative to the Weinberg-type dimension-five operators.

  2. On Closed Timelike Curves and Warped Brane World Models

    NASA Astrophysics Data System (ADS)

    Slagter, Reinoud Jan

    2013-09-01

    At first glance, it seems possible to construct in general relativity theory causality violating solutions. The most striking one is the Gott spacetime. Two cosmic strings, approaching each other with high velocity, could produce closed timelike curves. It was quickly recognized that this solution violates physical boundary conditions. The effective one particle generator becomes hyperbolic, so the center of mass is tachyonic. On a 5-dimensional warped spacetime, it seems possible to get an elliptic generator, so no obstruction is encountered and the velocity of the center of mass of the effective particle has an overlap with the Gott region. So a CTC could, in principle, be constructed. However, from the effective 4D field equations on the brane, which are influenced by the projection of the bulk Weyl tensor on the brane, it follows that no asymptotic conical space time is found, so no angle deficit as in the 4D counterpart model. This could also explain why we do not observe cosmic strings.

  3. Flowing to higher dimensions: a new strongly-coupled phase on M2 branes

    DOE PAGES

    Pilch, Krzysztof; Tyukov, Alexander; Warner, Nicholas P.

    2015-11-24

    We describe a one-parameter family of new holographic RG flows that start from AdS 4 × S 7 and go to AdS 5ˆ×B6, where B6 is conformal to a Kahler manifold and AdS 5ˆ is Poincaré AdS 5 with one spatial direction compactified and fibered over B6. The new solutions “flow up dimensions,” going from the (2 + 1)-dimensional conformal field theory on M2 branes in the UV to a (3 + 1)-dimensional field theory on intersecting M5 branes in the infra-red. The M2 branes completely polarize into M5 branes along the flow and the Poincare sections of the AdSmore » 5ˆ are the (3 + 1)-dimensional common intersection of the M5 branes. The emergence of the extra dimension in the infra-red suggests a new strongly-coupled phase of the M2 brane and ABJM theories in which charged solitons are becoming massless. The flow solution is first analyzed by finding a four-dimensional N=2 supersymmetric flow in N=8 gauged supergravity. This is then generalized to a one parameter family of non-supersymmetric flows. The infra-red limit of the solutions appears to be quite singular in four dimensions but the uplift to eleven-dimensional supergravity is remarkable and regular (up to orbifolding). Our construction is a non-trivial application of the recently derived uplift formulae for fluxes, going well beyond the earlier constructions of stationary points solutions. As a result, the eleven-dimensional supersymmetry is also analyzed and shows how, for the supersymmetric flow, the M2-brane supersymmetry in the UV is polarized entirely into M5-brane supersymmetry in the infra-red.« less

  4. Flowing to higher dimensions: a new strongly-coupled phase on M2 branes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pilch, Krzysztof; Tyukov, Alexander; Warner, Nicholas P.

    We describe a one-parameter family of new holographic RG flows that start from AdS 4 × S 7 and go to AdS 5ˆ×B6, where B6 is conformal to a Kahler manifold and AdS 5ˆ is Poincaré AdS 5 with one spatial direction compactified and fibered over B6. The new solutions “flow up dimensions,” going from the (2 + 1)-dimensional conformal field theory on M2 branes in the UV to a (3 + 1)-dimensional field theory on intersecting M5 branes in the infra-red. The M2 branes completely polarize into M5 branes along the flow and the Poincare sections of the AdSmore » 5ˆ are the (3 + 1)-dimensional common intersection of the M5 branes. The emergence of the extra dimension in the infra-red suggests a new strongly-coupled phase of the M2 brane and ABJM theories in which charged solitons are becoming massless. The flow solution is first analyzed by finding a four-dimensional N=2 supersymmetric flow in N=8 gauged supergravity. This is then generalized to a one parameter family of non-supersymmetric flows. The infra-red limit of the solutions appears to be quite singular in four dimensions but the uplift to eleven-dimensional supergravity is remarkable and regular (up to orbifolding). Our construction is a non-trivial application of the recently derived uplift formulae for fluxes, going well beyond the earlier constructions of stationary points solutions. As a result, the eleven-dimensional supersymmetry is also analyzed and shows how, for the supersymmetric flow, the M2-brane supersymmetry in the UV is polarized entirely into M5-brane supersymmetry in the infra-red.« less

  5. Born-Infeld extension of Lovelock brane gravity in the system of M0-branes and its application for the emergence of Pauli exclusion principle in BIonic superconductors

    NASA Astrophysics Data System (ADS)

    Sepehri, Alireza

    2016-07-01

    Recently, some authors (Cruz and Rojas, 2013 [1]) have constructed a Born-Infeld type action which may be written in terms of the Lovelock brane Lagrangians for a given dimension p. We reconsider their model in M-theory and study the process of birth and growth of nonlinear spinor and bosonic gravity during the construction of Mp-branes. Then, by application of this idea to BIonic system, we construct a BIonic superconductor in the background of nonlinear gravity. In this model, first, M0-branes link to each other and build an M5-brane and an anti-M5-brane connected by an M2-brane. M0-branes are zero dimensional objects that only scalars are attached to them. By constructing higher dimensional branes from M0-branes, gauge fields are produced. Also, if M0-branes don't link to each other completely, the symmetry of system is broken and fermions are created. The curvature produced by fermions has the opposite sign the curvature produced by gauge fields. Fermions on M5-branes and M2 plays the role of bridge between them. By passing time, M2 dissolves in M5's and nonlinear bosonic and spinor gravities are produced. By closing M5-branes towards each other, coupling of two identical fermions on two branes to each other causes that the square mass of their system becomes negative and some tachyonic states are created. For removing these tachyons, M5-branes compact, the sign of gravity between branes reverses, anti-gravity is produced which causes that branes and identical fermions get away from each other. This is the reason for the emergence of Pauli exclusion principle in Bionic system. Also, the spinor gravity vanishes and its energy builds a new M2 between M5-branes. We obtain the resistivity in this system and find that its value decreases by closing M5 branes to each other and shrinks to zero at colliding point of branes. This idea has different applications. For example, in cosmology, universes are located on M5-branes and M2-brane has the role of bridge between

  6. Brane-world motion in compact dimensions

    NASA Astrophysics Data System (ADS)

    Greene, Brian; Levin, Janna; Parikh, Maulik

    2011-08-01

    The topology of extra dimensions can break global Lorentz invariance, singling out a globally preferred frame even in flat spacetime. Through experiments that probe global topology, an observer can determine her state of motion with respect to the preferred frame. This scenario is realized if we live on a brane universe moving through a flat space with compact extra dimensions. We identify three experimental effects due to the motion of our universe that one could potentially detect using gravitational probes. One of these relates to the peculiar properties of the twin paradox in multiply-connected spacetimes. Another relies on the fact that the Kaluza-Klein modes of any bulk field are sensitive to boundary conditions. A third concerns the modification to the Newtonian potential on a moving brane. Remarkably, we find that even small extra dimensions are detectable by brane observers if the brane is moving sufficiently fast. Communicated by P R L V Moniz

  7. Non-conservation of global charges in the Brane Universe and baryogenesis

    NASA Astrophysics Data System (ADS)

    Dvali, Gia; Gabadadze, Gregory

    1999-08-01

    We argue that global charges, such as baryon or lepton number, are not conserved in theories with the Standard Model fields localized on the brane which propagates in higher-dimensional space-time. The global-charge non-conservation is due to quantum fluctuations of the brane surface. These fluctuations create ``baby branes'' that can capture some global charges and carry them away into the bulk of higher-dimensional space. Such processes are exponentially suppressed at low-energies, but can be significant at high enough temperatures or energies. These effects can lead to a new, intrinsically high-dimensional mechanism of baryogenesis. Baryon asymmetry might be produced due either to ``evaporation'' into the baby branes, or creation of the baryon number excess in collisions of two Brane Universes. As an example we discuss a possible cosmological scenario within the recently proposed ``Brane Inflation'' framework. Inflation is driven by displaced branes which slowly fall on top of each other. When the branes collide inflation stops and the Brane Universe reheats. During this non-equilibrium collision baryon number can be transported from one brane to another one. This results in the baryon number excess in our Universe which exactly equals to the hidden ``baryon number'' deficit in the other Brane Universe. © 1999

  8. Lattice black branes: sphere packing in general relativity

    NASA Astrophysics Data System (ADS)

    Dias, Óscar J. C.; Santos, Jorge E.; Way, Benson

    2018-05-01

    We perturbatively construct asymptotically R^{1,3}× T^2 black branes with multiple inhomogeneous directions and show that some of them are thermodynamically preferred over uniform branes in both the microcanonical and canonical ensembles. This demonstrates that, unlike five-dimensional black strings, the instability of some unstable black branes has a plausible endpoint that does not require a violation of cosmic censorship.

  9. Rotating a curvaton brane in a warped throat

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Jun; Piao, Yun-Song; Cai, Yi-Fu, E-mail: zhangjun408@mails.gucas.ac.cn, E-mail: caiyf@ihep.ac.cn, E-mail: yspiao@gucas.ac.cn

    2010-05-01

    In this paper we study a curvaton model obtained by considering a probe anti-D3-brane with angular motion at the bottom of a KS throat with approximate isometries. We calculate the spectrum of curvature perturbations and the non-Gaussianities of this model. Specifically, we consider the limit of relativistic rotation of the curvaton brane which leads to a small sound speed, and thus it can be viewed as an implementation of the DBI-curvaton mechanism. We find that the primordial power spectrum is nearly scale-invariant while the non-Gaussianity of local type is sizable and that of equilateral type is usually large and negative.more » Moreover, we study both the theoretical and observational constraints on this model, and find that there exists a sizable allowed region for the phase space of this model.« less

  10. Differential cross sections in a thick brane world scenario

    NASA Astrophysics Data System (ADS)

    Pedraza, Omar; Arceo, R.; López, L. A.; Cerón, V. E.

    2018-04-01

    The elastic differential cross section is calculated at low energies for the elements He and Ne using an effective 4D electromagnetic potential coming from the contribution of the massive Kaluza-Klein modes of the 5D vector field in a thick brane scenario. The length scale is adjusted in the potential to compare with known experimental data and to set bounds for the parameter of the model.

  11. On `light' fermions and proton stability in `big divisor' D3/ D7 large volume compactifications

    NASA Astrophysics Data System (ADS)

    Misra, Aalok; Shukla, Pramod

    2011-06-01

    Building on our earlier work (Misra and Shukla, Nucl. Phys. B 827:112, 2010; Phys. Lett. B 685:347-352, 2010), we show the possibility of generating "light" fermion mass scales of MeV-GeV range (possibly related to the first two generations of quarks/leptons) as well as eV (possibly related to first two generations of neutrinos) in type IIB string theory compactified on Swiss-Cheese orientifolds in the presence of a mobile space-time filling D3-brane restricted to (in principle) stacks of fluxed D7-branes wrapping the "big" divisor Σ B . This part of the paper is an expanded version of the latter half of Sect. 3 of a published short invited review (Misra, Mod. Phys. Lett. A 26:1, 2011) written by one of the authors [AM]. Further, we also show that there are no SUSY GUT-type dimension-five operators corresponding to proton decay, and we estimate the proton lifetime from a SUSY GUT-type four-fermion dimension-six operator to be 1061 years. Based on GLSM calculations in (Misra and Shukla, Nucl. Phys. B 827:112, 2010) for obtaining the geometric Kähler potential for the "big divisor," using further the Donaldson's algorithm, we also briefly discuss in the first of the two appendices the metric for the Swiss-Cheese Calabi-Yau used, which we obtain and which becomes Ricci flat in the large-volume limit.

  12. Brane junctions in the Randall-Sundrum scenario

    NASA Astrophysics Data System (ADS)

    Csáki, Csaba; Shirman, Yuri

    2000-01-01

    We present static solutions to Einstein's equations corresponding to branes at various angles intersecting in a single 3-brane. Such configurations may be useful for building models with localized gravity via the Randall-Sundrum mechanism. We find that such solutions may exist only if the mechanical forces acting on the junction exactly cancel. In addition to this constraint there are further conditions that the parameters of the theory have to satisfy. We find that at least one of these involves only the brane tensions and cosmological constants, and thus cannot have a dynamical origin. We present these conditions in detail for two simple examples. We discuss the nature of the cosmological constant problem in the framework of these scenarios, and outline the desired features of the brane configurations which may bring us closer towards a resolution of the cosmological constant problem.

  13. Emergence and oscillation of cosmic space by joining M1-branes

    NASA Astrophysics Data System (ADS)

    Sepehri, Alireza; Rahaman, Farook; Capozziello, Salvatore; Ali, Ahmed Farag; Pradhan, Anirudh

    2016-05-01

    Recently, it has been proposed by Padmanabhan that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region leads to the expansion of the universe. Now, a natural question arises; how could this model explain the oscillation of the universe between contraction and expansion branches? We try to address this issue in the framework of a BIonic system. In this model, M0-branes join to each other and give rise to a pair of M1-anti- M1-branes. The fields which live on these branes play the roles of massive gravitons that cause the emergence of a wormhole between them and formation of a BIon system. This wormhole dissolves into M1-branes and causes a divergence between the number of degrees of freedom on the boundary surface of M1 and the bulk leading to an expansion of M1-branes. When M1-branes become close to each other, the square energy of their system becomes negative and some tachyonic states emerge. To remove these states, M1-branes become compact, the sign of compacted gravity changes, causing anti-gravity to arise: in this case, branes get away from each other. By articulating M1-BIons, an M3-brane and an anti- M3-brane are created and connected by three wormholes forming an M3-BIon. This new system behaves like the initial system and by closing branes to each other, they become compact and, by getting away from each other, they open. Our universe is located on one of these M3-branes and, by compactifying the M3-brane, it contracts and, by opening it, it expands.

  14. Anisotropic D3-D5 black holes with unquenched flavors

    NASA Astrophysics Data System (ADS)

    Penín, José Manuel; Ramallo, Alfonso V.; Zoakos, Dimitrios

    2018-02-01

    We construct a black hole geometry generated by the intersection of N c color D3- branes and N f flavor D5-branes along a 2+1 dimensional subspace. Working in the Veneziano limit in which N f is large and distributing homogeneously the D5-branes in the internal space, we calculate the solution of the equations of motion of supergravity plus sources which includes the backreaction of the flavor branes. The solution is analytic and dual to a 2+1 dimensional defect in a 3+1 dimensional gauge theory, with N f massless hypermultiplets living in the defect. The smeared background we obtain can be regarded as the holographic realization of a multilayered system. We study the thermodynamics of the resulting spatially anisotropic geometry and compute the first and second order transport coefficients for perturbations propagating along the defect. We find that, in our system, the dynamics of excitations within a layer can be described by a stack of effective D2-branes.

  15. Microstates of black holes in expanding universe from interacting branes

    NASA Astrophysics Data System (ADS)

    Shiba, Shotaro

    2017-05-01

    Thermodynamics of the near extremal black p-branes can be described by collective motions of gravitationally interacting branes. This proposal is called the p-soup model. In this paper, we check this proposal in the case of black brane system which is asymptotically Friedmann-Lemaître-Robertson-Walker universe in an infinite distance. As a result, we can show that the gravitationally interacting branes explain free energy, entropy, temperature and other physical quantities in these systems. This implies that the microstates of this kind of brane system can be also understood in the p-soup model.

  16. Interaction of the branes in the presence of the background fields: The dynamical, nonintersecting, perpendicular, wrapped-fractional configuration

    NASA Astrophysics Data System (ADS)

    Maghsoodi, Elham; Kamani, Davoud

    2017-05-01

    We shall obtain the interaction of the Dp1- and Dp2-branes in the toroidal-orbifold space-time Tn × ℝ1,d-n-5 × ℂ2/ℤ 2. The configuration of the branes is nonintersecting, perpendicular, moving-rotating, wrapped-fractional with background fields. For this, we calculate the bosonic boundary state corresponding to a dynamical fractional-wrapped Dp-brane in the presence of the Kalb-Ramond field, a U1 gauge potential and an open string tachyon field. The long-range behavior of the interaction amplitude will be extracted.

  17. Inflationary solutions in the brane world and their geometrical interpretation

    NASA Astrophysics Data System (ADS)

    Khoury, Justin; Steinhardt, Paul J.; Waldram, Daniel

    2001-05-01

    We consider the cosmology of a pair of domain walls bounding a five-dimensional bulk space-time with a negative cosmological constant, in which the distance between the branes is not fixed in time. Although there are strong arguments to suggest that this distance should be stabilized in the present epoch, no such constraints exist for the early universe and thus non-static solutions might provide relevant inflationary scenarios. We find the general solution for the standard ansatz where the bulk is foliated by planar-symmetric hypersurfaces. We show that in all cases the bulk geometry is that of anti-de Sitter (AdS5) space. We then present a geometrical interpretation for the solutions as embeddings of two de Sitter (dS4) surfaces in AdS5, which provide a simple interpretation of the physical properties of the solutions. A notable feature explained in the analysis is that two-way communication between branes expanding away from one another is possible for a finite amount of time, after which communication can proceed in one direction only. The geometrical picture also shows that our class of solutions (and related solutions in the literature) is not completely general, contrary to some claims. We then derive the most general solution for two walls in AdS5. This includes novel cosmologies where the brane tensions are not constrained to have opposite signs. The construction naturally generalizes to arbitrary FRW cosmologies on the branes.

  18. Large dimensions and small curvatures from supersymmetric brane back-reaction

    NASA Astrophysics Data System (ADS)

    Burgess, C. P.; van Nierop, L.

    2011-04-01

    We compute the back-reaction of pairs of codimension-two branes within an explicit flux-stabilized compactification, to trace how its properties depend on the parameters that define the brane-bulk couplings. Both brane tension and magnetic couplings to the stabilizing flux play an important role in the resulting dynamics, with the magnetic coupling allowing some of the flux to be localized on the branes (thus changing the flux-quantization conditions). We find that back-reaction lifts the classical flat directions of the bulk supergravity, and we calculate both the scalar potential and changes to the extra-dimensional and on-brane geometries that result, as functions of the assumed brane couplings. When linearized about simple rugby-ball geometries the resulting solutions allow a systematic exploration of the system's response. Several of the systems we explore have remarkable properties. Among these are a propensity for the extra dimensions to stabilize at exponentially large sizes, providing a mechanism for generating extremely large volumes. In some circumstances the brane-dilaton coupling allows the bulk dilaton to adjust to suppress the on-brane curvature parametrically below the change in brane tension, potentially providing a mechanism for reducing the vacuum energy. We explore the stability of this suppression to quantum effects in the case where their strength is controlled by the value of the field along the classical flat direction, and find it can (but need not) be stable.

  19. Simple inflationary models in Gauss-Bonnet brane-world cosmology

    NASA Astrophysics Data System (ADS)

    Okada, Nobuchika; Okada, Satomi

    2016-06-01

    In light of the recent Planck 2015 results for the measurement of the cosmic microwave background (CMB) anisotropy, we study simple inflationary models in the context of the Gauss-Bonnet (GB) brane-world cosmology. The brane-world cosmological effect modifies the power spectra of scalar and tensor perturbations generated by inflation and causes a dramatic change for the inflationary predictions of the spectral index (n s) and the tensor-to-scalar ratio (r) from those obtained in the standard cosmology. In particular, the predicted r values in the inflationary models favored by the Planck 2015 results are suppressed due to the GB brane-world cosmological effect, which is in sharp contrast with inflationary scenario in the Randall-Sundrum brane-world cosmology, where the r values are enhanced. Hence, these two brane-world cosmological scenarios are distinguishable. With the dramatic change of the inflationary predictions, the inflationary scenario in the GB brane-world cosmology can be tested by more precise measurements of n s and future observations of the CMB B-mode polarization.

  20. Lovelock branes

    NASA Astrophysics Data System (ADS)

    Kastor, David; Ray, Sourya; Traschen, Jennie

    2017-10-01

    We study the problem of finding brane-like solutions to Lovelock gravity, adopting a general approach to establish conditions that a lower dimensional base metric must satisfy in order that a solution to a given Lovelock theory can be constructed in one higher dimension. We find that for Lovelock theories with generic values of the coupling constants, the Lovelock tensors (higher curvature generalizations of the Einstein tensor) of the base metric must all be proportional to the metric. Hence, allowed base metrics form a subclass of Einstein metrics. This subclass includes so-called ‘universal metrics’, which have been previously investigated as solutions to quantum-corrected field equations. For specially tuned values of the Lovelock couplings, we find that the Lovelock tensors of the base metric need to satisfy fewer constraints. For example, for Lovelock theories with a unique vacuum there is only a single such constraint, a case previously identified in the literature, and brane solutions can be straightforwardly constructed.

  1. (2,2) and (0,4) supersymmetric boundary conditions in 3d N =4 theories and type IIB branes

    NASA Astrophysics Data System (ADS)

    Chung, Hee-Joong; Okazaki, Tadashi

    2017-10-01

    The half-BPS boundary conditions preserving N =(2 ,2 ) and N =(0 ,4 ) supersymmetry in 3d N =4 supersymmetric gauge theories are examined. The BPS equations admit decomposition of the bulk supermultiplets into specific boundary supermultiplets of preserved supersymmetry. Nahm-like equations arise in the vector multiplet BPS boundary condition preserving N =(0 ,4 ) supersymmetry, and Robin-type boundary conditions appear for the hypermultiplet coupled to the vector multiplet when N =(2 ,2 ) supersymmetry is preserved. The half-BPS boundary conditions are realized in the brane configurations of type IIB string theory.

  2. Towards an M5-brane model I: A 6d superconformal field theory

    NASA Astrophysics Data System (ADS)

    Sämann, Christian; Schmidt, Lennart

    2018-04-01

    We present an action for a six-dimensional superconformal field theory containing a non-abelian tensor multiplet. All of the ingredients of this action have been available in the literature. We bring these pieces together by choosing the string Lie 2-algebra as a gauge structure, which we motivated in previous work. The kinematical data contains a connection on a categorified principal bundle, which is the appropriate mathematical description of the parallel transport of self-dual strings. Our action can be written down for each of the simply laced Dynkin diagrams, and each case reduces to a four-dimensional supersymmetric Yang-Mills theory with corresponding gauge Lie algebra. Our action also reduces nicely to an M2-brane model which is a deformation of the Aharony-Bergman-Jafferis-Maldacena (ABJM) model. While this action is certainly not the desired M5-brane model, we regard it as a key stepping stone towards a potential construction of the (2, 0)-theory.

  3. Gauge Field Localization on Deformed Branes

    NASA Astrophysics Data System (ADS)

    Tofighi, A.; Moazzen, M.; Farokhtabar, A.

    2016-02-01

    In this paper, we utilise the Chumbes-Holf da Silva-Hott (CHH) mechanism to investigate the issue of gauge field localization on a deformed brane constructed with one scalar field, which can be coupled to gravity minimally or non-minimally. The study of deformed defects is important because they contain internal structures which may have implications in braneworld models. With the CHH mechanism, we find that the massless zero mode of gauge field, in the case of minimal or non-minimal coupling is localized on the brane. Moreover, in the case of non-minimal coupling, it is shown that, when the non-minimal coupling constant is larger than its critical value, then the zero mode is localized on each sub brane.

  4. Sizable electron/neutron electric dipole moment in D 3 /D 7 μ -split supersymmetry

    NASA Astrophysics Data System (ADS)

    Dhuria, Mansi; Misra, Aalok

    2014-10-01

    Within the framework of N =1 gauged supergravity, using a phenomenological model that can be obtained locally as a Swiss-cheese Calabi-Yau string-theoretic compactification with a mobile D 3 -brane localized on a nearly special Lagrangian three cycle in the Calabi-Yau and fluxed stacks of wrapped D 7 -branes, and which provides a natural realization of μ -split supersymmetry (SUSY), we show that in addition to getting a significant value of an [electron/neutron (e/n)] electron dipole moment (EDM) at two-loop level, one can obtain a sizable contribution of (e/n) EDM even at one-loop level due to the presence of heavy supersymmetric fermions nearly isospectral with heavy sfermions. Unlike traditional split SUSY models in which the one-loop diagrams do not give significant contribution to the EDM of the electron/neutron because of very heavy sfermions existing as propagators in the loop, we show that one obtains a "healthy" value of the EDM in our model because of the presence of a heavy Higgsino, neutralino/chargino, and gaugino as fermionic propagators in the loops. The independent C P -violating phases are generated from nontrivial distinct phase factors associated with four Wilson line moduli [identified with first-generation leptons and quarks and their S U (2 )L -singlet cousins] as well as the D 3 -brane position moduli (identified with two Higgses), and the same are sufficient to produce overall distinct phase factors corresponding to all possible effective Yukawas as well as effective gauge couplings that we discuss in the context of N =1 gauged supergravity action. However, the complex phases responsible to generate a nonzero EDM at one-loop level mainly appear from an off-diagonal contribution of sfermion as well as Higgs mass matrices at the electroweak scale (EW). In our analysis, we obtain a dominant contribution of the electron/neutron EDM around de/e ≡O (1 0-29) cm from two-loop diagrams involving heavy sfermions and a light Higgs, and de/e ≡O (1

  5. Black branes and black strings in the astrophysical and cosmological context

    NASA Astrophysics Data System (ADS)

    Akarsu, Özgür; Chopovsky, Alexey; Zhuk, Alexander

    2018-03-01

    We consider Kaluza-Klein models where internal spaces are compact flat or curved Einstein spaces. This background is perturbed by a compact gravitating body with the dust-like equation of state (EoS) in the external/our space and an arbitrary EoS parameter Ω in the internal space. Without imposing any restrictions on the form of the perturbed metric and the distribution of the perturbed energy densities, we perform the general analysis of the Einstein and conservation equations in the weak-field limit. All conclusions follow from this analysis. For example, we demonstrate that the perturbed model is static and perturbed metric preserves the block-diagonal form. In a particular case Ω = - 1 / 2, the found solution corresponds to the weak-field limit of the black strings/branes. The black strings/branes are compact gravitating objects which have the topology (four-dimensional Schwarzschild spacetime) × (d-dimensional internal space) with d ≥ 1. We present the arguments in favour of these objects. First, they satisfy the gravitational tests for the parameterized post-Newtonian parameter γ at the same level of accuracy as General Relativity. Second, they are preferable from the thermodynamical point of view. Third, averaging over the Universe, they do not destroy the stabilization of the internal space. These are the astrophysical and cosmological aspects of the black strings/branes.

  6. Fermion localization and resonances on a de Sitter thick brane

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu Yuxiao; Yang Jie; Zhao Zhenhua

    2009-09-15

    In C. A. S. Almeida, R. Casana, M. M. Ferreira, Jr., and A. R. Gomes, Phys. Rev. D 79, 125022 (2009), the simplest Yukawa coupling {eta}{psi}{phi}{chi}{psi} was considered for a two-scalar-generated Bloch brane model. Fermionic resonances for both chiralities were obtained, and their appearance is related to branes with internal structure. Inspired on this result, we investigate the localization and resonance spectrum of fermions on a one-scalar-generated de Sitter thick brane with a class of scalar-fermion couplings {eta}{psi}{phi}{sup k}{psi} with positive odd integer k. A set of massive fermionic resonances for both chiralities is obtained when provided large coupling constantmore » {eta}. We find that the masses and lifetimes of left and right chiral resonances are almost the same, which demonstrates that it is possible to compose massive Dirac fermions from the left and right chiral resonances. The resonance with lower mass has longer lifetime. For a same set of parameters, the number of resonances increases with k and the lifetime of the lower level resonance for larger k is much longer than the one for smaller k.« less

  7. Local D3/D7 μ-SPLIT SUSY, 125 GeV Higgs and Large Volume Ricci-Flat Swiss-Cheese Metrics:. a Brief Review

    NASA Astrophysics Data System (ADS)

    Misra, Aalok

    In this paper, we review briefly recent progress made in realizing local(ized around a mobile spacetime filling D3-brane in) D3/D7 μ-split Supersymmetry in (the large volume limit of Type IIB) String Theory (compactified on Swiss-Cheese Calabi-Yau orientifolds) as well as obtaining a 125 GeV (light) Higgs in the same setup. We also discuss obtaining the geometric Kähler potential (and hence the Ricci-flat metric) for the Swiss-Cheese Calabi-Yau in the large volume limit using the Donaldson's algorithm and intuition from GLSM-based calculations — we present new results for Swiss-Cheese Calabi-Yau (used in the setup) metrics at points finitely away from the "big" divisor.

  8. Supersymmetric M3-branes and G2 manifolds

    NASA Astrophysics Data System (ADS)

    Cvetič, M.; Gibbons, G. W.; Lü, H.; Pope, C. N.

    2002-01-01

    We obtain a generalisation of the original complete Ricci-flat metric of G2 holonomy on R4×S 3 to a family with a nontrivial parameter λ. For generic λ the solution is singular, but it is regular when λ={-1,0,+1}. The case λ=0 corresponds to the original G2 metric, and λ={-1,1} are related to this by an S3 automorphism of the SU(2) 3 isometry group that acts on the S3× S3 principal orbits. We then construct explicit supersymmetric M3-brane solutions in D=11 supergravity, where the transverse space is a deformation of this class of G2 metrics. These are solutions of a system of first-order differential equations coming from a superpotential. We also find M3-branes in the deformed backgrounds of new G2 holonomy metrics that include one found by A. Brandhuber, J. Gomis, S. Gubser and S. Gukov, and show that they also are supersymmetric.

  9. Constraints on brane-world inflation from the CMB power spectrum: revisited

    NASA Astrophysics Data System (ADS)

    Gangopadhyay, Mayukh R.; Mathews, Grant J.

    2018-03-01

    We analyze the Randal Sundrum brane-world inflation scenario in the context of the latest CMB constraints from Planck. We summarize constraints on the most popular classes of models and explore some more realistic inflaton effective potentials. The constraint on standard inflationary parameters changes in the brane-world scenario. We confirm that in general the brane-world scenario increases the tensor-to-scalar ratio, thus making this paradigm less consistent with the Planck constraints. Indeed, when BICEP2/Keck constraints are included, all monomial potentials in the brane-world scenario become disfavored compared to the standard scenario. However, for natural inflation the brane-world scenario could fit the constraints better due to larger allowed values of e-foldings N before the end of inflation in the brane-world.

  10. Central Charges of Liouville and Toda Theories from M5-Branes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Alday, Luis F.; Tachikawa, Yuji; Benini, Francesco

    We show that the central charge of the Liouville and Toda theories of type A, D, and E can be reproduced by equivariantly integrating the anomaly eight-form of the corresponding six-dimensional N=(0,2) theories, which describe the low-energy dynamics of M5-branes.

  11. NATO Human Resources (Manpower) Management (Gestion des ressources humaines (effectifs) de l’OTAN)

    DTIC Science & Technology

    2012-02-01

    performances , la gestion des récompenses et du salaire, et la motivation du personnel. En conséquence, il faut que la gestion des ressources humaines...importance au fil du temps. Les ressources humaines, chargées à l’origine de l’embauche, du licenciement, de la paie et de la gestion des ...les effets des systèmes d’évaluation des performances ;

  12. Branes and the Kraft-Procesi transition: classical case

    NASA Astrophysics Data System (ADS)

    Cabrera, Santiago; Hanany, Amihay

    2018-04-01

    Moduli spaces of a large set of 3 d N=4 effective gauge theories are known to be closures of nilpotent orbits. This set of theories has recently acquired a special status, due to Namikawa's theorem. As a consequence of this theorem, closures of nilpotent orbits are the simplest non-trivial moduli spaces that can be found in three dimensional theories with eight supercharges. In the early 80's mathematicians Hanspeter Kraft and Claudio Procesi characterized an inclusion relation between nilpotent orbit closures of the same classical Lie algebra. We recently [1] showed a physical realization of their work in terms of the motion of D3-branes on the Type IIB superstring embedding of the effective gauge theories. This analysis is restricted to A-type Lie algebras. The present note expands our previous discussion to the remaining classical cases: orthogonal and symplectic algebras. In order to do so we introduce O3-planes in the superstring description. We also find a brane realization for the mathematical map between two partitions of the same integer number known as collapse. Another result is that basic Kraft-Procesi transitions turn out to be described by the moduli space of orthosymplectic quivers with varying boundary conditions.

  13. Gravitational field of static p -branes in linearized ghost-free gravity

    NASA Astrophysics Data System (ADS)

    Boos, Jens; Frolov, Valeri P.; Zelnikov, Andrei

    2018-04-01

    We study the gravitational field of static p -branes in D -dimensional Minkowski space in the framework of linearized ghost-free (GF) gravity. The concrete models of GF gravity we consider are parametrized by the nonlocal form factors exp (-□/μ2) and exp (□2/μ4) , where μ-1 is the scale of nonlocality. We show that the singular behavior of the gravitational field of p -branes in general relativity is cured by short-range modifications introduced by the nonlocalities, and we derive exact expressions of the regularized gravitational fields, whose geometry can be written as a warped metric. For large distances compared to the scale of nonlocality, μ r →∞ , our solutions approach those found in linearized general relativity.

  14. Embedding of the brane into six dimensions

    NASA Astrophysics Data System (ADS)

    Gogberashvili, Merab

    2002-10-01

    Embedding of the brane metric into Euclidean (2+4)-space is found. Brane geometry can be visualized as the surface of the hypersphere in six dimensions which ``radius'' is governed by the cosmological constant. Minkowski space in this picture is placed on the intersection of this surface with the plane formed by the extra space-like and time-like coordinates.

  15. Mass hierarchy, mass gap and corrections to Newton's law on thick branes with Poincaré symmetry

    NASA Astrophysics Data System (ADS)

    Barbosa-Cendejas, Nandinii; Herrera-Aguilar, Alfredo; Kanakoglou, Konstantinos; Nucamendi, Ulises; Quiros, Israel

    2014-01-01

    We consider a scalar thick brane configuration arising in a 5D theory of gravity coupled to a self-interacting scalar field in a Riemannian manifold. We start from known classical solutions of the corresponding field equations and elaborate on the physics of the transverse traceless modes of linear fluctuations of the classical background, which obey a Schrödinger-like equation. We further consider two special cases in which this equation can be solved analytically for any massive mode with , in contrast with numerical approaches, allowing us to study in closed form the massive spectrum of Kaluza-Klein (KK) excitations and to analytically compute the corrections to Newton's law in the thin brane limit. In the first case we consider a novel solution with a mass gap in the spectrum of KK fluctuations with two bound states—the massless 4D graviton free of tachyonic instabilities and a massive KK excitation—as well as a tower of continuous massive KK modes which obey a Legendre equation. The mass gap is defined by the inverse of the brane thickness, allowing us to get rid of the potentially dangerous multiplicity of arbitrarily light KK modes. It is shown that due to this lucky circumstance, the solution of the mass hierarchy problem is much simpler and transparent than in the thin Randall-Sundrum (RS) two-brane configuration. In the second case we present a smooth version of the RS model with a single massless bound state, which accounts for the 4D graviton, and a sector of continuous fluctuation modes with no mass gap, which obey a confluent Heun equation in the Ince limit. (The latter seems to have physical applications for the first time within braneworld models). For this solution the mass hierarchy problem is solved with positive branes as in the Lykken-Randall (LR) model and the model is completely free of naked singularities. We also show that the scalar-tensor system is stable under scalar perturbations with no scalar modes localized on the braneworld

  16. Black branes in a box: hydrodynamics, stability, and criticality

    NASA Astrophysics Data System (ADS)

    Emparan, Roberto; Martınez, Marina

    2012-07-01

    We study the effective hydrodynamics of neutral black branes enclosed in a finite cylindrical cavity with Dirichlet boundary conditions. We focus on how the Gregory-Laflamme instability changes as we vary the cavity radius R. Fixing the metric at the cavity wall increases the rigidity of the black brane by hindering gradients of the redshift on the wall. In the effective fluid, this is reflected in the growth of the squared speed of sound. As a consequence, when the cavity is smaller than a critical radius the black brane becomes dynamically stable. The correlation with the change in thermodynamic stability is transparent in our approach. We compute the bulk and shear viscosities of the black brane and find that they do not run with R. We find mean-field theory critical exponents near the critical point.

  17. Effective monopoles within thick branes

    NASA Astrophysics Data System (ADS)

    Hoff da Silva, J. M.; da Rocha, Roldão

    2012-10-01

    The monopole mass is revealed to be considerably modified in the thick braneworld paradigm, and depends on the position of the monopole in the brane as well. Accordingly, the monopole radius continuously increases, leading to an unacceptable setting that can be circumvented when the brane thickness has an upper limit. Despite such peculiar behavior, the accrued quantum corrections —involving the classical monopole solution— are shown to be still under control. We analyze the monopole's peculiarities also taking into account the localization of the gauge fields. Furthermore, some additional analysis in the thick braneworld context and the similar behavior evinced by the topological string are investigated.

  18. A compact codimension-two braneworld with precisely one brane

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Akerblom, Nikolas; Cornelissen, Gunther; Department of Mathematics, Utrecht University

    Building on earlier work on football-shaped extra dimensions, we construct a compact codimension-two braneworld with precisely one brane. The two extra dimensions topologically represent a 2-torus which is stabilized by a bulk cosmological constant and magnetic flux. The torus has positive constant curvature almost everywhere, except for a single conical singularity at the location of the brane. In contradistinction to the football-shaped case, there is no fine-tuning required for the brane tension. We also present some plausibility arguments why the model should not suffer from serious stability issues.

  19. Lab-on-a-brane: nanofibrous polymer membranes to recreate organ-capillary interfaces

    NASA Astrophysics Data System (ADS)

    Budhwani, Karim I.; Thomas, Vinoy; Sethu, Palaniappan

    2016-03-01

    Drug discovery is a complex and time consuming process involving significant basic research and preclinical evaluation prior to testing in patients. Preclinical studies rely extensively on animal models which often fail in human trials. Biomimetic microphysiological systems (MPS) using human cells can be a promising alternative to animal models; where critical interactions between different organ systems are recreated to provide physiologically relevant in vitro human models. Central here are blood-vessel networks, the interface controlling transport of cellular and biomolecular components between the circulating fluid and underlying tissue. Here we present a novel lab-on-a-brane (or lab-on-a-membrane) nanofluidics MPS that combines the elegance of lab-on-a-chip with the more realistic morphology of 3D fibrous tissue-engineering constructs. Our blood-vessel lab-on-a-brane effectively simulates in vivo vessel-tissue interface for evaluating transendothelial transport in various pharmacokinetic and nanomedicine applications. Attributes of our platform include (a) nanoporous barrier interface enabling transmembrane molecular transport, (b) transformation of substrate into nanofibrous 3D tissue matrix, (c) invertible-sandwich architecture, and (d) simple co-culture mechanism for endothelial and smooth muscle layers to accurately mimic arterial anatomy. Structural, mechanical, and transport characterization using scanning electron microscopy, stress/strain analysis, infrared spectroscopy, immunofluorescence, and FITC-Dextran hydraulic permeability confirm viability of this in vitro system. Thus, our lab-on-a-brane provides an effective and efficient, yet considerably inexpensive, physiologically relevant alternative for pharmacokinetic evaluation; possibly reducing animals used in preclinical testing, costs from false starts, and time-to-market. Furthermore, it can be configured in multiple simultaneous arrays for personalized and precision medicine applications and for

  20. CASIMIR Effect in a Supersymmetry-Breaking Brane-World as Dark Energy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, P

    2004-09-29

    A new model for the origin of dark energy is proposed based on the Casimir effect in a supersymmetry-breaking brane-world. Supersymmetry is assumed to be preserved in the bulk while broken on a 3-brane. Due to the boundary conditions imposed on the compactified extra dimensions, there is an effective Casimir energy induced on the brane. The net Casimir energy contributed from the graviton and the gravitino modes as a result of supersymmetry-breaking on the brane is identified as the observed dark energy, which in our construction is a cosmological constant. We show that the smallness of the cosmological constant, whichmore » results from the huge contrast in the extra-dimensional volumes between that associated with the 3-brane and that of the bulk, is attainable under very relaxed condition.« less

  1. Gravitational baryogenesis in DGP brane cosmology

    NASA Astrophysics Data System (ADS)

    Atazadeh, K.

    2018-06-01

    We consider the imbalance of matter and antimatter by using a gravitational baryogenesis mechanism in the background of Dvali-Gabadadze-Porrati (DGP) brane cosmology. By taking into account a flat Friedmann-Lemaître-Robertson-Walker (FLRW) metric in the DGP brane model, we find that for a radiation dominated universe, w=1/3, the ratio of baryon number density to entropy from the gravitational baryogenesis is not zero, contrary to ordinary general relativity. Also, we study the ratio of baryon number density to entropy against the observational constraints in DGP cosmology.

  2. Brane universes with Gauss-Bonnet-induced-gravity

    NASA Astrophysics Data System (ADS)

    Brown, Richard A.

    2007-04-01

    The DGP brane world model allows us to get the observed late time acceleration via modified gravity, without the need for a “dark energy” field. This can then be generalised by the inclusion of high energy terms, in the form of a Gauss-Bonnet bulk. This is the basis of the Gauss-Bonnet-Induced-Gravity (GBIG) model explored here with both early and late time modifications to the cosmological evolution. Recently the simplest GBIG models (Minkowski bulk and no brane tension) have been analysed. Two of the three possible branches in these models start with a finite density “Big-Bang” and with late time acceleration. Here we present a comprehensive analysis of more general models where we include a bulk cosmological constant and brane tension. We show that by including these factors it is possible to have late time phantom behaviour.

  3. Effect of bulk Lorentz violation on anisotropic brane cosmologies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Heydari-Fard, Malihe, E-mail: heydarifard@qom.ac.ir

    2012-04-01

    The effect of Lorentz invariance violation in cosmology has attracted a considerable amount of attention. By using a dynamical vector field assumed to point in the bulk direction, with Lorentz invariance holding on the brane, we extend the notation of Lorentz violation in four dimensions Jacobson to a five-dimensional brane-world. We obtain the general solution of the field equations in an exact parametric form for Bianchi type I space-time, with perfect fluid as a matter source. We show that the brane universe evolves from an isotropic/anisotropic state to an isotropic de Sitter inflationary phase at late time. The early timemore » behavior of anisotropic brane universe is largely dependent on the Lorentz violating parameters β{sub i},i = 1,2,3 and the equation of state of the matter, while its late time behavior is independent of these parameters.« less

  4. Kaluza-Klein two-brane-worlds cosmology at low energy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feranie, S.; Arianto; Zen, Freddy P.

    2010-04-15

    We study two (4+n)-dimensional branes embedded in (5+n)-dimensional spacetime. Using the gradient expansion approximation, we find that the effective theory is described by (4+n)-dimensional scalar-tensor gravity with a specific coupling function. Based on this theory we investigate the Kaluza-Klein two-brane-worlds cosmology at low energy, in both the static and the nonstatic internal dimensions. In the case of the static internal dimensions, the effective gravitational constant in the induced Friedmann equation depends on the equations of state of the brane matter, and the dark radiation term naturally appears. In the nonstatic case we take a relation between the external and internalmore » scale factors of the form b(t)=a{sup {gamma}(t)} in which the brane world evolves with two scale factors. In this case, the induced Friedmann equation on the brane is modified in the effective gravitational constant and the term proportional to a{sup -4{beta}.} For dark radiation, we find {gamma}=-2/(1+n). Finally, we discuss the issue of conformal frames which naturally arises with scalar-tensor theories. We find that the static internal dimensions in the Jordan frame may become nonstatic in the Einstein frame.« less

  5. Interaction of moving branes with background massless and tachyon fields in superstring theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rezaei, Z., E-mail: z.rezaei@aut.ac.ir; Kamani, D., E-mail: kamani@aut.ac.ir

    2012-02-15

    Using the boundary state formalism, we study a moving Dp-brane in a partially compact space-time in the presence of background fields: the Kalb-Ramond field B{sub {mu}{nu}}, a U(1) gauge field A{sub {alpha}}, and the tachyon field. The boundary state enables us to obtain the interaction amplitude of two branes with the above back-ground fields. The branes are parallel or perpendicular to each other. Because of the presence of background fields, compactification of some space-time directions, motion of the branes, and the arbitrariness of the dimensions of the branes, the system is rather general. Due to the tachyon fields and velocitiesmore » of the branes, the behavior of the interaction amplitude reveals obvious differences from the conventional behavior.« less

  6. Cosmic space and Pauli exclusion principle in a system of M0-branes

    NASA Astrophysics Data System (ADS)

    Capozziello, Salvatore; Saridakis, Emmanuel N.; Bamba, Kazuharu; Sepehri, Alireza; Rahaman, Farook; Ali, Ahmed Farag; Pincak, Richard; Pradhan, Anirudh

    An emergence of cosmic space has been suggested by Padmanabhan [Emergence and expansion of cosmic space as due to the quest for holographic equipartition, arXiv:hep-th/1206.4916] where he proposed that the expansion of the universe originates from a difference between the number of degrees of freedom on a holographic surface and the one in the emerged bulk. Now, a natural question that arises is how this proposal would explain the production of fermions and an emergence of the Pauli exclusion principle during the evolution of the universe? We try to address this issue in a system of M0-branes. In this model, there is a high symmetry and the system is composed of M0-branes to which only scalar fields are attached that represent scalar modes of the graviton. Then, when M0-branes join each other and hence form M1-branes, this symmetry is broken and gauge fields are formed. Therefore, these M1-branes interact with the anti-M1-branes and the force between them leads to a break of a symmetry such as the lower and upper parts of these branes are not the same. In these conditions, gauge fields which are localized on M1-branes and scalars which are attached to them symmetrically, decay to fermions with upper and lower spins which attach to the upper and lower parts of the M1-branes anti-symmetrically. The curvature produced by the coupling of identical spins has the opposite sign of the curvature produced by non-identical spins which lead to an attractive force between anti-parallel spins and a repelling force between parallel spins and hence an emergence of the Pauli exclusion principle. By approaching M1-branes to each other, the difference between curvatures of parallel spins and curvatures of anti-parallel spins increases, which leads to an inequality between the number of degrees of freedom on the surface and the one in the emerged bulk and hence lead to an occurrence of the cosmic expansion. By approaching M1-branes to each other, the square of the energy of the

  7. Intersecting branes, Higgs sector, and chirality from N = 4 SYM with soft SUSY breaking

    NASA Astrophysics Data System (ADS)

    Sperling, Marcus; Steinacker, Harold C.

    2018-04-01

    We consider SU( N ) N = 4 super Yang-Mills with cubic and quadratic soft SUSY breaking potential, such that the global SU(4) R is broken to SU(3) or further. As shown recently, this set-up supports a rich set of non-trivial vacua with the geometry of self-intersecting SU(3) branes in 6 extra dimensions. The zero modes on these branes can be interpreted as 3 generations of bosonic and chiral fermionic strings connecting the branes at their intersections. Here, we uncover a large class of exact solutions consisting of branes connected by Higgs condensates, leading to Yukawa couplings between the chiral fermionic zero modes. Under certain decoupling conditions, the backreaction of the Higgs on the branes vanishes exactly. The resulting physics is that of a spontaneously broken chiral gauge theory on branes with fluxes. In particular, we identify combined brane plus Higgs configurations which lead to gauge fields that couple to chiral fermions at low energy. This turns out to be quite close to the Standard Model and its constructions via branes in string theory. As a by-product, we construct a G 2-brane solution corresponding to a squashed fuzzy coadjoint orbit of G 2.

  8. Brane decay and an initial spacelike singularity.

    PubMed

    Kawai, Shinsuke; Keski-Vakkuri, Esko; Leigh, Robert G; Nowling, Sean

    2006-01-27

    We present a novel string theory scenario where matter in a spacetime originates from a decaying brane at the origin of time. The decay could be considered as a big-bang-like event at X0=0. The closed string interpretation is a time-dependent spacetime with a semi-infinite time direction, with the initial energy of the brane converted into energy flux from the origin. The open string interpretation can be viewed as a string theoretic nonsingular initial condition.

  9. The strong energy condition and the S-brane singularity problem

    NASA Astrophysics Data System (ADS)

    McInnes, Brett

    2003-06-01

    Recently it has been argued that, because tachyonic matter satisfies the Strong Energy Condition [SEC], there is little hope of avoiding the singularities which plague S-Brane spacetimes. Meanwhile, however, Townsend and Wohlfarth have suggested an ingenious way of circumventing the SEC in such situations, and other suggestions for actually violating it in the S-Brane context have recently been proposed. Of course, the natural context for discussions of [effective or actual] violations of the SEC is the theory of asymptotically deSitter spacetimes, which tend to be less singular than ordinary FRW spacetimes. However, while violating or circumventing the SEC is necessary if singularities are to be avoided, it is not at all clear that it is sufficient. That is, we can ask: would an asymptotically deSitter S-brane spacetime be non-singular? We show that this is difficult to achieve; this result is in the spirit of the recently proved "S-brane singularity theorem". Essentially our results suggest that circumventing or violating the SEC may not suffice to solve the S-Brane singularity problem, though we do propose two ways of avoiding this conclusion.

  10. REVIEWS OF TOPICAL PROBLEMS: Cosmological branes and macroscopic extra dimensions

    NASA Astrophysics Data System (ADS)

    Barvinsky, Andrei O.

    2005-06-01

    The idea of adding extra dimensions to the physical world — thus making the observable universe a timelike surface (or brane) embedded in a higher-dimensional space-time — is briefly reviewed, which is believed to hold serious promise for solving fundamental problems concerning the hierarchy of physical interactions and the cosmological constant. Brane localization of massless gravitons is discussed as a mechanism leading to the effective four-dimensional Einstein gravity theory on the brane in the low-energy limit. It is shown that this mechanism is a corollary of the AdS/CFT correspondence principle well-known from string theory. Inflation and other cosmological evolution scenarios induced by the local and nonlocal structures of the effective action of the gravitational brane are considered, as are the effects that enable the developing gravitational-wave astronomy to be used in the search for extra dimensions. Finally, a new approach to the cosmological constant and cosmological acceleration problems is discussed, which involves variable local and nonlocal gravitational 'constants' arising in the infrared modifications of the Einstein theory that incorporate brane-induced gravity models and models of massive gravitons.

  11. New interpretation of matter-antimatter asymmetry based on branes and possible observational consequences

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cai Ronggen; Li Tong; Li Xueqian

    2007-11-15

    Motivated by the alpha-magnetic-spectrometer (AMS) project, we assume that after the big bang or inflation epoch, antimatter was repelled onto one brane which is separated from our brane where all the observational matter resides. It is suggested that CP may be spontaneously broken, the two branes would correspond to ground states for matter and antimatter, respectively. Generally a complex scalar field which is responsible for the spontaneous CP violation, exists in the space between the branes. The matter and antimatter on the two branes attract each other via gravitational force, meanwhile the scalar field causes a Casimir effect to resultmore » in a repulsive force against the gravitation. We find that the Casimir force is much stronger than the gravitational force, as long as the separation of the two branes is small. Thus at early epoch after the big bang, the two branes were closer and then have been separated by the Casimir repulsive force from each other. The trend will continue until the separation is sufficiently large and then the gravitational force observed in our four-space would obviously deviate from the Newton's universal gravitational law. We suppose that there is a potential barrier at the brane boundary, which is similar to the surface tension for a water membrane. The barrier prevents the matter (antimatter) particles from entering the space between two branes and jump from one brane to another. However, by the quantum tunneling, a sizable antimatter flux may come to our brane and be observed by the AMS. In this work by considering two possible models, i.e. the naive flat space-time and Randall-Sundrum models, and using the observational data on the visible matter in our universe as inputs, we derive the antimatter flux which comes to our detector in the nonrelativistic approximation and make a rough numerical estimate of possible numbers of antihelium at AMS.« less

  12. Vacuum thin shells in Einstein–Gauss–Bonnet brane-world cosmology

    NASA Astrophysics Data System (ADS)

    Ramirez, Marcos A.

    2018-04-01

    In this paper we construct new solutions of the Einstein–Gauss–Bonnet field equations in an isotropic Shiromizu–Maeda–Sasaki brane-world setting which represent a couple of Z 2-symmetric vacuum thin shells splitting from the central brane, and explore the main properties of the dynamics of the system. The matching of the separating vacuum shells with the brane-world is as smooth as possible and all matter fields are restricted to the brane. We prove the existence of these solutions, derive the criteria for their existence, analyse some fundamental aspects or their evolution and demonstrate the possibility of constructing cosmological examples that exhibit this feature at early times. We also comment on the possible implications for cosmology and the relation of this system with the thermodynamic instability of highly symmetric vacuum solutions of Lovelock theory.

  13. Cosmic superstrings: Observable remnants of brane inflation

    NASA Astrophysics Data System (ADS)

    Wyman, Mark Charles

    Brane inflation provides a natural dynamical model for the physics which underlie the inflationary paradigm. Besides their inflationary predictions, brane models imply another observable consequence: cosmic strings. In this dissertation I outline the background of how cosmic strings arise in brane inflationary models and how the properties of the strings and the models are mutually tied (Chapter 2). I then use cosmological observations to put limits on the properties of any actually-existing cosmic string network (Chapter 3). Next, I study the question of how cosmic superstrings, as the cosmic strings arising from string theory are known, could be distinct from classical gauge- theory cosmic strings. In particular, I propose an analytical model for the cosmological evolution of a network of binding cosmic strings (Chapter 4); I also describe the distinctive gravitational lensing phenomena that are caused by binding strings (Chapter 5). Finally, I lay out the background for the numerical study of a gauge theory model for the dynamics of cosmic superstring binding (Chapter 6).

  14. Thin limit of the 6D Cascading DGP model

    NASA Astrophysics Data System (ADS)

    Sbisà, Fulvio

    2018-05-01

    A thin limit description of the 6D Cascading DGP model is derived, starting from a configuration where both the codimension-1 and the codimension-2 branes are thick. Postulating that the thicknesses of the two branes obey a hierarchic relation, the thin limit is executed in two steps. First the thin limit of the codimension-1 brane is executed, obtaining a system where a "ribbon" codimension-2 brane is embedded inside a thin codimension-1 brane with induced gravity, and then the thin limit of the ribbon brane is considered. By proposing a geometric ansatz on the limit configuration, the junction conditions which are to hold at the thin codimension-2 brane are derived. The latters are fully non-perturbative and covariant and, together with the Israel junction conditions at the codimension-1 brane and the Einstein equations in the bulk, constitute the looked-for thin limit formulation of the 6D Cascading DGP model. It is commented on how wide is the class of thin source configurations which can be placed on the thin codimension-2 brane.

  15. Tachyon and quintessence in brane worlds

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chimento, Luis P.; Forte, Monica; Richarte, Martin G.

    2009-04-15

    Using tachyon or quintessence fields along with a barotropic fluid on the brane we examine the different cosmological stages in a Friedmann-Robertson-Walker universe, from the first radiation scenario to the later era dominated by cosmic string networks. We introduce a new algorithm to generalize previous works on exact solutions and apply it to study tachyon and quintessence fields localized on the brane. We also explore the low and high energy regimes of the solutions. Besides, we show that the tachyon and quintessence fields are driven by an inverse power law potential. Finally, we find several simple exacts solutions for tachyonmore » and/or quintessence fields.« less

  16. Dirac relaxation of the Israel junction conditions: Unified Randall-Sundrum brane theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Davidson, Aharon; Gurwich, Ilya

    2006-08-15

    Following Dirac's brane variation prescription, the brane must not be deformed during the variation process, or else the linearity of the variation may be lost. Alternatively, the variation of the brane is done, in a special Dirac frame, by varying the bulk coordinate system itself. Imposing appropriate Dirac-style boundary conditions on the constrained 'sandwiched' gravitational action, we show how Israel junction conditions get relaxed, but remarkably, all solutions of the original Israel equations are still respected. The Israel junction conditions are traded, in the Z{sub 2}-symmetric case, for a generalized Regge-Teitelboim type equation (plus a local conservation law), and inmore » the generic Z{sub 2}-asymmetric case, for a pair of coupled Regge-Teitelboim equations. The Randall-Sundrum model and its derivatives, such as the Dvali-Gabadadze-Porrati and the Collins-Holdom models, get generalized accordingly. Furthermore, Randall-Sundrum and Regge-Teitelboim brane theories appear now to be two different faces of the one and the same unified brane theory. Within the framework of unified brane cosmology, we examine the dark matter/energy interpretation of the effective energy/momentum deviations from general relativity.« less

  17. Black holes radiate mainly on the brane.

    PubMed

    Emparan, R; Horowitz, G T; Myers, R C

    2000-07-17

    We examine the evaporation of a small black hole on a brane in a world with large extra dimensions. Since the masses of many Kaluza-Klein modes are much smaller than the Hawking temperature of the black hole, it has been claimed that most of the energy is radiated into these modes. We show that this is incorrect. Most of the energy goes into the modes on the brane. This raises the possibility of observing Hawking radiation in future high energy colliders if there are large extra dimensions.

  18. Ramond and Neveu-Schwarz paraspinning strings in presence of D-branes

    NASA Astrophysics Data System (ADS)

    Hamam, D.; Belaloui, N.

    2018-03-01

    We investigate the theory of an open parafermionic string between two parallel Dp-, Dq-branes in Ramond and Neveu-Schwarz sectors. Trilinear commutation relations between the string variables are postulated and the corresponding ones in terms of modes are derived. The analysis of the spectrum shows that one can again have a free tachyon Neveu-Schwarz model for some values of the order of the paraquantization associated to some values of p and q. The consistency of this model requires the calculation of the partition function and its confrontation with the results of the degeneracies. A perfect agreement between the two results is obtained and the closure of the Virasoro superalgebra is confirmed.

  19. BlackMax: A black-hole event generator with rotation, recoil, split branes, and brane tension

    NASA Astrophysics Data System (ADS)

    Dai, De-Chang; Starkman, Glenn; Stojkovic, Dejan; Issever, Cigdem; Rizvi, Eram; Tseng, Jeff

    2008-04-01

    We present a comprehensive black-hole event generator, BlackMax, which simulates the experimental signatures of microscopic and Planckian black-hole production and evolution at the LHC in the context of brane world models with low-scale quantum gravity. The generator is based on phenomenologically realistic models free of serious problems that plague low-scale gravity, thus offering more realistic predictions for hadron-hadron colliders. The generator includes all of the black-hole gray-body factors known to date and incorporates the effects of black-hole rotation, splitting between the fermions, nonzero brane tension, and black-hole recoil due to Hawking radiation (although not all simultaneously). The generator can be interfaced with Herwig and Pythia. The main code can be downloaded from http://www-pnp.physics.ox.ac.uk/~issever/BlackMax/blackmax.html.

  20. M2- and M5-branes in E11 current algebra formulation of M-theory

    NASA Astrophysics Data System (ADS)

    Shiba, Shotaro; Sugawara, Hirotaka

    2018-03-01

    Equations of motion for M2- and M5-branes are written down in the E11 current algebra formulation of M-theory. These branes correspond to currents of the second and the fifth rank antisymmetric tensors in the E11 representation, whereas the electric and magnetic fields (coupled to M2- and M5-branes) correspond to currents of the third and the sixth rank antisymmetric tensors, respectively. We show that these equations of motion have solutions in terms of the coordinates on M2- and M5-branes. We also discuss the geometric equations, and show that there are static solutions when M2- or M5-brane exists alone and also when M5-brane wraps around M2-brane. This situation is realized because our Einstein-like equation contains an extra term which can be interpreted as gravitational energy contributing to the curvature, thus avoiding the usual intersection rule.

  1. Hair-brane ideas on the horizon

    DOE PAGES

    Martinec, Emil J.; Niehoff, Ben E.

    2015-11-27

    We continue an examination of the microstate geometries program begun in arXiv:1409.6017, focussing on the role of branes that wrap the cycles which degenerate when a throat in the geometry deepens and a horizon forms. An associated quiver quantum mechanical model of minimally wrapped branes exhibits a non-negligible fraction of the gravitational entropy, which scales correctly as a function of the charges. The results suggest a picture of AdS3/CFT2 duality wherein the long string that accounts for BTZ black hole entropy in the CFT description, can also be seen to inhabit the horizon of BPS black holes on the gravitymore » side.« less

  2. Relativistic elasticity of stationary fluid branes

    NASA Astrophysics Data System (ADS)

    Armas, Jay; Obers, Niels A.

    2013-02-01

    Fluid mechanics can be formulated on dynamical surfaces of arbitrary codimension embedded in a background space-time. This has been the main object of study of the blackfold approach in which the emphasis has primarily been on stationary fluid configurations. Motivated by this approach we show under certain conditions that a given stationary fluid configuration living on a dynamical surface of vanishing thickness and satisfying locally the first law of thermodynamics will behave like an elastic brane when the surface is subject to small deformations. These results, which are independent of the number of space-time dimensions and of the fluid arising from a gravitational dual, reveal the (electro)elastic character of (charged) black branes when considering extrinsic perturbations.

  3. M2-brane surface operators and gauge theory dualities in Toda

    NASA Astrophysics Data System (ADS)

    Gomis, Jaume; Le Floch, Bruno

    2016-04-01

    We give a microscopic two dimensional {N} = (2, 2) gauge theory description of arbitrary M2-branes ending on N f M5-branes wrapping a punctured Riemann surface. These realize surface operators in four dimensional {N} = 2 field theories. We show that the expectation value of these surface operators on the sphere is captured by a Toda CFT correlation function in the presence of an additional degenerate vertex operator labelled by a representation {R} of SU( N f ), which also labels M2-branes ending on M5-branes. We prove that symmetries of Toda CFT correlators provide a geometric realization of dualities between two dimensional gauge theories, including {N} = (2, 2) analogues of Seiberg and Kutasov-Schwimmer dualities. As a bonus, we find new explicit conformal blocks, braiding matrices, and fusion rules in Toda CFT.

  4. Cascading gauge theory on dS4 and String Theory landscape

    NASA Astrophysics Data System (ADS)

    Buchel, Alex; Galante, Damián A.

    2014-06-01

    Placing anti-D3 branes at the tip of the conifold in Klebanov-Strassler geometry provides a generic way of constructing meta-stable de Sitter (dS) vacua in String Theory. A local geometry of such vacua exhibit gravitational solutions with a D3 charge measured at the tip opposite to the asymptotic charge. We discuss a restrictive set of such geometries, where anti-D3 branes are smeared at the tip. Such geometries represent holographic dual of cascading gauge theory in dS4 with or without chiral symmetry breaking. We find that in the phase with unbroken chiral symmetry the D3 charge at the tip is always positive. Furthermore, this charge is zero in the phase with spontaneously broken chiral symmetry. We show that the effective potential of the chirally symmetric phase is lower than that in the symmetry broken phase, i.e., there is no spontaneous chiral symmetry breaking for cascading gauge theory in dS4. The positivity of the D3 brane charge in smooth de-Sitter deformed conifold geometries with fluxes presents difficulties in uplifting AdS vacua to dS ones in String Theory via smeared anti-D3 branes. First, turning on fluxes on Calabi-Yau compactifications of type IIB string theory produces highly warped geometry with stabilized complex structure (but not Kähler) moduli of the compactification [3]; Next, including non-perturbative effects (which are under control given the unbroken supersymmetry), one obtains anti-de Sitter (AdS4) vacua with all moduli fixed; Finally, one uses anti-D3 branes of type IIB string theory to uplift AdS4 to de Sitter (dS4) vacua. As the last step of the construction completely breaks supersymmetry, it is much less controlled. In fact, in [4-7] it was argued that putting anti-D3 branes at the tip of the Klebanov-Strassler (KS) [8] geometry (as done in KKLT construction) leads to a naked singularity. Whether or not the resulting singularity is physical is subject to debates. When M4=dS4 and the chiral symmetry is unbroken, the D3 brane

  5. BlackMax: A black-hole event generator with rotation, recoil, split branes, and brane tension

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Dai Dechang; Starkman, Glenn; Stojkovic, Dejan

    2008-04-01

    We present a comprehensive black-hole event generator, BlackMax, which simulates the experimental signatures of microscopic and Planckian black-hole production and evolution at the LHC in the context of brane world models with low-scale quantum gravity. The generator is based on phenomenologically realistic models free of serious problems that plague low-scale gravity, thus offering more realistic predictions for hadron-hadron colliders. The generator includes all of the black-hole gray-body factors known to date and incorporates the effects of black-hole rotation, splitting between the fermions, nonzero brane tension, and black-hole recoil due to Hawking radiation (although not all simultaneously). The generator can bemore » interfaced with Herwig and Pythia. The main code can be downloaded from http://www-pnp.physics.ox.ac.uk/{approx}issever/BlackMax/blackmax.html.« less

  6. Spherically symmetric solutions and gravitational collapse in brane-worlds

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Heydari-Fard, Malihe; Sepangi, Hamid R., E-mail: heydarifard@qom.ac.ir, E-mail: hr-sepangi@sbu.ac.ir

    2009-02-15

    We consider spherically symmetric solutions within the context of brane-world theory without mirror symmetry or any form of junction conditions. For a constant curvature bulk, we obtain the modified Tolman-Oppenheimer-Volkoff (TOV) interior solutions in two cases where one is matched to a schwarzschild-de Sitter exterior while the other is consistent with an exterior solution whose structure can be used to explain the galaxy rotation curves without postulating dark matter. We also find the upper bound to the mass of a static brane-world star and show that the influence of the bulk effects on the interior solutions is small. Finally, wemore » investigate the gravitational collapse on the brane and show that the exterior of a collapsing star can be static in this scenario.« less

  7. Generalized Israel junction conditions for a fourth-order brane world

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Balcerzak, Adam; Dabrowski, Mariusz P.

    2008-01-15

    We discuss a general fourth-order theory of gravity on the brane. In general, the formulation of the junction conditions (except for Euler characteristics such as Gauss-Bonnet term) leads to the higher powers of the delta function and requires regularization. We suggest the way to avoid such a problem by imposing the metric and its first derivative to be regular at the brane, while the second derivative to have a kink, the third derivative of the metric to have a step function discontinuity, and no sooner as the fourth derivative of the metric to give the delta function contribution to themore » field equations. Alternatively, we discuss the reduction of the fourth-order gravity to the second-order theory by introducing an extra tensor field. We formulate the appropriate junction conditions on the brane. We prove the equivalence of both theories. In particular, we prove the equivalence of the junction conditions with different assumptions related to the continuity of the metric along the brane.« less

  8. Scalar one-point functions and matrix product states of AdS/dCFT

    NASA Astrophysics Data System (ADS)

    de Leeuw, Marius; Kristjansen, Charlotte; Linardopoulos, Georgios

    2018-06-01

    We determine in a closed form all scalar one-point functions of the defect CFT dual to the D3-D5 probe brane system with k units of flux which amounts to calculating the overlap between a Bethe eigenstate of the integrable SO(6) spin chain and a certain matrix product state of bond dimension k. In particular, we show that the matrix product state is annihilated by all the parity odd charges of the spin chain which has recently been suggested as the criterion for such a state to correspond to an integrable initial state. Finally, we discuss the properties of the analogous matrix product state for the SO(5) symmetric D3-D7 probe brane set-up.

  9. Tachyon Condensation and Brane Annihilation in Bose-Einstein Condensates: Spontaneous Symmetry Breaking in Restricted Lower-Dimensional Subspace

    NASA Astrophysics Data System (ADS)

    Takeuchi, Hiromitsu; Kasamatsu, Kenichi; Tsubota, Makoto; Nitta, Muneto

    2013-05-01

    In brane cosmology, the Big Bang is hypothesized to occur by the annihilation of the brane-anti-brane pair in a collision, where the branes are three-dimensional objects in a higher-dimensional Universe. Spontaneous symmetry breaking accompanied by the formation of lower-dimensional topological defects, e.g. cosmic strings, is triggered by the so-called `tachyon condensation', where the existence of tachyons is attributable to the instability of the brane-anti-brane system. Here, we discuss the closest analogue of the tachyon condensation in atomic Bose-Einstein condensates. We consider annihilation of domain walls, namely branes, in strongly segregated two-component condensates, where one component is sandwiched by two domains of the other component. In this system, the process of the brane annihilation can be projected effectively as ferromagnetic ordering dynamics onto a two-dimensional space. Based on this correspondence, three-dimensional formation of vortices from a domain-wall annihilation is considered to be a kink formation due to spontaneous symmetry breaking in the two-dimensional space. We also discuss a mechanism to create a `vorton' when the sandwiched component has a vortex string bridged between the branes. We hope that this study motivates experimental researches to realize this exotic phenomenon of spontaneous symmetry breaking in superfluid systems.

  10. Diffusion constant of slowly rotating black three-brane

    NASA Astrophysics Data System (ADS)

    Amoozad, Z.; Sadeghi, J.

    2018-01-01

    In this paper, we take the slowly rotating black three-brane background and perturb it by introducing a vector gauge field. We find the components of the gauge field through Maxwell equations and Bianchi identities. Using currents and some ansatz we find Fick's first law at long wavelength regime. An interesting result for this non-trivial supergravity background is that the diffusion constant on the stretched horizon which emerges from Fick's first law is a complex constant. The pure imaginary part of the diffusion constant appears because the black three-brane has angular momentum. By taking the static limit of the corresponding black brane the well known diffusion constant will be recovered. On the other hand, from the point of view of the Fick's second law, we have the dispersion relation ω = - iDq2 and we found a damping of hydrodynamical flow in the holographically dual theory. Existence of imaginary term in the diffusion constant introduces an oscillating propagation of the gauge field in the dual field theory.

  11. The (2, 0) superalgebra, null M-branes and Hitchin's system

    NASA Astrophysics Data System (ADS)

    Kucharski, P.; Lambert, N.; Owen, M.

    2017-10-01

    We present an interacting system of equations with sixteen supersymmetries and an SO(2) × SO(6) R-symmetry where the fields depend on two space and one null dimensions that is derived from a representation of the six-dimensional (2, 0) superalgebra. The system can be viewed as two M5-branes compactified on {S}-^1× T^2 or equivalently as M2-branes on R+× R^2 , where ± refer to null directions. We show that for a particular choice of fields the dynamics can be reduced to motion on the moduli space of solutions to the Hitchin system. We argue that this provides a description of intersecting null M2-branes and is also related by U-duality to a DLCQ description of four-dimensional maximally supersymmetric Yang-Mills.

  12. Black branes as piezoelectrics.

    PubMed

    Armas, Jay; Gath, Jakob; Obers, Niels A

    2012-12-14

    We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.

  13. Corrections to Newton’s law of gravitation - application to hybrid Bloch brane

    NASA Astrophysics Data System (ADS)

    Almeida, C. A. S.; Veras, D. F. S.; Dantas, D. M.

    2018-02-01

    We present in this work, the calculations of corrections in the Newton’s law of gravitation due to Kaluza-Klein gravitons in five-dimensional warped thick braneworld scenarios. We consider here a recently proposed model, namely, the hybrid Bloch brane. This model couples two scalar fields to gravity and is engendered from a domain wall-like defect. Also, two other models the so-called asymmetric hybrid brane and compact brane are considered. Such models are deformations of the ϕ 4 and sine-Gordon topological defects, respectively. Therefore we consider the branes engendered by such defects and we also compute the corrections in their cases. In order to attain the mass spectrum and its corresponding eigenfunctions which are the essential quantities for computing the correction to the Newtonian potential, we develop a suitable numerical technique. The calculation of slight deviations in the gravitational potential may be used as a selection tool for braneworld scenarios matching with future experimental measurements in high energy collisions

  14. Covariant open bosonic string field theory on multiple D-branes in the proper-time gauge

    NASA Astrophysics Data System (ADS)

    Lee, Taejin

    2017-12-01

    We construct a covariant open bosonic string field theory on multiple D-branes, which reduces to a non-Abelian group Yang-Mills gauge theory in the zero-slope limit. Making use of the first quantized open bosonic string in the proper time gauge, we convert the string amplitudes given by the Polyakov path integrals on string world sheets into those of the second quantized theory. The world sheet diagrams generated by the constructed open string field theory are planar in contrast to those of the Witten's cubic string field theory. However, the constructed string field theory is yet equivalent to the Witten's cubic string field theory. Having obtained planar diagrams, we may adopt the light-cone string field theory technique to calculate the multi-string scattering amplitudes with an arbitrary number of external strings. We examine in detail the three-string vertex diagram and the effective four-string vertex diagrams generated perturbatively by the three-string vertex at tree level. In the zero-slope limit, the string scattering amplitudes are identified precisely as those of non-Abelian Yang-Mills gauge theory if the external states are chosen to be massless vector particles.

  15. (N)LSP decays and gravitino dark matter relic abundance in big divisor (nearly) SLagy D3/D7μ-split SUSY

    NASA Astrophysics Data System (ADS)

    Dhuria, Mansi; Misra, Aalok

    2013-02-01

    Using the (nearly) Ricci-flat Swiss-Cheese metric of Misra (2012) [1], in the context of a mobile space-time filling D3-brane restricted to a nearly special Lagrangian sub-manifold (in the large volume limit, the pull-back of the Kähler form close to zero and the real part of the pull-back of e, θ=π/2 times the nowhere-vanishing holomorphic three-form providing the volume form on the three-cycle) of the "big" divisor with (fluxed stacks of) space-time filling D7-branes also wrapping the "big" divisor (corresponding to a local minimum), we provide an explicit identification of the electron and the u-quark, as well as their SU (2-singlet cousins, with fermionic superpartners of four Wilson line moduli; their superpartners turn out to be very heavy, the Higgsino-mass parameter turns out to be large, one obtains one light (with a mass of 125 GeV) and one heavy Higgs and the gluino is long lived (from a collider point of view) providing a possible realization of "μ-Split Supersymmetry". By explicitly calculating the lifetimes of decays of the co-NLSPs - the first generation squark/slepton and a neutralino - to the LSP - the gravitino - as well as gravitino decays, we verify that BBN constraints relevant to the former as well as the requirement of the latter to be (more than) the age of the universe, are satisfied. For the purpose of calculation of the gravitino relic density in terms of the neutralino/slepton relic density, we evaluate the latter by evaluating the neutralino/slepton (co-)annihilation cross sections and hence show that the former satisfies the requirement for a dark matter candidate.

  16. Naked shell singularities on the brane

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Seahra, Sanjeev S.

    By utilizing nonstandard slicings of 5-dimensional Schwarzschild and Schwarzschild-AdS manifolds based on isotropic coordinates, we generate static and spherically-symmetric braneworld spacetimes containing shell-like naked null singularities. For planar slicings, we find that the brane-matter sourcing the solution is a perfect fluid with an exotic equation of state and a pressure singularity where the brane crosses the bulk horizon. From a relativistic point of view, such a singularity is required to maintain matter infinitesimally above the surface of a black hole. From the point of view of the AdS/CFT conjecture, the singular horizon can be seen as one possible quantum correctionmore » to a classical black hole geometry. Various generalizations of planar slicings are also considered for a Ricci-flat bulk, and we find that singular horizons and exotic matter distributions are common features.« less

  17. On asymptotic behavior of anisotropic branes with induced gravity inspired by L(R) term

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Heydari-Fard, Malihe, E-mail: heydarifard@qom.ac.ir

    2010-12-01

    The DGP brane-world scenario provides the accelerated expansion of the universe at late-time by large-distance modification of general relativity without any need for dark energy. Using the method in reference [33], we investigate the asymptotic behavior of homogeneous and anisotropic cosmologies on a generalization of DGP scenario where the effective theory of gravity induced on the brane is given by a L(R) term. We show that for a constant induced curvature term on the brane all Bianchi models except type IX isotropize, like general relativity, if the effective energy density and E{sub ab} term satisfy some energy conditions. Finally, wemore » compare the result of the model with the result of anisotropic DGP branes and general relativity.« less

  18. Linearized Israel matching conditions for cosmological perturbations in a moving brane background

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bucher, Martin; DAMTP, University of Cambridge, Cambridge CB3 0WA; Carvalho, Carla

    2005-04-15

    In the Randall-Sundrum cosmological models, a (3+1)-dimensional brane subject to a Z{sub 2} orbifold symmetry is embedded in a (4+1)-dimensional bulk spacetime empty except for a negative cosmological constant. The unperturbed braneworld cosmological solutions, subject to homogeneity and isotropy in the three transverse spatial dimensions, are most simply presented by means of a moving brane description. Owing to a generalization of Birkhoff's theorem, as long as there are no perturbations violating the three-dimensional spatial homogeneity and isotropy, the bulk spacetime remains stationary and trivial. For the spatially flat case, the bulk spacetime is described by one of three bulk solutions:more » a pure AdS{sup 5} solution, an AdS{sup 5}-Schwarzschild black hole solution, or an AdS{sup 5}-Schwarzschild naked singularity solution. The brane moves on the boundary of one of these simple bulk spacetimes, its trajectory determined by the evolution of the stress-energy localized on the brane. We derive here the form of the Israel matching conditions for the linearized cosmological perturbations in this moving brane picture. These Israel matching conditions must be satisfied in any gauge. However, they are not sufficient to determine how to describe in a specific gauge the reflection of the bulk gravitational waves off the brane boundary. In this paper we adopt a fully covariant Lorentz gauge condition in the bulk and find the supplementary gauge conditions that must be imposed on the boundary to ensure that the reflected waves do not violate the Lorentz gauge condition. Compared to the form obtained from Gaussian normal coordinates, the form of the Israel matching conditions obtained here is more complex. However, the propagation of the bulk gravitons is simpler because the coordinates used for the background exploit fully the symmetry of the bulk background solution.« less

  19. The evolution of Brown-York quasilocal energy as due to evolution of Lovelock gravity in a system of M0-branes

    NASA Astrophysics Data System (ADS)

    Sepehri, Alireza; Rahaman, Farook; Capozziello, Salvatore; Ali, Ahmed Farag; Pradhan, Anirudh

    Recently, it has been suggested in [S. Chakraborty and N. Dadhich, Brown-York quasilocal energy in Lanczos-Lovelock gravity and black hole horizons, J. High Energ. Phys. 12 (2015) 003.] that the Brown-York mechanism can be used to measure the quasilocal energy in Lovelock gravity. We have used this method in a system of M0-branes and show that the Brown-York energy evolves in the process of birth and growth of Lovelock gravity. This can help us to predict phenomenological events which are emerged as due to dynamical structure of Lovelock gravity in our universe. In this model, first, M0-branes join each other and form an M3-brane and an anti-M3-branes connected by an M2-brane. This system is named BIon. Universes and anti-universes live on M3-branes and M2 plays the role of wormhole between them. By passing time, M2 dissolves in M3’s and nonlinear massive gravities like Lovelock massive gravity emerges and grows. By closing M3-branes, BIon evolves and wormhole between branes makes a transition to black hole. During this stage, Brown-York energy increases and shrinks to large values at the colliding points of branes. By approaching M3-branes towards each other, the square energy of their system becomes negative and some tachyonic states are produced. To remove these states, M3-branes compact, the sign of compacted gravity changes, anti-gravity is created which leads to getting away of branes from each other. Also, the Lovelock gravity disappears and its energy forms a new M2 between M3-branes. By getting away of branes from each other, Brown-York energy decreases and shrinks to zero.

  20. Cosmological dynamics of brane f(R) gravity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Haghani, Zahra; Sepangi, Hamid Reza; Shahidi, Shahab, E-mail: z_haghani@sbu.ac.ir, E-mail: hr-sepangi@sbu.ac.ir, E-mail: s_shahidi@sbu.ac.ir

    2012-02-01

    The cosmological dynamics of a brane world scenario where the bulk action is taken as a generic function of the Ricci scalar is considered in a framework where the use of the Z{sub 2} symmetry and Israel junction conditions are relaxed. The corresponding cosmological solutions for some specific forms of f(R) are obtained and shown to be in the form of exponential as well as power law for a vacuum brane space-time. It is shown that the existence of matter dominated epoch for a bulk action in the form of a power law for R can only be obtained inmore » the presence of ordinary matter. Using phase space analysis, we show that the universe must start from an unstable matter dominated epoch and eventually falls into a stable accelerated expanding phase.« less

  1. On the universality of thermodynamics and η/s ratio for the charged Lovelock black branes

    NASA Astrophysics Data System (ADS)

    Cadoni, Mariano; Frassino, Antonia M.; Tuveri, Matteo

    2016-05-01

    We investigate general features of charged Lovelock black branes by giving a detailed description of geometrical, thermodynamic and holographic properties of charged Gauss-Bonnet (GB) black branes in five dimensions. We show that when expressed in terms of effective physical parameters, the thermodynamic behaviour of charged GB black branes is completely indistinguishable from that of charged Einstein black branes. Moreover, the extremal, near-horizon limit of the two classes of branes is exactly the same as they allow for the same AdS2 × R 3, near-horizon, exact solution. This implies that, although in the UV the associated dual QFTs are different, they flow in the IR to the same fixed point. The calculation of the shear viscosity to entropy ratio η/s confirms these results. Despite the GB dual plasma has in general a non-universal temperature-dependent η/s, it flows monotonically to the universal value 1 /4 π in the IR. For negative (positive) GB coupling constant, η/s is an increasing (decreasing) function of the temperature and the flow respects (violates) the KSS bound.

  2. Gravity and antigravity in a brane world with metastable gravitons

    NASA Astrophysics Data System (ADS)

    Gregory, R.; Rubakov, V. A.; Sibiryakov, S. M.

    2000-09-01

    In the framework of a five-dimensional three-brane model with quasi-localized gravitons we evaluate metric perturbations induced on the positive tension brane by matter residing thereon. We find that at intermediate distances, the effective four-dimensional theory coincides, up to small corrections, with General Relativity. This is in accord with Csaki, Erlich and Hollowood and in contrast to Dvali, Gabadadze and Porrati. We show, however, that at ultra-large distances this effective four-dimensional theory becomes dramatically different: conventional tensor gravity changes into scalar anti-gravity.

  3. Path integral formulation of the Hodge duality on the brane

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hahn, Sang-Ok; Kiem, Youngjai; Kim, Yoonbai

    In the warped compactification with a single Randall-Sundrum brane, a puzzling claim has been made that scalar fields can be bound to the brane but their Hodge dual higher-rank antisymmetric tensors cannot. By explicitly requiring the Hodge duality, a prescription to resolve this puzzle was recently proposed by Duff and Liu. In this Brief Report, we implement the Hodge duality via the path integral formulation in the presence of the background gravity fields of warped compactifications. It is shown that the prescription of Duff and Liu can be naturally understood within this framework.

  4. Casimir energies and special dimensions in a toy model for branes

    NASA Astrophysics Data System (ADS)

    Cohen, Isaac

    1988-12-01

    We consider a generalization to branes of the old action for the strings without reparamentrization invariance. These actions admit natural supplementary mass-shell conditions. By regularizing the Casimir energies we calculate the special dimensions at which these toy branes show vector massless states in its spectrum. They all turn out to be non-integers. On sabbatical leave from Departamento de Física, Facultad de Ciencias, Universidad Central de Venezuela, Apartado Postal 66961, Caracas 1061A, Venezuela.

  5. Phases of QCD3 from non-SUSY Seiberg duality and brane dynamics

    NASA Astrophysics Data System (ADS)

    Armoni, Adi; Niarchos, Vasilis

    2018-05-01

    We consider a nonsupersymmetric USp Yang-Mills Chern-Simons gauge theory coupled to fundamental flavors. The theory is realised in type-IIB string theory via an embedding in a Hanany-Witten brane configuration which includes an orientifold and antibranes. We argue that the theory admits a magnetic Seiberg dual. Using the magnetic dual we identify dynamics in field theory and brane physics that correspond to various phases, obtaining a better understanding of three-dimensional bosonization and dynamical breaking of flavor symmetry in USp QCD3 theory. In field theory both phases correspond to magnetic "squark" condensation. In string theory, they correspond to open string tachyon condensation and brane reconnection. We also discuss other phases where the magnetic `squark' is massive. Finally, we briefly comment on the case of unitary gauge groups.

  6. Lifshitz black branes and DC transport coefficients in massive Einstein-Maxwell-dilaton gravity

    NASA Astrophysics Data System (ADS)

    Kuang, Xiao-Mei; Papantonopoulos, Eleftherios; Wu, Jian-Pin; Zhou, Zhenhua

    2018-03-01

    We construct analytical Lifshitz massive black brane solutions in massive Einstein-Maxwell-dilaton gravity theory. We also study the thermodynamics of these black brane solutions and obtain the thermodynamical stability conditions. On the dual nonrelativistic boundary field theory with Lifshitz symmetry, we analytically compute the DC transport coefficients, including the electric conductivity, thermoelectric conductivity, and thermal conductivity. The novel property of our model is that the massive term supports the Lifshitz black brane solutions with z ≠1 in such a way that the DC transport coefficients in the dual field theory are finite. We also find that the Wiedemann-Franz law in this dual boundary field theory is violated, which indicates that it may involve strong interactions.

  7. Black hole as a point radiator and recoil effect on the brane world.

    PubMed

    Frolov, Valeri; Stojković, Dejan

    2002-10-07

    A small black hole attached to a brane in a higher-dimensional space emitting quanta into the bulk may leave the brane as a result of a recoil. We construct a field theory model in which such a black hole is described as a massive scalar particle with internal degrees of freedom. In this model, the probability of transition between the different internal levels is identical to the probability of thermal emission calculated for the Schwarzschild black hole. The discussed recoil effect implies that the thermal emission of the black holes, which might be created by interaction of high energy particles in colliders, could be terminated and the energy nonconservation can be observed in the brane experiments.

  8. Multiresonance modes in sine–Gordon brane models

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cruz, W.T., E-mail: wilamicruz@gmail.com; Maluf, R.V., E-mail: r.v.maluf@fisica.ufc.br; Dantas, D.M., E-mail: davi@fisica.ufc.br

    2016-12-15

    In this work, we study the localization of the vector gauge field in two five-dimensional braneworlds generated by scalar fields coupled to gravity. The sine–Gordon like potentials are employed to produce different thick brane setups. A zero mode localized is obtained, and we show the existence of reverberations with the wave solutions indicating a quasi-localized massive mode. More interesting results are achieved when we propose a double sine–Gordon potential to the scalar field. The resulting thick brane shows a more detailed topology with the presence of an internal structure composed by two kinks. The massive spectrum of the gauge fieldmore » is revalued on this scenario revealing the existence of various resonant modes. Furthermore, we compute the corrections to Coulomb law coming from these massive KK vector modes in these thick scenarios, which is concluded that the dilaton parameter regulates these corrections.« less

  9. Brane-world extra dimensions in light of GW170817

    NASA Astrophysics Data System (ADS)

    Visinelli, Luca; Bolis, Nadia; Vagnozzi, Sunny

    2018-03-01

    The search for extra dimensions is a challenging endeavor to probe physics beyond the Standard Model. The joint detection of gravitational waves (GW) and electromagnetic (EM) signals from the merging of a binary system of compact objects like neutron stars can help constrain the geometry of extra dimensions beyond our 3 +1 spacetime ones. A theoretically well-motivated possibility is that our observable Universe is a 3 +1 -dimensional hypersurface, or brane, embedded in a higher 4 +1 -dimensional anti-de Sitter (AdS5 ) spacetime, in which gravity is the only force which propagates through the infinite bulk space, while other forces are confined to the brane. In these types of brane-world models, GW and EM signals between two points on the brane would, in general, travel different paths. This would result in a time lag between the detection of GW and EM signals emitted simultaneously from the same source. We consider the recent near-simultaneous detection of the GW event GW170817 from the LIGO/Virgo collaboration, and its EM counterpart, the short gamma-ray burst GRB170817A detected by the Fermi Gamma-ray Burst Monitor and the International Gamma-Ray Astrophysics Laboratory Anti-Coincidence Shield spectrometer. Assuming the standard Λ -cold dark matter scenario and performing a likelihood analysis which takes into account astrophysical uncertainties associated to the measured time lag, we set an upper limit of ℓ≲0.535 Mpc at 68% confidence level on the AdS5 radius of curvature ℓ. Although the bound is not competitive with current Solar System constraints, it is the first time that data from a multimessenger GW-EM measurement is used to constrain extra-dimensional models. Thus, our work provides a proof of principle for the possibility of using multimessenger astronomy for probing the geometry of our space-time.

  10. Codimension-2 Brane Black Holes

    NASA Astrophysics Data System (ADS)

    Zamorano, Nelson; Arias, Cesar; Ordenes, Ariel; Guzman, Francisco

    2012-03-01

    We analyze the geometry associated to a six dimensional solution of the Einstein's equations. It describes a Schwarzschild de-Sitter black hole on a 3-brane, surrounded by a two dimensional compact bulk. A four dimensional effective cosmological constant and a Planck mass are matched to their six dimensional counterpart. Deviation from Newton's law are computed in both of the solutions found. To learn about the geometry of the bulk, we study the geodesics in this sector. At least, in our opinion, there are some features of these solutions that makes worth to pursue this analysis. The singularity associated to the warped bulk is controlled by the mass M of the black hole. It vanishes if we set M=0. In the same context, it makes an interesting problem to study the Gregory-Laflamme instability in this context [1]. Another feature is the rugby ball type of geometry exhibited by these solutions [2]. They end up in two conical singularities at its respective poles. The branes are located precisely at the poles. Besides, a Wick's rotation generates a connection between different solutions. [4pt] [1] R. Gregory and R. Laflamme, Phys. Rev Lett., 70,2837 (1993)[0pt] [2] S. M. Carroll and M. M. Guica, arXiv:hep-th/0302067

  11. Induced matter brane gravity and Einstein static universe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Heydarzade, Y.; Darabi, F., E-mail: heydarzade@azaruniv.edu, E-mail: f.darabi@azaruniv.edu

    We investigate stability of the Einstein static universe against the scalar, vector and tensor perturbations in the context of induced matter brane gravity. It is shown that in the framework of this model, the Einstein static universe has a positive spatial curvature. In contrast to the classical general relativity, it is found that a stable Einstein static universe against the scalar perturbations does exist provided that the variation of time dependent geometrical equation of state parameter is proportional to the minus of the variation of the scale factor, δ ω{sub g}(t) = −Cδ a(t). We obtain neutral stability against the vector perturbations, and themore » stability against the tensor perturbations is guaranteed due to the positivity of the spatial curvature of the Einstein static universe in induced matter brane gravity.« less

  12. Entanglement branes in a two-dimensional string theory

    DOE PAGES

    Donnelly, William; Wong, Gabriel

    2017-09-20

    What is the meaning of entanglement in a theory of extended objects such as strings? To address this question we consider the spatial entanglement between two intervals in the Gross-Taylor model, the string theory dual to two-dimensional Yang-Mills theory at large N. The string diagrams that contribute to the entanglement entropy describe open strings with endpoints anchored to the entangling surface, as first argued by Susskind. We develop a canonical theory of these open strings, and describe how closed strings are divided into open strings at the level of the Hilbert space. Here, we derive the modular Hamiltonian for themore » Hartle-Hawking state and show that the corresponding reduced density matrix describes a thermal ensemble of open strings ending on an object at the entangling surface that we call an entanglement brane, or E-brane.« less

  13. Cosmography of f(R)-brane cosmology

    NASA Astrophysics Data System (ADS)

    Bouhmadi-López, Mariam; Capozziello, Salvatore; Cardone, Vincenzo F.

    2010-11-01

    Cosmography is a useful tool to constrain cosmological models, in particular, dark energy models. In the case of modified theories of gravity, where the equations of motion are generally quite complicated, cosmography can contribute to select realistic models without imposing arbitrary choices a priori. Indeed, its reliability is based on the assumptions that the universe is homogeneous and isotropic on large scale and luminosity distance can be “tracked” by the derivative series of the scale factor a(t). We apply this approach to induced gravity brane-world models where an f(R) term is present in the brane effective action. The virtue of the model is to self-accelerate the normal and healthy Dvali-Gabadadze-Porrati branch once the f(R) term deviates from the Hilbert-Einstein action. We show that the model, coming from a fundamental theory, is consistent with the ΛCDM scenario at low redshift. We finally estimate the cosmographic parameters fitting the Union2 Type Ia Supernovae data set and the distance priors from baryon acoustic oscillations and then provide constraints on the present day values of f(R) and its second and third derivatives.

  14. Axionic black branes in the k -essence sector of the Horndeski model

    NASA Astrophysics Data System (ADS)

    Cisterna, Adolfo; Hassaine, Mokhtar; Oliva, Julio; Rinaldi, Massimiliano

    2017-12-01

    We construct new black brane solutions in the context of Horndeski gravity, in particular, in its K-essence sector. These models are supported by axion scalar fields that depend only on the horizon coordinates. The dynamics of these fields is determined by a K-essence term that includes the standard kinetic term X and a correction of the form Xk. We find both neutral and charged exact and analytic solutions in D -dimensions, which are asymptotically anti-de Sitter. Then, we describe in detail the thermodynamical properties of the four-dimensional solutions and we compute the dual holographic DC conductivity.

  15. Brane-world black hole solutions via a confining potential

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Heydari-Fard, M.; Sepangi, H. R.; Razmi, H.

    2007-09-15

    Using a confining potential, we consider spherically symmetric vacuum (static black hole) solutions in a brane-world scenario. Working with a constant curvature bulk, two interesting cases/solutions are studied. A Schwarzschild-de Sitter black hole solution similar to the standard solution in the presence of a cosmological constant is obtained which confirms the idea that an extra term in the field equations on the brane can play the role of a positive cosmological constant and may be used to account for the accelerated expansion of the universe. The other solution is one in which we can have a proper potential to explainmore » the galaxy rotation curves without assuming the existence of dark matter and without working with new modified theories (modified Newtonian dynamics)« less

  16. Lepton flavour violation in RS models with a brane- or nearly brane-localized Higgs

    NASA Astrophysics Data System (ADS)

    Beneke, M.; Moch, P.; Rohrwild, J.

    2016-05-01

    We perform a comprehensive study of charged lepton flavour violation in Randall-Sundrum (RS) models in a fully 5D quantum-field-theoretical framework. We consider the RS model with minimal field content and a ;custodially protected; extension as well as three implementations of the IR-brane localized Higgs field, including the non-decoupling effect of the KK excitations of a narrow bulk Higgs. Our calculation provides the first complete result for the flavour-violating electromagnetic dipole operator in Randall-Sundrum models. It contains three contributions with different dependence on the magnitude of the anarchic 5D Yukawa matrix, which can all be important in certain parameter regions. We study the typical range for the branching fractions of μ → eγ, μ → 3 e, μN → eN as well as τ → μγ, τ → 3 μ and the electron electric dipole moment by a numerical scan in both the minimal and the custodial RS model. The combination of μ → eγ and μN → eN currently provides the most stringent constraint on the parameter space of the model. A typical lower limit on the KK scale T is around 2 TeV in the minimal model (up to 4 TeV in the bulk Higgs case with large Yukawa couplings), and around 4 TeV in the custodially protected model, which corresponds to a mass of about 10 TeV for the first KK excitations, far beyond the lower limit from the non-observation of direct production at the LHC.

  17. Hamiltonian analysis of non-relativistic non-BPS Dp-brane

    NASA Astrophysics Data System (ADS)

    Klusoň, J.

    2017-07-01

    We perform Hamiltonian analysis of non-relativistic non-BPS Dp-brane. We find the constraint structure of this theory and determine corresponding equations of motion. We further discuss property of this theory at the tachyon vacuum.

  18. F-theoretic vs microscopic description of a conformal mathcal{N} = 2 SYM theory

    NASA Astrophysics Data System (ADS)

    Billò, Marco; Gallot, Laurent; Lerda, Alberto; Pesando, Igor

    2010-11-01

    The F-theory background of four D7 branes in a type I' orientifold was conjectured to be described by the Seiberg-Witten curve for the superconformal SU(2) gauge theory with four flavors. This relation was explained by considering in this background a probe D3 brane, which supports this theory with SU(2) realized as Sp(1). Here we explicitly compute the non-perturbative corrections to the D7/D3 system in type I' due to D-instantons. This computation provides both the quartic effective action on the D7 branes and the quadratic effective action on the D3 brane; the latter agrees with the F-theoretic prediction. The action obtained in this way is related to the one derived from the usual instanton calculus à la Nekrasov (or from its AGT realization in terms of Liouville conformal blocks) by means of a non-perturbative redefinition of the coupling constant. We also point out an intriguing relation between the four-dimensional theory on the probe D3 brane with SO(8) flavor symmetry and the eight-dimensional dynamics on the D7 branes. On the latter, SO(8) represents a gauge group and the flavor masses correspond to the vacuum expectation values of an adjoint scalar field m: what we find is that the exact effective coupling in four dimensions is obtained from its perturbative part by taking into account in its mass dependence the full quantum dynamics of the field m in eight dimensions.

  19. Large scale structure formation of the normal branch in the DGP brane world model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Song, Yong-Seon

    2008-06-15

    In this paper, we study the large scale structure formation of the normal branch in the DGP model (Dvail, Gabadadze, and Porrati brane world model) by applying the scaling method developed by Sawicki, Song, and Hu for solving the coupled perturbed equations of motion of on-brane and off-brane. There is a detectable departure of perturbed gravitational potential from the cold dark matter model with vacuum energy even at the minimal deviation of the effective equation of state w{sub eff} below -1. The modified perturbed gravitational potential weakens the integrated Sachs-Wolfe effect which is strengthened in the self-accelerating branch DGP model.more » Additionally, we discuss the validity of the scaling solution in the de Sitter limit at late times.« less

  20. Casimir force in brane worlds: Coinciding results from Green's and zeta function approaches

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Linares, Roman; Morales-Tecotl, Hugo A.; Pedraza, Omar

    2010-06-15

    Casimir force encodes the structure of the field modes as vacuum fluctuations and so it is sensitive to the extra dimensions of brane worlds. Now, in flat spacetimes of arbitrary dimension the two standard approaches to the Casimir force, Green's function, and zeta function yield the same result, but for brane world models this was only assumed. In this work we show that both approaches yield the same Casimir force in the case of universal extra dimensions and Randall-Sundrum scenarios with one and two branes added by p compact dimensions. Essentially, the details of the mode eigenfunctions that enter themore » Casimir force in the Green's function approach get removed due to their orthogonality relations with a measure involving the right hypervolume of the plates, and this leaves just the contribution coming from the zeta function approach. The present analysis corrects previous results showing a difference between the two approaches for the single brane Randall-Sundrum; this was due to an erroneous hypervolume of the plates introduced by the authors when using the Green's function. For all the models we discuss here, the resulting Casimir force can be neatly expressed in terms of two four-dimensional Casimir force contributions: one for the massless mode and the other for a tower of massive modes associated with the extra dimensions.« less

  1. Nonminimal kinetic coupled gravity: Inflation on the warped DGP brane

    NASA Astrophysics Data System (ADS)

    Darabi, F.; Parsiya, A.; Atazadeh, K.

    2016-03-01

    We consider the nonminimally kinetic coupled version of DGP brane model, where the kinetic term of the scalar field is coupled to the metric and Einstein tensor on the brane by a coupling constant ζ. We obtain the corresponding field equations, using the Friedmann-Robertson-Walker metric and the perfect fluid, and study the inflationary scenario to confront the numerical analysis of six typical scalar field potentials with the current observational results. We find that among the suggested potentials and coupling constants, subject to the e-folding N = 60, the potentials V (ϕ) = σϕ, V (ϕ) = σϕ2 and V (ϕ) = σϕ3 provide the best fits with both Planck+WP+highL data and Planck+WP+highL+BICEP2 data.

  2. Toward a proof of Montonen-Olive duality via multiple M2-branes

    NASA Astrophysics Data System (ADS)

    Hashimoto, Koji; Tai, Ta-Sheng; Terashima, Seiji

    2009-04-01

    We derive 4-dimensional Script N = 4 U(N) supersymmetric Yang-Mills theory from a 3-dimensional Chern-Simons-matter theory with product gauge group (U(N))2n. The latter describes M2-branes probing an orbifold where a torus emerges in a scaling limit. It is expected that the SL(2,Z) duality of the 4-dimensional Yang-Mills theory will be shown in M-theory point of view since it is trivially realized as modular transformations of the torus. Indeed, starting from one single Chern-Simons-matter theory, we find infinitely many equivalent 4-dimensional theories differing up to T-transformation of the SL(2,Z) redefinition of the gauge coupling τ = θ/2π + 4πi/g2 and a parity transformation in 4 dimensions. Although S-transformation can not be shown in our work, it is important that a part of the SL(2,Z) transformation is realized via the M2-brane action. Thus we think our work can be a step toward a proof of Montonen-Olive duality via M2-branes.

  3. Hydrogen-like spectrum of spontaneously created brane universes with de-Sitter ground state

    NASA Astrophysics Data System (ADS)

    Davidson, Aharon

    2018-05-01

    Unification of Randall-Sundrum and Regge-Teitelboim brane cosmologies gives birth to a serendipitous Higgs-deSitter interplay. A localized Dvali-Gabadadze-Porrati scalar field, governed by a particular (analytically derived) double-well quartic potential, becomes a mandatory ingredient for supporting a deSitter brane universe. When upgraded to a general Higgs potential, the brane surface tension gets quantized, resembling a Hydrogen atom spectrum, with deSitter universe serving as the ground state. This reflects the local/global structure of the Euclidean manifold: From finite energy density no-boundary initial conditions, via a novel acceleration divide filter, to exact matching conditions at the exclusive nucleation point. Imaginary time periodicity comes as a bonus, with the associated Hawking temperature vanishing at the continuum limit. Upon spontaneous creation, while a finite number of levels describe universes dominated by a residual dark energy combined with damped matter oscillations, an infinite tower of excited levels undergo a Big Crunch.

  4. Supersymmetric attractors, topological strings, and the M5-brane CFT

    NASA Astrophysics Data System (ADS)

    Guica, Monica M.

    One of the purposes of this thesis is to present the consistent and unifying picture that emerges in string and M-theory with eight supercharges. On one hand, this involves classifying and relating supersymmetric objects that occur in N = 2 compactifications of string and M-theory on a Calabi-Yau manifold. These come in a surprisingly wide variety of four and five-dimensional black holes, black rings and their sometimes very complicated bound states. On the other hand, the topological string also makes its appearance in theories with eight supercharges, and turns out to compute certain black hole degeneracies. We dedicate the introduction and the first chapter to summarizing and reviewing the beautiful relationships between black holes, black rings, their dual conformal field theory and the topological string, and we also outline the remaining puzzles and issues. Some of the black holes in question can be obtained by multiply-wrapping an M-theory M5-brane on a self-intersecting four-cycle in the Calabi-Yau manifold. Their dual microscopic description is known, and consists of a two-dimensional conformal field theory (CFT) which is the low-energy limit of the gauge theory that resides on the worldvolume of the M5 brane. We show that in a certain limit the M5-brane CFT is - perhaps surprisingly - able to reproduce the entropy of a completely different type of black holes, those obtained from wrapped M2-branes, whose microscopic description has not yet been understood. We also argue that certain black hole bound states should also be described by the same CFT, which suggests a unifying description of the various black objects in eight-supercharge supergravity theories. Finally, we describe and present a proof of the so-called OSV conjecture, which states that the mixed partition function of N = 2 four-dimensional BPS black holes equals the modulus square of the type A topological string partition function. We also attempt to use this relationship to better understand

  5. p-brane actions and higher Roytenberg brackets

    NASA Astrophysics Data System (ADS)

    Jurčo, Branislav; Schupp, Peter; Vysoký, Jan

    2013-02-01

    Motivated by the quest to understand the analog of non-geometric flux compactification in the context of M-theory, we study higher dimensional analogs of generalized Poisson sigma models and corresponding dual string and p-brane models. We find that higher generalizations of the algebraic structures due to Dorfman, Roytenberg and Courant play an important role and establish their relation to Nambu-Poisson structures.

  6. String inspired brane world cosmology.

    PubMed

    Germani, Cristiano; Sopuerta, Carlos F

    2002-06-10

    We consider brane world scenarios including the leading correction to the Einstein-Hilbert action suggested by superstring theory, the Gauss-Bonnet term. We obtain and study the complete set of equations governing the cosmological dynamics. We find they have the same form as those in Randall-Sundrum scenarios but with time-varying four-dimensional gravitational and cosmological constants. By studying the bulk geometry we show that this variation is produced by bulk curvature terms parametrized by the mass of a black hole. Finally, we show there is a coupling between these curvature terms and matter that can be relevant for early universe cosmology.

  7. Dynamically SUSY breaking SQCD on F-theory seven-branes

    NASA Astrophysics Data System (ADS)

    Buchbinder, Evgeny I.

    2008-09-01

    We study how dynamically breaking SQCD can be obtained on two intersecting seven-branes in F-theory. In the mechanism which we present in this paper one of the seven-branes is responsible for producing the low-energy gauge group and the other one is for generating vector bundle moduli. The fundamental matter charged under the gauge group is localized on the intersection. The mass of the matter fields is controlled by the vector bundle moduli. The analysis of under what conditions a sufficient number of the fundamental flavors becomes light turns out to be equivalent to the analysis of non-perturbative superpotentials for vector bundle moduli in Heterotic M-theory. We give an example in which we present an explicit equation in the moduli space whose zero locus corresponds to the fundamental fields becoming light. This allows us to provide a local F-theory realization of massive Script N = 1, SU(Nc) SQCD in the free magnetic range which dynamically breaks supersymmetry.

  8. Bulk scalar field in brane-worlds with induced gravity inspired by the L(R) term

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Heydari-Fard, M.; Sepangi, H.R., E-mail: heydarifard@qom.ac.ir, E-mail: hr-sepangi@sbu.ac.ir

    2009-01-15

    We obtain the effective field equations in a brane-world scenario within the framework of a DGP model where the action on the brane is an arbitrary function of the Ricci scalar, L(R), and the bulk action includes a scalar field in the matter Lagrangian. We obtain the Friedmann equations and acceleration conditions in the presence of the bulk scalar field for the R{sup n} term in four-dimensional gravity.

  9. Super-Luminal Effects for Finsler Branes as a Way to Preserve the Paradigm of Relativity Theories

    NASA Astrophysics Data System (ADS)

    Vacaru, Sergiu I.

    2013-06-01

    Using Finsler brane solutions [see details and methods in: S. Vacaru, Class. Quant. Grav. 28:215001, 2011], we show that neutrinos may surpass the speed of light in vacuum which can be explained by trapping effects from gravity theories on eight dimensional (co) tangent bundles on Lorentzian manifolds to spacetimes in general and special relativity. In nonholonomic variables, the bulk gravity is described by Finsler modifications depending on velocity/momentum coordinates. Possible super-luminal phenomena are determined by the width of locally anisotropic brane (spacetime) and induced by generating functions and integration functions and constants in coefficients of metrics and nonlinear connections. We conclude that Finsler brane gravity trapping mechanism may explain neutrino super-luminal effects and almost preserve the paradigm of Einstein relativity as the standard one for particle physics and gravity.

  10. GUT Model Hierarchies from Intersecting Branes

    NASA Astrophysics Data System (ADS)

    Kokorelis, Christos

    2002-08-01

    By employing D6-branes intersecting at angles in D = 4 type I strings, we construct the first examples of three generation string GUT models (PS-A class), that contain at low energy exactly the standard model spectrum with no extra matter and/or extra gauge group factors. They are based on the group SU(4)C × SU(2)L × SU(2)R. The models are non-supersymmetric, even though SUSY is unbroken in the bulk. Baryon number is gauged and its anomalies are cancelled through a generalized Green-Schwarz mechanism. We also discuss models (PS-B class) which at low energy have the standard model augmented by an anomaly free U(1) symmetry and show that multibrane wrappings correspond to a trivial redefinition of the surviving global U(1) at low energies. There are no colour triplet couplings to mediate proton decay and proton is stable. The models are compatible with a low string scale of energy less that 650 GeV and are directly testable at present or future accelerators as they predict the existence of light left handed weak fermion doublets at energies between 90 and 246 GeV. The neutrinos get a mass through an unconventional see-saw mechanism. The mass relation me = md at the GUT scale is recovered. Imposing supersymmetry at particular intersections generates non-zero Majorana masses for right handed neutrinos as well providing the necessary singlets needed to break the surviving anomaly free U(1), thus suggesting a gauge symmetry breaking method that can be applied in general left-right symmetric models.

  11. Large-scale structure in brane-induced gravity. I. Perturbation theory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Scoccimarro, Roman

    2009-11-15

    We study the growth of subhorizon perturbations in brane-induced gravity using perturbation theory. We solve for the linear evolution of perturbations taking advantage of the symmetry under gauge transformations along the extra-dimension to decouple the bulk equations in the quasistatic approximation, which we argue may be a better approximation at large scales than thought before. We then study the nonlinearities in the bulk and brane equations, concentrating on the workings of the Vainshtein mechanism by which the theory becomes general relativity (GR) at small scales. We show that at the level of the power spectrum, to a good approximation, themore » effect of nonlinearities in the modified gravity sector may be absorbed into a renormalization of the gravitational constant. Since the relation between the lensing potential and density perturbations is entirely unaffected by the extra physics in these theories, the modified gravity can be described in this approximation by a single function, an effective gravitational constant for nonrelativistic motion that depends on space and time. We develop a resummation scheme to calculate it, and provide predictions for the nonlinear power spectrum. At the level of the large-scale bispectrum, the leading order corrections are obtained by standard perturbation theory techniques, and show that the suppression of the brane-bending mode leads to characteristic signatures in the non-Gaussianity generated by gravity, generic to models that become GR at small scales through second-derivative interactions. We compare the predictions in this work to numerical simulations in a companion paper.« less

  12. Warped AdS 6 × S 2 in Type IIB supergravity III. Global solutions with seven-branes

    NASA Astrophysics Data System (ADS)

    D'Hoker, Eric; Gutperle, Michael; Uhlemann, Christoph F.

    2017-11-01

    We extend our previous construction of global solutions to Type IIB super-gravity that are invariant under the superalgebra F(4) and are realized on a spacetime of the form AdS 6 × S 2 warped over a Riemann surface Σ by allowing the supergravity fields to have non-trivial SL(2, ℝ) monodromy at isolated punctures on Σ. We obtain explicit solutions for the case where Σ is a disc, and the monodromy generators are parabolic elements of SL(2, ℝ) physically corresponding to the monodromy allowed in Type IIB string theory. On the boundary of Σ the solutions exhibit singularities at isolated points which correspond to semi-infinite five-branes, as is familiar from the global solutions without monodromy. In the interior of Σ, the solutions are everywhere regular, except at the punctures where SL(2, ℝ) monodromy resides and which physically correspond to the locations of [ p, q] seven-branes. The solutions have a compelling physical interpretation corresponding to fully localized five-brane intersections with additional seven-branes, and provide candidate holographic duals to the five-dimensional superconformal field theories realized on such intersections.

  13. Solitons on Noncommutative Torus as Elliptic Calogero-Gaudin Models, Branes and Laughlin Wave Functions

    NASA Astrophysics Data System (ADS)

    Hou, Bo-Yu; Peng, Dan-Tao; Shi, Kang-Jie; Yue, Rui-Hong

    For the noncommutative torus T, in the case of the noncommutative parameter θ = (Z)/(n), we construct the basis of Hilbert space Hn in terms of θ functions of the positions zi of n solitons. The wrapping around the torus generates the algebra An, which is the Zn × Zn Heisenberg group on θ functions. We find the generators g of a local elliptic su(n), which transform covariantly by the global gauge transformation of An. By acting on Hn we establish the isomorphism of An and g. We embed this g into the L-matrix of the elliptic Gaudin and Calogero-Moser models to give the dynamics. The moment map of this twisted cotangent sunT) bundle is matched to the D-equation with the Fayet-Illiopoulos source term, so the dynamics of the noncommutative solitons become that of the brane. The geometric configuration (k, u) of the spectral curve det|L(u) - k| = 0 describes the brane configuration, with the dynamical variables zi of the noncommutative solitons as the moduli T⊗ n/Sn. Furthermore, in the noncommutative Chern-Simons theory for the quantum Hall effect, the constrain equation with quasiparticle source is identified also with the moment map equation of the noncommutative sunT cotangent bundle with marked points. The eigenfunction of the Gaudin differential L-operators as the Laughlin wave function is solved by Bethe ansatz.

  14. Aksz Construction of Topological Open p-BRANE Action and Nambu Brackets

    NASA Astrophysics Data System (ADS)

    Bouwknegt, Peter; Jurčo, Branislav

    2013-04-01

    We review the AKSZ construction as applied to the topological open membranes and Poisson sigma models. We describe a generalization to open topological p-branes. Also, we propose a related (not necessarily BV) Nambu-Poisson sigma model.

  15. From the currency rate quotations onto strings and brane world scenarios

    NASA Astrophysics Data System (ADS)

    Horváth, D.; Pincak, R.

    2012-11-01

    In the paper, we study the projections of the real exchange rate dynamics onto the string-like topology. Our approach is inspired by the contemporary movements in the string theory. The string map of data is defined here by the boundary conditions, characteristic length, real valued and the method of redistribution of information. As a practical matter, this map represents the detrending and data standardization procedure. We introduced maps onto 1-end-point and 2-end-point open strings that satisfy the Dirichlet and Neumann boundary conditions. The questions of the choice of extra-dimensions, symmetries, duality and ways to the partial compactification are discussed. Subsequently, we pass to higher dimensional and more complex objects. The 2D-Brane was suggested which incorporated bid-ask spreads. Polarization by the spread was considered which admitted analyzing arbitrage opportunities on the market where transaction costs are taken into account. The model of the rotating string which naturally yields calculation of angular momentum is suitable for tracking of several currency pairs. The systematic way which allows one suggest more structured maps suitable for a simultaneous study of several currency pairs was analyzed by means of the Gâteaux generalized differential calculus. The effect of the string and brane maps on test data was studied by comparing their mean statistical characteristics. The study revealed notable differences between topologies. We review the dependence on the characteristic string length, mean fluctuations and properties of the intra-string statistics. The study explores the coupling of the string amplitude and volatility. The possible utilizations of the string theory approach in financial markets are slight.

  16. Meson thermalization by baryon injection in D4/D6 model

    NASA Astrophysics Data System (ADS)

    Rezaei, Z.

    2016-12-01

    We study meson thermalization in a strongly coupled plasma of quarks and gluons using AdS/CFT duality technique. Four dimensional large-Nc QCD is considered as a theory governing this quark-gluon plasma (QGP) and D4/D6-brane model is chosen to be its holographic dual theory. In order to investigate meson thermalization, we consider a time-dependent change of baryon number chemical potential. Thermalization in gauge theory side corresponds to horizon formation on the probe flavor brane in the gravity side. The gravitational dual theory is compactified on a circle that the inverse of its radius is proportional to energy scale of dual gauge theory. It is seen that increase of this energy scale results in thermalization time dilation. In addition we study the effect of magnetic field on meson thermalization. It will be seen that magnetic field also prolongs thermalization process by making mesons more stable.

  17. Kicking the rugby ball: perturbations of 6D gauged chiral supergravity

    NASA Astrophysics Data System (ADS)

    Burgess, C. P.; de Rham, C.; Hoover, D.; Mason, D.; Tolley, A. J.

    2007-02-01

    We analyse the axially symmetric scalar perturbations of 6D chiral gauged supergravity compactified on the general warped geometries in the presence of two source branes. We find that all of the conical geometries are marginally stable for normalizable perturbations (in disagreement with some recent calculations) and the non-conical ones for regular perturbations, even though none of them are supersymmetric (apart from the trivial Salam Sezgin solution, for which there are no source branes). The marginal direction is the one whose presence is required by the classical scaling property of the field equations, and all other modes have positive squared mass. In the special case of the conical solutions, including (but not restricted to) the unwarped 'rugby-ball' solutions, we find closed-form expressions for the mode functions in terms of Legendre and hypergeometric functions. In so doing we show how to match the asymptotic near-brane form for the solution to the physics of the source branes, and thereby how to physically interpret perturbations which can be singular at the brane positions.

  18. Nonlinear viscosity in brane-world cosmology with a Gauss–Bonnet term

    NASA Astrophysics Data System (ADS)

    Debnath, P. S.; Beesham, A.; Paul, B. C.

    2018-06-01

    Cosmological solutions are obtained with nonlinear bulk viscous cosmological fluid in the Randall–Sundrum type II (RS) brane-world model with or without Gauss–Bonnet (GB) terms. To describe such a viscous fluid, we consider the nonlinear transport equation which may be used far from equilibrium during inflation or reheating. Cosmological models are explored for both (i) power law and (ii) exponential evolution of the early universe in the presence of an imperfect fluid described by the non-linear Israel and Stewart theory (nIS). We obtain analytic solutions and the complex field equations are also analyzed numerically to study the evolution of the universe. The stability analysis of the equilibrium points of the dynamical system associated with the evolution of the nonlinear bulk viscous fluid in the RS Brane in the presence (or absence) of a GB term are also studied.

  19. Brane world in non-Riemannian geometry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Maier, R.; Falciano, F. T.

    2011-03-15

    We carefully investigate the modified Einstein's field equation in a 4-dimensional (3-brane) arbitrary manifold embedded in a 5-dimensional non-Riemannian bulk spacetime with a noncompact extra dimension. In this context the Israel-Darmois matching conditions are extended assuming that the torsion in the bulk is continuous. The discontinuity in the torsion first derivatives are related to the matter distribution through the field equation. In addition, we develop a model that describes a flat FLRW model embedded in a 5-dimensional de Sitter or anti-de Sitter, where a 5-dimensional cosmological constant emerges from the torsion.

  20. Brane with variable tension as a possible solution to the problem of the late cosmic acceleration

    NASA Astrophysics Data System (ADS)

    García-Aspeitia, Miguel A.; Hernandez-Almada, A.; Magaña, Juan; Amante, Mario H.; Motta, V.; Martínez-Robles, C.

    2018-05-01

    Braneworld models have been proposed as a possible solution to the problem of the accelerated expansion of the Universe. The idea is to dispense the dark energy (DE) and drive the late-time cosmic acceleration with a five-dimensional geometry. We investigate a brane model with variable brane tension as a function of redshift called chrono-brane. We propose the polynomial λ =(1 +z )n function inspired in tracker-scalar-field potentials. To constrain the n exponent we use the latest observational Hubble data from cosmic chronometers, Type Ia Supernovae from the full joint-light-analysis sample, baryon acoustic oscillations and the posterior distance from the cosmic microwave background of Planck 2015 measurements. A joint analysis of these data estimates n ≃6.19 ±0.12 which generates a DE-like (cosmological-constantlike at late times) term, in the Friedmann equation arising from the extra dimensions. This model is consistent with these data and can drive the Universe to an accelerated phase at late times.

  1. The D-material universe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Elghozi, Thomas; Mavromatos, Nick E.; Sakellariadou, Mairi

    In a previous publication by some of the authors (N.E.M., M.S. and M.F.Y.), we have argued that the ''D-material universe'', that is a model of a brane world propagating in a higher-dimensional bulk populated by collections of D-particle stringy defects, provides a model for the growth of large-scale structure in the universe via the vector field in its spectrum. The latter corresponds to D-particle recoil velocity excitations as a result of the interactions of the defects with stringy matter and radiation on the brane world. In this article, we first elaborate further on the results of the previous study onmore » the galactic growth era and analyse the circumstances under which the D-particle recoil velocity fluid may ''mimic'' dark matter in galaxies. A lensing phenomenology is also presented for some samples of galaxies, which previously were known to provide tension for modified gravity (TeVeS) models. The current model is found in agreement with these lensing data. Then we discuss a cosmic evolution for the D-material universe by analysing the conditions under which the late eras of this universe associated with large-scale structure are connected to early epochs, where inflation takes place. It is shown that inflation is induced by dense populations of D-particles in the early universe, with the rôle of the inflaton field played by the condensate of the D-particle recoil-velocity fields under their interaction with relativistic stringy matter, only for sufficiently large brane tensions and low string mass scales compared to the Hubble scale. On the other hand, for large string scales, where the recoil-velocity condensate fields are weak, inflation cannot be driven by the D-particle defects alone. In such cases inflation may be driven by dilaton (or other moduli) fields in the underlying string theory.« less

  2. Forbidden territories in the string landscape

    NASA Astrophysics Data System (ADS)

    Kumar, Alok; Mukhopadhyay, Subir; Ray, Koushik

    2007-12-01

    Problems of stabilizing moduli of the type-IIB string theory on toroidal orientifolds T6/Z2, in presence of worldvolume fluxes on various D-branes, are considered. For Z2 actions, introducing either O9 or O3 planes, we rule out the possibility of moduli stabilization in a wide class of models with Script N = 1 supersymmetry, characterized by the type of fluxes turned on along D-brane worldvolume. Our results, in particular, imply that Abelian worldvolume fluxes can not by themselves stabilize closed string moduli, in a consistent supersymmtric model, for above orientifold compactifications. We also discuss other Z2 orientifolds of T6 and show that certain other brane wrappings are also ruled out by similar consistency requirements. In specific setups we consider examples with D9-branes wrapping on a complex three-torus with its world-volume fluxes taken to be semi-homogeneous bundles and D7-branes wrapping holomorphic four-cycles of the complex three-torus carrying world-volume fluxes.

  3. Lab-on-a-brane: A novel physiologically relevant planar arterial model to study transendothelial transport

    NASA Astrophysics Data System (ADS)

    Budhwani, Karim Ismail

    The tremendous quality of life impact notwithstanding, cardiovascular diseases and Cancer add up to over US$ 700bn each year in financial costs alone. Aging and population growth are expected to further expand the problem space while drug research and development remain expensive. However, preclinical costs can be substantially mitigated by substituting animal models with in vitro devices that accurately model human cardiovascular transport. Here we present a novel physiologically relevant lab-on-a-brane that simulates in vivo pressure, flow, strain, and shear waveforms associated with normal and pathological conditions in large and small blood vessels for studying molecular transport across the endothelial monolayer. The device builds upon previously demonstrated integrated microfluidic loop design by: (a) introducing nanoscale pores in the substrate membrane to enable transmembrane molecular transport, (b) transforming the substrate membrane into a nanofibrous matrix for 3D smooth muscle cell (SMC) tissue culture, (c) integrating electrospinning fabrication methods, (d) engineering an invertible sandwich cell culture device architecture, and (e) devising a healthy co-culture mechanism for human arterial endothelial cell (HAEC) monolayer and multiple layers of human smooth muscle cells (HSMC) to accurately mimic arterial anatomy. Structural and mechanical characterization was conducted using confocal microscopy, SEM, stress/strain analysis, and infrared spectroscopy. Transport was characterized using FITC-Dextran hydraulic permeability protocol. Structure and transport characterization successfully demonstrate device viability as a physiologically relevant arterial mimic for testing transendothelial transport. Thus, our lab-on-a-brane provides a highly effective and efficient, yet considerably inexpensive, physiologically relevant alternative for pharmacokinetic evaluation; possibly reducing animals used in pre-clinical testing, clinical trials cost from false

  4. Grand unified brane world scenario

    NASA Astrophysics Data System (ADS)

    Arai, Masato; Blaschke, Filip; Eto, Minoru; Sakai, Norisuke

    2017-12-01

    We present a field theoretical model unifying grand unified theory (GUT) and brane world scenario. As a concrete example, we consider S U (5 ) GUT in 4 +1 dimensions where our 3 +1 dimensional spacetime spontaneously arises on five domain walls. A field-dependent gauge kinetic term is used to localize massless non-Abelian gauge fields on the domain walls and to assure the charge universality of matter fields. We find the domain walls with the symmetry breaking S U (5 )→S U (3 )×S U (2 )×U (1 ) as a global minimum and all the undesirable moduli are stabilized with the mass scale of MGUT. Profiles of massless standard model particles are determined as a consequence of wall dynamics. The proton decay can be exponentially suppressed.

  5. The effect of the Gauss-Bonnet term on Hawking radiation from arbitrary dimensional black brane

    NASA Astrophysics Data System (ADS)

    Kuang, Xiao-Mei; Saavedra, Joel; Övgün, Ali

    2017-09-01

    We investigate the probabilities of the tunneling and the radiation spectra of massive spin-1 particles from arbitrary dimensional Gauss-Bonnet-Axions (GBA) Anti-de Sitter (AdS) black branes, via using the WKB approximation to the Proca spin-1 field equation. The tunneling probabilities and Hawking temperature of the arbitrary dimensional GBA AdS black brane is calculated via the Hamilton-Jacobi approach. We also compute the Hawking temperature via the Parikh-Wilczek tunneling approach. The results obtained from the two methods are consistent. In our setup, the Gauss-Bonnet (GB) coupling affects the Hawking temperature if and only if the momentum of the axion fields is non-vanishing.

  6. Delocalizing entanglement of anisotropic black branes

    NASA Astrophysics Data System (ADS)

    Jahnke, Viktor

    2018-01-01

    We study the mutual information between pairs of regions on the two asymptotic boundaries of maximally extended anisotropic black branes. This quantity characterizes the local pattern of entanglement of the thermofield double states which are dual to these geometries. We analyze the disruption of the mutual information in anisotropic shock wave geometries and show that the entanglement velocity plays an important role in this phenomenon. Moreover, we compute several chaos-related properties of this system, such as the entanglement velocity, the butterfly velocity, and the scrambling time. We find that the butterfly velocity and the entanglement velocity violate the upper bounds proposed in [1-3], but remain bounded by their corresponding values in the infrared effective theory.

  7. AdS7/CFT6 with orientifolds

    NASA Astrophysics Data System (ADS)

    Apruzzi, Fabio; Fazzi, Marco

    2018-01-01

    AdS7 solutions of massive type IIA have been classified, and are dual to a large class of six-dimensional (1, 0) SCFT's whose tensor branch deformations are described by linear quivers of SU groups. Quivers and AdS vacua depend solely on the group theory data of the NS5-D6-D8 brane configurations engineering the field theories. This has allowed for a direct holographic match of their a conformal anomaly. In this paper we extend the match to cases where O6 and O8-planes are present, thereby introducing SO and USp groups in the quivers. In all of them we show that the a anomaly computed in supergravity agrees with the holographic limit of the exact field theory result, which we extract from the anomaly polynomial. As a byproduct we construct special AdS7 vacua dual to nonperturbative F-theory configurations. Finally, we propose a holographic a-theorem for six-dimensional Higgs branch RG flows.

  8. (Compactified) black branes in four dimensional f(R)-gravity

    NASA Astrophysics Data System (ADS)

    Dimakis, N.; Giacomini, Alex; Paliathanasis, Andronikos

    2018-02-01

    A new family of analytical solutions in a four dimensional static spacetime is presented for f (R) -gravity. In contrast to General Relativity, we find that a non trivial black brane/string solution is supported in vacuum power law f (R) -gravity for appropriate values of the parameters characterizing the model and when axisymmetry is introduced in the line element. For the aforementioned solution, we perform a brief investigation over its basic thermodynamic quantities.

  9. Dark SU (N ) glueball stars on fluid branes

    NASA Astrophysics Data System (ADS)

    da Rocha, Roldão

    2017-06-01

    The glueball dark matter, in the pure SU (N ) Yang-Mills theory, engenders dark SU (N ) stars that comprise self-gravitating compact configurations of scalar glueball fields. Corrections to the highest frequency of gravitational wave radiation emitted by dark SU (N ) star mergers on a fluid brane with variable tension, implemented by the minimal geometric deformation, are derived, and their consequences are analyzed. Hence, dark SU (N ) star mergers on a fluid braneworld are shown to be better detectable by the LIGO and the eLISA experiments.

  10. Traitement des séquelles de brûlures de la main dans les pays à ressources limitées ; notre expérience en république démocratique du Congo

    PubMed Central

    Kibadi, K.; Moutet, F.

    2015-01-01

    Summary Les séquelles de brûlures de la main sont encore fréquentes dans les pays à ressources limitées. Trente-deux patients, représentant 38 mains, ont été admis et traités, entre le 1er décembre 2010 et le 1er mai 2014 aux Cliniques Universitaires de Kinshasa en République Démocratique du Congo (RDC). nous avons observé 22 patients (69 %) dans le groupe de jeunes (patients âgés de moins de 18 ans), et 10 patients (31 %) chez les adultes (18 à 59 ans). Aucun patient dans le groupe de seniors (60 ans et plus) n’a été observé. Dans le groupe de jeunes, la tranche d’âge de 1 à 5 ans a été la plus atteinte avec 13 malades (40 %). l’accident à la maison était le plus fréquent (72 %). le mécanisme de la brûlure était le plus souvent thermique par flammes (51 %) ou par liquide chaud (34 %). les rétractions et brides sont les lésions le plus observées (84 %). la rétraction dorsale globale « main en griffe» est observée chez 40 % de patients traités, associée à des cicatrices hypertrophiques et chéloïdiennes dans 84 % de cas. Chez les 32 mains traitées chirurgicalement, des excision-greffes ont été réalisées dans 43,7 %, des lambeaux locaux dans 43,7 % et des lambeaux à distance dans 12,5 % de cas. A la sortie de l’hôpital, 84 % de « bons » résultats ont été observés. le suivi a été de 18 mois. le traitement des séquelles de brûlures de la main est possible dans ces pays, exemple de la rDC. Mais les défis à surmonter dans ces pays sont nombreux : la faible accessibilité aux techniques actuelles de la chirurgie plastique, la prise en charge initiale inadéquate des brûlures, la pauvreté. PMID:26668560

  11. Vertex operator algebras of Argyres-Douglas theories from M5-branes

    NASA Astrophysics Data System (ADS)

    Song, Jaewon; Xie, Dan; Yan, Wenbin

    2017-12-01

    We study aspects of the vertex operator algebra (VOA) corresponding to Argyres-Douglas (AD) theories engineered using the 6d N=(2, 0) theory of type J on a punctured sphere. We denote the AD theories as ( J b [ k], Y), where J b [ k] and Y represent an irregular and a regular singularity respectively. We restrict to the `minimal' case where J b [ k] has no associated mass parameters, and the theory does not admit any exactly marginal deformations. The VOA corresponding to the AD theory is conjectured to be the W-algebra W^{k_{2d}}(J, Y ) , where {k}_{2d}=-h+b/b+k with h being the dual Coxeter number of J. We verify this conjecture by showing that the Schur index of the AD theory is identical to the vacuum character of the corresponding VOA, and the Hall-Littlewood index computes the Hilbert series of the Higgs branch. We also find that the Schur and Hall-Littlewood index for the AD theory can be written in a simple closed form for b = h. We also test the conjecture that the associated variety of such VOA is identical to the Higgs branch. The M5-brane construction of these theories and the corresponding TQFT structure of the index play a crucial role in our computations.

  12. Superbranes, D = 11 CJS Supergravity and Enlarged Superspace Coordinates/Fields Correspondence

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Azcarraga, J.A. de; IFIC - CSIC-UVEG, Facultad de Fisica, 46100-Burjassot, Valencia

    2005-04-25

    We discuss the role of enlarged superspaces in two seemingly different contexts, the structure of the p-brane actions and that of the Cremmer-Julia-Scherk eleven-dimensional supergravity. Both provide examples of a common principle: the existence of an enlarged superspaces coordinates/fields correspondence by which all the (worldvolume or spacetime) fields of the theory are associated to coordinates of enlarged superspaces. In the context of p-branes, enlarged superspaces may be used to construct manifestly supersymmetry-invariant Wess-Zumino terms and as a way of expressing the Born-Infeld worldvolume fields of D-branes and the worldvolume M5-brane two-form in terms of fields associated to the coordinates ofmore » these enlarged superspaces. This is tantamount to saying that the Born-Infeld fields have a superspace origin, as do the other worldvolume fields, and that they have a composite structure. In D=11 supergravity theory enlarged superspaces arise when its underlying gauge structure is investigated and, as a result, the composite nature of the A3 field is revealed: there is a full one-parametric family of enlarged superspace groups that solve the problem of expressing A3 in terms of spacetime fields associated to their coordinates. The corresponding enlarged supersymmetry algebras turn out to be deformations of an expansion of the osp(1 vertical bar 32) algebra. The unifying mathematical structure underlying all these facts is the cohomology of the supersymmetry algebras involved.« less

  13. D1 string dynamics in curved backgrounds with fluxes

    NASA Astrophysics Data System (ADS)

    Banerjee, Aritra; Biswas, Sagar; Nayak, Rashmi R.

    2016-04-01

    We study various rotating and oscillating D-string configurations in some general backgrounds with fluxes. In particular, we look for solutions to the equations of motion of various rigidly rotating D-strings in AdS3 background with mixed flux, and in the intersecting D-brane geometries. We find out relations among various conserved charges corresponding to the breathing and rotating D-string configurations.

  14. Exciting gauge field and gravitons in brane-antibrane annihilation.

    PubMed

    Mazumdar, Anupam; Stoica, Horace

    2009-03-06

    In this Letter we point out the inevitability of an explosive production of gauge field and gravity wave during an open string tachyon condensation in a cosmological setting, in an effective field theory model. We will be particularly studying a toy model of brane-antibrane inflation in a warped throat where inflation ends via tachyon condensation. We point out that a tachyonic instability helps fragmenting the homogeneous tachyon and excites gauge field and contributes to the stress-energy tensor which also feeds into the gravity waves.

  15. Solutions on a brane in a bulk spacetime with Kalb–Ramond field

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chakraborty, Sumanta, E-mail: sumanta@iucaa.in; SenGupta, Soumitra, E-mail: tpssg@iacs.res.in

    Effective gravitational field equations on a brane have been derived, when the bulk spacetime is endowed with the second rank antisymmetric Kalb–Ramond field. Since both the graviton and the Kalb–Ramond field are closed string excitations, they can propagate in the bulk. After deriving the effective gravitational field equations on the brane, we solve them for a static spherically symmetric solution. It turns out that the solution so obtained represents a black hole or naked singularity depending on the parameter space of the model. The stability of this model is also discussed. Cosmological solutions to the gravitational field equations have beenmore » obtained, where the Kalb–Ramond field is found to behave as normal pressure free matter. For certain specific choices of the parameters in the cosmological solution, the solution exhibits a transition in the behaviour of the scale factor and hence a transition in the expansion history of the universe. The possibility of accelerated expansion of the universe in this scenario is also discussed.« less

  16. Beyond Aztec Castles: Toric Cascades in the dP 3 Quiver

    NASA Astrophysics Data System (ADS)

    Lai, Tri; Musiker, Gregg

    2017-12-01

    Given one of an infinite class of supersymmetric quiver gauge theories, string theorists can associate a corresponding toric variety (which is a Calabi-Yau 3-fold) as well as an associated combinatorial model known as a brane tiling. In combinatorial language, a brane tiling is a bipartite graph on a torus and its perfect matchings are of interest to both combinatorialists and physicists alike. A cluster algebra may also be associated to such quivers and in this paper we study the generators of this algebra, known as cluster variables, for the quiver associated to the cone over the del Pezzo surface d P 3. In particular, mutation sequences involving mutations exclusively at vertices with two in-coming arrows and two out-going arrows are referred to as toric cascades in the string theory literature. Such toric cascades give rise to interesting discrete integrable systems on the level of cluster variable dynamics. We provide an explicit algebraic formula for all cluster variables that are reachable by toric cascades as well as a combinatorial interpretation involving perfect matchings of subgraphs of the d P 3 brane tiling for these formulas in most cases.

  17. AdS and dS Entropy from String Junctions or The Function of Junction Conjunctions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Silverstein, Eva M

    Flux compactifications of string theory exhibiting the possibility of discretely tuning the cosmological constant to small values have been constructed. The highly tuned vacua in this discretuum have curvature radii which scale as large powers of the flux quantum numbers, exponential in the number of cycles in the compactification. By the arguments of Susskind/Witten (in the AdS case) and Gibbons/Hawking (in the dS case), we expect correspondingly large entropies associated with these vacua. If they are to provide a dual description of these vacua on their Coulomb branch, branes traded for the flux need to account for this entropy atmore » the appropriate energy scale. In this note, we argue that simple string junctions and webs ending on the branes can account for this large entropy, obtaining a rough estimate for junction entropy that agrees with the existing rough estimates for the spacing of the discretuum. In particular, the brane entropy can account for the (A)dS entropy far away from string scale correspondence limits.« less

  18. Applications of warped geometries: From cosmology to cold atoms

    NASA Astrophysics Data System (ADS)

    Brown, C. M.

    This thesis describes several interrelated projects furthering the study of branes on warped geometries in string theory. First, we consider the non-perturbative interaction between D3 and D7 branes which stabilizes the overall volume in braneworld compactification scenarios. This interaction might offer stable nonsupersymmetric vacua which would naturally break supersymmetry if occupied by D3 branes. We derive the equations for the nonsupersymmetric vacua of the D3-brane and analyze them in the case of two particular 7-brane embeddings at the bottom of the warped deformed conifold. These geometries have negative dark energy. Stability of these models is possible but not generic. Further, we reevaluate brane/flux annihilation in a warped throat with one stabilized Kahler modulus. We find that depending on the relative size of various fluxes three things can occur: the decay process proceeds unhindered, the D3-branes are forbidden to decay classically, or the entire space decompactifies. Additionally, we show that the Kahler modulus receives a contribution from the collective 3-brane tension allowing significant changes in the compactified volume during the transition. Next, furthering the effort to describe cold atoms using AdS/CFT, we construct charged asymptotically Schrodinger black hole solutions of IIB supergravity. We begin by obtaining a closed-form expression for the null Melvin twist of many type IIB backgrounds and identify the resulting five-dimensional effective action. We use these results to demonstrate that the near-horizon physics and thermodynamics of asymptotically Schrodinger black holes obtained in this way are essentially inherited from their AdS progenitors, and verify that they admit zero-temperature extremal limits with AdS2 near-horizon geometries. Finally, in an effort to understand rotating nonrelativistic systems we use the null Melvin twist technology on a charged rotating AdS black hole and discover a type of Godel space-time. We

  19. Large-D gravity and low-D strings.

    PubMed

    Emparan, Roberto; Grumiller, Daniel; Tanabe, Kentaro

    2013-06-21

    We show that in the limit of a large number of dimensions a wide class of nonextremal neutral black holes has a universal near-horizon limit. The limiting geometry is the two-dimensional black hole of string theory with a two-dimensional target space. Its conformal symmetry explains the properties of massless scalars found recently in the large-D limit. For black branes with string charges, the near-horizon geometry is that of the three-dimensional black strings of Horne and Horowitz. The analogies between the α' expansion in string theory and the large-D expansion in gravity suggest a possible effective string description of the large-D limit of black holes. We comment on applications to several subjects, in particular to the problem of critical collapse.

  20. Comments on new multiple-brane solutions based on Hata-Kojita duality in open string field theory

    NASA Astrophysics Data System (ADS)

    Masuda, Toru

    2014-05-01

    Recently, Hata and Kojita proposed a new energy formula for a class of solutions in Witten's open string field theory based on a novel symmetry of correlation functions they found. Their energy formula can be regarded as a generalization of the conventional energy formula by Murata and Schnabl. Following their proposal, we investigate their new ansatz for the classical solution representing double D-branes. We present a regularized definition of this solution and show that the solution satisfies the equation of motion when it is contracted with the solution itself and when it is contracted with any states in the Fock space. However, the Ellwood invariant and the boundary state of the solution are the same as those for the perturbative vacuum. This result disagrees with an expectation from the Ellwood conjecture.

  1. Cosmology of a Friedmann-Lamaître-Robertson-Walker 3-brane, late-time cosmic acceleration, and the cosmic coincidence.

    PubMed

    Doolin, Ciaran; Neupane, Ishwaree P

    2013-04-05

    A late epoch cosmic acceleration may be naturally entangled with cosmic coincidence--the observation that at the onset of acceleration the vacuum energy density fraction nearly coincides with the matter density fraction. In this Letter we show that this is indeed the case with the cosmology of a Friedmann-Lamaître-Robertson-Walker (FLRW) 3-brane in a five-dimensional anti-de Sitter spacetime. We derive the four-dimensional effective action on a FLRW 3-brane, from which we obtain a mass-reduction formula, namely, M(P)(2) = ρ(b)/|Λ(5)|, where M(P) is the effective (normalized) Planck mass, Λ(5) is the five-dimensional cosmological constant, and ρ(b) is the sum of the 3-brane tension V and the matter density ρ. Although the range of variation in ρ(b) is strongly constrained, the big bang nucleosynthesis bound on the time variation of the effective Newton constant G(N) = (8πM(P)(2))(-1) is satisfied when the ratio V/ρ ≳ O(10(2)) on cosmological scales. The same bound leads to an effective equation of state close to -1 at late epochs in accordance with astrophysical and cosmological observations.

  2. Quantum vacua of 2d maximally supersymmetric Yang-Mills theory

    NASA Astrophysics Data System (ADS)

    Koloğlu, Murat

    2017-11-01

    We analyze the classical and quantum vacua of 2d N=(8,8) supersymmetric Yang-Mills theory with SU( N) and U( N) gauge group, describing the worldvolume interactions of N parallel D1-branes with flat transverse directions {R}^8 . We claim that the IR limit of the SU( N) theory in the superselection sector labeled M (mod N) — identified with the internal dynamics of ( M, N)-string bound states of the Type IIB string theory — is described by the symmetric orbifold N=(8,8) sigma model into ({R}^8)^{D-1}/S_D when D = gcd( M, N) > 1, and by a single massive vacuum when D = 1, generalizing the conjectures of E. Witten and others. The full worldvolume theory of the D1-branes is the U( N) theory with an additional U(1) 2-form gauge field B coming from the string theory Kalb-Ramond field. This U( N) + B theory has generalized field configurations, labeled by the Z-valued generalized electric flux and an independent {Z}_N -valued 't Hooft flux. We argue that in the quantum mechanical theory, the ( M, N)-string sector with M units of electric flux has a {Z}_N -valued discrete θ angle specified by M (mod N) dual to the 't Hooft flux. Adding the brane center-of-mass degrees of freedom to the SU( N) theory, we claim that the IR limit of the U( N) + B theory in the sector with M bound F-strings is described by the N=(8,8) sigma model into {Sym}^D({R}^8) . We provide strong evidence for these claims by computing an N=(8,8) analog of the elliptic genus of the UV gauge theories and of their conjectured IR limit sigma models, and showing they agree. Agreement is established by noting that the elliptic genera are modular-invariant Abelian (multi-periodic and meromorphic) functions, which turns out to be very restrictive.

  3. Holographic cosmology from BIonic solutions

    NASA Astrophysics Data System (ADS)

    Sepehri, Alireza; Faizal, Mir; Setare, Mohammad Reza; Ali, Ahmed Farag

    2017-02-01

    In this paper, we will use a BIonic solution for analyzing the holographic cosmology. A BIonic solution is a configuration of a D3-brane and an anti-D3-brane connected by a wormhole, and holographic cosmology is a recent proposal to explain cosmic expansion by using the holographic principle. In our model, a BIonic configuration will be produced by the transition of fundamental black strings. The formation of a BIonic configuration will cause inflation. As the D3-brane moves away from the anti-D3-brane, the wormhole will get annihilated, and the inflation will end with the annihilation of this wormhole. However, it is possible for a D3-brane to collide with an anti-D3-brane. Such a collision will occur if the distance between the D3-brane and the anti-D3-brane reduces, and this will create tachyonic states. We will demonstrate that these tachyonic states will lead to the formation of a new wormhole, and this will cause acceleration of the universe before such a collision.

  4. Holographic studies of thermal gauge theories with flavour

    NASA Astrophysics Data System (ADS)

    Thomson, Rowan F. M.

    The AdS/CFT correspondence and its extensions to more general gauge/gravity dualities have provided a powerful framework for the study of strongly coupled gauge theories. This thesis explores properties of a large class of thermal strongly coupled gauge theories using the gravity dual. In order to bring the holographic framework closer to Quantum Chromodynamics (QCD), we study theories with matter in the fundamental representation. In particular, we focus on the holographic dual of SU ( N c ) supersymmetric Yang-Mills theory coupled to N f = N c flavours of fundamental matter at finite temperature, which is realised as N f Dq-brane probes in the near horizon (black hole) geometry of N c black Dp-branes. We explore many aspects of these Dp/Dq brane systems, often focussing on the D3/D7 brane system which is dual to a four dimensional gauge theory. We study the thermodynamics of the Dq-brane probes in the black hole geometry. At low temperature, the branes sit outside the black hole and the meson spectrum is discrete and possesses a mass gap. As the temperature increases, the branes approach a critical solution. Eventually, they fall into the horizon and a phase transition occurs. At large N c and large 't Hooft coupling, we show that this phase transition is always first order. We calculate the free energy, entropy and energy densities, as well as the speed of sound in these systems. We compute the meson spectrum for brane embeddings outside the horizon and find that tachyonic modes appear where this phase is expected to be unstable from thermodynamic considerations. We study the system at non-zero baryon density n b and find that there is a line of phase transitions for small n b , terminating at a critical point with finite n b . We demonstrate that, to leading order in N f / N c , the viscosity to entropy density ratio in these theories saturates the conjectured universal bound e/ S >= 1/4p. Finally, we compute spectral functions and diffusion constants for

  5. On the localisation of four-dimensional brane-world black holes: II. The general case

    NASA Astrophysics Data System (ADS)

    Kanti, P.; Pappas, N.; Pappas, T.

    2016-01-01

    We perform a comprehensive analysis of a number of scalar field theories in an attempt to find analytically five-dimensional, localised-on-the-brane, black-hole solutions. Extending a previous analysis, we assume a generalised Vaidya ansatz for the five-dimensional metric tensor that allows for a time-dependent, non-trivial profile of the mass function in terms of the bulk coordinate and a deviation from the over-restricting Schwarzschild-type solution on the brane. In order to support such a solution, we study a variety of theories including single or multiple scalar fields, with canonical or non-canonical kinetic terms, minimally or non-minimally coupled to gravity. We demonstrate that for such a metric ansatz and for a carefully chosen energy-momentum tensor which is non-isotropic in five dimensions, solutions that have the form of a Schwarzschild-(anti)de Sitter or Reissner-Nordstrom type of solution do emerge. However, the resulting profile of the mass function along the bulk coordinate, when allowed, is not the correct one for eliminating bulk singularities.

  6. Complex Chern-Simons from M5-branes on the squashed three-sphere

    NASA Astrophysics Data System (ADS)

    Córdova, Clay; Jafferis, Daniel L.

    2017-11-01

    We derive an equivalence between the (2,0) superconformal M5-brane field theory dimensionally reduced on a squashed three-sphere, and Chern-Simons theory with complex gauge group. In the reduction, the massless fermions obtain an action which is second order in derivatives and are reinterpreted as ghosts for gauge fixing the emergent non-compact gauge symmetry. A squashing parameter in the geometry controls the imaginary part of the complex Chern-Simons level.

  7. Evolution and End Point of the Black String Instability: Large D Solution.

    PubMed

    Emparan, Roberto; Suzuki, Ryotaku; Tanabe, Kentaro

    2015-08-28

    We derive a simple set of nonlinear, (1+1)-dimensional partial differential equations that describe the dynamical evolution of black strings and branes to leading order in the expansion in the inverse of the number of dimensions D. These equations are easily solved numerically. Their solution shows that thin enough black strings are unstable to developing inhomogeneities along their length, and at late times they asymptote to stable nonuniform black strings. This proves an earlier conjecture about the end point of the instability of black strings in a large enough number of dimensions. If the initial black string is very thin, the final configuration is highly nonuniform and resembles a periodic array of localized black holes joined by short necks. We also present the equations that describe the nonlinear dynamics of anti-de Sitter black branes at large D.

  8. PhD7Faster: predicting clones propagating faster from the Ph.D.-7 phage display peptide library.

    PubMed

    Ru, Beibei; 't Hoen, Peter A C; Nie, Fulei; Lin, Hao; Guo, Feng-Biao; Huang, Jian

    2014-02-01

    Phage display can rapidly discover peptides binding to any given target; thus, it has been widely used in basic and applied research. Each round of panning consists of two basic processes: Selection and amplification. However, recent studies have showed that the amplification step would decrease the diversity of phage display libraries due to different propagation capacity of phage clones. This may induce phages with growth advantage rather than specific affinity to appear in the final experimental results. The peptides displayed by such phages are termed as propagation-related target-unrelated peptides (PrTUPs). They would mislead further analysis and research if not removed. In this paper, we describe PhD7Faster, an ensemble predictor based on support vector machine (SVM) for predicting clones with growth advantage from the Ph.D.-7 phage display peptide library. By using reduced dipeptide composition (ReDPC) as features, an accuracy (Acc) of 79.67% and a Matthews correlation coefficient (MCC) of 0.595 were achieved in 5-fold cross-validation. In addition, the SVM-based model was demonstrated to perform better than several representative machine learning algorithms. We anticipate that PhD7Faster can assist biologists to exclude potential PrTUPs and accelerate the finding of specific binders from the popular Ph.D.-7 library. The web server of PhD7Faster can be freely accessed at http://immunet.cn/sarotup/cgi-bin/PhD7Faster.pl.

  9. Multiple D3-Instantons and Mock Modular Forms I

    NASA Astrophysics Data System (ADS)

    Alexandrov, Sergei; Banerjee, Sibasish; Manschot, Jan; Pioline, Boris

    2017-07-01

    We study D3-instanton corrections to the hypermultiplet moduli space in type IIB string theory compactified on a Calabi-Yau threefold. In a previous work, consistency of D3-instantons with S-duality was established at first order in the instanton expansion, using the modular properties of the M5-brane elliptic genus. We extend this analysis to the two-instanton level, where wall-crossing phenomena start playing a role. We focus on the contact potential, an analogue of the Kähler potential which must transform as a modular form under S-duality. We show that it can be expressed in terms of a suitable modification of the partition function of D4-D2-D0 BPS black holes, constructed out of the generating function of MSW invariants (the latter coincide with Donaldson-Thomas invariants in a particular chamber). Modular invariance of the contact potential then requires that, in the case where the D3-brane wraps a reducible divisor, the generating function of MSW invariants must transform as a vector-valued mock modular form, with a specific modular completion built from the MSW invariants of the constituents. Physically, this gives a powerful constraint on the degeneracies of BPS black holes. Mathematically, our result gives a universal prediction for the modular properties of Donaldson-Thomas invariants of pure two-dimensional sheaves.

  10. Vertex Operator Formulation of Scattering around Black-Hole

    NASA Astrophysics Data System (ADS)

    Park, I. Y.

    We propose a full-fledged open string framework that seems suited to study the black hole information paradox. We set up a configuration to compute the scattering amplitude of a IIB open string around a D5-brane. The D5-brane is situated at the origin of a transverse D3-brane. A string perturbation theory is employed where the geometry of the D5-brane is treated as a potential. We reason that the setup is capable of reconciling the unitary evolution of states and information loss that is measured by an observer on the D3 brane. With the configurations of these kinds, the information loss is an apparent phenomenon: it is just a manifestation of the fact that the D3-observer does not have access to the "hair" of the D5 black brane.

  11. Nonperturbative corrections to 4D string theory effective actions from SL(2,Z) duality and supersymmetry.

    PubMed

    Robles-Llana, Daniel; Rocek, Martin; Saueressig, Frank; Theis, Ulrich; Vandoren, Stefan

    2007-05-25

    We find the D(-1)- and D1-brane instanton contributions to the hypermultiplet moduli space of type IIB string compactifications on Calabi-Yau threefolds. These combine with known perturbative and world sheet instanton corrections into a single modular invariant function that determines the hypermultiplet low-energy effective action.

  12. Canonical coordinates and meson spectra for scalar deformed Script N = 4 SYM from the AdS/CFT correspondence

    NASA Astrophysics Data System (ADS)

    Shock, Jonathan P.

    2006-10-01

    Two points on the Coulomb branch of Script N = 4 super Yang Mills are investigated using their supergravity duals. By switching on condensates for the scalars in the Script N = 4 multiplet with a form which preserves a subgroup of the original R-symmetry, disk and sphere configurations of D3-branes are formed in the dual supergravity background. The analytic, canonical metric for these geometries is formulated and the singularity structure is studied. Quarks are introduced into the corresponding field theories using D7-brane probes and the meson spectrum is calculated. For one of the condensate configurations, a mass gap is found and shown analytically to be present in the massless limit. It is also found that there is a stepped spectrum with eigenstate degeneracy in the limit of small quark masses and this result is shown analytically. In the second, similar deformation it is necessary to understand the full D3-D7 brane interaction to study the limit of small quark masses. For quark masses larger than the condensate scale the spectrum is calculated and shown to be discrete as expected.

  13. BPS States, Crystals, and Matrices

    DOE PAGES

    Sułkowski, Piotr

    2011-01-01

    We review free fermion, melting crystal, and matrix model representations of wall-crossing phenomena on local, toric Calabi-Yau manifolds. We consider both unrefined and refined BPS counting of closed BPS states involving D2- and D0-branes bound to a D6-brane, as well as open BPS states involving open D2-branes ending on an additional D4-brane. Appropriate limit of these constructions provides, among the others, matrix model representation of refined and unrefined topological string amplitudes.

  14. Triality in little string theories

    NASA Astrophysics Data System (ADS)

    Bastian, Brice; Hohenegger, Stefan; Iqbal, Amer; Rey, Soo-Jong

    2018-02-01

    We study a class of eight-supercharge little string theories (LSTs) on the world volume of N M5-branes with transverse space S1×(C2/ZM). These M-brane configurations compactified on a circle are dual to M D5-branes intersecting N NS5-branes on T2×R7 ,1 as well as to F-theory compactified on a toric Calabi-Yau threefold XN ,M. We argue that the Kähler cone of XN ,M admits three regions associated with weakly coupled quiver gauge theories of gauge groups [U (N )]M,[U (M )]N, and [U (N/M k )]k where k =gcd (N ,M ). These provide low-energy descriptions of different LSTs. The duality between the first two gauge theories is well known and is a consequence of the S-duality between D5- and NS5-branes or the T-duality of the LSTs. The triality involving the third gauge theory is new, and we demonstrate it using several examples. We also discuss implications of this triality for the W-algebras associated with the Alday-Gaiotto-Tachikawa dual theories.

  15. Effect of the chameleon scalar field on brane cosmological evolution

    NASA Astrophysics Data System (ADS)

    Bisabr, Y.; Ahmadi, F.

    2017-11-01

    We have investigated a brane world model in which the gravitational field in the bulk is described both by a metric tensor and a minimally coupled scalar field. This scalar field is taken to be a chameleon with an appropriate potential function. The scalar field interacts with matter and there is an energy transfer between the two components. We find a late-time asymptotic solution which exhibits late-time accelerating expansion. We also show that the Universe recently crosses the phantom barrier without recourse to any exotic matter. We provide some thermodynamic arguments which constrain both the direction of energy transfer and dynamics of the extra dimension.

  16. 19 CFR 4.7d - Container status messages.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Container status messages. 4.7d Section 4.7d... TREASURY VESSELS IN FOREIGN AND DOMESTIC TRADES Arrival and Entry of Vessels § 4.7d Container status messages. (a) Container status messages required. In addition to the advance filing requirements pursuant...

  17. Nambu sigma model and effective membrane actions

    NASA Astrophysics Data System (ADS)

    Jurčo, Branislav; Schupp, Peter

    2012-07-01

    We propose an effective action for a p‧-brane with open p-branes ending on it. The action has dual descriptions similar to the commutative and non-commutative ones of the DBI action for D-branes and open strings. The Poisson structure governing the non-commutativity of the D-brane is replaced by a Nambu structure and the open-closed string relations are generalized to the case of p-branes utilizing a novel Nambu sigma model description of p-branes. In the case of an M5-brane our action interpolates between M5-actions already proposed in the literature and matrix-model like actions involving Nambu structures.

  18. Constraining the cosmology of the phantom brane using distance measures

    NASA Astrophysics Data System (ADS)

    Alam, Ujjaini; Bag, Satadru; Sahni, Varun

    2017-01-01

    The phantom brane has several important distinctive features: (i) Its equation of state is phantomlike, but there is no future "big rip" singularity, and (ii) the effective cosmological constant on the brane is dynamically screened, because of which the expansion rate is smaller than that in Λ CDM at high redshifts. In this paper, we constrain the Phantom braneworld using distance measures such as type-Ia supernovae (SNeIa), baryon acoustic oscillations (BAO), and the compressed cosmic microwave background (CMB) data. We find that the simplest braneworld models provide a good fit to the data. For instance, BAO +SNeIa data can be accommodated by the braneworld for a large region in parameter space 0 ≤Ωℓ≲0.3 at 1 σ . The Hubble parameter can be as high as H0≲78 km s-1 Mpc-1 , and the effective equation of state at present can show phantomlike behavior with w0≲-1.2 at 1 σ . We note a correlation between H0 and w0, with higher values of H0 leading to a lower, and more phantomlike, value of w0. Inclusion of CMB data provides tighter constraints Ωℓ≲0.1 . (Here Ωℓ encodes the ratio of the five- and four-dimensional Planck mass.) The Hubble parameter in this case is more tightly constrained to H0≲71 km s-1 Mpc-1 , and the effective equation of state to w0≲-1.1 . Interestingly, we find that the Universe is allowed to be closed or open, with -0.5 ≲Ωκ≲0.5 , even on including the compressed CMB data. There appears to be some tension in the low and high-z BAO data which may either be resolved by future data, or act as a pointer to interesting new cosmology.

  19. Vacuum Polarization in AN Anti-De Sitter Space as AN Origin for a Cosmological Constant in a Brane World

    NASA Astrophysics Data System (ADS)

    Li, Li-Xin

    We show that the vacuum polarization of quantum fields in an anti-de Sitter space can naturally give rise to a small but nonzero cosmological constant in a brane world living in it. To explain the extremely small ratio of mass density in the cosmological constant to the Planck mass density in our universe (≈10-123) as suggested by cosmological observations, all we need is a four-dimensional brane world (our universe) living in a five-dimensional anti-de Sitter space with a curvature radius r0 10-3 cm and a fundamental Planck energy MP 109 GeV, and a scalar field with a mass m ˜ r-10 ˜ 10-2 eV. Probing gravity down to a scale 10-3 cm, which is attainable in the near future, will provide a test of the model.

  20. Entanglement asymmetry for boosted black branes and the bound

    NASA Astrophysics Data System (ADS)

    Mishra, Rohit; Singh, Harvendra

    2017-06-01

    We study the effects of asymmetry in the entanglement thermodynamics of CFT subsystems. It is found that “boosted” Dp-brane backgrounds give rise to the first law of the entanglement thermodynamics where the CFT pressure asymmetry plays a decisive role in the entanglement. Two different strip like subsystems, one parallel to the boost and the other perpendicular, are studied in the perturbative regime Tthermal ≪ TE. We mainly seek to quantify this entanglement asymmetry as a ratio of the first-order entanglement entropies of the excitations. We discuss the AdS-wave backgrounds at zero temperature having maximum asymmetry from where a bound on entanglement asymmetry is obtained. The entanglement asymmetry reduces as we switch on finite temperature in the CFT while it is maximum at zero temperature.

  1. 7 CFR 15d.3 - Compliance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Compliance. 15d.3 Section 15d.3 Agriculture Office of the Secretary of Agriculture NONDISCRIMINATION IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.3 Compliance. The Director of the Office of Civil Rights shall...

  2. 7 CFR 15d.3 - Compliance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Compliance. 15d.3 Section 15d.3 Agriculture Office of the Secretary of Agriculture NONDISCRIMINATION IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.3 Compliance. The Director of the Office of Civil Rights shall...

  3. D-type conformal matter and SU/USp quivers

    NASA Astrophysics Data System (ADS)

    Kim, Hee-Cheol; Razamat, Shlomo S.; Vafa, Cumrun; Zafrir, Gabi

    2018-06-01

    We discuss the four dimensional models obtained by compactifying a single M5 brane probing D N singularity (minimal D-type (1 , 0) conformal matter in six dimensions) on a torus with flux for abelian subgroups of the SO(4 N) flavor symmetry. We derive the resulting quiver field theories in four dimensions by first compactifying on a circle and relating the flux to duality domain walls in five dimensions. This leads to novel N=1 dualities in 4 dimensions which arise from distinct five dimensional realizations of the circle compactifications of the D-type conformal matter.

  4. Black hole formation due to collapsing dark matter in a presence of dark energy in the brane-world scenario

    NASA Astrophysics Data System (ADS)

    Shah, Hasrat Hussain

    In the last three to four decades, various programs have been studied in order to investigate the final fate of gravitational collapse of massive astronomical objects. In the theoretical context, Black Holes (BHs) are the consequence of final stage of the gravitational collapse. In this work, we investigated the gravitational collapse process of a spherically symmetric star constituted of dark matter (DM), ρM, and Dark Energy (DE), ρ in the context of the brane-world scenario. In our model, we discussed the anisotropy of the pressure in a fluid with Equation of State (EoS) pt = kρ and pr = lρ, (l + 2k < ‑1). We briefly discussed various cases of gravitational collapse and it is found that BH can be formed by the gravitational collapse in brane-world regime while in some cases there is only a naked singularity at their end state.

  5. Apport maternel chez la balane tropicale : Plasticite de l'allocation de la ressource trophique pour la production larvaire en conditions de limitation nutritionnelle et de stress environnemental

    NASA Astrophysics Data System (ADS)

    Freuchet, Florian

    Dans le milieu marin, l'abondance du recrutement depend des processus qui vont affecter les adultes et le stock de larves. Sous l'influence de signaux fiables de la qualite de l'habitat, la mere peut augmenter (effet maternel anticipatoire, 'anticipatory mother effects', AME) ou reduire (effet maternel egoiste, 'selfish maternai effects', SME) la condition physiologique de la progeniture. Dans les zones tropicales, generalement plus oligotrophes, la ressource nutritive et la temperature sont deux composantes importantes pouvant limiter le recrutement. Les effets de l'apport nutritionnel et du stress thermique sur la production de larves et sur la stategie maternelle adoptee ont ete testes dans cette etude. Nous avons cible la balane Chthamalus bisinuatus (Pilsbry) comme modele biologique car el1e domine les zones intertidales superieures le long des cotes rocheuses du Sud-Est du Bresil (region tropicale). Les hypotheses de depart stipulaient que l'apport nutritionnel permet aux adultes de produire des larves de qualite elevee et que le stress thermique genere une ponte precoce, produisant des larves de faible qualite. Afin de tester ces hypotheses, des populations de C. bisinuatus ont ete elevees selon quatre groupes experimentaux differents, en combinant des niveaux d'apport nutritionnel (eleve et faible) et de stress thermique (stresse et non stresse). Des mesures de survie et de conditions physiologiques des adultes et des larves ont permis d'identifier les reponses parentales pouvant etre avantageuses dans un environnement tropical hostile. L'analyse des profils en acides gras a ete la methode utilisee pour evaluer la qualite physiologique des adultes et de larves. Les resultats du traitement alimentaire (fort ou faible apport nutritif), ne montrent aucune difference dans l'accumulation de lipides neutres, la taille des nauplii, l'effort de reproduction ou le temps de survie des nauplii en condition de jeune. Il semble que la faible ressource nutritive est

  6. Cross-section measurement of 7Be + d and 7Li + d with ANASEN* and its implication in the Big Bang Nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Rijal, Nabin; Wiedenhover, Ingo; Baby, L. T.; Blackmon, J. C.; Rogachev, G.

    2017-09-01

    Astrophysically observed 7Li is 3 -4 times less than predicted amount by current models of Standard Big Bang Nucleosynthesis (SBBN). The nuclear reaction 7Be + d at energies relevant to SBBN, has been discussed as a possible means to destroy mass-7 nuclei. We investigated the 7Be + d and it's mirror nuclear reaction 7Li + d at SBBN energies using a radioactive 7Be and stable 7Li beam both in deuterium gas target inside ANASEN at Florida State University. ANASEN is an active target detector system which tracks the charged particles using a position sensitive proportional counter and 24-SX3 and 4-QQQ position sensitive Silicon detectors, all backed up by CsI detectors. ANASEN has wide angular coverage. The experiment measures a continuous excitation function by slowing down the beam in the target gas down to zero energy by using a single beam energy. Our set-up provides a high detection efficiency for all relevant reaction channels including (d , p) , (d , α) and/or direct breakup that can destroy mass-7 nuclei in contrast to previous measurements. The preliminary results of these experiments along with details of ANASEN detector will be presented. *ANASEN: Array for Nuclear Astrophysics and Structure with Exotic Nuclei. This work is supported by the US NSF MRI program, Grant No. PHY-0821308 and NSF Grant PHY-1401574.

  7. 42 CFR 52d.7 - Expenditure of grant funds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Expenditure of grant funds. 52d.7 Section 52d.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL CANCER INSTITUTE CLINICAL CANCER EDUCATION PROGRAM § 52d.7 Expenditure of grant funds. (a) Any funds granted...

  8. 42 CFR 52d.7 - Expenditure of grant funds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Expenditure of grant funds. 52d.7 Section 52d.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL CANCER INSTITUTE CLINICAL CANCER EDUCATION PROGRAM § 52d.7 Expenditure of grant funds. (a) Any funds granted...

  9. 42 CFR 52d.7 - Expenditure of grant funds.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Expenditure of grant funds. 52d.7 Section 52d.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL CANCER INSTITUTE CLINICAL CANCER EDUCATION PROGRAM § 52d.7 Expenditure of grant funds. (a) Any funds granted...

  10. 42 CFR 52d.7 - Expenditure of grant funds.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Expenditure of grant funds. 52d.7 Section 52d.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL CANCER INSTITUTE CLINICAL CANCER EDUCATION PROGRAM § 52d.7 Expenditure of grant funds. (a) Any funds granted...

  11. 42 CFR 52d.7 - Expenditure of grant funds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Expenditure of grant funds. 52d.7 Section 52d.7 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL CANCER INSTITUTE CLINICAL CANCER EDUCATION PROGRAM § 52d.7 Expenditure of grant funds. (a) Any funds granted...

  12. NMR structural studies of the ionizing radiation adduct 7-hydro-8-oxodeoxyguanosine (8-oxo-7H-dG) opposite deoxyadenosine in a DNA duplex. 8-oxo-7H-dG(syn)ter dot dA(anti) alignment at lesion site

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kouchakdjian, M.; Patel, D.J.; Bodepudi, V.

    1991-02-05

    Proton NMR studies are reported on the complementary d(C1-C2-A3-C4-T5-A6-oxo-G7-T8-C9-A10-C11-C12){center dot}d(G13-G14-T15-G16-A17-A18-T19-A20-G21-T22-G23-G24) dodecanucleotide duplex (designated 8-oxo-7H-dG{center dot}dA 12-mer), which contains a centrally located 7-hydro-8-oxodeoxyguanosine (8-oxo-7H-dG) residue, a group commonly found in DNA that has been exposed to ionizing radiation or oxidizing free radicals. From the NMR spectra it can be deduced that this moiety exists as two tautomers, or gives rise to two DNA conformations, that are in equilibrium and that exchange slowly. The present study focuses on the major component of the equilibrium that originates in the 6,8-dioxo tautomer of 8-oxo-7H-dG. The authors have assigned the exchangeable NH1, NH7, and NH{submore » 2}-2 base protons located on the Watson-Crick and Hoogsteen edges of 8-oxo-7H-dG7 in the 8-oxo-7H-dG{center dot}dA 12-mer duplex, using an analysis of one- and two-dimensional nuclear Overhauser enhancement (NOE) data in H{sub 2}O solution. They were able to detect a set of intra- and interstrand NOEs between protons (exchangeable and nonexchangeable) on adjacent residues in the d(A6-oxo-G7-T8){center dot}d(A17-A18-T19) trinucleotide segment centered about the lesion site that establishes stacking of the oxo-dG7(syn){center dot}dA(anti) pair between stable Watson-Crick dA6{center dot}dT19 and dT8{center dot}A17 base pairs with minimal perturbation of the helix. The structural studies demonstrate that 8-oxo-7H-dG(syn){center dot}dA(anti) forms a stable pair in the interior of the helix, providing a basis for the observed incorporation of dA opposite 8-oxo-7H-dG when readthrough occurs past this oxidized nucleoside base.« less

  13. Localized gravity in string theory.

    PubMed

    Karch, A; Randall, L

    2001-08-06

    We propose a string realization of the AdS4 brane in AdS5 that is known to localize gravity. Our theory is M D5 branes in the near horizon geometry of N D3 branes, where M and N are appropriately tuned.

  14. 21 CFR 74.2307 - D&C Red No. 7

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2307 D&C Red No. 7 (a) Identity and specifications. The color additive D&C Red No. 7 shall conform in identity and specifications to the requirements of § 74.1307 (a)(1) and (b). (b) Uses and restrictions. The color additive D&C Red No. 7 may be safely used for...

  15. 21 CFR 74.2307 - D&C Red No. 7

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2307 D&C Red No. 7 (a) Identity and specifications. The color additive D&C Red No. 7 shall conform in identity and specifications to the requirements of § 74.1307 (a)(1) and (b). (b) Uses and restrictions. The color additive D&C Red No. 7 may be safely used for...

  16. 21 CFR 74.2307 - D&C Red No. 7

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2307 D&C Red No. 7 (a) Identity and specifications. The color additive D&C Red No. 7 shall conform in identity and specifications to the requirements of § 74.1307 (a)(1) and (b). (b) Uses and restrictions. The color additive D&C Red No. 7 may be safely used for...

  17. 21 CFR 74.2307 - D&C Red No. 7

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2307 D&C Red No. 7 (a) Identity and specifications. The color additive D&C Red No. 7 shall conform in identity and specifications to the requirements of § 74.1307 (a)(1) and (b). (b) Uses and restrictions. The color additive D&C Red No. 7 may be safely used for...

  18. On a boundary-localized Higgs boson in 5D theories.

    PubMed

    Barceló, Roberto; Mitra, Subhadip; Moreau, Grégory

    In the context of a simple five-dimensional (5D) model with bulk matter coupled to a brane-localized Higgs boson, we point out a non-commutativity in the 4D calculation of the mass spectrum for excited fermion towers: the obtained expression depends on the choice in ordering the limits, [Formula: see text] (infinite Kaluza-Klein tower) and [Formula: see text] ([Formula: see text] being the parameter introduced for regularizing the Higgs Dirac peak). This introduces the question of which one is the correct order; we then show that the two possible orders of regularization (called I and II) are experimentally equivalent, as both can typically reproduce the measured observables, but that the one with less degrees of freedom (I) could be uniquely excluded by future experimental constraints. This conclusion is based on the exact matching between the 4D and 5D analytical calculations of the mass spectrum - via regularizations of type I and II. Beyond a deeper insight into the Higgs peak regularizations, this matching brings another confirmation of the validity of the 5D mixed formalism. All the conclusions, deduced from regularizing the Higgs peak through a brane shift or a smoothed square profile, are expected to remain similar in realistic models with a warped extra-dimension. The complementary result of the study is that the non-commutativity disappears, both in the 4D and the 5D calculations, in the presence of higher order derivative operators. For clarity, the 4D and 5D analytical calculations, matching with each other, are presented in the first part of the paper, while the second part is devoted to the interpretation of the results.

  19. Enhanced peculiar velocities in brane-induced gravity

    NASA Astrophysics Data System (ADS)

    Wyman, Mark; Khoury, Justin

    2010-08-01

    The mounting evidence for anomalously large peculiar velocities in our Universe presents a challenge for the ΛCDM paradigm. The recent estimates of the large-scale bulk flow by Watkins et al. are inconsistent at the nearly 3σ level with ΛCDM predictions. Meanwhile, Lee and Komatsu have recently estimated that the occurrence of high-velocity merging systems such as the bullet cluster (1E0657-57) is unlikely at a 6.5-5.8σ level, with an estimated probability between 3.3×10-11 and 3.6×10-9 in ΛCDM cosmology. We show that these anomalies are alleviated in a broad class of infrared-modifed gravity theories, called brane-induced gravity, in which gravity becomes higher-dimensional at ultralarge distances. These theories include additional scalar forces that enhance gravitational attraction and therefore speed up structure formation at late times and on sufficiently large scales. The peculiar velocities are enhanced by 24-34% compared to standard gravity, with the maximal enhancement nearly consistent at the 2σ level with bulk flow observations. The occurrence of the bullet cluster in these theories is ≈104 times more probable than in ΛCDM cosmology.

  20. Short alleles revealed by PCR demonstrate no heterozygote deficiency at minisatellite loci D1S7, D7S21, and D12S11

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Alonso, S.; Castro, A.; Fernandez-Fernandez, I.

    1997-02-01

    Short VNTR alleles that go undetected after conventional Southern blot hybridization may constitute an alternative explanation for the heterozygosity deficiency observed at some minisatellite loci. To examine this hypothesis, we have employed a screening procedure based on PCR amplification of those individuals classified as homozygotes in our databases for the loci D1S7, D7S21, and D12S11. The results obtained indicate that the frequency of these short alleles is related to the heterozygosity deficiency observed. For the most polymorphic locus, D1S7, {approximately}60% of those individuals previously classified as homozygotes were in fact heterozygotes for a short allele. After the inclusion of thesemore » new alleles, the agreement between observed and expected heterozygosity, along with other statistical tests employed, provide additional evidence for lack of population substructuring. Comparisons of allele frequency distributions reveal greater differences between racial groups than between closely related populations. 45 refs., 3 figs., 6 tabs.« less

  1. 7 CFR 15d.2 - Discrimination prohibited.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 1 2014-01-01 2014-01-01 false Discrimination prohibited. 15d.2 Section 15d.2... THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.2 Discrimination prohibited. (a) No agency, officer... participation in, deny the benefits of, or subject to discrimination any person in the United States under any...

  2. 7 CFR 15d.2 - Discrimination prohibited.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Discrimination prohibited. 15d.2 Section 15d.2... THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.2 Discrimination prohibited. (a) No agency, officer... participation in, deny the benefits of, or subject to discrimination any person in the United States under any...

  3. 7 CFR 15d.2 - Discrimination prohibited.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Discrimination prohibited. 15d.2 Section 15d.2... THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.2 Discrimination prohibited. (a) No agency, officer... participation in, deny the benefits of, or subject to discrimination any person in the United States under any...

  4. 7 CFR 15d.2 - Discrimination prohibited.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Discrimination prohibited. 15d.2 Section 15d.2... THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.2 Discrimination prohibited. (a) No agency, officer... participation in, deny the benefits of, or subject to discrimination any person in the United States under any...

  5. 7 CFR 15d.2 - Discrimination prohibited.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Discrimination prohibited. 15d.2 Section 15d.2... THE UNITED STATES DEPARTMENT OF AGRICULTURE § 15d.2 Discrimination prohibited. (a) No agency, officer... participation in, deny the benefits of, or subject to discrimination any person in the United States under any...

  6. Large field inflation from axion mixing

    NASA Astrophysics Data System (ADS)

    Shiu, Gary; Staessens, Wieland; Ye, Fang

    2015-06-01

    We study the general multi-axion systems, focusing on the possibility of large field inflation driven by axions. We find that through axion mixing from a non-diagonal metric on the moduli space and/or from Stückelberg coupling to a U(1) gauge field, an effectively super-Planckian decay constant can be generated without the need of "alignment" in the axion decay constants. We also investigate the consistency conditions related to the gauge symmetries in the multi-axion systems, such as vanishing gauge anomalies and the potential presence of generalized Chern-Simons terms. Our scenario applies generally to field theory models whose axion periodicities are intrinsically sub-Planckian, but it is most naturally realized in string theory. The types of axion mixings invoked in our scenario appear quite commonly in D-brane models, and we present its implementation in type II superstring theory. Explicit stringy models exhibiting all the characteristics of our ideas are constructed within the frameworks of Type IIA intersecting D6-brane models on and Type IIB intersecting D7-brane models on Swiss-Cheese Calabi-Yau orientifolds.

  7. Taub-NUT Spacetime in the (A)dS/CFT and M-Theory [electronic resource

    NASA Astrophysics Data System (ADS)

    Clarkson, Richard

    In the following thesis, I will conduct a thermodynamic analysis of the Taub-NUT spacetime in various dimensions, as well as show uses for Taub-NUT and other Hyper-Kahler spacetimes. Thermodynamic analysis (by which I mean the calculation of the entropy and other thermodynamic quantities, and the analysis of these quantities) has in the past been done by use of background subtraction. The recent derivation of the (A)dS/CFT correspondences from String theory has allowed for easier and quicker analysis. I will use Taub-NUT space as a template to test these correspondences against the standard thermodynamic calculations (via the N?ether method), with (in the Taub-NUT-dS case especially) some very interesting results. There is also interest in obtaining metrics in eleven dimensions that can be reduced down to ten dimensional string theory metrics. Taub-NUT and other Hyper-Kahler metrics already possess the form to easily facilitate the Kaluza-Klein reduction, and embedding such metricsinto eleven dimensional metrics containing M2 or M5 branes produces metrics with interesting Dp-brane results.

  8. DOE Office of Scientific and Technical Information (OSTI.GOV)

    McGreevy, John Austen; /Stanford U., Phys. Dept.

    This thesis is a study of D-branes in string compactifications. In this context, D-branes are relevant as an important component of the nonperturbative spectrum, as an incisive probe of these backgrounds, and as a natural stringy tool for localizing gauge interactions. In the first part of the thesis, we discuss half-BPS D-branes in compactifications of type II string theory on Calabi-Yau threefolds. The results we describe for these objects are pertinent both in their role as stringy brane-worlds, and in their role as solitonic objects. In particular, we determine couplings of these branes to the moduli determining the closed-string geometry,more » both perturbatively and non-perturbatively in the worldsheet expansion. We provide a local model for transitions in moduli space where the BPS spectrum jumps, and discuss the extension of mirror symmetry between Calabi-Yau manifolds to the case when D-branes are present. The next section is an interlude which provides some applications of D-branes to other curved backgrounds of string theory. In particular, we discuss a surprising phenomenon in which fundamental strings moving through background Ramond-Ramond fields dissolve into large spherical D3-branes. This mechanism is used to explain a previously-mysterious fact discovered via the AdS-CFT correspondence. Next, we make a connection between type IIA string vacua of the type discussed in the first section and M-theory compactifications on manifolds of G{sub 2} holonomy. Finally we discuss constructions of string vacua which do not have large radius limits. In the final part of the thesis, we develop techniques for studying the worldsheets of open strings ending on the curved D-branes studied in the first section. More precisely, we formulate a large class of massive two-dimensional gauge theories coupled to boundary matter, which flow in the infrared to the relevant boundary conformal field theories. Along with many other applications, these techniques are used to

  9. U(1){sub R} mediation from the flux compactification in six dimensions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, Hyun Min

    We consider a supersymmetric completion of codimension-two branes with nonzero tension in a 6D gauged supergravity. As a consequence, we obtain the football solution with 4D Minkowski space as a new supersymmetric background that preserves 4D N = 1 SUSY. In the presence of brane multiplets, we derive the 4D effective supergravity action for the football background and show that the remaining modulus can be stabilized by a bulk non-perturbative correction with brane uplifting potentials at a zero vacuum energy. We find that the U(1){sub R} mediation can be a dominant source of SUSY breaking for a brane scalar withmore » nonzero R charge.« less

  10. Equivalence of several descriptions for 6d SCFT

    NASA Astrophysics Data System (ADS)

    Hayashi, Hirotaka; Kim, Sung-Soo; Lee, Kimyeong; Yagi, Futoshi

    2017-01-01

    We show that the three different looking BPS partition functions, namely the elliptic genus of the 6d N=(1, 0) Sp(1) gauge theory with 10 flavors and a tensor multiplet, the Nekrasov partition function of the 5d N=1 Sp(2) gauge theory with 10 flavors, and the Nekrasov partition function of the 5d N=1 SU(3) gauge theory with 10 flavors, are all equal to each other under specific maps among gauge theory parameters. This result strongly suggests that the three gauge theories have an identical UV fixed point. Type IIB 5-brane web diagrams play an essential role to compute the SU(3) Nekrasov partition function as well as establishing the maps.

  11. Wind Ressources in Complex Terrain investigated with Synchronized Lidar Measurements

    NASA Astrophysics Data System (ADS)

    Mann, J.; Menke, R.; Vasiljevic, N.

    2017-12-01

    The Perdigao experiment was performed by a number of European and American universities in Portugal 2017, and it is probably the largest field campaign focussing on wind energy ressources in complex terrain ever conducted. 186 sonic anemometers on 50 masts, 20 scanning wind lidars and a host of other instruments were deployed. The experiment is a part of an effort to make a new European wind atlas. In this presentation we investigate whether scanning the wind speed over ridges in this complex terrain with multiple Doppler lidars can lead to an efficient mapping of the wind resources at relevant positions. We do that by having pairs of Doppler lidars scanning 80 m above the ridges in Perdigao. We compare wind resources obtained from the lidars and from the mast-mounted sonic anemometers at 80 m on two 100 m masts, one on each of the two ridges. In addition, the scanning lidar measurements are also compared to profiling lidars on the ridges. We take into account the fact that the profiling lidars may be biased due to the curvature of the streamlines over the instrument, see Bingol et al, Meteorolog. Z. vol. 18, pp. 189-195 (2009). We also investigate the impact of interruptions of the lidar measurements on the estimated wind resource. We calculate the relative differences of wind along the ridge from the lidar measurements and compare those to the same obtained from various micro-scale models. A particular subject investigated is how stability affects the wind resources. We often observe internal gravity waves with the scanning lidars during the night and we quantify how these affect the relative wind speed on the ridges.

  12. 7 CFR 993.21d - Reserve prunes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Reserve prunes. 993.21d Section 993.21d Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE DRIED PRUNES PRODUCED IN CALIFORNIA...

  13. 7 CFR 993.21d - Reserve prunes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Reserve prunes. 993.21d Section 993.21d Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE DRIED PRUNES PRODUCED IN CALIFORNIA...

  14. 7 CFR 993.21d - Reserve prunes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Reserve prunes. 993.21d Section 993.21d Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE DRIED PRUNES PRODUCED IN CALIFORNIA...

  15. 7 CFR 993.21d - Reserve prunes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Reserve prunes. 993.21d Section 993.21d Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE DRIED PRUNES PRODUCED IN CALIFORNIA...

  16. A microscopic description of black hole evaporation via holography

    DOE PAGES

    Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan

    2016-07-19

    Here, we propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically close to thermal when the black hole is large. The black hole, while initially cold, gradually becomes an extremely hot and stringy object as it evaporates. As it emits D0-branes, its emission rate speeds up and it evaporates completely without leaving any remnant. Hence this system provides us with a concrete holographic description of black hole evaporation without information loss.

  17. A microscopic description of black hole evaporation via holography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan

    Here, we propose a description of how a large, cold black hole (black zero-brane) in type IIA superstring theory evaporates into freely propagating D0-branes, by solving the dual gauge theory quantitatively. The energy spectrum of emitted D0-branes is parametrically close to thermal when the black hole is large. The black hole, while initially cold, gradually becomes an extremely hot and stringy object as it evaporates. As it emits D0-branes, its emission rate speeds up and it evaporates completely without leaving any remnant. Hence this system provides us with a concrete holographic description of black hole evaporation without information loss.

  18. Enhanced peculiar velocities in brane-induced gravity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wyman, Mark; Khoury, Justin

    The mounting evidence for anomalously large peculiar velocities in our Universe presents a challenge for the {Lambda}CDM paradigm. The recent estimates of the large-scale bulk flow by Watkins et al. are inconsistent at the nearly 3{sigma} level with {Lambda}CDM predictions. Meanwhile, Lee and Komatsu have recently estimated that the occurrence of high-velocity merging systems such as the bullet cluster (1E0657-57) is unlikely at a 6.5-5.8{sigma} level, with an estimated probability between 3.3x10{sup -11} and 3.6x10{sup -9} in {Lambda}CDM cosmology. We show that these anomalies are alleviated in a broad class of infrared-modifed gravity theories, called brane-induced gravity, in which gravitymore » becomes higher-dimensional at ultralarge distances. These theories include additional scalar forces that enhance gravitational attraction and therefore speed up structure formation at late times and on sufficiently large scales. The peculiar velocities are enhanced by 24-34% compared to standard gravity, with the maximal enhancement nearly consistent at the 2{sigma} level with bulk flow observations. The occurrence of the bullet cluster in these theories is {approx_equal}10{sup 4} times more probable than in {Lambda}CDM cosmology.« less

  19. Evolutionary dynamics of HBV-D7 subgenotype in Tunisia.

    PubMed

    Ciccozzi, Massimo; Chaouch, Houda; Lo Presti, Alessandra; Taffon, Stefania; Villano, Umbertina; Equestre, Michele; Bruni, Roberto; Marcantonio, Cinzia; Tritarelli, Elena; Cella, Eleonora; Blasi, Aletheia; Aouni, Mahjoub; Letaief, Amel; Ciccaglione, Anna Rita

    2017-03-01

    Hepatitis B virus (HBV) is the main cause of diseases liver related infecting more than 200 milion persons worldwide. HBV infection shows high level of prevalence in South-East Europe and in Mediterranean basin. In Tunisia, a country with an intermediate level endemicity, HbsAg prevalence ranges from 2 to 5%. Most of the HBV isolates from Tunisia were classified as subgenotype D7 whose circulation is restricted to a specific area of North Africa including Maghreb region. In this paper, the phylogeny of HBV-D7 isolated from 38 Tunisian patients was investigated by analyzing the S gene region of HBV. A Bayesian coalescent-based framework was used to estimate the origin of the HBV-D7 in the country. The Tunisian D7 isolates were found to share a common ancestor whose origin was traced back to 1958. Population dynamics indicated that HBV-D7 epidemic in Tunisia grew exponentially from 1960s to 1990s. After that, the curve reached a plateau around the years 2000 likely due to the implementation of the infant vaccination program in 1996. Epidemiological data suggested that the exponential growth phase was likely sustained by intra-familial transmission events occurring during infancy. Further characterization of HBV-D7 isolates should be performed to evaluate, in the post-vaccination era, the emergence of new transmission routes, and to monitor the efficacy of the vaccination program. J. Med. Virol. 89:469-475, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. FUN3D Manual: 12.7

    NASA Technical Reports Server (NTRS)

    Biedron, Robert T.; Carlson, Jan-Renee; Derlaga, Joseph M.; Gnoffo, Peter A.; Hammond, Dana P.; Jones, William T.; Kleb, Bil; Lee-Rausch, Elizabeth M.; Nielsen, Eric J.; Park, Michael A.; hide

    2015-01-01

    This manual describes the installation and execution of FUN3D version 12.7, including optional dependent packages. FUN3D is a suite of computational fluid dynamics simulation and design tools that uses mixed-element unstructured grids in a large number of formats, including structured multiblock and overset grid systems. A discretely-exact adjoint solver enables efficient gradient-based design and grid adaptation to reduce estimated discretization error. FUN3D is available with and without a reacting, real-gas capability. This generic gas option is available only for those persons that qualify for its beta release status.

  1. 21 CFR 74.2707 - D&C Yellow No. 7.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2707 D&C Yellow No. 7. (a) Identity and specifications. The color additive D&C Yellow No. 7 shall conform in identity and specifications to the requirements... coloring externally applied cosmetics in amounts consistent with good manufacturing practice. (c) Labeling...

  2. 21 CFR 74.2707 - D&C Yellow No. 7.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2707 D&C Yellow No. 7. (a) Identity and specifications. The color additive D&C Yellow No. 7 shall conform in identity and specifications to the requirements... coloring externally applied cosmetics in amounts consistent with good manufacturing practice. (c) Labeling...

  3. 21 CFR 74.2707 - D&C Yellow No. 7.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2707 D&C Yellow No. 7. (a) Identity and specifications. The color additive D&C Yellow No. 7 shall conform in identity and specifications to the requirements... coloring externally applied cosmetics in amounts consistent with good manufacturing practice. (c) Labeling...

  4. 21 CFR 74.2707 - D&C Yellow No. 7.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2707 D&C Yellow No. 7. (a) Identity and specifications. The color additive D&C Yellow No. 7 shall conform in identity and specifications to the requirements... coloring externally applied cosmetics in amounts consistent with good manufacturing practice. (c) Labeling...

  5. Non-perturbative effects and wall-crossing from topological strings

    NASA Astrophysics Data System (ADS)

    Collinucci, Andrés; Soler, Pablo; Uranga, Angel M.

    2009-11-01

    We argue that the Gopakumar-Vafa interpretation of the topological string partition function can be used to compute and resum certain non-perturbative brane instanton effects of type II CY compactifications. In particular the topological string A-model encodes the non-perturbative corrections to the hypermultiplet moduli space metric from general D1/D(-1)-brane instantons in 4d Script N = 2 IIB models. We also discuss the reduction to 4d Script N = 1 by fluxes and/or orientifolds and/or D-branes, and the prospects to resum brane instanton contributions to non-perturbative superpotentials. We argue that the connection between non-perturbative effects and the topological string underlies the continuity of non-perturbative effects across lines of BPS stability. We also confirm this statement in mirror B-model matrix model examples, relating matrix model instantons to non-perturbative D-brane instantons. The computation of non-perturbative effects from the topological string requires a 3d circle compactification and T-duality, relating effects from particles and instantons, reminiscent of that involved in the physical derivation of the Kontsevich-Soibelmann wall-crossing formula.

  6. 7 CFR 993.21d - Reserve prunes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Reserve prunes. 993.21d Section 993.21d Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... percentage established by the Secretary pursuant to § 993.54. [30 FR 9798, Aug. 6, 1965] Effective Date Note...

  7. Emergent dimensions and branes from large-N confinement

    NASA Astrophysics Data System (ADS)

    Cherman, Aleksey; Poppitz, Erich

    2016-12-01

    N =1 S U (N ) super-Yang-Mills theory on R3×S1 is believed to have a smooth dependence on the circle size L . Making L small leads to calculable nonperturbative color confinement, mass gap, and string tensions. For finite N , the small-L low-energy dynamics is described by a three-dimensional effective theory. The large-N limit, however, reveals surprises: the infrared dual description is in terms of a theory with an emergent fourth dimension, curiously reminiscent of T-duality in string theory. Here, however, the emergent dimension is a lattice, with momenta related to the S1-winding of the gauge field holonomy, which takes values in ZN. Furthermore, the low-energy description is given by a nontrivial gapless theory, with a space-like z =2 Lifshitz scale invariance and operators that pick up anomalous dimensions as L is increased. Supersymmetry-breaking deformations leave the long-distance theory scale-invariant, but change the Lifshitz scaling exponent to z =1 , and lead to an emergent Lorentz symmetry at small L . Adding a small number of fundamental fermion fields leads to matter localized on three-dimensional branes in the emergent four-dimensional theory.

  8. World sheet instantons via the Myers effect and Script N = 1* quiver superpotentials

    NASA Astrophysics Data System (ADS)

    Hollowood, Timothy J.; Kumar, S. Prem

    2002-10-01

    In this note we explore the stringy interpretation of non-perturbative effects in Script N = 1* deformations of the Ak-1 quiver models. For certain types of deformations we argue that the massive vacua are described by Nk fractional D3-branes at the orbifold polarizing into k concentric 5-brane spheres each carrying fractional brane charge. The polarization of the D3-branes induces a polarization of D-instantons into string world-sheets wrapped on the Myers spheres. We show that the superpotentials in these models are indeed generated by these world-sheet instantons. We point out that for certain parameter values the condensates yield the exact superpotential for a relevant deformation of the Klebanov-Witten conifold theory.

  9. Perturbations and moduli space dynamics of tachyon kinks

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hindmarsh, Mark; Li Huiquan

    2008-03-15

    The dynamic process of unstable D-branes decaying into stable ones with one dimension lower can be described by a tachyon field with a Dirac-Born-Infeld effective action. In this paper we investigate the fluctuation modes of the tachyon field around a two-parameter family of static solutions representing an array of brane-antibrane pairs. Besides a pair of zero modes associated with the parameters of the solution, and instabilities associated with annihilation of the brane-antibrane pairs, we find states corresponding to excitations of the tachyon field around the brane and in the bulk. In the limit that the brane thickness tends to zero,more » the support of the eigenmodes is limited to the brane, consistent with the idea that propagating tachyon modes drop out of the spectrum as the tachyon field approaches its ground state. The zero modes, and other low-lying excited states, show a fourfold degeneracy in this limit, which can be identified with some of the massless superstring modes in the brane-antibrane system. Finally, we also discuss the slow motion of the solution corresponding to the decay process in the moduli space, finding a trajectory which oscillates periodically between the unstable D-brane and the brane-antibrane pairs of one dimension lower.« less

  10. Contractions of AdS brane algebra and superGalileon Lagrangians

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kamimura, Kiyoshi; Onda, Seiji

    2013-06-15

    We examine AdS Galileon Lagrangians using the method of nonlinear realization. By contractions (1) flat curvature limit, (2) non-relativistic brane algebra limit, and (3) (1) + (2) limits we obtain DBI, Newton-Hoock, and Galilean Galileons, respectively. We make clear how these Lagrangians appear as invariant 4-forms and/or pseudo-invariant Wess-Zumino (WZ) terms using Maurer-Cartan (MC) equations on the coset G/SO(3, 1). We show the equations of motion are written in terms of the MC forms only and explain why the inverse Higgs condition is obtained as the equation of motion for all cases. The supersymmetric extension is also examined using amore » supercoset SU(2, 2 Double-Vertical-Line 1)/(SO(3, 1) Multiplication-Sign U(1)) and five WZ forms are constructed. They are reduced to the corresponding five Galileon WZ forms in the bosonic limit and are candidates for supersymmetric Galileon action.« less

  11. Singular gauge transformation and the Erler-Maccaferri solution in bosonic open string field theory

    NASA Astrophysics Data System (ADS)

    Miwa, Akitsugu; Sugita, Kazuhiro

    2017-09-01

    We study candidate multiple-brane solutions of bosonic open string field theory. They are constructed by performing a singular gauge transformation n times for the Erler-Maccaferri solution. We check the equation of motion in the strong sense, and find that it is satisfied only when we perform the gauge transformation once. We calculate the energy for that case and obtain a support that the solution is a multiple-brane solution. We also check the tachyon profile for a specific solution that we interpret as describing a D24-brane placed on a D25-brane.

  12. Brane SUSY breaking and the gravitino mass

    NASA Astrophysics Data System (ADS)

    Kitazawa, Noriaki

    2018-04-01

    Supergravity models with spontaneously broken supersymmetry have been widely investigated over the years, together with some notable non-linear limits. Although in these models the gravitino becomes naturally massive absorbing the degrees of freedom of a Nambu-Goldstone fermion, there are cases in which the naive counting of degrees of freedom does not apply, in particular because of the absence of explicit gravitino mass terms in unitary gauge. The corresponding models require non-trivial de Sitter-like backgrounds, and it becomes of interest to clarify the fate of their Nambu-Goldstone modes. We elaborate on the fact that these non-trivial backgrounds can accommodate, consistently, gravitino fields carrying a number of degrees of freedom that is intermediate between those of massless and massive fields in a flat spacetime. For instance, in a simple supergravity model of this type with de Sitter background, the overall degrees of freedom of gravitino are as many as for a massive spin-3/2 field in flat spacetime, while the gravitino remains massless in the sense that it undergoes null-cone propagation in the stereographic picture. On the other hand, in the ten-dimensional USp(32) Type I Sugimoto model with "brane SUSY breaking", which requires a more complicated background, the degrees of freedom of gravitino are half as many of those of a massive one, and yet it somehow behaves again as a massless one.

  13. 21 CFR 82.1307 - D&C Red No. 7.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false D&C Red No. 7. 82.1307 Section 82.1307 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF CERTIFIED...) and (b) of this chapter. (b) The color additive D&C Red No. 7 may be safely used for coloring drugs...

  14. 21 CFR 82.1307 - D&C Red No. 7.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false D&C Red No. 7. 82.1307 Section 82.1307 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF CERTIFIED...) and (b) of this chapter. (b) The color additive D&C Red No. 7 may be safely used for coloring drugs...

  15. Elliptic genus of E-strings

    NASA Astrophysics Data System (ADS)

    Kim, Joonho; Kim, Seok; Lee, Kimyeong; Park, Jaemo; Vafa, Cumrun

    2017-09-01

    We study a family of 2d N=(0, 4) gauge theories which describes at low energy the dynamics of E-strings, the M2-branes suspended between a pair of M5 and M9 branes. The gauge theory is engineered using a duality with type IIA theory, leading to the D2-branes suspended between an NS5-brane and 8 D8-branes on an O8-plane. We compute the elliptic genus of this family of theories, and find agreement with the known results for single and two E-strings. The partition function can in principle be computed for arbitrary number of E-strings, and we compute them explicitly for low numbers. We test our predictions against the partially known results from topological strings, as well as from the instanton calculus of 5d Sp(1) gauge theory. Given the relation to topological strings, our computation provides the all genus partition function of the refined topological strings on the canonical bundle over 1/2K3.

  16. Do alien particles exist, and can they be detected?

    NASA Astrophysics Data System (ADS)

    Gasperini, M.

    2016-07-01

    We may call “alien particles” those particles belonging to the matter/field content of a d-dimensional brane other than the 3-brane (or stack of branes) sweeping the spacetime in which we live. They can appear in our spacetime at the regions of intersection between our and their brane. They can be identified (or not) as alien matter depending on their properties, on the physical laws governing their evolution in the “homeland” brane, and on the details of our detection techniques.

  17. Quantum gravity in the Southern Cone Conference. Proceedings. Conference, Bariloche (Argentina), 7 - 10 Jan 1998.

    NASA Astrophysics Data System (ADS)

    1999-04-01

    The following topics are discussed: Black hole formation by canonical dynamics of gravitating shells; canonical quantum gravity; Vassiliev invariants; midisuperspace models; quantum spacetime; large-N limit of superconformal field theories and supergravity; world-volume fields and background coupling of branes; gauge enhancement and chirality changes in nonperturbative orbifold models; chiral p-forms; formally renormalizable gravitationally self-interacting string models; gauge supergravities for all odd dimensions; black hole radiation and S-matrix; primordial black holes; fluctuations in a thermal field and dissipation of a black hole spacetime in far-field limit; adiabatic interpretation of particle creation in a de Sitter universe; nonequilibrium dynamics of quantum fields in inflationary cosmology; magnetic fields in the early Universe; classical regime of a quantum universe obtained through a functional method; decoherence and correlations in semiclassical cosmology; fluid of primordial fluctuations; causal statistical mechanics calculation of initial cosmic entropy and quantum gravity prospects and black hole-D-brane correspondence.

  18. Long-range magnetic order in the Heisenberg pyrochlore antiferromagnets G d2G e2O7 and G d2P t2O7 synthesized under high pressure

    NASA Astrophysics Data System (ADS)

    Li, X.; Cai, Y. Q.; Cui, Q.; Lin, C. J.; Dun, Z. L.; Matsubayashi, K.; Uwatoko, Y.; Sato, Y.; Kawae, T.; Lv, S. J.; Jin, C. Q.; Zhou, J.-S.; Goodenough, J. B.; Zhou, H. D.; Cheng, J.-G.

    2016-12-01

    G d2S n2O7 and G d2T i2O7 have been regarded as good experimental realizations of the classical Heisenberg pyrochlore antiferromagnet with dipolar interaction. The former was found to adopt the Palmer-Chalker state via a single, first-order transition at TN≈1 K , while the latter enters a distinct, partially ordered state through two successive transitions at TN 1≈1 K and TN 2= 0.75 K . To shed more light on their distinct magnetic ground states, we have synthesized two more gadolinium-based pyrochlore oxides, G d2G e2O7 and G d2P t2O7 , under high-pressure conditions and performed detailed characterizations via x-ray powder diffraction, dc and ac magnetic susceptibility, and specific heat measurements down to 100 mK. We found that both compounds enter a long-range antiferromagnetically ordered state through a single, first-order transition at TN= 1.4 K for G d2G e2O7 and TN= 1.56 K for G d2P t2O7 , with the specific heat anomaly similar to that of G d2S n2O7 rather than G d2T i2O7 . Interestingly, the low-temperature magnetic specific heat values of both G d2G e2O7 and G d2P t2O7 were found to follow nicely the T3 dependence as expected for a three-dimensional antiferromagnet with gapless spin-wave excitations. We have rationalized the enhancement of TN in terms of the reduced Gd-Gd distances for the chemically pressurized G d2G e2O7 and the addition of extra superexchange pathways through the empty Pt -eg orbitals for G d2P t2O7 . Our current study has expanded the family of gadolinium-based pyrochlores and permits us to achieve a better understanding of their distinct magnetic properties in a more comprehensive perspective.

  19. Dopamine D4 receptor, but not the ADHD-associated D4.7 variant, forms functional heteromers with the dopamine D2S receptor in the brain

    PubMed Central

    González, Sergio; Rangel-Barajas, Claudia; Peper, Marcela; Lorenzo, Ramiro; Moreno, Estefanía; Ciruela, Francisco; Borycz, Janusz; Ortiz, Jordi; Lluís, Carme; Franco, Rafael; McCormick, Peter J.; Volkow, Nora D.; Rubinstein, Marcelo; Floran, Benjamin; Ferré, Sergi

    2011-01-01

    Polymorphic variants of the dopamine D4 receptor have been consistently associated with attention-deficit hyperactivity disorder (ADHD). However the functional significance of the risk polymorphism (variable number of tandem repeats in exon 3) is still unclear. Here we show that whereas the most frequent 4-repeat (D4.4) and the 2-repeat (D4.2) variants form functional heteromers with the short isoform of the dopamine D2 receptor (D2S), the 7-repeat risk allele (D4.7) does not. D2 receptor activation in the D2S-D4 receptor heteromer potentiates D4 receptor-mediated MAPK signaling in transfected cells and in the striatum, which did not occur in cells expressing D4.7 or in the striatum of knock-in mutant mice carrying the 7 repeats of the human D4.7 in the third intracellular loop of the D4 receptor. In the striatum D4 receptors are localized in cortico-striatal glutamatergic terminals, where they selectively modulate glutamatergic neurotransmission by interacting with D2S receptors. This interaction shows the same qualitative characteristics than the D2S-D4 receptor heteromer-mediated MAPK signaling and D2S receptor activation potentiates D4 receptor-mediated inibition of striatal glutamate release. It is therefore postulated that dysfunctional D2S-D4.7 heteromers may impair presynaptic dopaminergic control of corticostriatal glutamatergic neurotransmission and explain functional deficits associated with ADHD. PMID:21844870

  20. 7 CFR 29.3018 - Dark red color (D).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Dark red color (D). 29.3018 Section 29.3018 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Type 93) § 29.3018 Dark red color (D). A dark reddish brown. [24 FR 8771, Oct. 29, 1959. Redesignated...

  1. 7 CFR 29.3018 - Dark red color (D).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Dark red color (D). 29.3018 Section 29.3018 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Type 93) § 29.3018 Dark red color (D). A dark reddish brown. [24 FR 8771, Oct. 29, 1959. Redesignated...

  2. 7 CFR 29.3018 - Dark red color (D).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Dark red color (D). 29.3018 Section 29.3018 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Type 93) § 29.3018 Dark red color (D). A dark reddish brown. [24 FR 8771, Oct. 29, 1959. Redesignated...

  3. 7 CFR 29.3018 - Dark red color (D).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Dark red color (D). 29.3018 Section 29.3018 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Type 93) § 29.3018 Dark red color (D). A dark reddish brown. [24 FR 8771, Oct. 29, 1959. Redesignated...

  4. 7 CFR 29.3018 - Dark red color (D).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Dark red color (D). 29.3018 Section 29.3018 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Type 93) § 29.3018 Dark red color (D). A dark reddish brown. [24 FR 8771, Oct. 29, 1959. Redesignated...

  5. dSAP18 and dHDAC1 contribute to the functional regulation of the Drosophila Fab-7 element.

    PubMed

    Canudas, Silvia; Pérez, Silvia; Fanti, Laura; Pimpinelli, Sergio; Singh, Navjot; Hanes, Steven D; Azorín, Fernando; Espinás, M Lluïsa

    2005-01-01

    It was described earlier that the Drosophila GAGA factor [Trithorax-like (Trl)] interacts with dSAP18, which, in mammals, was reported to be a component of the Sin3-HDAC co-repressor complex. GAGA-dSAP18 interaction was proposed to contribute to the functional regulation of the bithorax complex (BX-C). Here, we show that mutant alleles of Trl, dsap18 and drpd3/hdac1 enhance A6-to-A5 transformation indicating a contribution to the regulation of Abd-B expression at A6. In A6, expression of Abd-B is driven by the iab-6 enhancer, which is insulated from iab-7 by the Fab-7 element. Here, we report that GAGA, dSAP18 and dRPD3/HDAC1 co-localize to ectopic Fab-7 sites in polytene chromosomes and that mutant Trl, dsap18 and drpd3/hdac1 alleles affect Fab-7-dependent silencing. Consistent with these findings, chromatin immunoprecipitation analysis shows that, in Drosophila embryos, the endogenous Fab-7 element is hypoacetylated at histones H3 and H4. These results indicate a contribution of GAGA, dSAP18 and dRPD3/HDAC1 to the regulation of Fab-7 function.

  6. Vacuum polarization effects on flat branes due to a global monopole

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bezerra de Mello, E.R.

    2006-05-15

    In this paper we analyze the vacuum polarization effects associated with a massless scalar field in the higher-dimensional spacetime. Specifically we calculate the renormalized vacuum expectation value of the square of the field, <{phi}{sup 2}(x)>{sub Ren}, induced by a global monopole in the 'braneworld' scenario. In this context the global monopole lives in a n=3-dimensional submanifold of the higher-dimensional (bulk) spacetime, and our universe is represented by a transverse flat (p-1)-dimensional brane. In order to develop this analysis we calculate the general Green function admitting that the scalar field propagates in the bulk. Also a general curvature coupling parameter betweenmore » the field and the geometry is assumed. We explicitly show that the vacuum polarization effects depend crucially on the values attributed to p. We also investigate the general structure of the renormalized vacuum expectation value of the energy-momentum tensor, {sub Ren}, for p=3.« less

  7. A new synthesis of certain 7-(beta-D-ribofuranosyl) and 7-(2-deoxy-beta-D-ribofuranosyl) derivatives of 3-deazaguanine via the sodium salt glycosylation procedure.

    PubMed Central

    Gupta, P K; Robins, R K; Revankar, G R

    1985-01-01

    A facile synthesis of 7-beta-D-ribofuranosyl-3-deazaguanine (1) and certain 8-substituted derivatives of 1 via the sodium salt glycosylation method has been developed. Glycosylation of the sodium salt of methyl 2-chloro(or methylthio)-4(5)-cyanomethylimidazole-5(4)-carboxylate (5 and 13b) with 2,3,5-tri-O-benzoyl-D-ribofuranosyl bromide (6) gave exclusively methyl 2-chloro(or methylthio)-4-cyanomethyl-1-(2,3, 5-tri-O-benzoyl-beta-D-ribofuranosyl)imidazole-5-carboxylate (7 and 14a), respectively. Ammonolysis of 7 and 14a provided 6-amino-2-chloro(or methylthio)-3-beta-D-ribofuranosylimidazo-[4,5-c]pyridin-4(5H)-one (11 and 17), which on subsequent dehalogenation (or dethiation) gave 1. Similarly, reaction of the sodium salt of 5 and 13b with 1-chloro-2-deoxy-3,5-di-O-p-toluoyl-alpha-D-erythro-pentofuranose (8), and ammonolysis of the glycosylated imidazole precursors (9 and 16) gave 6-amino-2-chloro(or methylthio)-3-(2-deoxy-beta-D-erythro-pentofuranosyl) imidazo[4,5-c]-pyridin-4(5H)-one (10a and 15), respectively. Dehalogenation of 10a or dethiation of 15 gave 2'-deoxy-7-beta-D-ribofuranosyl-3-deazaguanine (10b). This procedure provided a direct method of obtaining 10b without the contaminating 9-glycosyl isomer 4. PMID:4022783

  8. Black hole acoustics in the minimal geometric deformation of a de Laval nozzle

    NASA Astrophysics Data System (ADS)

    da Rocha, Roldão

    2017-05-01

    The correspondence between sound waves, in a de Laval propelling nozzle, and quasinormal modes emitted by brane-world black holes deformed by a 5D bulk Weyl fluid are here explored and scrutinized. The analysis of sound waves patterns in a de Laval nozzle in the laboratory, reciprocally, is here shown to provide relevant data about the 5D bulk Weyl fluid and its on-brane projection, comprised by the minimal geometrically deformed compact stellar distribution on the brane. Acoustic perturbations of the gas fluid flow in the de Laval nozzle are proved to coincide with the quasinormal modes of black holes solutions deformed by the 5D Weyl fluid, in the geometric deformation procedure. Hence, in a phenomenological Eötvös-Friedmann fluid brane-world model, the realistic shape of a de Laval nozzle is derived and its consequences studied.

  9. Flowing BIon

    NASA Astrophysics Data System (ADS)

    Grignani, Gianluca; Harmark, Troels; Kift, Callum; Marini, Andrea; Orselli, Marta

    2017-11-01

    In this paper we use the effective blackfold description of branes to extend the study of the thermal BIon, a D-brane, and parallel anti-D-brane connected by a wormhole with F-string charge in hot flat space, by introducing a radial boost along the brane. The boosted system behaves qualitatively differently from both the extremal and the thermal BIon considered previously. Interestingly, we are able to formulate a first law of thermodynamics for the system as a whole, despite the fact that it is not a stationary blackfold. In particular, the global temperature is given by the rest frame temperature times the gamma factor of special relativity which is the inverse transformation compared to the case of stationary blackfolds. In addition we define two new kinds of thermodynamic conjugate variables, the energy flux W and the integrated velocity on the brane. We find that a phase transition occurs by varying the energy flux W . Below a critical value of W the brane separation Δ changes only slightly with W . Instead above the critical value Δ grows exponentially.

  10. On the role of mobile nanoclusters in 2D island nucleation on Si(111)-(7 × 7) surface

    NASA Astrophysics Data System (ADS)

    Rogilo, D. I.; Fedina, L. I.; Kosolobov, S. S.; Latyshev, A. V.

    2018-01-01

    Two-dimensional (2D) Si island nucleation has been studied by in situ reflection electron microscopy within a wide temperature range (650-1090 °C ) on large-scale (∼10-100 μm) terraces to exclude the impact of step permeability and adatom sink to steps. The dependence of 2D island concentration N2D on substrate temperature T and Si deposition rate R displays N2D∝Rχexp (E2D/kT) scaling which parameters change from χ≈0.81, E2D≈1.02 eV to χ≈0.5, E2D≈1.8 eV when Si(111) surface converts from (1 × 1) structure to (7 × 7) reconstruction. We propose that this strong E2D rise accompanied by χ reduction is caused by the change of dominating diffusing particles from adatoms to reconstruction induced nanoclusters. Using a rate-equation model developed to account the dynamics of both diffusing species on the Si(111)-(7 × 7) surface, we show that a stable nucleus of a 2D island appears when two mobile nanoclusters merge together while nucleation kinetics is limited by their attachment to island edges.

  11. 21 CFR 74.2707a - Ext. D&C Yellow No. 7.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... COLOR ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2707a Ext. D&C Yellow No. 7. (a) Identity and specifications. The color additive Ext. D&C Yellow No. 7 shall conform in identity and specifications to the... for coloring externally applied cosmetics in amounts consistent with good manufacturing practice. (c...

  12. 21 CFR 74.2707a - Ext. D&C Yellow No. 7.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... COLOR ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2707a Ext. D&C Yellow No. 7. (a) Identity and specifications. The color additive Ext. D&C Yellow No. 7 shall conform in identity and specifications to the... for coloring externally applied cosmetics in amounts consistent with good manufacturing practice. (c...

  13. 21 CFR 74.2707a - Ext. D&C Yellow No. 7.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... COLOR ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2707a Ext. D&C Yellow No. 7. (a) Identity and specifications. The color additive Ext. D&C Yellow No. 7 shall conform in identity and specifications to the... for coloring externally applied cosmetics in amounts consistent with good manufacturing practice. (c...

  14. 21 CFR 74.2707a - Ext. D&C Yellow No. 7.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... COLOR ADDITIVES SUBJECT TO CERTIFICATION Cosmetics § 74.2707a Ext. D&C Yellow No. 7. (a) Identity and specifications. The color additive Ext. D&C Yellow No. 7 shall conform in identity and specifications to the... for coloring externally applied cosmetics in amounts consistent with good manufacturing practice. (c...

  15. Prostaglandin F2α 7 d prior to initiation of the 7-d CO-synch + CIDR protocol failed to enhance estrus response and pregnancy rates in beef heifers.

    PubMed

    Oosthuizen, Nicola; Canal, Luara B; Fontes, Pedro L P; Sanford, Carla D; DiLorenzo, Nicolas; Dahlen, Carl R; Seidel, George E; Lamb, G Cliff

    2018-04-14

    To determine the effects of administration of 25 mg of PGF2α 7 d prior to the initiation of the 7-d CO-Synch + controlled internal drug release (CIDR) fixed-time AI (TAI) protocol, 985 Bos taurus beef heifers were enrolled in a completely randomized design at 9 locations from April to July of 2016. Within location, all heifers were randomly assigned to 1 of 2 treatments: 1) CONTROL (n = 496); 100 µg injection of GnRH and a CIDR insert for 7 d [day 7], administration of 25 mg of PGF2α at CIDR removal [day 0], followed by a second injection of GnRH and TAI 54 ± 2 h later; or 2) PRESYNCH (n = 489); same as CONTROL but heifers received an additional injection of 25 mg of PGF2α 7 d prior [day 14] to CIDR insertion. Estrous detection patches were applied to all heifers on day 14 and were evaluated for estrual activity on day 7. Similarly, estrus alert patches were placed on all heifers on day 0 and evaluated for estrual activity at the time of TAI. Pregnancy was diagnosed via transrectal ultrasonography between 35 and 55 d after TAI. The percentage of heifers exhibiting estrus between days 14 and 7 was greater (P < 0.001) for the PRESYNCH (70.1 ± 2.4%) than the CONTROL (41.1 ± 2.3%) treatment, whereas the percentage of heifers exhibiting estrus between day 0 and TAI was greater (P < 0.001) for the CONTROL (55.6 ± 2.4%) than the PRESYNCH (39.7 ± 2.5%) treatment. Estrus response rates differed (P < 0.001) among locations. Pregnancy rates to TAI differed (P = 0.023) among locations; however, they did not differ (P = 0.739) between CONTROL and PRESYNCH treatments (45.4 ± 2.5 vs. 43.2 ± 2.5%, respectively). Final breeding season pregnancy rates did not differ (P = 0.811) between treatments. Therefore, an injection of PGF2α 7 d prior to initiation of the 7-d CO-Synch + CIDR protocol failed to improve pregnancy rates to TAI in replacement beef heifers.

  16. K-theoretic aspects of string theory dualities

    NASA Astrophysics Data System (ADS)

    Mendez-Diez, Stefan Milo

    String theory is a a physical field theory in which point particles are replaced by 1-manifolds propagating in time, called strings. The 2-manifold representing the time evolution of a string is called the string worldsheet. Strings can be either closed (meaning their worldsheets are closed surfaces) or open (meaning their worldsheets have boundary). A D-brane is a submanifold of the spacetime manifold on which string endpoints are constrained to lie. There are five different string theories that have supersymmetry, and they are all related by various dualities. This dissertation will review how D-branes are classified by K-theory. We will then explore the K-theoretic aspects of a hypothesized duality between the type I theory compactified on a 4-torus and the type IIA theory compactified on a K3 surface, by looking at a certain blow down of the singular limit of K3. This dissertation concludes by classifying D-branes on the type II orientifold Tn/Z2 when the Z2 action is multiplication by -1 and the H-flux is trivial. We find that classifying D-branes on the singular limit of K3, T4/Z2 by equivariant K-theory agrees with the classification of D-branes on a smooth K3 surface by ordinary K-theory.

  17. Configurational entropy as a tool to select a physical thick brane model

    NASA Astrophysics Data System (ADS)

    Chinaglia, M.; Cruz, W. T.; Correa, R. A. C.; de Paula, W.; Moraes, P. H. R. S.

    2018-04-01

    We analize braneworld scenarios via a configurational entropy (CE) formalism. Braneworld scenarios have drawn attention mainly due to the fact that they can explain the hierarchy problem and unify the fundamental forces through a symmetry breaking procedure. Those scenarios localize matter in a (3 + 1) hypersurface, the brane, which is inserted in a higher dimensional space, the bulk. Novel analytical braneworld models, in which the warp factor depends on a free parameter n, were recently released in the literature. In this article we will provide a way to constrain this parameter through the relation between information and dynamics of a system described by the CE. We demonstrate that in some cases the CE is an important tool in order to provide the most probable physical system among all the possibilities. In addition, we show that the highest CE is correlated to a tachyonic sector of the configuration, where the solutions for the corresponding model are dynamically unstable.

  18. String theory origin of constrained multiplets

    NASA Astrophysics Data System (ADS)

    Kallosh, Renata; Vercnocke, Bert; Wrase, Timm

    2016-09-01

    We study the non-linearly realized spontaneously broken supersymmetry of the (anti-)D3-brane action in type IIB string theory. The worldvolume fields are one vector A μ , three complex scalars ϕ i and four 4d fermions λ 0, λ i. These transform, in addition to the more familiar {N}=4 linear supersymmetry, also under 16 spontaneously broken, non-linearly realized supersymmetries. We argue that the worldvolume fields can be packaged into the following constrained 4d non-linear {N}=1 multiplets: four chiral multiplets S, Y i that satisfy S 2 = SY i =0 and contain the worldvolume fermions λ 0 and λ i ; and four chiral multiplets W α , H i that satisfy S{W}_{α }=S{overline{D}}_{overset{\\cdotp }{α }}{overline{H}}^{overline{imath}}=0 and contain the vector A μ and the scalars ϕ i . We also discuss how placing an anti-D3-brane on top of intersecting O7-planes can lead to an orthogonal multiplet Φ that satisfies S(Φ -overline{Φ})=0 , which is particularly interesting for inflationary cosmology.

  19. 125 GeV Higgs boson mass and muon g 2 in 5D MSSM

    DOE PAGES

    Okada, Nobuchika; Tran, Hieu Minh

    2016-10-26

    In the minimal supersymmetric standard model (MSSM), the tension between the observed Higgs boson mass and the experimental result of the muon g-2 measurement requires a large mass splitting between stops and smuons/charginos/neutralinos. Here, we consider a five-dimensional (5D) framework of the MSSM with the Randall-Sundrum warped background metric, and show that such a mass hierarchy is naturally achieved in terms of geometry. In our setup, the supersymmetry is broken at the ultraviolet (UV) brane, while all the MSSM multiplets reside in the 5D bulk. An appropriate choice of the bulk mass parameters for the MSSM matter multiplets can naturallymore » realize the sparticle mass hierarchy desired to resolve the tension. Furthermore, the gravitino is localized at the UV brane and hence becomes very heavy, while the gauginos spreading over the bulk acquire their masses suppressed by the fifth dimensional volume. As a result, the lightest sparticle neutralino is a candidate for the dark matter as usual in the MSSM. In addition to reproducing the SM-like Higgs boson mass of around 125 GeV and the measured value of the muon g-2, we consider a variety of phenomenological constraints, and present the benchmark particle mass spectra that can be explored at the LHC Run-2 in the near future.« less

  20. Flowing holographic anyonic superfluid

    NASA Astrophysics Data System (ADS)

    Jokela, Niko; Lifschytz, Gilad; Lippert, Matthew

    2014-10-01

    We investigate the flow of a strongly coupled anyonic superfluid based on the holographic D3-D7' probe brane model. By analyzing the spectrum of fluctuations, we find the critical superfluid velocity, as a function of the temperature, at which the flow stops being dissipationless when flowing past a barrier. We find that at a larger velocity the flow becomes unstable even in the absence of a barrier.

  1. In vivo 1D and 2D correlation MR spectroscopy of the soleus muscle at 7T

    PubMed Central

    Ramadan, Saadallah; Ratai, Eva-Maria; Wald, Lawrence L.; Mountford, Carolyn E.

    2013-01-01

    Aim This study aims to (1) undertake and analyse 1D and 2D MR correlation spectroscopy from human soleus muscle in vivo at 7T, and (2) determine T1 and T2 relaxation time constants at 7T field strength due to their importance in sequence design and spectral quantitation. Method Six healthy, male volunteers were consented and scanned on a 7T whole-body scanner (Siemens AG, Erlangen, Germany). Experiments were undertaken using a 28 cm diameter detunable birdcage coil for signal excitation and an 8.5 cm diameter surface coil for signal reception. The relaxation time constants, T1 and T2 were recorded using a STEAM sequence, using the ‘progressive saturation’ method for the T1 and multiple echo times for T2. The 2D L-Correlated SpectroscopY (L-COSY) method was employed with 64 increments (0.4 ms increment size) and eight averages per scan, with a total time of 17 min. Results T1 and T2 values for the metabolites of interest were determined. The L-COSY spectra obtained from the soleus muscle provided information on lipid content and chemical structure not available, in vivo, at lower field strengths. All molecular fragments within multiple lipid compartments were chemically shifted by 0.20–0.26 ppm at this field strength. 1D and 2D L-COSY spectra were assigned and proton connectivities were confirmed with the 2D method. Conclusion In vivo 1D and 2D spectroscopic examination of muscle can be successfully recorded at 7T and is now available to assess lipid alterations as well as other metabolites present with disease. T1 and T2 values were also determined in soleus muscle of male healthy volunteers. PMID:20206561

  2. Evaluation of 3D-Jury on CASP7 models.

    PubMed

    Kaján, László; Rychlewski, Leszek

    2007-08-21

    3D-Jury, the structure prediction consensus method publicly available in the Meta Server http://meta.bioinfo.pl/, was evaluated using models gathered in the 7th round of the Critical Assessment of Techniques for Protein Structure Prediction (CASP7). 3D-Jury is an automated expert process that generates protein structure meta-predictions from sets of models obtained from partner servers. The performance of 3D-Jury was analysed for three aspects. First, we examined the correlation between the 3D-Jury score and a model quality measure: the number of correctly predicted residues. The 3D-Jury score was shown to correlate significantly with the number of correctly predicted residues, the correlation is good enough to be used for prediction. 3D-Jury was also found to improve upon the competing servers' choice of the best structure model in most cases. The value of the 3D-Jury score as a generic reliability measure was also examined. We found that the 3D-Jury score separates bad models from good models better than the reliability score of the original server in 27 cases and falls short of it in only 5 cases out of a total of 38. We report the release of a new Meta Server feature: instant 3D-Jury scoring of uploaded user models. The 3D-Jury score continues to be a good indicator of structural model quality. It also provides a generic reliability score, especially important for models that were not assigned such by the original server. Individual structure modellers can also benefit from the 3D-Jury scoring system by testing their models in the new instant scoring feature http://meta.bioinfo.pl/compare_your_model_example.pl available in the Meta Server.

  3. Evaluation of 3D-Jury on CASP7 models

    PubMed Central

    Kaján, László; Rychlewski, Leszek

    2007-01-01

    Background 3D-Jury, the structure prediction consensus method publicly available in the Meta Server , was evaluated using models gathered in the 7th round of the Critical Assessment of Techniques for Protein Structure Prediction (CASP7). 3D-Jury is an automated expert process that generates protein structure meta-predictions from sets of models obtained from partner servers. Results The performance of 3D-Jury was analysed for three aspects. First, we examined the correlation between the 3D-Jury score and a model quality measure: the number of correctly predicted residues. The 3D-Jury score was shown to correlate significantly with the number of correctly predicted residues, the correlation is good enough to be used for prediction. 3D-Jury was also found to improve upon the competing servers' choice of the best structure model in most cases. The value of the 3D-Jury score as a generic reliability measure was also examined. We found that the 3D-Jury score separates bad models from good models better than the reliability score of the original server in 27 cases and falls short of it in only 5 cases out of a total of 38. We report the release of a new Meta Server feature: instant 3D-Jury scoring of uploaded user models. Conclusion The 3D-Jury score continues to be a good indicator of structural model quality. It also provides a generic reliability score, especially important for models that were not assigned such by the original server. Individual structure modellers can also benefit from the 3D-Jury scoring system by testing their models in the new instant scoring feature available in the Meta Server. PMID:17711571

  4. Anisotropic inflation with derivative couplings

    NASA Astrophysics Data System (ADS)

    Holland, Jonathan; Kanno, Sugumi; Zavala, Ivonne

    2018-05-01

    We study anisotropic power-law inflationary solutions when the inflaton and its derivative couple to a vector field. This type of coupling is motivated by D-brane inflationary models, in which the inflaton, and a vector field living on the D-brane, couple disformally (derivatively). We start by studying a phenomenological model where we show the existence of anisotropic solutions and demonstrate their stability via a dynamical system analysis. Compared to the case without a derivative coupling, the anisotropy is reduced and thus can be made consistent with current limits, while the value of the slow-roll parameter remains almost unchanged. We also discuss solutions for more general cases, including D-brane-like couplings.

  5. Warm p-soup and near extremal black holes

    NASA Astrophysics Data System (ADS)

    Morita, Takeshi; Shiba, Shotaro; Wiseman, Toby; Withers, Benjamin

    2014-04-01

    We consider a model of D-dimensional supergravity coupled to elementary p-branes. We use gravitational arguments to deduce the low energy effective theory of N nearly parallel branes. This is a (p + 1)-dimensional scalar field theory, where the scalars represent the positions of the branes in their transverse space. We propose that the same theory in a certain temperature regime describes a ‘soup’ of strongly interacting branes, giving a microscopic description of near extremal black p-branes. We use natural approximations to estimate the energy density of this soup as a function of the physical parameters; N, temperature, brane tension and gravitational coupling. We also characterize the horizon radius, measured in the metric natural to the branes, with the thermal vev of the scalars. For both quantities we find agreement with the corresponding supergravity black brane results. Surprisingly, beyond the physical parameters, we are naturally able to reproduce certain irrational factors such as πs. We comment on how these ideas may explain why black hole thermodynamics arises in gauge theories with holographic duals at finite temperature.

  6. Toward holographic reconstruction of bulk geometry from lattice simulations

    NASA Astrophysics Data System (ADS)

    Rinaldi, Enrico; Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan; Vranas, Pavlos

    2018-02-01

    A black hole described in SU( N ) gauge theory consists of N D-branes. By separating one of the D-branes from others and studying the interaction between them, the black hole geometry can be probed. In order to obtain quantitative results, we employ the lattice Monte Carlo simulation. As a proof of the concept, we perform an explicit calculation in the matrix model dual to the black zero-brane in type IIA string theory. We demonstrate this method actually works in the high temperature region, where the stringy correction is large. We argue possible dual gravity interpretations.

  7. Toward holographic reconstruction of bulk geometry from lattice simulations

    DOE PAGES

    Rinaldi, Enrico; Berkowitz, Evan; Hanada, Masanori; ...

    2018-02-07

    A black hole described in SU(N ) gauge theory consists of N D-branes. By separating one of the D-branes from others and studying the interaction between them, the black hole geometry can be probed. In order to obtain quantitative results, we employ the lattice Monte Carlo simulation. As a proof of the concept, we perform an explicit calculation in the matrix model dual to the black zero-brane in type IIA string theory. We demonstrate this method actually works in the high temperature region, where the stringy correction is large. We argue possible dual gravity interpretations.

  8. Use Cases for Dynamic Secure Wireless Networking in Coalition Environments (Cas d utilisation de r seau sans fil dynamique et s curis dans des environnements de coalition)

    DTIC Science & Technology

    2015-05-01

    la dénomination « STO », « RTO » ou « AGARD » selon le cas, suivi du numéro de série. Des informations analogues, telles que le titre est la ...supplémentaire de nécessiter moins de déploiement et de ressources de gestion que les réseaux fixes. Néanmoins, les propriétés qui, précisément, rendent...ces réseaux séduisants de prime abord – support ouvert, topologie souple, règles d’adhésion dynamiques, algorithmes simples de formation du

  9. 77 FR 55693 - D&C Red No. 6 and D&C Red No. 7; Change in Specification; Confirmation of Effective Date

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 74 [Docket No. FDA-2011-C-0050] D&C Red No. 6 and D&C Red No. 7; Change in Specification; Confirmation of Effective... the requirements for D&C Red No. 6 and D&C Red No. 7 by replacing the current specification for...

  10. Black p-branes versus black holes in non-asymptotically flat Einstein-Yang-Mills theory

    NASA Astrophysics Data System (ADS)

    Habib Mazharimousavi, S.; Halilsoy, M.

    2016-09-01

    We present a class of non-asymptotically flat (NAF) charged black p-branes (BpB) with p-compact dimensions in higher-dimensional Einstein-Yang-Mills theory. Asymptotically the NAF structure manifests itself as an anti-de sitter spacetime. We determine the total mass/energy enclosed in a thin shell located outside the event horizon. By comparing the entropies of BpB with those of black holes in the same dimensions we derive transition criteria between the two types of black objects. Given certain conditions satisfied, our analysis shows that BpB can be considered excited states of black holes. An event horizon r+ versus charge square Q2 plot for the BpB reveals such a transition where r+ is related to the horizon radius rh of the black hole (BH) both with the common charge Q.

  11. La haute fiabilité en soins de santé: la création d'une culture et d'une mentalité favorisant la sécurité des patients.

    PubMed

    Cochrane, Bonnie S; Hagins, Mitch; Picciano, Gino; King, John A; Marshall, David A; Nelson, Brian; Deao, Craig

    2017-03-01

    Les préjudices que subissent les patients recevant des soins de santé représentent un fardeau considérable et peuvent avoir de graves répercussions sur les patients et les familles ainsi que sur la capacité des systèmes de santé de gérer l'accès des patients, leurs déplacements dans le système et les temps d'attente. L'intérêt pour la science de la haute fiabilité, mise au point à l'origine dans des secteurs comme l'aviation commerciale, qui ont un bilan exceptionnel en matière de sécurité, est une nouvelle tendance en soins de santé qui pourrait aider les organisations et les systèmes à atteindre le but ultime : zéro préjudice subi par les patients. Cet article fait valoir que zéro préjudice au patient est un impératif fondamental et que la science de la haute fiabilité peut aider à accélérer et à soutenir les progrès vers ce but vital. Bien que les pratiques utilisées dans d'autres secteurs ne soient pas facilement transférables aux soins de santé et qu'il n'existe pas encore un seul modèle éprouvé pour les organisations à haute fiabilité en santé, des organisations de premier plan commencent à faire la démonstration de stratégies efficaces propres aux soins de santé. L'expérience du réseau international d'organisations partenaires du groupe Studer est utilisée pour illustrer et comprendre ces premiers efforts. Le cadre Evidence-Based Leadership SM (leadership fondé sur les données probantes) du groupe Studer est appliqué dans différents milieux de soins de santé pour transformer la culture et la gestion du changement visant à favoriser une haute fiabilité. Il propose une démarche et des ressources pour progresser vers le but zéro préjudice subi par les patients et tous les avantages liés à l'utilisation efficiente de nos précieuses ressources en soins de santé.

  12. Quasinormal modes of charged magnetic black branes & chiral magnetic transport

    NASA Astrophysics Data System (ADS)

    Ammon, Martin; Kaminski, Matthias; Koirala, Roshan; Leiber, Julian; Wu, Jackson

    2017-04-01

    We compute quasinormal modes (QNMs) of the metric and gauge field perturbations about black branes electrically and magnetically charged in the Einstein-Maxwell-Chern-Simons theory. By the gauge/gravity correspondence, this theory is dual to a particular class of field theories with a chiral anomaly, in a thermal charged plasma state subjected to a constant external magnetic field, B. The QNMs are dual to the poles of the two-point functions of the energy-momentum and axial current operators, and they encode information about the dissipation and transport of charges in the plasma. Complementary to the gravity calculation, we work out the hydrodynamic description of the dual field theory in the presence of a chiral anomaly, and a constant external B. We find good agreement with the weak field hydrodynamics, which can extend beyond the weak B regime into intermediate regimes. Furthermore, we provide results that can be tested against thermodynamics and hydrodynamics in the strong B regime. We find QNMs exhibiting Landau level behavior, which become long-lived at large B if the anomaly coefficient exceeds a critical magnitude. Chiral transport is analyzed beyond the hydrodynamic approximation for the five (formerly) hydrodynamic modes, including a chiral magnetic wave.

  13. Role of Hunk and Punc in Breast Cancer and Mammary Development

    DTIC Science & Technology

    2000-08-01

    embryonic development of other organs, it is branes ( Santoro et al., 1996; Tamagnone and Comoglio, 1997; possible that EphA7 may play a lineage...Jacque- mammary carcinogenesis. Lab. Invest. 57, 112-137. mier, J., Jordan, B., Birnbaum, D., and Pebusque, M. J. (1999). Santoro , M. M., Collesi, C...involved may shed light on the broader physiological Centanni, J. M., de Miguel , M., Gopalan, G., Gilbert, D. J., Copeland, N. G., Jenkins, N. A

  14. One-loop Pfaffians and large-field inflation in string theory

    NASA Astrophysics Data System (ADS)

    Ruehle, Fabian; Wieck, Clemens

    2017-06-01

    We study the consistency of large-field inflation in low-energy effective field theories of string theory. In particular, we focus on the stability of Kähler moduli in the particularly interesting case where the non-perturbative superpotential of the Kähler sector explicitly depends on the inflaton field. This situation arises generically due to one-loop corrections to the instanton action. The field dependence of the modulus potential feeds back into the inflationary dynamics, potentially impairing slow roll. We distinguish between world-sheet instantons from Euclidean D-branes, which typically yield polynomial one-loop Pfaffians, and gaugino condensates, which can yield exponential or periodic corrections. In all scenarios successful slow-roll inflation imposes bounds on the magnitude of the one-loop correction, corresponding to constraints on possible compactifications. While we put a certain emphasis on Type IIB constructions with mobile D7-branes, our results seem to apply more generally.

  15. Four-qubit systems and dyonic black Hole-Black branes in superstring theory

    NASA Astrophysics Data System (ADS)

    Belhaj, A.; Bensed, M.; Benslimane, Z.; Sedra, M. B.; Segui, A.

    Using dyonic solutions in the type IIA superstring theory on Calabi-Yau (CY) manifolds, we reconsider the study of black objects and quantum information theory using string/string duality in six dimensions. Concretely, we relate four-qubits with a stringy quaternionic moduli space of type IIA compactification associated with a dyonic black solution formed by black holes (BHs) and black 2-branes (B2B) carrying eight electric charges and eight magnetic charges. This connection is made by associating the cohomology classes of the heterotic superstring on T4 to four-qubit states. These states are interpreted in terms of such dyonic charges resulting from the quaternionic symmetric space SO(4,4) SO(4)×SO(4) corresponding to a N = 4 sigma model superpotential in two dimensions. The superpotential is considered as a functional depending on four quaternionic fields mapped to a class of Clifford algebras denoted as Cl0,4. A link between such an algebra and the cohomology classes of T4 in heterotic superstring theory is also given.

  16. StarD7 behaves as a fusogenic protein in model and cell membrane bilayers.

    PubMed

    Angeletti, Sofía; Sanchez, Julieta M; Chamley, Larry W; Genti-Raimondi, Susana; Perillo, María A

    2012-03-01

    StarD7 is a surface active protein, structurally related with the START lipid transport family. So, the present work was aimed at elucidating a potential mechanism of action for StarD7 that could be related to its interaction with a lipid-membrane interface. We applied an assay based on the fluorescence de-quenching of BD-HPC-labeled DMPC-DMPS 4:1 mol/mol SUVs (donor liposomes) induced by the dilution with non-labeled DMPC-DMPS 4:1 mol/mol LUVs (acceptor liposomes). Recombinant StarD7 accelerated the dilution of BD-HPC in a concentration-dependent manner. This result could have been explained by either a bilayer fusion or monomeric transport of the labeled lipid between donor and acceptor liposomes. Further experiments (fluorescence energy transfer between DPH-HPC/BD-HPC, liposome size distribution analysis by dynamic light scattering, and the multinuclear giant cell formation induced by recombinant StarD7) strongly indicated that bilayer fusion was the mechanism responsible for the StarD7-induced lipid dilution. The efficiency of lipid dilution was dependent on StarD7 electrostatic interactions with the lipid-water interface, as shown by the pH- and salt-induced modulation. Moreover, this process was favored by phosphatidylethanolamine which is known to stabilize non-lamellar phases considered as intermediary in the fusion process. Altogether these findings allow postulate StarD7 as a fusogenic protein. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Temperature-Dependent Fermentation of d-Sorbitol in Escherichia coli O157:H7

    PubMed Central

    Bouvet, O. M. M.; Pernoud, S.; Grimont, P. A. D.

    1999-01-01

    The influence of growth temperature on the ability to ferment d-sorbitol was investigated in Escherichia coli O157:H7. It was found that O157:H7 strains have a temperature-sensitive sorbitol phenotype. d-Sorbitol transport and sorbitol-6-phosphate dehydrogenase activities were expressed in sorbitol-fermenting cells grown at 30°C but only at a low level at 40°C. Sorbitol-positive variants able to transport d-sorbitol were easily selected at 30°C from culture of Sor− E. coli O157:H7 strains. PMID:10473445

  18. Particle creation and reheating in a braneworld inflationary scenario

    NASA Astrophysics Data System (ADS)

    Bilić, Neven; Domazet, Silvije; Djordjevic, Goran S.

    2017-10-01

    We study the cosmological particle creation in the tachyon inflation based on the D-brane dynamics in the Randall-Sundrum (RSII) model extended to include matter in the bulk. The presence of matter modifies the warp factor which results in two effects: a modification of the RSII cosmology and a modification of the tachyon potential. Besides, a string theory D-brane supports among other fields a U(1) gauge field reflecting open strings attached to the brane. We demonstrate how the interaction of the tachyon with the U(1) gauge field drives cosmological creation of massless particles and estimate the resulting reheating at the end of inflation.

  19. 3C Protease of Enterovirus D68 Inhibits Cellular Defense Mediated by Interferon Regulatory Factor 7

    PubMed Central

    Xiang, Zichun; Liu, Lulu; Lei, Xiaobo; Zhou, Zhuo

    2015-01-01

    ABSTRACT Human enterovirus 68 (EV-D68) is a member of the EV-D species, which belongs to the EV genus of the Picornaviridae family. Over the past several years, clusters of EV-D68 infections have occurred worldwide. A recent outbreak in the United States is the largest one associated with severe respiratory illness and neurological complication. Although clinical symptoms are recognized, the virus remains poorly understood. Here we report that EV-D68 inhibits innate antiviral immunity by downregulation of interferon regulatory factor 7 (IRF7), an immune factor with a pivotal role in viral pathogenesis. This process depends on 3Cpro, an EV-D68-encoded protease, to mediate IRF7 cleavage. When expressed in host cells, 3Cpro targets Q167 and Q189 within the constitutive activation domain, resulting in cleavage of IRF7. Accordingly, wild-type IRF7 is fully active. However, IRF7 cleavage abrogated its capacity to activate type I interferon expression and limit replication of EV-D68. Notably, IRF7 cleavage strictly requires the protease activity of 3Cpro. Together, these results suggest that a dynamic interplay between 3Cpro and IRF7 may determine the outcome of EV-D68 infection. IMPORTANCE EV-D68 is a globally emerging pathogen, but the molecular basis of EV-D68 pathogenesis is unclear. Here we report that EV-D68 inhibits innate immune responses by targeting an immune factor, IRF7. This involves the 3C protease encoded by EV-D68, which mediates the cleavage of IRF7. These observations suggest that the 3Cpro-IRF7 interaction may represent an interface that dictates EV-D68 infection. PMID:26608321

  20. Metabolism of the broad-spectrum neuropeptide growth factor antagonist: [D-Arg1, D-Phe5, D-Trp7,9, Leu11]-substance P.

    PubMed Central

    Jones, D. A.; Cummings, J.; Langdon, S. P.; Maclellan, A. J.; Higgins, T.; Rozengurt, E.; Smyth, J. F.

    1996-01-01

    Broad-spectrum neuropeptide growth factor antagonists, such as [D-Arg1, D-Phe5, D-Trp7,9, Leu11]substance P (antagonist D) and [Arg6, D-Trp7,9, NmePhe8]substance P(6-11) (antagonist G), are currently being investigated as possible anti-tumour agents. These compounds are hoped to be effective against neuropeptide-driven cancers such as small-cell lung cancer. Antagonist D possesses a broader antagonistic spectrum than antagonist G and hence may be of greater therapeutic use. The in vitro metabolism of antagonist D has been characterised and the structures of two major metabolites have been elucidated by amino acid analysis and mass spectrometry. Metabolism was confined to the C-terminus where serine carboxypeptidase action produced [deamidated]-antagonist D (metabolite 1) and [des-Leu11]-antagonist D (metabolite 2) as the major metabolites. Biological characterisation of the metabolites demonstrated that these relatively minor changes in structure resulted in a loss of antagonist activity. These results provide some of the first structure-activity information on the factors that determine which neuropeptides these compounds inhibit and on the relative potency of that inhibition. PMID:8611370

  1. Cocaine Modulates the Expression of Opioid Receptors and miR-let-7d in Zebrafish Embryos

    PubMed Central

    López-Bellido, Roger; Barreto-Valer, Katherine; Sánchez-Simón, Fátima Macho; Rodríguez, Raquel E.

    2012-01-01

    Prenatal exposure to cocaine, in mammals, has been shown to interfere with the expression of opioid receptors, which can have repercussions in its activity. Likewise, microRNAs, such as let-7, have been shown to regulate the expression of opioid receptors and hence their functions in mammals and in vitro experiments. In light of this, using the zebrafish embryos as a model our aim here was to evaluate the actions of cocaine in the expression of opioid receptors and let-7d miRNA during embryogenesis. In order to determine the effects produced by cocaine on the opioid receptors (zfmor, zfdor1 and zfdor2) and let-7d miRNA (dre-let-7d) and its precursors (dre-let-7d-1 and dre-let-7d-2), embryos were exposed to 1.5 µM cocaine hydrochloride (HCl). Our results revealed that cocaine upregulated dre-let-7d and its precursors, and also increased the expression of zfmor, zfdor1 and zfdor2 during early developmental stages and decreased them in late embryonic stages. The changes observed in the expression of opioid receptors might occur through dre-let-7d, since DNA sequences and the morpholinos of opioid receptors microinjections altered the expression of dre-let-7d and its precursors. Likewise, opioid receptors and dre-let-7d showed similar distributions in the central nervous system (CNS) and at the periphery, pointing to a possible interrelationship between them. In conclusion, the silencing and overexpression of opioid receptors altered the expression of dre-let-7d, which points to the notion that cocaine via dre-let-7 can modulate the expression of opioid receptors. Our study provides new insights into the actions of cocaine during zebrafish embryogenesis, indicating a role of miRNAs, let-7d, in development and its relationship with gene expression of opioid receptors, related to pain and addiction process. PMID:23226419

  2. Flat connections in open string mirror symmetry

    NASA Astrophysics Data System (ADS)

    Alim, Murad; Hecht, Michael; Jockers, Hans; Mayr, Peter; Mertens, Adrian; Soroush, Masoud

    2012-06-01

    We study a flat connection defined on the open-closed deformation space of open string mirror symmetry for type II compactifications on Calabi-Yau threefolds with D-branes. We use flatness and integrability conditions to define distinguished flat coordinates and the superpotential function at an arbitrary point in the open-closed deformation space. Integrability conditions are given for concrete deformation spaces with several closed and open string deformations. We study explicit examples for expansions around different limit points, including orbifold Gromov-Witten invariants, and brane configurations with several brane moduli. In particular, the latter case covers stacks of parallel branes with non-Abelian symmetry.

  3. Gauge/Gravity correspondence and black hole attractors in various dimensions

    NASA Astrophysics Data System (ADS)

    Li, Wei

    This thesis investigates several topics on Gauge/Gravity correspondence and black hole attractors in various dimensions. The first chapter contains a brief review and summary of main results. Chapters 2 and 3 aim at a microscopic description of black objects in five dimensions. Chapter 2 studies higher-derivative corrections for 5D black rings and spinning black holes. It shows that certain R 2 terms found in Calabi-Yau compactifications of M-theory yield macroscopic corrections to the entropies that match the microscopic corrections. Chapter 3 constructs probe brane configurations that preserve half of the enhanced near-horizon supersymmetry of 5D spinning black holes, whose near-horizon geometry is squashed AdS2 x S 3. There are supersymmetric zero-brane probes stabilized by orbital angular momentum on S3 and one-brane probes with momentum and winding around a U(1)L x U(1)R torus in S3. Chapter 4 constructs and analyzes generic single-centered and multi-centered black hole attractor solutions in various four-dimensional models which, after Kaluza-Klein reduction, admit a description in terms of 3D gravity coupled to a sigma model whose target space is symmetric coset space. The solutions correspond to certain nilpotent generators of the coset algebra. The non-BPS black hole attractors are found to be drastically different from their BPS counterparts. Chapter 5 examines three-dimensional topologically massive gravity with negative cosmological constant in asymptotically AdS 3 spacetimes. It proves that the theory is unitary and stable only at a special value of Chern-Simons coupling, where the theory becomes chiral. This suggests the existence of a stable, consistent quantum gravity theory at the chiral point which is dual to a holomorphic boundary CFT 2. Finally, Chapter 6 studies the two-dimensional N = 1 critical string theory with a linear dilaton background. It constructs time-dependent boundary state solutions that correspond to D0-branes falling toward the

  4. Measurement of D-7Li Neutron Production in Neutron Generators Using the Threshold Activation Foil Technique

    NASA Astrophysics Data System (ADS)

    Coventry, M. D.; Krites, A. M.

    Measurements to determine the absolute D-D and D-7Li neutron production rates with a neutron generator running at 100-200 kV acceleration potential were performed using the threshold activation foil technique. This technique provides a clear measure of fast neutron flux and with a suitable model, the neutron output. This approach requires little specialized equipment and is used to calibrate real-time neutron detectors and to verify neutron output. We discuss the activation foil measurement technique and describe its use in determining the relative contributions of D-D and D-7Li reactions to the total neutron yield and real-time detector response and compare to model predictions. The D-7Li reaction produces neutrons with a continuum of energies and a sharp peak around 13.5 MeV for measurement techniques outside of what D-D generators can perform. The ability to perform measurements with D-D neutrons alone, then add D-7Li neutrons for inelastic gamma production presents additional measurement modalities with the same neutron source without the use of tritium. Typically, D-T generators are employed for inelastic scattering applications but have a high regulatory burden from a radiological aspect (tritium inventory, liability concerns) and are export-controlled. D-D and D-7Li generators avoid these issues completely.

  5. IIB duals of D = 3 {N} = 4 circular quivers

    NASA Astrophysics Data System (ADS)

    Assel, Benjamin; Bachas, Costas; Estes, John; Gomis, Jaume

    2012-12-01

    We construct the type-IIB AdS4 ⋉ K supergravity solutions which are dual to the three-dimensional {N} = 4 superconformal field theories that arise as infrared fixed points of circular-quiver gauge theories. These superconformal field theories are labeled by a triple ( {ρ, hat{ρ},L} ) subject to constraints, where ρ and hat{ρ} are two partitions of a number N, and L is a positive integer. We show that in the limit of large L the localized five- branes in our solutions are effectively smeared, and these type-IIB solutions are dual to the near-horizon geometry of M-theory M2-branes at a {{{{{{C}}^4}}} / {{( {{Z_k}× {Z_{widehat{k}}}} )}} .} orbifold singularity. Our IIB solutions resolve the singularity into localized five-brane throats, without breaking the conformal symmetry. The constraints satisfied by the triple ( {ρ, hat{ρ},L} ) , together with the enhanced non-abelian flavour symmetries of the superconformal field theories are precisely reproduced by the type-IIB supergravity solutions. As a bonus, we uncover a novel type of "orbifold equivalence" between different quantum field theories and provide quantitative evidence for this equivalence.

  6. Establishing a threshold for the number of missing days using 7 d pedometer data.

    PubMed

    Kang, Minsoo; Hart, Peter D; Kim, Youngdeok

    2012-11-01

    The purpose of this study was to examine the threshold of the number of missing days of recovery using the individual information (II)-centered approach. Data for this study came from 86 participants, aged from 17 to 79 years old, who had 7 consecutive days of complete pedometer (Yamax SW 200) wear. Missing datasets (1 d through 5 d missing) were created by a SAS random process 10,000 times each. All missing values were replaced using the II-centered approach. A 7 d average was calculated for each dataset, including the complete dataset. Repeated measure ANOVA was used to determine the differences between 1 d through 5 d missing datasets and the complete dataset. Mean absolute percentage error (MAPE) was also computed. Mean (SD) daily step count for the complete 7 d dataset was 7979 (3084). Mean (SD) values for the 1 d through 5 d missing datasets were 8072 (3218), 8066 (3109), 7968 (3273), 7741 (3050) and 8314 (3529), respectively (p > 0.05). The lower MAPEs were estimated for 1 d missing (5.2%, 95% confidence interval (CI) 4.4-6.0) and 2 d missing (8.4%, 95% CI 7.0-9.8), while all others were greater than 10%. The results of this study show that the 1 d through 5 d missing datasets, with replaced values, were not significantly different from the complete dataset. Based on the MAPE results, it is not recommended to replace more than two days of missing step counts.

  7. Cascading gravity is ghost free

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rham, Claudia de; Khoury, Justin; Tolley, Andrew J.

    2010-06-15

    We perform a full perturbative stability analysis of the 6D cascading gravity model in the presence of 3-brane tension. We demonstrate that for sufficiently large tension on the (flat) 3-brane, there are no ghosts at the perturbative level, consistent with results that had previously only been obtained in a specific 5D decoupling limit. These results establish the cascading gravity framework as a consistent infrared modification of gravity.

  8. 20. Photocopy of photograph. Horgan, February 7, 1921. Negative #D ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Photocopy of photograph. Horgan, February 7, 1921. Negative #D & H 21895 Original negative can be found in D & H collection of the Anthracite Heritage Museum, Scranton, Pennsylvania. INTERIOR VIEW OF BREAKER, TOP FLOORS, SHOWING DETAIL OF TOP SCREENS AND CRUSHERS AT TIME OF CONSTRUCTION - Marvine Colliery, Breaker No. 2, West side Boulevard Avenue, between East Parker Street & Route 380, Scranton, Lackawanna County, PA

  9. 7. Historic American Buildings Survey Cortlandt V. D. Hubbard, Photographer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Historic American Buildings Survey Cortlandt V. D. Hubbard, Photographer June 1965 DETAIL, PAINTING ON FLOOR OF SECOND FLOOR - Swain-Mitchell House, 1 Vestal Street, Nantucket, Nantucket County, MA

  10. Holographic renormalization group and cosmology in theories with quasilocalized gravity

    NASA Astrophysics Data System (ADS)

    Csáki, Csaba; Erlich, Joshua; Hollowood, Timothy J.; Terning, John

    2001-03-01

    We study the long distance behavior of brane theories with quasilocalized gravity. The five-dimensional (5D) effective theory at large scales follows from a holographic renormalization group flow. As intuitively expected, the graviton is effectively four dimensional at intermediate scales and becomes five dimensional at large scales. However, in the holographic effective theory the essentially 4D radion dominates at long distances and gives rise to scalar antigravity. The holographic description shows that at large distances the Gregory-Rubakov-Sibiryakov (GRS) model is equivalent to the model recently proposed by Dvali, Gabadadze, and Porrati (DGP), where a tensionless brane is embedded into 5D Minkowski space, with an additional induced 4D Einstein-Hilbert term on the brane. In the holographic description the radion of the GRS model is automatically localized on the tensionless brane, and provides the ghostlike field necessary to cancel the extra graviton polarization of the DGP model. Thus, there is a holographic duality between these theories. This analysis provides physical insight into how the GRS model works at intermediate scales; in particular it sheds light on the size of the width of the graviton resonance, and also demonstrates how the holographic renormalization group can be used as a practical tool for calculations.

  11. Holographic renormalization group and cosmology in theories with quasilocalized gravity

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Csaki, Csaba; Erlich, Joshua; Hollowood, Timothy J.

    2001-03-15

    We study the long distance behavior of brane theories with quasilocalized gravity. The five-dimensional (5D) effective theory at large scales follows from a holographic renormalization group flow. As intuitively expected, the graviton is effectively four dimensional at intermediate scales and becomes five dimensional at large scales. However, in the holographic effective theory the essentially 4D radion dominates at long distances and gives rise to scalar antigravity. The holographic description shows that at large distances the Gregory-Rubakov-Sibiryakov (GRS) model is equivalent to the model recently proposed by Dvali, Gabadadze, and Porrati (DGP), where a tensionless brane is embedded into 5D Minkowskimore » space, with an additional induced 4D Einstein-Hilbert term on the brane. In the holographic description the radion of the GRS model is automatically localized on the tensionless brane, and provides the ghostlike field necessary to cancel the extra graviton polarization of the DGP model. Thus, there is a holographic duality between these theories. This analysis provides physical insight into how the GRS model works at intermediate scales; in particular it sheds light on the size of the width of the graviton resonance, and also demonstrates how the holographic renormalization group can be used as a practical tool for calculations.« less

  12. Black hole attractors and gauge theories

    NASA Astrophysics Data System (ADS)

    Huang, Lisa Li Fang

    2007-12-01

    This thesis is devoted to the study of supersymmetric black holes that arise from string compactifications. We begin by studying the R 2 corrections to the entropy of two solutions of five dimensional supergravity, the supersymmetric black ring and the spinning black hole. Using Wald's formula we compute the R2 corrections to the entropy of the black ring and BMPV black hole. We study N D4-branes wrapping a 4 cycle and M DO-branes on the quintic. For N D4-branes, we resolve the naive mismatch between the moduli space of the Higgs branch of the gauge theory and the moduli of a degree N hypersurface which the D4-brane wraps. The degree N surface must admit a holomorphic divisor and is a determinantal variety. Adding a single DO brane to probe the deformed geometry, we recover the determinant equation from F and D flatness condition which was previously discovered from a classical geometry approach. We next generalize the qunitic story for Calabi-Yau manifolds arising from complete intersections in toric varieties. We recover the moduli space of N D4-branes in terms of the moduli space of a U( N) x U(N) gauge theory with bi-fundamentals com ing from a D6 - D6 system. We also recast the tachyon condensation of the D6 - D6 system in the language of open string gauged linear sigma model. We obtain the determinant equation from F-term constraints arising from a boundary coupling. We set out to understand the Ooguri-Strominger-Vafa conjecture directly in the D4-DO black hole attractor geometry. We show that the lift to the euclidean IIA attractor geometry gives a complexified M-theory geometry whose asymptotic boundary is a torus. Employing AdS3/CFT 2 duality, we argue that the string partition function computes the elliptic genus of the Maldacena-Strominger-Witten conformal field theory. We evaluate the IIA partition function using the Green-Schwarz formalism and show that it gives ZtopZ top, coming from instantons and anti-instantons respectively. Finally, we determine

  13. Late time behaviors of an inhomogeneous rolling tachyon

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kwon, O-Kab; Lee, Chong Oh; Basic Science Research Institute, Chonbuk National University, Chonju 561-756

    2006-06-15

    We study an inhomogeneous decay of an unstable D-brane in the context of Dirac-Born-Infeld (DBI)-type effective action. We consider tachyon and electromagnetic fields with dependence of time and one spatial coordinate, and an exact solution is found under an exponentially decreasing tachyon potential, e{sup -|T|/{radical}}{sup (2)}, which is valid for the description of the late time behavior of an unstable D-brane. Though the obtained solution contains both time and spatial dependence, the corresponding momentum density vanishes over the entire spacetime region. The solution is governed by two parameters. One adjusts the distribution of energy density in the inhomogeneous direction, andmore » the other interpolates between the homogeneous rolling tachyon and static configuration. As time evolves, the energy of the unstable D-brane is converted into the electric flux and tachyon matter.« less

  14. On B-type Open-Closed Landau-Ginzburg Theories Defined on Calabi-Yau Stein Manifolds

    NASA Astrophysics Data System (ADS)

    Babalic, Elena Mirela; Doryn, Dmitry; Lazaroiu, Calin Iuliu; Tavakol, Mehdi

    2018-05-01

    We consider the bulk algebra and topological D-brane category arising from the differential model of the open-closed B-type topological Landau-Ginzburg theory defined by a pair (X,W), where X is a non-compact Calabi-Yau manifold and W is a complex-valued holomorphic function. When X is a Stein manifold (but not restricted to be a domain of holomorphy), we extract equivalent descriptions of the bulk algebra and of the category of topological D-branes which are constructed using only the analytic space associated to X. In particular, we show that the D-brane category is described by projective factorizations defined over the ring of holomorphic functions of X. We also discuss simplifications of the analytic models which arise when X is holomorphically parallelizable and illustrate these in a few classes of examples.

  15. The cat lipocalin Fel d 7 and its cross-reactivity with the dog lipocalin Can f 1.

    PubMed

    Apostolovic, D; Sánchez-Vidaurre, S; Waden, K; Curin, M; Grundström, J; Gafvelin, G; Cirkovic Velickovic, T; Grönlund, H; Thomas, W R; Valenta, R; Hamsten, C; van Hage, M

    2016-10-01

    We investigated the prevalence of sensitization to the cat lipocalin Fel d 7 among 140 cat-sensitized Swedish patients and elucidated its allergenic activity and cross-reactivity with the dog lipocalin Can f 1. Sixty-five of 140 patients had IgE to rFel d 7 whereof 60 also had IgE to rCan f 1. A moderate correlation between IgE levels to rFel d 7 and rCan f 1 was found. rFel d 7 activated basophils in vitro and inhibited IgE binding to rCan f 1 in 4 of 13 patients, whereas rCan f 1 inhibited IgE binding to rFel d 7 in 7 of 13 patients. Fel d 7 and Can f 1 showed high similarities in protein structure and epitopes in common were found using cross-reactive antisera. Fel d 7 is a common allergen in a Swedish cat-sensitized population that cross-reacts with Can f 1, and may contribute to symptoms in cat- but also in dog-allergic patients. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Statistics of SU(5) D-brane models on a type II orientifold

    NASA Astrophysics Data System (ADS)

    Gmeiner, Florian; Stein, Maren

    2006-06-01

    We perform a statistical analysis of models with SU(5) and flipped SU(5) gauge group in a type II orientifold setup. We investigate the distribution and correlation of properties of these models, including the number of generations and the hidden sector gauge group. Compared to the recent analysis [F. Gmeiner, R. Blumenhagen, G. Honecker, D. Lüst, and T. Weigand, J. High Energy Phys.JHEPFG1029-8479 01 (2006) 004; F. Gmeiner, Fortschr. Phys.FPYKA60015-8208 54, 391 (2006).10.1088/1126-6708/2006/01/004] of models with a standard model-like gauge group, we find very similar results.

  17. let-7d-3p is associated with apoptosis and response to neoadjuvant chemotherapy in ovarian cancer.

    PubMed

    García-Vázquez, Raúl; Gallardo Rincón, Dolores; Ruiz-García, Erika; Meneses García, Abelardo; Hernández De La Cruz, Olga N; Astudillo-De La Vega, Horacio; Isla-Ortiz, David; Marchat, Laurence A; Salinas-Vera, Yarely M; Carlos-Reyes, Ángeles; López-González, Sullivan; Ramos-Payan, Rosalio; López-Camarillo, César

    2018-06-01

    Altered expression of microRNAs contributes to the heterogeneous biological behavior of human malignancies and it may correlate with the clinical pathological features of patients. The let-7 microRNA family is frequently downregulated in human cancers and its aberrant expression may be a useful marker for prediction of the clinical response to therapy in patients. In the present study, we analyzed the expression of three members of the let-7 family (let-7a-3p, let-7d-3p and let-7f), which remains largely uncharacterized in ovarian cancer tissues. We also investigated the function of let-7d-3p in the apoptosis and sensitization to chemotherapy in ovarian cancer cells. Our data from stem-loop quantitative RT-PCR showed that expression of let-7a-3p and let-7d-3p, but not let-7f, was significantly (P<0.04) upregulated in ovarian tumors relative to that noted in normal ovarian tissues. Markedly, an increased expression of let‑7d-3p (also known as let-7d-3*) was associated with positive response to carboplatin/paclitaxel treatment in ovarian cancer patients. To investigate the biological relevance of let‑7d-3p, we knocked down its expression in SKOV-3 ovarian cancer cell line using antagomiRs. Loss of function analysis showed that inhibition of let-7d-3p significantly (P<0.05) impaired cell proliferation and activated apoptosis. In contrast, scratch/wound healing and Transwell chamber assays showed that migration and invasion abilities were not affected in the let-7d-3p-deficient SKOV-3 cancer cells. Notably, Annexin V assays showed a significant (P<0.05) increase in cell death of cancer cells treated with the let-7d-3p inhibitor plus carboplatin indicating a synergistic effect of the drug with antagomiR therapy. Gene ontology classification of predicted targets of let-7d-3p identified a number of genes involved in cellular pathways associated with therapy resistance such as ABC transporters, HIF-1, RAS and ErbB signaling. In summary, our findings showed that

  18. Genes in FRA16D and FRA7G Mutated in Prostate Cancer.

    DTIC Science & Technology

    1999-06-01

    Huang H, Nelson M , Smith DI. Cloning and characterization of keratin 21 (K21) highly induced by histone deacetylase inhibitors during differentiation...A395. Kawakami M , Hartmann L, Huntley B, Smith DI, Shridhar V. Allele loss on 16q in high-grade invasive epithelial ovarian cancer. Amer. J. Hum...CEN m N CO o < 1 WC7.7 I-- CD co r-- Q CO CO CD CO Q _L_ 921B4 912D9 _1_ 887 D11 WC7.6 A GAP BETWEEN YAC CONTIGS tu O CD

  19. Full-dimensional quantum calculations of the dissociation energy, zero-point, and 10 K properties of H7+/D7+ clusters using an ab initio potential energy surface.

    PubMed

    Barragán, Patricia; Pérez de Tudela, Ricardo; Qu, Chen; Prosmiti, Rita; Bowman, Joel M

    2013-07-14

    Diffusion Monte Carlo (DMC) and path-integral Monte Carlo computations of the vibrational ground state and 10 K equilibrium state properties of the H7 (+)/D7 (+) cations are presented, using an ab initio full-dimensional potential energy surface. The DMC zero-point energies of dissociated fragments H5 (+)(D5 (+))+H2(D2) are also calculated and from these results and the electronic dissociation energy, dissociation energies, D0, of 752 ± 15 and 980 ± 14 cm(-1) are reported for H7 (+) and D7 (+), respectively. Due to the known error in the electronic dissociation energy of the potential surface, these quantities are underestimated by roughly 65 cm(-1). These values are rigorously determined for first time, and compared with previous theoretical estimates from electronic structure calculations using standard harmonic analysis, and available experimental measurements. Probability density distributions are also computed for the ground vibrational and 10 K state of H7 (+) and D7 (+). These are qualitatively described as a central H3 (+)/D3 (+) core surrounded by "solvent" H2/D2 molecules that nearly freely rotate.

  20. Low expression of a Ddm7/Ldm7-hybrid mutant (D/Ldm7) in the novel haplotype H-2nc identified in atopic dermatitis model NC/Nga mice.

    PubMed

    Ohkusu-Tsukada, Kozo; Yamashita, Tadashi; Tsukada, Teruyo; Takahashi, Kimimasa

    2017-12-22

    Environmental factors and the major histocompatibility complex (MHC) are involved in the pathogenesis of atopic dermatitis (AD). However, MHC type (H2 haplotype) of AD model mice NC/Nga is poorly understood. Alloreactive CD8 + or CD4 + T cells in NC/Nga strongly responded to each antigen-presenting cells (A/J: H-2 a , C57BL/6: H-2 b , BALB/c: H-2 d , or C3H/HeJ: H-2 k ), suggesting that NC/Nga has other H2 haplotype. Polymorphic microsatellite (CA) n repeats in TNF-α gene differ based on the H2 haplotype at present. NC/Nga's (CA) n repeats (n = 19) were different from other examined strains, A/J (n = 14), BALB/c (n = 14), C3H/HeJ (n = 16), and C57BL/6 (n = 20). Using flow cytometry and genotyping, we demonstrated the NC/Nga H2 haplotype had a unique phenotype (K d , I-A k , and I-E k ) in which D d and L d lacked as protein despite sensitive mRNA detection. The loss of D d and L d was caused by forming a unique D dm7 /L dm7 -hybrid mutant (D/L dm7 ). We propose to call this novel H2 haplotype the "H-2 nc ," and provide the important information regarding the AD research using NC/Nga mice.

  1. Facile and enantiospecific syntheses of (6S,7R)-6-chloro-7-benzyloxy-, (7S)-halo-, and (7S)-hydroxy-cocaine and natural (-)-cocaine from D-(-)-ribose.

    PubMed

    Shing, Tony K M; So, King H

    2011-06-03

    First syntheses of C6,7 and C7 enantiopure cocaine analogues were achieved from D-(-)-ribose via a trans-acetonide controlled endo-selective intramolecular nitrone-alkene cycloaddition (INAC) as the key step. This synthetic scheme allows practical preparation of cocaine analogues for bioevaluation as potential candidates for the treatment of cocaine addiction and as potential conjugates for immunotherapy.

  2. 21 CFR 74.2707 - D&C Yellow No. 7.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false D&C Yellow No. 7. 74.2707 Section 74.2707 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... coloring externally applied cosmetics in amounts consistent with good manufacturing practice. (c) Labeling...

  3. 21 CFR 74.2307 - D&C Red No. 7

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false D&C Red No. 7 74.2307 Section 74.2307 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... coloring cosmetics generally in amounts consistent with current good manufacturing practice. (c) Labeling...

  4. Phased Array 3D MR Spectroscopic Imaging of the Brain at 7 Tesla

    PubMed Central

    Xu, Duan; Cunningham, Charles H; Chen, Albert P.; Li, Yan; Kelley, Douglas AC; Mukherjee, Pratik; Pauly, John M.; Nelson, Sarah J.; Vigneron, Daniel B.

    2008-01-01

    Ultrahigh field 7T MR scanners offer the potential for greatly improved MR spectroscopic imaging due to increased sensitivity and spectral resolution. Prior 7T human single-voxel MRS studies have shown significant increases in SNR and spectral resolution as compared to lower magnetic fields, but have not demonstrated the increase in spatial resolution and multivoxel coverage possible with 7T MR spectroscopic imaging. The goal of this study was to develop specialized rf pulses and sequences for 3D MRSI at 7T to address the challenges of increased chemical shift misregistration, B1 power limitations, and increased spectral bandwidth. The new 7T MRSI sequence was tested in volunteer studies and demonstrated the feasibility of obtaining high SNR phased-array 3D MRSI from the human brain. PMID:18486386

  5. Herbimycins D-F, ansamycin analogues from Streptomyces sp. RM-7-15.

    PubMed

    Shaaban, Khaled A; Wang, Xiachang; Elshahawi, Sherif I; Ponomareva, Larissa V; Sunkara, Manjula; Copley, Gregory C; Hower, James C; Morris, Andrew J; Kharel, Madan K; Thorson, Jon S

    2013-09-27

    Bacterial strains belonging to the class actinomycetes were isolated from the soil near a thermal vent of the Ruth Mullins coal fire (Appalachian Mountains of eastern Kentucky). High-resolution electrospray ionization mass spectrometry and ultraviolet absorption profiles of metabolites from one of the isolates (Streptomyces sp. RM-7-15) revealed the presence of a unique set of metabolites ultimately determined to be herbimycins D-F (1-3). In addition, herbimycin A (4), dihydroherbimycin A (TAN 420E) (7), and the structurally distinct antibiotic bicycylomycin were isolated from the crude extract of Streptomyces sp. RM-7-15. Herbimycins A and D-F (1-3) displayed comparable binding affinities to the Hsp90α. While the new analogues were found to be inactive in cancer cell cytotoxicity and antimicrobial assays, they may offer new insights in the context of nontoxic ansamycin-based Hsp90 inhibitors for the treatment of neurodegenerative disease.

  6. 45 CFR 303.7 - Provision of services in intergovernmental IV-D cases.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ENFORCEMENT (CHILD SUPPORT ENFORCEMENT PROGRAM), ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES STANDARDS FOR PROGRAM OPERATIONS § 303.7 Provision of services in intergovernmental IV-D cases. (a) General responsibilities. A State IV-D agency must: (1) Establish and use...

  7. Double relaxation via AdS/CFT

    NASA Astrophysics Data System (ADS)

    Amiri-Sharifi, S.; Ali-Akbari, M.; Kishani-Farahani, A.; Shafie, N.

    2016-08-01

    We exploit the AdS/CFT correspondence to investigate thermalization in an N = 2 strongly coupled gauge theory including massless fundamental matter (quark). More precisely, we consider the response of a zero temperature state of the gauge theory under influence of an external electric field which leads to a time-dependent current. The holographic dual of the above set-up is given by introducing a time-dependent electric field on the probe D7-brane embedded in an AdS5 ×S5 background. In the dual gravity theory an apparent horizon forms on the brane which, according to AdS/CFT dictionary, is the counterpart of the thermalization process in the gauge theory side. We classify different functions for time-dependent electric field and study their effect on the apparent horizon formation. In the case of pulse functions, where the electric field varies from zero to zero, apart from non-equilibrium phase, we observe the formation of two separate apparent horizons on the brane. This means that the state of the gauge theory experiences two different temperature regimes during its time evolution.

  8. Measurement of $$D^{*\\pm}$$, $$D^\\pm$$ and $$D_s^\\pm$$ meson production cross sections in pp collisions at $$\\sqrt{s} = 7$$ TeV with the ATLAS detector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aad, G.

    The production ofmore » $$D^{*\\pm}$$, $$D^\\pm$$ and $$D_s^\\pm$$ charmed mesons has been measured with the ATLAS detector in pp collisions at √s = 7 TeV at the LHC, using data corresponding to an integrated luminosity of 280 nb -1. The charmed mesons have been reconstructed in the range of transverse momentum 3.5 < pT(D) < 100 GeV and pseudorapidity |η(D)| < 2.1. The differential cross sections as a function of transverse momentum and pseudorapidity were measured for $$D^{*\\pm}$$, $$D^\\pm$$ production. The next-to-leading-order QCD predictions are consistent with the data in the visible kinematic region within the large theoretical uncertainties. Lastly, using the visible D cross sections and an extrapolation to the full kinematic phase space, the strangeness-suppression factor in charm fragmentation, the fraction of charged non-strange D mesons produced in a vector state, and the total cross section of charm production at √s = 7TeV were derived.« less

  9. Measurement of $$D^{*\\pm}$$, $$D^\\pm$$ and $$D_s^\\pm$$ meson production cross sections in pp collisions at $$\\sqrt{s} = 7$$ TeV with the ATLAS detector

    DOE PAGES

    Aad, G.

    2016-04-25

    The production ofmore » $$D^{*\\pm}$$, $$D^\\pm$$ and $$D_s^\\pm$$ charmed mesons has been measured with the ATLAS detector in pp collisions at √s = 7 TeV at the LHC, using data corresponding to an integrated luminosity of 280 nb -1. The charmed mesons have been reconstructed in the range of transverse momentum 3.5 < pT(D) < 100 GeV and pseudorapidity |η(D)| < 2.1. The differential cross sections as a function of transverse momentum and pseudorapidity were measured for $$D^{*\\pm}$$, $$D^\\pm$$ production. The next-to-leading-order QCD predictions are consistent with the data in the visible kinematic region within the large theoretical uncertainties. Lastly, using the visible D cross sections and an extrapolation to the full kinematic phase space, the strangeness-suppression factor in charm fragmentation, the fraction of charged non-strange D mesons produced in a vector state, and the total cross section of charm production at √s = 7TeV were derived.« less

  10. 21 CFR 74.1307 - D&C Red No. 7.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false D&C Red No. 7. 74.1307 Section 74.1307 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... medium with 3-hydroxy-2-naphthalenecarboxylic acid and the resulting dye converted to the calcium salt...

  11. 21 CFR 74.1307 - D&C Red No. 7.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false D&C Red No. 7. 74.1307 Section 74.1307 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... medium with 3-hydroxy-2-naphthalenecarboxylic acid and the resulting dye converted to the calcium salt...

  12. 21 CFR 74.1307 - D&C Red No. 7.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false D&C Red No. 7. 74.1307 Section 74.1307 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... medium with 3-hydroxy-2-naphthalenecarboxylic acid and the resulting dye converted to the calcium salt...

  13. Antitumor properties of (5E,7E) analogs of vitamin D3.

    PubMed

    Filip, B; Milczarek, M; Wietrzyk, J; Chodyński, M; Kutner, A

    2010-07-01

    Geometric isomers (5E,7E) of major active metabolites of vitamin D3 [1alpha,25(OH)2D3 and (24R)-1,24(OH)2D3] were synthesized by a new convenient procedure. Vitamin D triene system of the metabolites was first derivatized as a Diels-Alder adduct. Removal of the triene protecting group, in a key synthetic step, yielded the title compounds PRI-2208 and PRI-2209, respectively. The analogs were examined for their antiproliferative activity in vitro against human breast cancer cells (MCF-7) and promyelocytic leukemia (HL-60) cells. The activity was compared with one of the parent compounds. Both analogs examined revealed similar or higher antiproliferative activity compared to 1alpha,25(OH)2D3 or to (24R)-1,24(OH)2D3. The studies of calcemic activity in vivo showed that analogs PRI-2208 and PRI-2209 did not influence the serum calcium level in doses, in which 1alpha,25(OH)2D3 or (24R)-1,24(OH)2D3 significantly increased this level. The antitumor activity of these analogs in the LLC mice tumor model was studied. Analog PRI-2208 was found to be more active in inhibiting LLC tumor growth than 1alpha,25(OH)2D3, as well as than PRI-2191 and PRI-2209. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  14. Evaluating the impact of missenses mutations in CYP2D6*7 and CYP2D6*14A: does it compromise tamoxifen metabolism?

    PubMed

    Borba, Maria Acsm; Melo-Neto, Renato P; Leitão, Glauber M; Castelletti, Carlos Hm; Lima-Filho, José L; Martins, Danyelly Bg

    2016-04-01

    CYP2D6 is a high polymorphic enzyme from P450, responsible for metabolizing almost 25% of drugs. The distribution of different mutations among CYP2D6 alleles has been associated with poor, intermediate, extensive and ultra-metabolizers. To evaluate how missenses mutations in CYP2D6*7 and CYP2D6*14A poor metabolizer alleles affect CYP2D6 stability and function. CYPalleles database was used to collect polymorphisms data present in 105 alleles. We selected only poor metabolizers alleles that presented exclusively missenses mutations. They were analyzed through seven algorithms to predict the impact on CYP2D6 structure and function. H324P, the unique mutation in CYP2D6*7, has high impact in enzyme function due to its occurrence between two alpha-helixes involved in active site dynamics. G169R, a mutation that occurs only in CYP2D6*14A, leads to the gain of solvent accessibility and severe protein destabilization. Our in silico analysis showed that missenses mutations in CYP2D6*7 and CYP2D6*14A cause CYP2D6 dysfunction.

  15. 4D superfield reduction of 5D orbifold SUGRA and heterotic M-theory

    NASA Astrophysics Data System (ADS)

    Paccetti Correia, Filipe; Schmidt, Michael G.; Tavartkiladze, Zurab

    2006-09-01

    We present a detailed study of the reduction to 4D of 5D supergravity compactified on the S/Z orbifold. For this purpose we develop and employ a recently proposed N=1 conformal superfield description of the 5D supergravity couplings to Abelian vector and hypermultiplets. In particular, we obtain a unique relation of the "radion" to chiral superfields as in global 5D SUSY and we can embed the universal hypermultiplet into this formalism. In our approach, it is transparent how the superconformal structure of the effective 4D actions is inherited from the one of the original 5D supergravity. We consider both ungauged and gauged 5D supergravities. This includes compactifications in unwarped geometries, generalizations of the supersymmetric Randall-Sundrum (RS) model as well as 5D heterotic M-theory. In the unwarped case, after obtaining the effective Kähler potentials and superpotentials, we demonstrate that the tree-level 4D potentials have flat and/or tachyonic directions. One-loop corrections to the Kähler potential and gaugino condensation are presented as suitable tools for moduli stabilization to be discussed in subsequent work. Turning to the RS-like models, we obtain a master formula for the Kähler potential for an arbitrary number of vector and hyper moduli, which we evaluate exactly for special cases. Finally, we formulate the superfield description of 5D heterotic M-theory and obtain its effective 4D description for the universal ( h=1) case, in the presence of an arbitrary number of bulk 5-branes. We present, as a check of our expressions, time-dependent solutions of 4D heterotic M-theory, which uplift to 5D solutions generalizing the ones recently found in [W. Chen, Z.-W. Chong, G.W. Gibbons, H. Lü, C.N. Pope, Hořava-Witten stability: Eppur si muove, Nucl. Phys. B 732 (2006) 118, hep-th/0502077].

  16. SOVRaD - A Digest of Recent Soviet R and D Articles. Volume 1, Number 7, July 1975

    DTIC Science & Technology

    1975-07-01

    mmm^m* w—P AD-A015 652 SOVRaD - A DIGEST OF RECENT SOVIET R AND D ARTICLES . VOLUME 1, NUMBER 7, JULY 1975 S. Hibben, et al Informatics...a comparison article on the same topic, the author considers the r-f effect on electron density Ne and temperature of the lower ionosphere, for...hi(i;h-frequency measurements). Kiyev, Izd-vo Tekhnika, 1975, 142 p. (LC-VKP) Galushkin, A. I. Sintez mnogosloynykh sistem

  17. Chaos in matrix models and black hole evaporation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan

    Is the evaporation of a black hole described by a unitary theory? In order to shed light on this question—especially aspects of this question such as a black hole’s negative specific heat—we consider the real-time dynamics of a solitonic object in matrix quantum mechanics, which can be interpreted as a black hole (black zero-brane) via holography. We point out that the chaotic nature of the system combined with the flat directions of its potential naturally leads to the emission of D0-branes from the black brane, which is suppressed in the large N limit. Simple arguments show that the black zero-brane,more » like the Schwarzschild black hole, has negative specific heat, in the sense that the temperature goes up when it evaporates by emitting D0-branes. While the largest Lyapunov exponent grows during the evaporation, the Kolmogorov-Sinai entropy decreases. These are consequences of the generic properties of matrix models and gauge theory. Based on these results, we give a possible geometric interpretation of the eigenvalue distribution of matrices in terms of gravity. Applying the same argument in the M-theory parameter region, we provide a scenario to derive the Hawking radiation of massless particles from the Schwarzschild black hole. In conclusion, we suggest that by adding a fraction of the quantum effects to the classical theory, we can obtain a matrix model whose classical time evolution mimics the entire life of the black brane, from its formation to the evaporation.« less

  18. Chaos in matrix models and black hole evaporation

    DOE PAGES

    Berkowitz, Evan; Hanada, Masanori; Maltz, Jonathan

    2016-12-19

    Is the evaporation of a black hole described by a unitary theory? In order to shed light on this question—especially aspects of this question such as a black hole’s negative specific heat—we consider the real-time dynamics of a solitonic object in matrix quantum mechanics, which can be interpreted as a black hole (black zero-brane) via holography. We point out that the chaotic nature of the system combined with the flat directions of its potential naturally leads to the emission of D0-branes from the black brane, which is suppressed in the large N limit. Simple arguments show that the black zero-brane,more » like the Schwarzschild black hole, has negative specific heat, in the sense that the temperature goes up when it evaporates by emitting D0-branes. While the largest Lyapunov exponent grows during the evaporation, the Kolmogorov-Sinai entropy decreases. These are consequences of the generic properties of matrix models and gauge theory. Based on these results, we give a possible geometric interpretation of the eigenvalue distribution of matrices in terms of gravity. Applying the same argument in the M-theory parameter region, we provide a scenario to derive the Hawking radiation of massless particles from the Schwarzschild black hole. In conclusion, we suggest that by adding a fraction of the quantum effects to the classical theory, we can obtain a matrix model whose classical time evolution mimics the entire life of the black brane, from its formation to the evaporation.« less

  19. Expression of VEGF-D, SMAD4, and SMAD7 and Their Relationship with Lymphangiogenesis and Prognosis in Colon Cancer.

    PubMed

    Su, Fei; Li, Xuemei; You, Kai; Chen, Mingwei; Xiao, Jianbing; Zhang, Yafang; Ma, Jing; Liu, Baoquan

    2016-12-01

    The vascular endothelial growth factor (VEGF) and TGF-β1 pathways play important roles in cancer. However, few studies have evaluated the expression and roles of VEGF-D, SMAD4, and SMAD7 in colon cancer, and the conclusions remain controversial. To clarify the roles of VEGF-D, SMAD4, and SMAD7 in colon cancer, we examined their expression and evaluated correlations with lymphangiogenesis, prognosis, and chemotherapeutic outcome. The expression of VEGF-D, SMAD4, and SMAD7 was immunohistochemically examined in 251 primary colon cancer samples obtained from the Harbin Medical University. The expression of VEGF-D, SMAD4, and SMAD7 was identified in 71.7, 41.0, and 69.7 % of samples, respectively. Positive expression of VEGF-D and SMAD7 and lost expression of SMAD4 were significantly correlated with lymph node metastasis and high lymphatic vessel density. VEGF-D and SMAD7 were found to be independent indicators of prognosis and chemotherapy outcome, and positive expression of either VEGF-D or SMAD7 was associated with significantly shorter overall survival and disease-free survival (OS and DFS) than negative expression in all 251 patients (P < 0.001 for OS and DFS) and patients following chemotherapy (P < 0.001 for OS and DFS). VEGF-D, SMAD4, and SMAD7 were involved in lymphangiogenesis and lymph node metastasis. VEGF-D and SMAD7 can serve as predictors of prognosis and chemotherapeutic outcome in colon cancer.

  20. 7 CFR Exhibit D to Subpart N of... - Project Selection Criteria-Outline Rating Form

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 13 2011-01-01 2009-01-01 true Project Selection Criteria-Outline Rating Form D Exhibit D to Subpart N of Part 1944 Agriculture Regulations of the Department of Agriculture (Continued... Preservation Grants Pt. 1944, Subpt. N, Exh. D Exhibit D to Subpart N of Part 1944—Project Selection Criteria...

  1. 7 CFR Exhibit D to Subpart N of... - Project Selection Criteria-Outline Rating Form

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 13 2010-01-01 2009-01-01 true Project Selection Criteria-Outline Rating Form D Exhibit D to Subpart N of Part 1944 Agriculture Regulations of the Department of Agriculture (Continued... Preservation Grants Pt. 1944, Subpt. N, Exh. D Exhibit D to Subpart N of Part 1944—Project Selection Criteria...

  2. How changing physical constants and violation of local position invariance may occur?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Flambaum, V. V.; Shuryak, E. V.

    2008-04-04

    Light scalar fields very naturally appear in modern cosmological models, affecting such parameters of Standard Model as electromagnetic fine structure constant {alpha}, dimensionless ratios of electron or quark mass to the QCD scale, m{sub e,q}/{lambda}{sub QCD}. Cosmological variations of these scalar fields should occur because of drastic changes of matter composition in Universe: the latest such event is rather recent (redshift z{approx}0.5), from matter to dark energy domination. In a two-brane model (we use as a pedagogical example) these modifications are due to changing distance to 'the second brane', a massive companion of 'our brane'. Back from extra dimensions, massivemore » bodies (stars or galaxies) can also affect physical constants. They have large scalar charge Q{sub d} proportional to number of particles which produces a Coulomb-like scalar field {phi} = Q{sub d}/r. This leads to a variation of the fundamental constants proportional to the gravitational potential, e.g. {delta}{alpha}/{alpha} = k{sub {alpha}}{delta}(GM/rc{sup 2}). We compare different manifestations of this effect, which is usually called violation of local position invariance. The strongest limits k{sub {alpha}}+0.17k{sub e} (-3.5{+-}6)*10{sup -7} are obtained from the measurements of dependence of atomic frequencies on the distance from Sun (the distance varies due to the ellipticity of the Earth's orbit)« less

  3. The Plasmodium falciparum exported protein PF3D7_0402000 binds to erythrocyte ankyrin and band 4.1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shakya, Bikash; Penn, Wesley D.; Nakayasu, Ernesto S.

    Plasmodium falciparum extensively modifies the infected red blood cell (RBC), resulting in changes in deformability, shape and surface properties. These alterations suggest that the RBC cytoskeleton is a major target for modification during infection. However, the molecular mechanisms leading to these changes are largely unknown. To begin to address this question, we screened for exported P. falciparum proteins that bound to the erythrocyte cytoskeleton proteins ankyrin 1 (ANK1) and band 4.1 (4.1R), which form critical interactions with other cytoskeletal proteins that contribute to the deformability and stability of RBCs. Yeast two-hybrid screens with ANK1 and 4.1R identified eight interactions withmore » P. falciparum exported proteins, including an interaction between 4.1R and PF3D7_0402000 (PFD0090c). This interaction was first identified in a large-scale screen (Vignali et al., Malaria J, 7:211, 2008), which also reported an interaction between PF3D7_0402000 and ANK1. We confirmed the interactions of PF3D7_0402000 with 4.1R and ANK1 in pair-wise yeast two-hybrid and co-precipitation assays. In both cases, an intact PHIST domain in PF3D7_0402000 was required for binding. Complex purification followed by mass spectrometry analysis provided additional support for the interaction of PF3D7_0402000 with ANK1 and 4.1R. RBC ghost cells loaded with maltose-binding protein (MBP)-PF3D7_0402000 passed through a metal microsphere column less efficiently than mock- or MBP-loaded controls, consistent with an effect of PF3D7_0402000 on RBC rigidity or membrane stability. This study confirmed the interaction of PF3D7_0402000 with 4.1R in multiple independent assays, provided the first evidence that PF3D7_0402000 also binds to ANK1, and suggested that PF3D7_0402000 affects deformability or membrane stability of uninfected RBC ghosts.« less

  4. Metric 3-Leibniz algebras and M2-branes

    NASA Astrophysics Data System (ADS)

    Méndez-Escobar, Elena

    2010-08-01

    This thesis is concerned with superconformal Chern-Simons theories with matter in 3 dimensions. The interest in these theories is two-fold. On the one hand, it is a new family of theories in which to test the AdS/CFT correspondence and on the other, they are important to study one of the main objects of M-theory (M2-branes). All these theories have something in common: they can be written in terms of 3-Leibniz algebras. Here we study the structure theory of such algebras, paying special attention to a subclass of them that gives rise to maximal supersymmetry and that was the first to appear in this context: 3-Lie algebras. In chapter 2, we review the structure theory of metric Lie algebras and their unitary representations. In chapter 3, we study metric 3-Leibniz algebras and show, by specialising a construction originally due to Faulkner, that they are in one to one correspondence with pairs of real metric Lie algebras and unitary representations of them. We also show a third characterisation for six extreme cases of 3-Leibniz algebras as graded Lie (super)algebras. In chapter 4, we study metric 3-Lie algebras in detail. We prove a structural result and also classify those with a maximally isotropic centre, which is the requirement that ensures unitarity of the corresponding conformal field theory. Finally, in chapter 5, we study the universal structure of superpotentials in this class of superconformal Chern-Simons theories with matter in three dimensions. We provide a uniform formulation for all these theories and establish the connection between the amount of supersymmetry preserved and the gauge Lie algebra and the appropriate unitary representation to be used to write down the Lagrangian. The conditions for supersymmetry enhancement are then expressed equivalently in the language of representation theory of Lie algebras or the language of 3-Leibniz algebras.

  5. Open strings and electric fields in compact spaces

    NASA Astrophysics Data System (ADS)

    Condeescu, Cezar; Dudas, Emilian; Pradisi, Gianfranco

    2018-05-01

    We analyse open strings with background electric fields in the internal space, T-dual to branes moving with constant velocities in the internal space. We find that the direction of the electric fields inside a two torus, dual to the D-brane velocities, has to be quantised such that the corresponding direction is compact. This implies that D-brane motion in the internal torus is periodic, with a periodicity that can be parametrically large in terms of the internal radii. By S-duality, this is mapped into an internal magnetic field in a three torus, a quantum mechanical analysis of which yields a similar result, i.e. the parallel direction to the magnetic field has to be compact. Furthermore, for the magnetic case, we find the Landau level degeneracy as being given by the greatest common divisor of the flux numbers. We carry on the string quantisation and derive the relevant partition functions for these models. Our analysis includes also the case of oblique electric fields which can arise when several stacks of branes are present. Compact dimensions and/or oblique sectors influence the energy loss of the system through pair-creation and thus can be relevant for inflationary scenarios with branes. Finally, we show that the compact energy loss is always larger than the non-compact one.

  6. Loss of MYC and E-box3 binding contributes to defective MYC-mediated transcriptional suppression of human MC-let-7a-1~let-7d in glioblastoma

    PubMed Central

    Wang, Zifeng; Lin, Sheng; Zhang, Ji; Xu, Zhenhua; Xiang, Yu; Yao, Hong; Ge, Lei; Xie, Dan; Kung, Hsiang-fu; Lu, Gang; Poon, Wai Sang; Liu, Quentin; Lin, Marie Chia-mi

    2016-01-01

    Previously, we reported that MYC oncoprotein down-regulates the transcription of human MC-let-7a-1~let-7d microRNA cluster in hepatocarcinoma (HCC). Surprisingly, in silico analysis indicated that let-7 miRNA expression levels are not reduced in glioblastoma (GBM). Here we investigated the molecular basis of this differential expression. Using human GBM U87 and U251 cells, we first demonstrated that forced over-expression of MYC indeed could not down-regulate the expression of human MC-let-7a-1~let-7d microRNA cluster in GBM. Furthermore, analysis of MC-let-7a-1~let-7d promoter in GBM indicated that MYC failed to inhibit the promoter activity. Pearson's correlation and Linear Regression analysis using the expression data from GSE55092 (HCC) and GSE4290 (GBM) demonstrated a converse relationship of MC-let-7a-1~let-7d and MYC only in HCC but not in GBM. To understand the underlying mechanisms, we examined whether MYC could bind to the non-canonical E-box 3 located in the promoter of MC-let-7a-1~let-7d. Results from both chromatin immune-precipitation (ChIP) and super-shift assays clearly demonstrated the loss of MYC and E-box 3 binding in GBM, suggesting for the first time that a defective MYC and E-box3 binding in GBM is responsible for the differential MYC mediated transcriptional inhibition of MC-let-7a-1~let-7d and potentially other tumor suppressors. MYC and let-7 are key oncoprotein and tumor suppressor, respectively. Understanding the molecular mechanisms of their regulations will provide new insight and have important implications in the therapeutics of GBM as well as other cancers. PMID:27409345

  7. The Casimir effect in rugby-ball type flux compactifications

    NASA Astrophysics Data System (ADS)

    Minamitsuji, M.

    2008-04-01

    We discuss volume stabilization in a 6D braneworld model based on 6D supergravity theory. The internal space is compactified by magnetic flux and contains codimension two 3-branes (conical singularities) as its boundaries. In general the external 4D spacetime is warped and in the unwrapped limit the shape of the internal space looks like a 'rugby ball'. The size of the internal space is not fixed due to the scale invariance of the supergravity theory. We discuss the possibility of volume stabilization by the Casimir effect for a massless, minimally coupled bulk scalar field. The main obstacle in studying this case is that the brane (conical) part of the relevant heat kernel coefficient (a6) has not been formulated. Thus as a first step, we consider the 4D analog model with boundary codimension two 1-branes. The spacetime structure of the 4D model is very similar to that of the original 6D model, where now the relevant heat kernel coefficient is well known. We derive the one-loop effective potential induced by a scalar field in the bulk by employing zeta function regularization with heat kernel analysis. As a result, the volume is stabilized for most possible choices of the parameters. Especially, for a larger degree of warping, our results imply that a large hierarchy between the mass scales and a tiny amount of effective cosmological constant can be realized on the brane. In the non-warped limit the ratio tends to converge to the same value, independently of the bulk gauge coupling constant. Finally, we will analyze volume stabilization in the original model 6D by employing the same mode-sum technique.

  8. Notes on S-folds and {N} = 3 theories

    NASA Astrophysics Data System (ADS)

    Agarwal, Prarit; Amariti, Antonio

    2016-09-01

    We consider D3 branes in presence of an S-fold plane. The latter is a non-perturbative object, arising from the combined projection of an S-duality twist and a discrete orbifold of the R-symmetry group. This construction naively gives rise to 4d {N} = 3 SCFTs. Nevertheless it has been observed that in some cases supersymmetry is enhanced to {N} = 4. In this paper we study the explicit counting of degrees of freedom arising from vector multiplets associated to strings suspended between the D3 branes probing the S-fold. We propose that, for trivial discrete torsion, there is no vector multiplet associated to (1, 0) strings stretched between a brane and its image. We then focus on the case of rank 2 {N} = 3 theory that enhances to SU(3) {N} = 4 SYM, explicitly spelling out the isomorphism between the BPS-spectrum of the manifestly {N} = 3 theory and that of three D3 branes in flat spacetime. Subsequently, we consider 3-pronged strings in these setups and show how wall-crossing in the S-fold background implies wall crossing in the flat geometry. This can be considered a consistency check of the conjectured SUSY enhancement. We also find that the above isomorphism implies that a (1, 0) string, suspended between a brane and its image in the S-fold, corresponds to a 3-string junction in the flat geometry. This is in agreement with our claim on the absence of a vector multiplet associated to such (1, 0) strings. This is because the 3-string junction in flat geometry gives rise to a 1/4-th BPS multiplet of the {N} = 4 algebra. Such multiplets always include particles with spin > 1 as opposed to a vector multiplet which is restricted by the requirement that the spins must be ≤ 1.

  9. Antagonists of substance P. Further modifications of substance P antagonists obtained by replacing either positions 7, 9 or 7, 8 and 11 of SP with D-amino acid residues.

    PubMed

    Dutta, A S; Gormley, J J; Graham, A S; Briggs, I; Growcott, J W; Jamieson, A

    1986-07-01

    Antagonists of SP and the C-terminal (6-11)-hexapeptide have been obtained by multiple D-amino acid substitutions in various positions of SP and by protecting the N alpha-Arg1 and N epsilon Lys3 amino groups with benzyloxycarbonyl groups. On the guinea pig ileum a number of these antagonized both SP and the hexapeptide. Except [N alpha-Z-Arg1,D-Pro2,N epsilon-Z-Lys3,Asn5,Arg6,D-Phe7,D-Trp9]-SP-OMe (4) and the corresponding amide 7, which were more potent antagonists of SP than the hexapeptide, all the others, e.g., [N alpha-Z-Arg1,D-Pro2,4,N epsilon-Z-Lys3,D-Phe7,8,Sar9,D-Met11]-SP-OMe (9), [N alpha-Z-Arg1,D-Pro2,4,N epsilon-Z-Lys3,D-Phe7,8,Sar9,MeLeu10,D-Met11]-SP -OMe (11), were more potent antagonists of the hexapeptide. On the rat spinal cord preparation, most of the antagonists were only active against the hexapeptide. A few antagonized SP, but these also reduced carbachol or both carbachol and glutamate responses. Two of the antagonists, [D-Pro2,Asn5,Lys6,D-Phe7,D-Trp9]-SP-OMe (2) and [Boc-D-Pro4,D-Phe7,8,Sar9,D-Met11]-SP(4-11)-OMe (10), were inactive on the ileum but still antagonized the hexapeptide on the spinal cord. The smallest peptides to antagonize SP and the hexapeptide were two heptapeptides, 6 and 21, [Z-Asn5,Arg6,D-Phe7,8,Gly9 psi (CH2S)D-Leu10,D-Met11]-SP(5-11)-OMe (21) being more potent than 6. None of the antagonists showed significant analgesic activity without side effects. Some of the antagonists were shown to release histamine from isolated rat peritoneal cells.

  10. Magnetically-enhanced open string pair production

    NASA Astrophysics Data System (ADS)

    Lu, J. X.

    2017-12-01

    We consider the stringy interaction between two parallel stacks of D3 branes placed at a separation. Each stack of D3 branes in a similar fashion carry an electric flux and a magnetic flux with the two sharing no common field strength index. The interaction amplitude has an imaginary part, giving rise to the Schwinger-like pair production of open strings. We find a significantly enhanced rate of this production when the two electric fluxes are almost identical and the brane separation is on the order of string scale. This enhancement will be largest if the two magnetic fluxes are opposite in direction. This novel enhancement results from the interplay of the non-perturbative Schwinger-type pair production due to the electric flux and the stringy tachyon due to the magnetic flux, and may have realistic physical applications.

  11. Bibliographie annotee de ressources complementaires. Etudes sociales: Secondaire, 7e a 12e (Annotated Bibliography of Further Resources. Social Studies: Secondary School, Grades 7-12).

    ERIC Educational Resources Information Center

    Soucy, Claire, Comp.; Hebert, Lorraine, Comp.

    This annotated bibliography offers resources for teaching the social studies for grades 7 through 12. Subject areas include: (1) grade 7 - culture of Canada and Japan, as well as multicultural and bilingual Canada; (2) grade 8 - the geography of Canada, the United States, and the case of Brazil in South America; (3) grade 9 - economic perspectives…

  12. Soins primaires aux adultes ayant des déficiences intellectuelles et développementales

    PubMed Central

    Sullivan, William F.; Diepstra, Heidi; Heng, John; Ally, Shara; Bradley, Elspeth; Casson, Ian; Hennen, Brian; Kelly, Maureen; Korossy, Marika; McNeil, Karen; Abells, Dara; Amaria, Khush; Boyd, Kerry; Gemmill, Meg; Grier, Elizabeth; Kennie-Kaulbach, Natalie; Ketchell, Mackenzie; Ladouceur, Jessica; Lepp, Amanda; Lunsky, Yona; McMillan, Shirley; Niel, Ullanda; Sacks, Samantha; Shea, Sarah; Stringer, Katherine; Sue, Kyle; Witherbee, Sandra

    2018-01-01

    Résumé Objectif Mettre à jour les Lignes directrices consensuelles canadiennes 2011 en matière de soins primaires aux adultes ayant une déficience développementale. Méthodes Des médecins de famille et d’autres professionnels de la santé expérimentés dans les soins aux personnes ayant des DID ont examiné et synthétisé les récentes connaissances empiriques, d’écosystèmes, expertes et expérientielles. Un système a été conçu pour catégoriser la qualité des recommandations. Recommandations Les adultes ayant des DID sont un groupe hétérogène de patients qui présentent des affections médicales et des facteurs qui influent sur leur santé, qui diffèrent de ceux qui touchent les autres membres de la communauté de par leur nature, leurs manifestations, leur gravité ou leur complexité. Ces personnes nécessitent une approche de soins et des interventions adaptées à leurs besoins. Les présentes lignes directrices offrent des conseils en matière de normes de soins. Nous avons incorporé des références à des outils cliniques et à d’autres ressources pratiques. Les approches de soins décrites ici s’appliquent aussi à d’autres groupes de patients ayant un déficit cognitif ou de la communication, ou d’autres déficits des fonctions adaptatives. Conclusion À titre de fournisseurs de soins de première ligne, les médecins de famille jouent un rôle vital de promotion de la santé et de bien-être auprès des adultes ayant des DID. Ces lignes directrices peuvent les aider à prendre des décisions avec les patients et les aidants naturels. PMID:29650617

  13. Orientifolds and duality cascades: confinement before the wall

    NASA Astrophysics Data System (ADS)

    Argurio, Riccardo; Bertolini, Matteo

    2018-02-01

    We consider D-branes at orientifold singularities and discuss two properties of the corresponding low energy four-dimensional effective theories which are not shared, generically, by other Calabi-Yau singularities. The first property is that duality cascades are finite and, unlike ordinary ones, do not require an infinite number of degrees of freedom to be UV-completed. The second is that orientifolds tend to stabilize runaway directions. These two properties can have interesting implications and widen in an intriguing way the variety of gauge theories one can describe using D-branes.

  14. Strong Enrichment of Aromatic Residues in Binding Sites from a Charge-neutralized Hyperthermostable Sso7d Scaffold Library*

    PubMed Central

    Kiefer, Jonathan D.; Srinivas, Raja R.; Lobner, Elisabeth; Tisdale, Alison W.; Mehta, Naveen K.; Yang, Nicole J.; Tidor, Bruce; Wittrup, K. Dane

    2016-01-01

    The Sso7d protein from the hyperthermophilic archaeon Sulfolobus solfataricus is an attractive binding scaffold because of its small size (7 kDa), high thermal stability (Tm of 98 °C), and absence of cysteines and glycosylation sites. However, as a DNA-binding protein, Sso7d is highly positively charged, introducing a strong specificity constraint for binding epitopes and leading to nonspecific interaction with mammalian cell membranes. In the present study, we report charge-neutralized variants of Sso7d that maintain high thermal stability. Yeast-displayed libraries that were based on this reduced charge Sso7d (rcSso7d) scaffold yielded binders with low nanomolar affinities against mouse serum albumin and several epitopes on human epidermal growth factor receptor. Importantly, starting from a charge-neutralized scaffold facilitated evolutionary adaptation of binders to differentially charged epitopes on mouse serum albumin and human epidermal growth factor receptor, respectively. Interestingly, the distribution of amino acids in the small and rigid binding surface of enriched rcSso7d-based binders is very different from that generally found in more flexible antibody complementarity-determining region loops but resembles the composition of antibody-binding energetic hot spots. Particularly striking was a strong enrichment of the aromatic residues Trp, Tyr, and Phe in rcSso7d-based binders. This suggests that the rigidity and small size of this scaffold determines the unusual amino acid composition of its binding sites, mimicking the energetic core of antibody paratopes. Despite the high frequency of aromatic residues, these rcSso7d-based binders are highly expressed, thermostable, and monomeric, suggesting that the hyperstability of the starting scaffold and the rigidness of the binding surface confer a high tolerance to mutation. PMID:27582495

  15. Strong Enrichment of Aromatic Residues in Binding Sites from a Charge-neutralized Hyperthermostable Sso7d Scaffold Library.

    PubMed

    Traxlmayr, Michael W; Kiefer, Jonathan D; Srinivas, Raja R; Lobner, Elisabeth; Tisdale, Alison W; Mehta, Naveen K; Yang, Nicole J; Tidor, Bruce; Wittrup, K Dane

    2016-10-21

    The Sso7d protein from the hyperthermophilic archaeon Sulfolobus solfataricus is an attractive binding scaffold because of its small size (7 kDa), high thermal stability (T m of 98 °C), and absence of cysteines and glycosylation sites. However, as a DNA-binding protein, Sso7d is highly positively charged, introducing a strong specificity constraint for binding epitopes and leading to nonspecific interaction with mammalian cell membranes. In the present study, we report charge-neutralized variants of Sso7d that maintain high thermal stability. Yeast-displayed libraries that were based on this reduced charge Sso7d (rcSso7d) scaffold yielded binders with low nanomolar affinities against mouse serum albumin and several epitopes on human epidermal growth factor receptor. Importantly, starting from a charge-neutralized scaffold facilitated evolutionary adaptation of binders to differentially charged epitopes on mouse serum albumin and human epidermal growth factor receptor, respectively. Interestingly, the distribution of amino acids in the small and rigid binding surface of enriched rcSso7d-based binders is very different from that generally found in more flexible antibody complementarity-determining region loops but resembles the composition of antibody-binding energetic hot spots. Particularly striking was a strong enrichment of the aromatic residues Trp, Tyr, and Phe in rcSso7d-based binders. This suggests that the rigidity and small size of this scaffold determines the unusual amino acid composition of its binding sites, mimicking the energetic core of antibody paratopes. Despite the high frequency of aromatic residues, these rcSso7d-based binders are highly expressed, thermostable, and monomeric, suggesting that the hyperstability of the starting scaffold and the rigidness of the binding surface confer a high tolerance to mutation. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Genetic Variation of an Odorant Receptor OR7D4 and Sensory Perception of Cooked Meat Containing Androstenone

    PubMed Central

    Lunde, Kathrine; Egelandsdal, Bjørg; Skuterud, Ellen; Mainland, Joel D.; Lea, Tor; Hersleth, Margrethe; Matsunami, Hiroaki

    2012-01-01

    Although odour perception impacts food preferences, the effect of genotypic variation of odorant receptors (ORs) on the sensory perception of food is unclear. Human OR7D4 responds to androstenone, and genotypic variation in OR7D4 predicts variation in the perception of androstenone. Since androstenone is naturally present in meat derived from male pigs, we asked whether OR7D4 genotype correlates with either the ability to detect androstenone or the evaluation of cooked pork tainted with varying levels of androstenone within the naturally-occurring range. Consistent with previous findings, subjects with two copies of the functional OR7D4 RT variant were more sensitive to androstenone than subjects carrying a non-functional OR7D4 WM variant. When pork containing varying levels of androstenone was cooked and tested by sniffing and tasting, subjects with two copies of the RT variant tended to rate the androstenone-containing meat as less favourable than subjects carrying the WM variant. Our data is consistent with the idea that OR7D4 genotype predicts the sensory perception of meat containing androstenone and that genetic variation in an odorant receptor can alter food preferences. PMID:22567099

  17. Distributed SUSY breaking: dark energy, Newton's law and the LHC

    NASA Astrophysics Data System (ADS)

    Burgess, C. P.; van Nierop, L.; Williams, M.

    2014-07-01

    We identify the underlying symmetry mechanism that suppresses the low-energy effective 4D cosmological constant within some 6D supergravity models, generically leading to results suppressed by powers of the KK scale, m {/K K 2}, relative to the much larger size, m 4, associated with mass- m particles localized in these models on codimension-2 branes. These models are examples for which the local conditions for unbroken supersymmetry can be satisfied locally everywhere within the extra dimensions, but are obstructed only by global conditions like flux quantization or by the mutual inconsistency of the boundary conditions required at the various branes. Consequently quantities (like vacuum energies) forbidden by supersymmetry cannot become nonzero until wavelengths of order the KK scale are integrated out, since only such long wavelength modes can see the entire space and so `know' that supersymmetry has broken. We verify these arguments by extending earlier rugby-ball calculations of one-loop vacuum energies within these models to more general pairs of branes within two warped extra dimensions. For the Standard Model confined to one of two otherwise identical branes, the predicted effective 4D vacuum energy density is of order ρ vac ⋍ C( mM g /4 πM p )4 = C(5 .6 × 10-5 eV)4, where M g ≳ 10 TeV (corresponding to extra-dimensional size r ≲ 1 μm) and M p = 2 .44 × 1018 GeV are the 6D and 4D rationalized Planck scales, and m is the heaviest brane-localized particle. (For numerical purposes we take m to be the top-quark mass and take M g as small as possible, consistent with energy-loss bounds from supernovae.) C is a constant depending on the details of the bulk spectrum, which could easily be of order 500 for each of hundreds of fields in the bulk. The value C ˜ 6 × 106 would give the observed Dark Energy density.

  18. Energy-momentum tensor of bouncing gravitons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Iofa, Mikhail Z.

    2015-07-14

    In models of the Universe with extra dimensions gravity propagates in the whole space-time. Graviton production by matter on the brane is significant in the early hot Universe. In a model of 3-brane with matter embedded in 5D space-time conditions for gravitons emitted from the brane to the bulk to return back to the brane are found. For a given 5-momentum of graviton falling back to the brane the interval between the times of emission and return to the brane is calculated. A method to calculate contribution to the energy-momentum tensor from multiple graviton bouncings is developed. Explicit expressions formore » contributions to the energy-momentum tensor of gravitons which have made one, two and three bounces are obtained and their magnitudes are numerically calculated. These expressions are used to solve the evolution equation for dark radiation. A relation connecting reheating temperature and the scale of extra dimension is obtained. For the reheating temperature T{sub R}∼10{sup 6} GeV we estimate the scale of extra dimension μ to be of order 10{sup −9} GeV (μ{sup −1}∼10{sup −5} cm)« less

  19. Energy-momentum tensor of bouncing gravitons

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Iofa, Mikhail Z., E-mail: iofa@theory.sinp.msu.ru

    2015-07-01

    In models of the Universe with extra dimensions gravity propagates in the whole space-time. Graviton production by matter on the brane is significant in the early hot Universe. In a model of 3-brane with matter embedded in 5D space-time conditions for gravitons emitted from the brane to the bulk to return back to the brane are found. For a given 5-momentum of graviton falling back to the brane the interval between the times of emission and return to the brane is calculated. A method to calculate contribution to the energy-momentum tensor from multiple graviton bouncings is developed. Explicit expressions formore » contributions to the energy-momentum tensor of gravitons which have made one, two and three bounces are obtained and their magnitudes are numerically calculated. These expressions are used to solve the evolution equation for dark radiation. A relation connecting reheating temperature and the scale of extra dimension is obtained. For the reheating temperature T{sub R}∼ 10{sup 6} GeV we estimate the scale of extra dimension μ to be of order 10{sup −9} GeV (μ{sup −1}∼ 10{sup −5} cm)« less

  20. 51. LOFT. HEATING. PLANS, ELEVATIONS 7 DETAILS, Y&D No. 107729 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. LOFT. HEATING. PLANS, ELEVATIONS 7 DETAILS, Y&D No. 107729 Scales 3/16', 1/4', 1/2', and 1'; July 2, 1929 - U.S. Naval Submarine Base, New London Submarine Escape Training Tank, Albacore & Darter Roads, Groton, New London County, CT

  1. Structural Basis for the Binding of the Neutralizing Antibody, 7D11, to the Poxvirus L1 Protein

    DTIC Science & Technology

    2007-08-01

    pCR- 7D11-vHC and pCR-7D11- vLC , respectively. Crystallization of the complex between L1 and 7D11-Fab VACV L1 protein was expressed and purified as...2005. Vaccinia virus H3L envelope protein is a major target of neutralizing antibodies in humans and elicits protection against lethal challenge in...D.M., Schmaljohn, C., Schmaljohn, A., 2000. DNA vaccination with vaccinia virus L1R and A33R genes protects mice against a lethal poxvirus challenge

  2. Novel hydroxyamides and amides containing D-glucopyranose or D-fructose units: Biological assays in MCF-7 and MDST8 cell lines.

    PubMed

    Carreiro, Elisabete P; Costa, Ana R; Cordeiro, Maria M; Martins, Rute; Pires, Tiago O; Saraiva, Mafalda; Antunes, Célia M; Burke, Anthony J

    2016-02-01

    A novel library of 15 compounds, hydroxyamides and amides containing a β-D-glucopyranose (D-Gluc) or a β-D-fructose (D-Fruc) units was designed and synthesized for antiproliferative assays in breast (MCF-7) and colon (MDST8) cancer cell lines. Twelve of them were hydroxyamides and were successfully synthesized from β-D-glucuronic acid (D-GluA). Six of these hydroxyamides which were acetylated hydroxy-β-D-glucopyranuronamide 2a-2f (1st Family) and the other six were their respective isomers, that is, hydroxy-β-D-fructuronamide 3a-3f (2nd Family), obtained by acid-base catalyzed isomerization. These compounds have the general structure, D-Gluc-C=ONH-CHR-(CH2)n-OH and D-Fruc-C=ONH-CHR-(CH2)n-OH, where R=an aromatic, alkyl or a hydrogen substituent, with n=0 or 1. Eight of these contained a chiral aminoalcohol group. Three compounds were amides containing a D-glucopyranose unit (3rd Family). SAR studies were conducted with these compounds. Antiproliferative studies showed that compound 4a, the bromo-amide containing the β-D-glucopyranose ring, potently inhibits the proliferation of the MDST8 cells. Five compounds (2e, 2f, 3d, 3e, and 3f) were shown to potently selectively inhibit the proliferation of the MCF-7 cells. Compound 4b was the only one showing inhibition in both cell lines. In general, the more active compounds were the amides and hydroxyamides containing the β-D-fructose moiety, and containing an alkyl group or hydrogen. Half-inhibitory concentrations (IC50) of between 0.01 and 10 μM, were observed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. MicroRNA let-7d regulates the TLX/microRNA-9 cascade to control neural cell fate and neurogenesis

    PubMed Central

    Zhao, Chunnian; Sun, GuoQiang; Ye, Peng; Li, Shengxiu; Shi, Yanhong

    2013-01-01

    MicroRNAs have important functions in the nervous system through post-transcriptional regulation of neurogenesis genes. Here we show that microRNA let-7d, which has been implicated in cocaine addiction and other neurological disorders, targets the neural stem cell regulator TLX. Overexpression of let-7d in vivo reduced neural stem cell proliferation and promoted premature neuronal differentiation and migration, a phenotype similar to those induced by TLX knockdown or overexpression of its negatively-regulated target, microRNA-9. We found a let-7d binding sequence in the tlx 3′ UTR and demonstrated that let-7d reduced TLX expression levels in neural stem cells, which in turn, up-regulated miR-9 expression. Moreover, co-expression of let-7d and TLX lacking its 3′ UTR in vivo restored neural stem cell proliferation and reversed the premature neuronal differentiation and migration. Therefore, manipulating let-7d and its downstream targets could be a novel strategy to unravel neurogenic signaling pathways and identify potential interventions for relevant neurological disorders. PMID:23435502

  4. MicroRNA let-7d regulates the TLX/microRNA-9 cascade to control neural cell fate and neurogenesis.

    PubMed

    Zhao, Chunnian; Sun, GuoQiang; Ye, Peng; Li, Shengxiu; Shi, Yanhong

    2013-01-01

    MicroRNAs have important functions in the nervous system through post-transcriptional regulation of neurogenesis genes. Here we show that microRNA let-7d, which has been implicated in cocaine addiction and other neurological disorders, targets the neural stem cell regulator TLX. Overexpression of let-7d in vivo reduced neural stem cell proliferation and promoted premature neuronal differentiation and migration, a phenotype similar to those induced by TLX knockdown or overexpression of its negatively-regulated target, microRNA-9. We found a let-7d binding sequence in the tlx 3' UTR and demonstrated that let-7d reduced TLX expression levels in neural stem cells, which in turn, up-regulated miR-9 expression. Moreover, co-expression of let-7d and TLX lacking its 3' UTR in vivo restored neural stem cell proliferation and reversed the premature neuronal differentiation and migration. Therefore, manipulating let-7d and its downstream targets could be a novel strategy to unravel neurogenic signaling pathways and identify potential interventions for relevant neurological disorders.

  5. D-foam-induced flavor condensates and breaking of supersymmetry in free Wess-Zumino fluids

    NASA Astrophysics Data System (ADS)

    Mavromatos, Nick E.; Sarkar, Sarben; Tarantino, Walter

    2011-08-01

    Recently [N. E. Mavromatos and S. Sarkar, New J. Phys. 10, 073009 (2008) NJOPFM1367-263010.1088/1367-2630/10/7/073009; N. E. Mavromatos, S. Sarkar, and W. Tarantino, Phys. Rev. DPRVDAQ1550-7998 80, 084046 (2009)10.1103/PhysRevD.80.084046], we argued that a particular model of string-inspired quantum space-time foam (D-foam) may induce oscillations and mixing among flavored particles. As a result, rather than the mass-eigenstate vacuum, the correct ground state to describe the underlying dynamics is the flavor vacuum, proposed some time ago by Blasone and Vitiello as a description of quantum field theories with mixing. At the microscopic level, the breaking of target-space supersymmetry is induced in our space-time foam model by the relative transverse motion of brane defects. Motivated by these results, we show that the flavor vacuum, introduced through an inequivalent representation of the canonical (anti-) commutation relations, provides a vehicle for the breaking of supersymmetry at a low-energy effective field-theory level; on considering the flavor-vacuum expectation value of the energy-momentum tensor and comparing with the form of a perfect relativistic fluid, it is found that the bosonic sector contributes as dark energy while the fermion contribution is like dust. This indicates a strong and novel breaking of supersymmetry, of a nonperturbative nature, which may characterize the low-energy field theory of certain quantum-gravity models.

  6. Nonspherically symmetric black string perturbations in the large dimension limit

    NASA Astrophysics Data System (ADS)

    Sadhu, Amruta; Suneeta, Vardarajan

    2016-06-01

    We consider nonspherically symmetric perturbations of the uncharged black string/flat black brane in the large dimension (D) limit of general relativity. We express the perturbations in a simplified form using variables introduced by Ishibashi and Kodama. We apply the large D limit to the equations and show that this leads to decoupling of the equations in the near-horizon and asymptotic regions. It also enables use of matched asymptotic expansions to obtain approximate analytical solutions and to analyze stability of the black string/brane. For a large class of nonspherically symmetric perturbations, we prove that there are no instabilities in the large D limit. For the rest, we provide additional matching arguments that indicate that the black string/brane is stable. In the static limit, we show that for all nonspherically symmetric perturbations, there is no instability. This is proof that the Gross-Perry-Yaffe mode for semiclassical black hole perturbations is the unique unstable mode even in the large D limit. This work is also a direct analytical indication that the only instability of the black string is the Gregory-Laflamme instability.

  7. Holographic models with anisotropic scaling

    NASA Astrophysics Data System (ADS)

    Brynjolfsson, E. J.; Danielsson, U. H.; Thorlacius, L.; Zingg, T.

    2013-12-01

    We consider gravity duals to d+1 dimensional quantum critical points with anisotropic scaling. The primary motivation comes from strongly correlated electron systems in condensed matter theory but the main focus of the present paper is on the gravity models in their own right. Physics at finite temperature and fixed charge density is described in terms of charged black branes. Some exact solutions are known and can be used to obtain a maximally extended spacetime geometry, which has a null curvature singularity inside a single non-degenerate horizon, but generic black brane solutions in the model can only be obtained numerically. Charged matter gives rise to black branes with hair that are dual to the superconducting phase of a holographic superconductor. Our numerical results indicate that holographic superconductors with anisotropic scaling have vanishing zero temperature entropy when the back reaction of the hair on the brane geometry is taken into account.

  8. Exact results in 3d N = 2 Spin(7) gauge theories with vector and spinor matters

    NASA Astrophysics Data System (ADS)

    Nii, Keita

    2018-05-01

    We study three-dimensional N = 2 Spin(7) gauge theories with N S spinorial matters and with N f vectorial matters. The quantum Coulomb branch on the moduli space of vacua is one- or two-dimensional depending on the matter contents. For particular values of ( N f , N S ), we find s-confinement phases and derive exact superpotentials. The 3d dynamics of Spin(7) is connected to the 4d dynamics via KK-monopoles. Along the Higgs branch of the Spin(7) theories, we obtain 3d N = 2 G 2 or SU(4) theories and some of them lead to new s-confinement phases. As a check of our analysis we compute superconformal indices for these theories.

  9. Work/Family Balancing and 24/7 Work Schedules: Network Analysis of Strategies in a Transport Company Cleaning Service: Concilier travail-famille et horaires 24/7: analyse réseau des stratégies au sein du service de nettoyage d'une compagnie de transport.

    PubMed

    Lefrançois, Mélanie; Saint-Charles, Johanne; Riel, Jessica

    2017-11-01

    Whether or not official work/family balance measures exist within an organization, scheduling accommodations often go through informal channels involving colleagues and superiors and are negotiated within interpersonal relationships. This study examines the relationship dimensions of the scheduling strategies of cleaners working atypical hours in the transport sector through the lenses of ergonomic activity, network, and gender analyses. Using semi-directed interviews, observation, and network analysis, we revealed the effect of gender on relationship dynamics and the influence of these dynamics on work/family balance strategies deployed by cleaners. One of the main contributions of this study is to demonstrate the decisive effect of relationships by revealing inequalities in access to organizational social networks. Creating spaces to discuss work/family balancing and a more equitable circulation of information could contribute to reducing inequalities associated with gender, social status, and family responsibilities and support the work/family strategies developed by workers dealing with restrictive work schedules. Résumé Les accommodements du temps de travail pour la conciliation travail-famille (CTF) passent souvent par des ententes informelles qui s'inscrivent dans les relations entre collègues ou avec des gestionnaires. Notre étude, intégrant l'ergonomie et la communication dans une perspective de genre, porte sur les dimensions relationnelles des stratégies de choix d'horaire d'agentes et agents de nettoyage devant composer avec des horaires atypiques dans le secteur des transports. À partir d'entretiens semi-dirigés, d'observations et d'analyse de réseaux, nous avons pu observer l'influence des dynamiques relationnelles, notamment de genre, sur les stratégies de CTF. Un apport central de cette étude est de montrer l'effet structurant des relations en révélant notamment des inégalités dans l'accès aux ressources facilitant le choix d

  10. Constraints on wrapped Dirac-Born-Infeld inflation in a warped throat

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kobayashi, Takeshi; Mukohyama, Shinji; Kinoshita, Shunichiro, E-mail: tkobayashi@utap.phys.s.u-tokyo.ac.jp, E-mail: mukoyama@phys.s.u-tokyo.ac.jp, E-mail: kinoshita@utap.phys.s.u-tokyo.ac.jp

    2008-01-15

    We derive constraints on the tensor to scalar ratio and on the background charge of the warped throat for Dirac-Born-Infeld inflation driven by D5- and D7-branes wrapped over cycles of the throat. It is shown that background charge well beyond the known maximal value is required in most cases for Dirac-Born-Infeld inflation to generate cosmological observables compatible with the WMAP3 (Wilkinson Microwave Anisotropy Probe 3) data. Most of the results derived in this paper are insensitive to the details of the inflaton potential, and could be applied to generic warped throats.

  11. Peptide hydrogelation and cell encapsulation for 3D culture of MCF-7 breast cancer cells.

    PubMed

    Huang, Hongzhou; Ding, Ying; Sun, Xiuzhi S; Nguyen, Thu A

    2013-01-01

    Three-dimensional (3D) cell culture plays an invaluable role in tumor biology by providing in vivo like microenviroment and responses to therapeutic agents. Among many established 3D scaffolds, hydrogels demonstrate a distinct property as matrics for 3D cell culture. Most of the existing pre-gel solutions are limited under physiological conditions such as undesirable pH or temperature. Here, we report a peptide hydrogel that shows superior physiological properties as an in vitro matrix for 3D cell culture. The 3D matrix can be accomplished by mixing a self-assembling peptide directly with a cell culture medium without any pH or temperature adjustment. Results of dynamic rheological studies showed that this hydrogel can be delivered multiple times via pipetting without permanently destroying the hydrogel architecture, indicating the deformability and remodeling ability of the hydrogel. Human epithelial cancer cells, MCF-7, are encapsulated homogeneously in the hydrogel matrix during hydrogelation. Compared with two-dimensional (2D) monolayer culture, cells residing in the hydrogel matrix grow as tumor-like clusters in 3D formation. Relevant parameters related to cell morphology, survival, proliferation, and apoptosis were analyzed using MCF-7 cells in 3D hydrogels. Interestingly, treatment of cisplatin, an anti-cancer drug, can cause a significant decrease of cell viability of MCF-7 clusters in hydrogels. The responses to cisplatin were dose- and time-dependent, indicating the potential usage of hydrogels for drug testing. Results of confocal microscopy and Western blotting showed that cells isolated from hydrogels are suitable for downstream proteomic analysis. The results provided evidence that this peptide hydrogel is a promising 3D cell culture material for drug testing.

  12. Peptide Hydrogelation and Cell Encapsulation for 3D Culture of MCF-7 Breast Cancer Cells

    PubMed Central

    Sun, Xiuzhi S.; Nguyen, Thu A.

    2013-01-01

    Three-dimensional (3D) cell culture plays an invaluable role in tumor biology by providing in vivo like microenviroment and responses to therapeutic agents. Among many established 3D scaffolds, hydrogels demonstrate a distinct property as matrics for 3D cell culture. Most of the existing pre-gel solutions are limited under physiological conditions such as undesirable pH or temperature. Here, we report a peptide hydrogel that shows superior physiological properties as an in vitro matrix for 3D cell culture. The 3D matrix can be accomplished by mixing a self-assembling peptide directly with a cell culture medium without any pH or temperature adjustment. Results of dynamic rheological studies showed that this hydrogel can be delivered multiple times via pipetting without permanently destroying the hydrogel architecture, indicating the deformability and remodeling ability of the hydrogel. Human epithelial cancer cells, MCF-7, are encapsulated homogeneously in the hydrogel matrix during hydrogelation. Compared with two-dimensional (2D) monolayer culture, cells residing in the hydrogel matrix grow as tumor-like clusters in 3D formation. Relevant parameters related to cell morphology, survival, proliferation, and apoptosis were analyzed using MCF-7 cells in 3D hydrogels. Interestingly, treatment of cisplatin, an anti-cancer drug, can cause a significant decrease of cell viability of MCF-7 clusters in hydrogels. The responses to cisplatin were dose- and time-dependent, indicating the potential usage of hydrogels for drug testing. Results of confocal microscopy and Western blotting showed that cells isolated from hydrogels are suitable for downstream proteomic analysis. The results provided evidence that this peptide hydrogel is a promising 3D cell culture material for drug testing. PMID:23527204

  13. Higher derivative couplings in theories with sixteen supersymmetries

    DOE PAGES

    Lin, Ying -Hsuan; Shao, Shu -Heng; Yin, Xi; ...

    2015-12-15

    We give simple arguments for new non-renormalization theorems on higher derivative couplings of gauge theories to supergravity, with sixteen supersymmetries, by considerations of brane-bulk superamplitudes. This leads to some exact results on the effective coupling of D3-branes in type IIB string theory. As a result, we also derive exact results on higher dimensional operators in the torus compactification of the six dimensional (0, 2) superconformal theory.

  14. G-theory: The generator of M-theory and supersymmetry

    NASA Astrophysics Data System (ADS)

    Sepehri, Alireza; Pincak, Richard

    2018-04-01

    In string theory with ten dimensions, all Dp-branes are constructed from D0-branes whose action has two-dimensional brackets of Lie 2-algebra. Also, in M-theory, with 11 dimensions, all Mp-branes are built from M0-branes whose action contains three-dimensional brackets of Lie 3-algebra. In these theories, the reason for difference between bosons and fermions is unclear and especially in M-theory there is not any stable object like stable M3-branes on which our universe would be formed on it and for this reason it cannot help us to explain cosmological events. For this reason, we construct G-theory with M dimensions whose branes are formed from G0-branes with N-dimensional brackets. In this theory, we assume that at the beginning there is nothing. Then, two energies, which differ in their signs only, emerge and produce 2M degrees of freedom. Each two degrees of freedom create a new dimension and then M dimensions emerge. M-N of these degrees of freedom are removed by symmetrically compacting half of M-N dimensions to produce Lie-N-algebra. In fact, each dimension produces a degree of freedom. Consequently, by compacting M-N dimensions from M dimensions, N dimensions and N degrees of freedom is emerged. These N degrees of freedoms produce Lie-N-algebra. During this compactification, some dimensions take extra i and are different from other dimensions, which are known as time coordinates. By this compactification, two types of branes, Gp and anti-Gp-branes, are produced and rank of tensor fields which live on them changes from zero to dimension of brane. The number of time coordinates, which are produced by negative energy in anti-Gp-branes, is more sensible to number of times in Gp-branes. These branes are compactified anti-symmetrically and then fermionic superpartners of bosonic fields emerge and supersymmetry is born. Some of gauge fields play the role of graviton and gravitino and produce the supergravity. The question may arise that what is the physical reason

  15. La prévention des blessures chez les enfants et les adolescents : une démarche de santé publique

    PubMed Central

    Yanchar, Natalie L; Warda, Lynne J; Fuselli, Pamela

    2012-01-01

    RÉSUMÉ La majorité des blessures dont sont victimes les enfants et les adolescents sont évitables. Le présent document de principes contient des renseignements généraux, des conseils et une déclaration d’engagement à l’égard de la prévention des blessures au Canada. Il sert de base sur laquelle construire en s’attardant d’abord aux définitions, à l’étendue et aux priorités en matière de prévention des blessures. Il contient également une description du fardeau et du profil des blessures non intentionnelles, de même que les principes d’interventions de prévention efficaces. La version intégrale renferme une liste de ressources en vue d’obtenir des données et de l’information probante (www.cps.ca). Enfin, le présent document de principes peut être utilisé pour la défense généralisée de la prévention des blessures.

  16. 3. Côte D'Ivoire

    NASA Astrophysics Data System (ADS)

    Cisse, M'badiala

    1996-01-01

    Entreprendre une recherche sur la politique et la législation en matière d'éducation des adultes, qui couvre plusieurs secteurs, paraît une gageure pour plusieurs raisons: difficultés dans la constitution de plusieurs équipes de recherche avec plusieurs spécialistes ou personnes ressources, difficultés dans la collecte des données, étendue et complexité des domaines à explorer et des points à prendre en compte dans la rédaction, etc. En dépit de ces difficultés majeures, l'essentiel du travail a été accompli dans le souci de respecter les exigences imposées. A l'analyse, nous constatons que plusieurs partenaires interviennent dans la formation, l'éducation et l'encadrement des adultes, et que dans le secteur public, les structures ne sont pas "logées à la même enseigne": Si la formation professionnelle a bénéficié de conditions réellement favorables pour son expansion et son développement, les autres secteurs, sans avoir été négligés, n'ont pas connu les mêmes faveurs. Ainsi plusieurs lois et mesures importantes ont été votées et prises en vue de la dynamisation de la formation professionnelle, alors que le secteur de l'agriculture, qui est la base de succès du développement du pays et occupe 55% de la population, n'a pas bénéficié d'une véritable politique éducative en faveur des agriculteurs. Il en est de même pour l'alphabétisation. On déplore constamment l'absence de politique élaborée et appliquée à l'échelle nationale. Aucune mesure politique n'a été votée par l'Assemblée nationale, alors que l'alphabétisation devrait constituer le levier du développement de l'éducation des adultes en Côte d'lvoire.

  17. Higher Rank ABJM Wilson Loops from Matrix Models

    NASA Astrophysics Data System (ADS)

    Cookmeyer, Jonathan; Liu, James; Zayas, Leopoldo

    2017-01-01

    We compute the expectation values of 1/6 supersymmetric Wilson Loops in ABJM theory in higher rank representations. Using standard matrix model techniques, we calculate the expectation value in the rank m fully symmetric and fully antisymmetric representation where m is scaled with N. To leading order, we find agreement with the classical action of D6 and D2 branes in AdS4 ×CP3 respectively. Further, we compute the first subleading order term, which, on the AdS side, makes a prediction for the one-loop effective action of the corresponding D6 and D2 branes. Supported by the National Science Foundation under Grant No. PHY 1559988 and the US Department of Energy under Grant No. DE-SC0007859.

  18. 77 FR 39921 - D&C Red No. 6 and D&C Red No. 7; Change in Specification

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ..., OH 45232, had filed a color additive petition (CAP 1C0290) requesting that FDA amend its regulations....2306 and 74.2307. Both color additives are required to be batch certified by FDA before they may... D&C Red Nos. 6 and 7 contained ether-soluble matter for which the proponents of the color additives...

  19. Characterization and cross calibration of Agfa D4, D7, and D8 and Kodak SR45 x-ray films against direct exposure film at 4.0-5.5 keV

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lanier, N.E.; Cowan, J.S.; Workman, J.

    2006-04-15

    Kodak direct exposure film (DEF) [B. L. Henke et al., J. Opt. Soc. Am. B 3, 1540 (1986)] has been the standard for moderate energy (1-10 keV) x-ray diagnostic applications among the high-energy-density and inertial confinement fusion research communities. However, market forces have prompted Kodak to discontinue production of DEF, leaving these specialized communities searching for a replacement. We have conducted cross-calibration experiments and film characterizations on five possible substitutes for Kodak DEF. The film types studied were Kodak's Biomax MR (BMR) and SR45 along with Agfa's D8, D7, and D4sc. None of the films tested matched the speed ofmore » DEF. BMR and D8 were closest but D8 exhibited lower noise, with superior resolution and dynamic range. Agfa D7, Agfa D4sc, and Kodak SR45 were significantly less sensitive than BMR and D8, however, the improvements they yielded in resolution and dynamic range warrant their use if experimental constraints allow.« less

  20. The KMOS3D Survey: Design, First Results, and the Evolution of Galaxy Kinematics from 0.7 <= z <= 2.7

    NASA Astrophysics Data System (ADS)

    Wisnioski, E.; Förster Schreiber, N. M.; Wuyts, S.; Wuyts, E.; Bandara, K.; Wilman, D.; Genzel, R.; Bender, R.; Davies, R.; Fossati, M.; Lang, P.; Mendel, J. T.; Beifiori, A.; Brammer, G.; Chan, J.; Fabricius, M.; Fudamoto, Y.; Kulkarni, S.; Kurk, J.; Lutz, D.; Nelson, E. J.; Momcheva, I.; Rosario, D.; Saglia, R.; Seitz, S.; Tacconi, L. J.; van Dokkum, P. G.

    2015-02-01

    We present the KMOS3D survey, a new integral field survey of over 600 galaxies at 0.7 < z < 2.7 using KMOS at the Very Large Telescope. The KMOS3D survey utilizes synergies with multi-wavelength ground- and space-based surveys to trace the evolution of spatially resolved kinematics and star formation from a homogeneous sample over 5 Gyr of cosmic history. Targets, drawn from a mass-selected parent sample from the 3D-HST survey, cover the star formation-stellar mass (M *) and rest-frame (U - V) - M * planes uniformly. We describe the selection of targets, the observations, and the data reduction. In the first-year of data we detect Hα emission in 191 M * = 3 × 109-7 × 1011 M ⊙ galaxies at z = 0.7-1.1 and z = 1.9-2.7. In the current sample 83% of the resolved galaxies are rotation dominated, determined from a continuous velocity gradient and v rot/σ0 > 1, implying that the star-forming "main sequence" is primarily composed of rotating galaxies at both redshift regimes. When considering additional stricter criteria, the Hα kinematic maps indicate that at least ~70% of the resolved galaxies are disk-like systems. Our high-quality KMOS data confirm the elevated velocity dispersions reported in previous integral field spectroscopy studies at z >~ 0.7. For rotation-dominated disks, the average intrinsic velocity dispersion decreases by a factor of two from 50 km s-1at z ~ 2.3 to 25 km s-1at z ~ 0.9. Combined with existing results spanning z ~ 0-3, we show that disk velocity dispersions follow an evolution that is consistent with the dependence of velocity dispersion on gas fractions predicted by marginally stable disk theory. Based on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO program IDS 092A-0091, 093.A-0079).

  1. Gravity and large black holes in Randall-Sundrum II braneworlds.

    PubMed

    Figueras, Pau; Wiseman, Toby

    2011-08-19

    We show how to construct low energy solutions to the Randall-Sundrum II (RSII) model by using an associated five-dimensional anti-de Sitter space (AdS(5)) and/or four-dimensional conformal field theory (CFT(4)) problem. The RSII solution is given as a perturbation of the AdS(5)-CFT(4) solution, with the perturbation parameter being the radius of curvature of the brane metric compared to the AdS length ℓ. The brane metric is then a specific perturbation of the AdS(5)-CFT(4) boundary metric. For low curvatures the RSII solution reproduces 4D general relativity on the brane. Recently, AdS(5)-CFT(4) solutions with a 4D Schwarzschild boundary metric were numerically constructed. We modify the boundary conditions to numerically construct large RSII static black holes with radius up to ~20ℓ. For a large radius, the RSII solutions are indeed close to the associated AdS(5)-CFT(4) solution. © 2011 American Physical Society

  2. 7 CFR Exhibit D to Subpart K of... - Amendment to Technical and Supervisory Assistance Grant Agreement

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 13 2012-01-01 2012-01-01 false Amendment to Technical and Supervisory Assistance Grant Agreement D Exhibit D to Subpart K of Part 1944 Agriculture Regulations of the Department of... Technical and Supervisory Assistance Grants Pt. 1944, Subpt. K, Exh. D Exhibit D to Subpart K of Part 1944...

  3. 7 CFR Exhibit D to Subpart K of... - Amendment to Technical and Supervisory Assistance Grant Agreement

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 13 2013-01-01 2013-01-01 false Amendment to Technical and Supervisory Assistance Grant Agreement D Exhibit D to Subpart K of Part 1944 Agriculture Regulations of the Department of... Technical and Supervisory Assistance Grants Pt. 1944, Subpt. K, Exh. D Exhibit D to Subpart K of Part 1944...

  4. 7 CFR Exhibit D to Subpart K of... - Amendment to Technical and Supervisory Assistance Grant Agreement

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 13 2014-01-01 2013-01-01 true Amendment to Technical and Supervisory Assistance Grant Agreement D Exhibit D to Subpart K of Part 1944 Agriculture Regulations of the Department of... Technical and Supervisory Assistance Grants Pt. 1944, Subpt. K, Exh. D Exhibit D to Subpart K of Part 1944...

  5. 7 CFR Exhibit D to Subpart K of... - Amendment to Technical and Supervisory Assistance Grant Agreement

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 13 2011-01-01 2009-01-01 true Amendment to Technical and Supervisory Assistance Grant Agreement D Exhibit D to Subpart K of Part 1944 Agriculture Regulations of the Department of... Technical and Supervisory Assistance Grants Pt. 1944, Subpt. K, Exh. D Exhibit D to Subpart K of Part 1944...

  6. 7 CFR Exhibit D to Subpart K of... - Amendment to Technical and Supervisory Assistance Grant Agreement

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 13 2010-01-01 2009-01-01 true Amendment to Technical and Supervisory Assistance Grant Agreement D Exhibit D to Subpart K of Part 1944 Agriculture Regulations of the Department of... Technical and Supervisory Assistance Grants Pt. 1944, Subpt. K, Exh. D Exhibit D to Subpart K of Part 1944...

  7. 7Li(d,p)8Li transfer reaction in the NCSM/RGM approach

    NASA Astrophysics Data System (ADS)

    Raimondi, F.; Hupin, G.; Navrátil, P.; Quaglioni, S.

    2018-03-01

    Recently, we applied an ab initio method, the no-core shell model combined with the resonating group method, to the transfer reactions with light p-shell nuclei as targets and deuteron as the projectile. In particular, we studied the elastic scattering of deuterium on 7Li and the 7Li(d,p)8Li transfer reaction starting from a realistic two-nucleon interaction. In this contribution, we review of our main results on the 7Li(d,p)8Li transfer reaction, and we extend the study of the relevant reaction channels, by showing the dominant resonant phase shifts of the scattering matrix. We assess also the impact of the polarization effects of the deuteron below the breakup on the positive-parity resonant states in the reaction. For this purpose, we perform an analysis of the convergence trend of the phase and eigenphase shifts, with respect to the number of deuteron pseudostates included in the model space.

  8. Fbxw7 Deletion Accelerates KrasG12D-Driven Pancreatic Tumorigenesis via Yap Accumulation.

    PubMed

    Zhang, Qiang; Zhang, Yaqing; Parsels, Joshua D; Lohse, Ines; Lawrence, Theodore S; Pasca di Magliano, Marina; Sun, Yi; Morgan, Meredith A

    2016-11-01

    Pancreatic cancers driven by KRAS mutations require additional mutations for tumor progression. The tumor suppressor FBXW7 is altered in pancreatic cancers, but its contribution to pancreatic tumorigenesis is unknown. To determine potential cooperation between Kras mutation and Fbxw7 inactivation in pancreatic tumorigenesis, we generated P48-Cre;LSL-Kras G12D ;Fbxw7 fl/fl (KFC fl/fl ) compound mice. We found that KFC fl/fl mice displayed accelerated tumorigenesis: all mice succumbed to pancreatic ductal adenocarcinoma (PDA) by 40 days of age, with PDA onset occurring by 2 weeks of age. PDA in KFC fl/fl mice was preceded by earlier onset of acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN) lesions, and associated with chromosomal instability and the accumulation of Fbxw7 substrates Yes-associated protein (Yap), c-Myc, and Notch. Using KFC fl/fl and FBXW7-deficient human pancreatic cancer cells, we found that Yap silencing attenuated growth promotion by Fbxw7 deletion. Our data demonstrate that Fbxw7 is a potent suppressor of Kras G12D -induced pancreatic tumorigenesis due, at least in part, to negative regulation of Yap. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  9. D242N, a KV7.1 LQTS mutation uncovers a key residue for IKs voltage dependence.

    PubMed

    Moreno, Cristina; Oliveras, Anna; Bartolucci, Chiara; Muñoz, Carmen; de la Cruz, Alicia; Peraza, Diego A; Gimeno, Juan R; Martín-Martínez, Mercedes; Severi, Stefano; Felipe, Antonio; Lambiase, Pier D; Gonzalez, Teresa; Valenzuela, Carmen

    2017-09-01

    K V 7.1 and KCNE1 co-assemble to give rise to the I Ks current, one of the most important repolarizing currents of the cardiac action potential. Its relevance is underscored by the identification of >500 mutations in K V 7.1 and, at least, 36 in KCNE1, that cause Long QT Syndrome (LQTS). The aim of this study was to characterize the biophysical and cellular consequences of the D242N K V 7.1 mutation associated with the LQTS. The mutation is located in the S4 transmembrane segment, within the voltage sensor of the K V 7.1 channel, disrupting the conserved charge balance of this region. Perforated patch-clamp experiments show that, unexpectedly, the mutation did not disrupt the voltage-dependent activation but it removed the inactivation and slowed the activation kinetics of D242N K V 7.1 channels. Biotinylation of cell-surface protein and co-immunoprecipitation experiments revealed that neither plasma membrane targeting nor co-assembly between K V 7.1 and KCNE1 was altered by the mutation. However, the association of D242N K V 7.1 with KCNE1 strongly shifted the voltage dependence of activation to more depolarized potentials (+50mV), hindering I Ks current at physiologically relevant membrane potentials. Both functional and computational analysis suggest that the clinical phenotype of the LQTS patients carrying the D242N mutation is due to impaired action potential adaptation to exercise and, in particular, to increase in heart rate. Moreover, our data identify D242 aminoacidic position as a potential residue involved in the KCNE1-mediated regulation of the voltage dependence of activation of the K V 7.1 channel. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. 21 CFR 74.2707a - Ext. D&C Yellow No. 7.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Ext. D&C Yellow No. 7. 74.2707a Section 74.2707a Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF... for coloring externally applied cosmetics in amounts consistent with good manufacturing practice. (c...

  11. The D1CT-7 mouse model of Tourette syndrome displays sensorimotor gating deficits in response to spatial confinement.

    PubMed

    Godar, Sean C; Mosher, Laura J; Strathman, Hunter J; Gochi, Andrea M; Jones, Cori M; Fowler, Stephen C; Bortolato, Marco

    2016-07-01

    The D1CT-7 mouse is one of the best known animal models of Tourette syndrome (TS), featuring spontaneous tic-like behaviours sensitive to standard TS therapies; these characteristics ensure a high face and predictive validity of this model, yet its construct validity remains elusive. To address this issue, we studied the responses of D1CT-7 mice to two critical components of TS pathophysiology: the exacerbation of tic-like behaviours in response to stress and the presence of sensorimotor gating deficits, which are thought to reflect the perceptual alterations causing the tics. D1CT-7 and wild-type (WT) littermates were subjected to a 20 min session of spatial confinement (SC) within an inescapable, 10 cm wide cylindrical enclosure. Changes in plasma corticosterone levels, tic-like behaviours and other spontaneous responses were measured. SC-exposed mice were also tested for the prepulse inhibition (PPI) of the startle response (a sensorimotor gating index) and other TS-related behaviours, including open-field locomotion, novel object exploration and social interaction and compared with non-confined counterparts. SC produced a marked increase in corticosterone concentrations in both D1CT-7 and WT mice. In D1CT-7, but not WT mice, SC exacerbated tic-like and digging behaviours, and triggered PPI deficits and aggressive responses. Conversely, SC did not modify locomotor activity or novel object exploration in D1CT-7 mice. Both tic-like behaviours and PPI impairments in SC-exposed D1CT-7 mice were inhibited by standard TS therapies and D1 dopamine receptor antagonism. These findings collectively support the translational and construct validity of D1CT-7 mice with respect to TS. This article is part of a themed section on Updating Neuropathology and Neuropharmacology of Monoaminergic Systems. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v173.13/issuetoc. © 2015 The British Pharmacological Society.

  12. Report on the Evaluation Results of the Course "Mechanic Undercarriage Leopard 2"

    DTIC Science & Technology

    1998-01-14

    is onderdeel van TNO Defensieonderzoek waartoe verder behoren: TNO Fysisch en Elektronisch Laboratorium TNO Prins Maurits Laboratorium ...beroepsonderwijs MFO Militaire Functie Opleiding NBC Nucleair Biologisch Chemisch OCLOG Onderwijs Centrum Logistiek OCTD Onderhouds Centrum Technische

  13. 30 CFR 50.20-7 - Criteria-MSHA Form 7000-1, Section D.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., INJURIES, ILLNESSES, EMPLOYMENT, AND PRODUCTION IN MINES NOTIFICATION, INVESTIGATION, REPORTS AND RECORDS OF ACCIDENTS, INJURIES, ILLNESSES, EMPLOYMENT, AND COAL PRODUCTION IN MINES Reporting of Accidents, Injuries, and Illnesses § 50.20-7 Criteria—MSHA Form 7000-1, Section D. This section requires information...

  14. 30 CFR 50.20-7 - Criteria-MSHA Form 7000-1, Section D.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., INJURIES, ILLNESSES, EMPLOYMENT, AND PRODUCTION IN MINES NOTIFICATION, INVESTIGATION, REPORTS AND RECORDS OF ACCIDENTS, INJURIES, ILLNESSES, EMPLOYMENT, AND COAL PRODUCTION IN MINES Reporting of Accidents, Injuries, and Illnesses § 50.20-7 Criteria—MSHA Form 7000-1, Section D. This section requires information...

  15. 30 CFR 50.20-7 - Criteria-MSHA Form 7000-1, Section D.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., INJURIES, ILLNESSES, EMPLOYMENT, AND PRODUCTION IN MINES NOTIFICATION, INVESTIGATION, REPORTS AND RECORDS OF ACCIDENTS, INJURIES, ILLNESSES, EMPLOYMENT, AND COAL PRODUCTION IN MINES Reporting of Accidents, Injuries, and Illnesses § 50.20-7 Criteria—MSHA Form 7000-1, Section D. This section requires information...

  16. 30 CFR 50.20-7 - Criteria-MSHA Form 7000-1, Section D.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., INJURIES, ILLNESSES, EMPLOYMENT, AND PRODUCTION IN MINES NOTIFICATION, INVESTIGATION, REPORTS AND RECORDS OF ACCIDENTS, INJURIES, ILLNESSES, EMPLOYMENT, AND COAL PRODUCTION IN MINES Reporting of Accidents, Injuries, and Illnesses § 50.20-7 Criteria—MSHA Form 7000-1, Section D. This section requires information...

  17. Hawking radiation in a d-dimensional static spherically symmetric black hole surrounded by quintessence

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen Songbai; Wang Bin; Su Rukeng

    2008-06-15

    We present a solution of Einstein equations with quintessential matter surrounding a d-dimensional black hole, whose asymptotic structures are determined by the state of the quintessential matter. We examine the thermodynamics of this black hole and find that the mass of the black hole depends on the equation of state of the quintessence, while the first law is universal. Investigating the Hawking radiation in this black hole background, we observe that the Hawking radiation dominates on the brane in the low-energy regime. For different asymptotic structures caused by the equation of state of the quintessential matter surrounding the black hole,more » we learn that the influences by the state parameter of the quintessence on Hawking radiation are different.« less

  18. 2D radially compensating excitation pulse in combination with an internal transceiver antenna for 3D MRI of the rectum at 7 T.

    PubMed

    van Kalleveen, I M L; Kroeze, H; Sbrizzi, A; Boer, V O; Reerink, O; Philippens, M E P; van de Berg, C A T; Luijten, P R; Klomp, D W J

    2016-07-01

    The high precession frequency in ultrahigh field MRI coincides with reduced RF penetration, increased RF power deposition and consequently can lead to reduced scan efficiency. However, the shorter wavelength enables the use of efficient antennas rather than loop coils. In fact, ultrathin monopole antennas have been demonstrated at 7 T, which fit in natural cavities like the rectum in the human body. As the RF field generated by the antenna provides an extremely nonuniform B1 field, the use of conventional RF pulses will lead to severe image distortions and highly nonuniform contrast. However, using the two predominant dimensions (orthogonal to the antenna), 2D RF pulses can be designed that counteract the nonuniform B1 into uniform flip angles. In this study the authors investigate the use of an ultrathin antenna not only for reception, but also for transmission in 7 T MRI of the rectum. The 2D radially compensating excitation (2D RACE) pulse was designed in matlab. SAR calculations between the 2D RACE pulse and an adiabatic RF pulse (BIR-4) have been obtained, to visualize the gain in decreasing the SAR when using the 2D RACE pulse instead of an adiabatic RF pulse. The authors used the 7 T whole body MR system in combination with an internally placed monopole antenna used for transceiving and obtained 3D gradient echo images with a conventional sinc pulse and with the 2D RACE pulse. For extra clarity, they also reconstructed an image where the receive field of the antenna was removed. Comparing the results of the SAR simulations of the 2D RACE pulse with a BIR-4 pulse shows that for low flip angles (θ < 41°) the SAR can be decreased with a factor of 4.8 or even more, when using the 2D RACE pulse. Relative to a conventional sinc excitation, the 2D RACE pulse achieves more uniform flip angle distributions than a BIR-4 pulse with a smaller SAR increase (16 × versus 64 ×). The authors have shown that the 2D RACE pulse provides more homogeneous flip angles for

  19. Cyclic guanidines: synthesis and antiplatelet activity of 4,6,7,8-tetrahydro-1H-imidazo[1,2-a]pyrazolo[3,4-d]pyrimidin-7-ones and 1,4,6,7,8,9-hexahydropyrazolo [3',4':4,5]pyrimido[2,1-c] [1,2,4]triazin-7-ones.

    PubMed

    Ferroni, R; Simoni, D; Orlandini, P; Bardi, A; Franze, G P; Guarneri, M

    1990-12-01

    A series of 4,6,7,8-tetrahydro-1H-imidazo[1,2-a]pyrazolo [3,4-d]pyrimidin-7-ones (1b-n) and 1,4,6,7,8,9-hexahydropyrazolo [3',4':4,5]pyrimido [2,1-c][1,2,4]triazin-7-ones (2a-d) has been synthesized. In view of their potential anti-aggregating activity the compounds were tested in vitro for inhibitory activity towards ADP- and collagen-induced aggregation of human platelets. Among the compounds studied, 8-benzyl-1-(2,5-dichlorophenyl)-4,6,7,8-tetrahydro-1H-imidazo [1,2-a]pyrazolo[3,4-d]pyrimidin-7-one (1n) exhibited the most favorable activity. The 2,5-dichlorophenyl side chain is an important lipophilic and/or steric pharmacophore.

  20. Expression of porcine fusion protein IRF7/3(5D) efficiently controls foot-and-mouth disease virus replication.

    PubMed

    Ramírez-Carvajal, Lisbeth; Díaz-San Segundo, Fayna; Hickman, Danielle; Long, Charles R; Zhu, James; Rodríguez, Luis L; de los Santos, Teresa

    2014-10-01

    Several studies have demonstrated that the delivery of type I, II, or III interferons (IFNs) by inoculation of a replication-defective human adenovirus 5 (Ad5) vector expressing IFNs can effectively control foot-and-mouth disease (FMD) in cattle and swine during experimental infections. However, relatively high doses are required to achieve protection. In this study, we identified the functional properties of a porcine fusion protein, poIRF7/3(5D), as a biotherapeutic and enhancer of IFN activity against FMD virus (FMDV). We showed that poIRF7/3(5D) is a potent inducer of type I IFNs, including alpha IFN (IFN-α), IFN-β, and IFN-ω but not type III IFN (interleukin-28B), without inducing cytotoxicity. Expression of poIRF7/3(5D) significantly and steadily reduced FMDV titers by up to 6 log10 units in swine and bovine cell lines. Treatment with an IFN receptor inhibitor (B18R) combined with an anti-IFN-α antibody neutralized the antiviral activity in the supernatants of cells transduced with an Ad5 vector expressing poIRF7/3(5D) [Ad5-poIRF7/3(5D)]. However, several transcripts with known antiviral function, including type I IFNs, were still highly upregulated (range of increase, 8-fold to over 500-fold) by poIRF7/3(5D) in the presence of B18R. Furthermore, the sera of mice treated with Ad5-poIRF7/3(5D) showed antiviral activity that was associated with the induction of high levels of IFN-α and resulted in complete protection against FMDV challenge at 6, 24, or 48 h posttreatment. This study highlights for the first time the antiviral potential of Ad5-poIRF7/3(5D) in vitro and in vivo against FMDV. FMD remains one of the most devastating diseases that affect livestock worldwide. Effective vaccine formulations are available but are serotype specific and require approximately 7 days before they are able to elicit protective immunity. We have shown that vector-delivered IFN is an option to protect animals against many FMDV serotypes as soon as 24 h and for about 4

  1. Holographic Chern-Simons defects

    DOE PAGES

    Fujita, Mitsutoshi; Melby-Thompson, Charles M.; Meyer, René; ...

    2016-06-28

    Here, we study SU(N ) Yang-Mills-Chern-Simons theory in the presence of defects that shift the Chern-Simons level from a holographic point of view by embedding the system in string theory. The model is a D3-D7 system in Type IIB string theory, whose gravity dual is given by the AdS soliton background with probe D7 branes attaching to the AdS boundary along the defects. We holographically renormalize the free energy of the defect system with sources, from which we obtain the correlation functions for certain operators naturally associated to these defects. We find interesting phase transitions when the separation of themore » defects as well as the temperature are varied. We also discuss some implications for the Fractional Quantum Hall Effect and for 2-dimensional QCD.« less

  2. The Tn7 transposition regulator TnsC interacts with the transposase subunit TnsB and target selector TnsD

    PubMed Central

    Choi, Ki Young; Spencer, Jeanelle M.; Craig, Nancy L.

    2014-01-01

    The excision of transposon Tn7 from a donor site and its insertion into its preferred target site, attachment site attTn7, is mediated by four Tn7-encoded transposition proteins: TnsA, TnsB, TnsC, and TnsD. Transposition requires the assembly of a nucleoprotein complex containing all four Tns proteins and the DNA substrates, the donor site containing Tn7, and the preferred target site attTn7. TnsA and TnsB together form the heteromeric Tn7 transposase, and TnsD is a target-selecting protein that binds specifically to attTn7. TnsC is the key regulator of transposition, interacting with both the TnsAB transposase and TnsD-attTn7. We show here that TnsC interacts directly with TnsB, and identify the specific region of TnsC involved in the TnsB–TnsC interaction during transposition. We also show that a TnsC mutant defective in interaction with TnsB is defective for Tn7 transposition both in vitro and in vivo. Tn7 displays cis-acting target immunity, which blocks Tn7 insertion into a target DNA that already contains Tn7. We provide evidence that the direct TnsB–TnsC interaction that we have identified also mediates cis-acting Tn7 target immunity. We also show that TnsC interacts directly with the target selector protein TnsD. PMID:24982178

  3. 7. VIEW TO NORTH. FROM WEST PLATFORM. SAME AS IL1D3, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW TO NORTH. FROM WEST PLATFORM. SAME AS IL-1D-3, AFTER TRAIN HAS DEPARTED EAST PLATFORM. - Union Elevated Railroad, Randolph-Wabash Avenue Station, Randolph Street & Wabash Avenue, Chicago, Cook County, IL

  4. Deformations, moduli stabilisation and gauge couplings at one-loop

    NASA Astrophysics Data System (ADS)

    Honecker, Gabriele; Koltermann, Isabel; Staessens, Wieland

    2017-04-01

    We investigate deformations of Z_2 orbifold singularities on the toroidal orbifold {T}^6/(Z_2× Z_6) with discrete torsion in the framework of Type IIA orientifold model building with intersecting D6-branes wrapping special Lagrangian cycles. To this aim, we employ the hypersurface formalism developed previously for the orbifold {T}^6/(Z_2× Z_6) with discrete torsion and adapt it to the (Z_2× Z_6× Ω R) point group by modding out the remaining Z_3 subsymmetry and the orientifold projection Ω R. We first study the local behaviour of the Z_3× Ω R invariant deformation orbits under non-zero deformation and then develop methods to assess the deformation effects on the fractional three-cycle volumes globally. We confirm that D6-branes supporting USp(2 N) or SO(2 N) gauge groups do not constrain any deformation, while deformation parameters associated to cycles wrapped by D6-branes with U( N) gauge groups are constrained by D-term supersymmetry breaking. These features are exposed in global prototype MSSM, Left-Right symmetric and Pati-Salam models first constructed in [1, 2], for which we here count the number of stabilised moduli and study flat directions changing the values of some gauge couplings.

  5. Deforming baryons into confining strings

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hartnoll, Sean A.; Portugues, Ruben

    2004-09-15

    We find explicit probe D3-brane solutions in the infrared of the Maldacena-Nunez background. The solutions describe deformed baryon vertices: q external quarks are separated in spacetime from the remaining N-q. As the separation is taken to infinity we recover known solutions describing infinite confining strings in N=1 gauge theory. We present results for the mass of finite confining strings as a function of length. We also find probe D2-brane solutions in a confining type IIA geometry, the reduction of a G{sub 2} holonomy M theory background. The relation between these deformed baryons and confining strings is not as straightforward.

  6. Transmogrifying fuzzy vortices

    NASA Astrophysics Data System (ADS)

    Murugan, Jeff; Millner, Antony

    2004-04-01

    We show that the construction of vortex solitons of the noncommutative abelian-Higgs model can be extended to a critically coupled gauged linear sigma model with Fayet-Illiopolous D-terms. Like its commutative counterpart, this fuzzy linear sigma model has a rich spectrum of BPS solutions. We offer an explicit construction of the degree-k static semilocal vortex and study in some detail the infinite coupling limit in which it descends to a degree-k Bbb CBbb PkN instanton. This relation between the fuzzy vortex and noncommutative lump is used to suggest an interpretation of the noncommutative sigma model soliton as tilted D-strings stretched between an NS5-brane and a stack of D3-branes in type-IIB superstring theory.

  7. Holography, black holes and condensed matter physics

    NASA Astrophysics Data System (ADS)

    Gentle, Simon Adam

    In this thesis we employ holographic techniques to explore strongly-coupled quantum field theories at non-zero temperature and density. First we consider a state dual to a charged black hole with planar horizon and compute retarded Green's functions for conserved currents in the shear channel. We demonstrate the intricate motion of their poles and stress the importance of the residues at the poles beyond the hydrodynamic regime. We then explore the collective excitations of holographic quantum liquids arising on D3/D5 and D3/D7 brane intersections as a function of temperature and magnetic field in the probe limit. We observe a crossover from hydrodynamic charge diffusion to a sound mode similar to the zero sound mode in the collisionless regime of a Landau Fermi liquid. The location of this crossover is approximately independent of the magnetic field. The sound mode has a gap proportional to the magnetic field, leading to strong suppression of spectral weight for intermediate frequencies and sufficiently large magnetic fields. In the second part we explore the solution space of AdS gravity in the hope of learning general lessons about such theories. First we study charged scalar solitons in global AdS4. These solutions have a rich phase space and exhibit critical behaviour as a function of the scalar charge and scalar boundary conditions. We demonstrate how the planar limit of global solitons coincides generically with the zero-temperature limit of black branes with charged scalar hair. We exhibit these features in both phenomenological models and consistent truncations of eleven-dimensional supergravity. We then discover new branches of hairy black brane in SO(6) gauged supergravity. Despite the imbalance provided by three chemical potentials conjugate to the three R-charges, there is always at least one branch with charged scalar hair, emerging at a temperature where the normal phase is locally thermodynamically stable.

  8. 7 CFR Exhibit D to Subpart I of... - Self-Help Technical Assistance Grant Predevelopment Agreement

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 13 2011-01-01 2009-01-01 true Self-Help Technical Assistance Grant Predevelopment... SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) HOUSING Self-Help Technical Assistance Grants Pt. 1944, Subpt. I, Exh. D Exhibit D to Subpart I of Part 1944—Self-Help...

  9. 7 CFR Exhibit D to Subpart I of... - Self-Help Technical Assistance Grant Predevelopment Agreement

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 13 2010-01-01 2009-01-01 true Self-Help Technical Assistance Grant Predevelopment... SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) HOUSING Self-Help Technical Assistance Grants Pt. 1944, Subpt. I, Exh. D Exhibit D to Subpart I of Part 1944—Self-Help...

  10. Quantum Field Theories Coupled to Supergravity: AdS/CFT and Local Couplings

    NASA Astrophysics Data System (ADS)

    Große, Johannes

    2007-11-01

    This article is based on my PhD thesis and covers the following topics: Holographic meson spectra in a dilaton flow background, the mixed Coulomb-Higgs branch in terms of instantons on D7 branes, and a dual description of heavy-light mesons. Moreover, in a second part the conformal anomaly of four dimensional supersymmetric quantum field theories coupled to classical N=1 supergravity is explored in a superfield formulation. The complete basis for the anomaly and consistency conditions, which arise from cohomological considerations, are given. Possible implications for an extension of Zamolodchikov's c-theorem to four dimensional supersymmetric quantum field theories are discussed.

  11. 6d $$ \\mathcal{N}=\\left(1,\\;0\\right) $$ theories on S 1/T 2 and class S theories: part II

    DOE PAGES

    Ohmori, Kantaro; Shimizu, Hiroyuki; Tachikawa, Yuji; ...

    2015-12-21

    Here, we study the T 2 compactification of a class of 6dmore » $$ \\mathcal{N}=\\left(1,\\;0\\right) $$ theories that is Higgsable to $$ \\mathcal{N}=\\left(2,\\;0\\right) $$ theories. We show that the resulting 4d N=2 theory at the origin of the Coulomb branch and the parameter space is generically given by two superconformal matter sectors coupled by an infrared-free gauge multiplet and another conformal gauge multiplet. Our analysis utilizes the 5d theories obtained by putting the same class of 6d theories on S 1. Our class includes, among others, the 6d theories describing multiple M 5 branes on an ALE singularity, and we analyze them in detail. The resulting 4d theory has manifestly both the SL(2,Z) and the full flavor symmetry. We also discuss in detail the special cases of 6d theories where the infrared-free gauge multiplet is absent. In an appendix, we give a field-theoretical argument for an F-theoretic constraint that forbids a particular 6d anomaly-free matter content, as an application of our analysis.« less

  12. 6d $$ \\mathcal{N}=\\left(1,\\;0\\right) $$ theories on S 1/T 2 and class S theories: part II

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ohmori, Kantaro; Shimizu, Hiroyuki; Tachikawa, Yuji

    Here, we study the T 2 compactification of a class of 6dmore » $$ \\mathcal{N}=\\left(1,\\;0\\right) $$ theories that is Higgsable to $$ \\mathcal{N}=\\left(2,\\;0\\right) $$ theories. We show that the resulting 4d N=2 theory at the origin of the Coulomb branch and the parameter space is generically given by two superconformal matter sectors coupled by an infrared-free gauge multiplet and another conformal gauge multiplet. Our analysis utilizes the 5d theories obtained by putting the same class of 6d theories on S 1. Our class includes, among others, the 6d theories describing multiple M 5 branes on an ALE singularity, and we analyze them in detail. The resulting 4d theory has manifestly both the SL(2,Z) and the full flavor symmetry. We also discuss in detail the special cases of 6d theories where the infrared-free gauge multiplet is absent. In an appendix, we give a field-theoretical argument for an F-theoretic constraint that forbids a particular 6d anomaly-free matter content, as an application of our analysis.« less

  13. ACE I/D and MMP-7 A-181G variants and the risk of end stage renal disease.

    PubMed

    Rahimi, Zohreh; Abdi, Hamed; Tanhapoor, Maryam; Rahimi, Ziba; Vaisi-Raygani, Asad; Nomani, Hamid

    2017-03-01

    The variants of angiotensin converting enzyme ( ACE ) and matrix metalloproteinases (MMPs) genes might be involved in the pathogenesis of end stage renal disease (ESRD) and hypertension. We studied the ACE insertion/deletion (I/D) and MMP-7 A-181G variants in 99 unrelated ESRD patients and 117 individuals without renal complications from Western Iran with Kurdish ethnic background. The frequency of ACE I/D variants was not significantly different between ESRD patients and controls. However, the presence of ACE D allele increased the risk of hypertension in ESRD patients by 2.14-fold (P=0.036). The MMP-7 -181 AG genotype increased the risk of ESRD by 2.04 times (P=0.026). The present study indicated the absence of an association between the ACE I/D polymorphism with the risk of ESRD. However, the ACE D allele increased the risk of hypertension in ESRD patients. Also, the present study suggests a role for MMP-7 AG genotype in the pathogenesis of ESRD.

  14. Measurement of D*±, D± and D s ± meson production cross sections in pp collisions at s = 7  TeV with the ATLAS detector

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aad, G.; Abbott, B.; Abdallah, J.

    The production of D *±, D ± and Dmore » $$±\\atop{s}$$charmed mesons has been measured with the ATLAS detector in pp collisions at √s = 7 TeV at the LHC, using data corresponding to an integrated luminosity of 280 nb -1. The charmed mesons have been reconstructed in the range of transverse momentum 3.5T(D)<100 GeV and pseudorapidity |η(D)|<2.1. The differential cross sections as a function of transverse momentum and pseudorapidity were measured for D *± and D ± production. The next-to-leading-order QCD predictions are consistent with the data in the visible kinematic region within the large theoretical uncertainties. Using the visible D cross sections and an extrapolation to the full kinematic phase space, the strangeness-suppression factor in charm fragmentation, the fraction of charged non-strange D mesons produced in a vector state, and the total cross section of charm production at √s = 7 TeV were derived.« less

  15. Engine component improvement: Performance improvement, JT9D-7 3.8 AR fan

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1980-01-01

    A redesigned, fuel efficient fan for the JT9D-7 engine was tested. Tests were conducted to determine the effect of the 3.8 AR fan on performance, stability, operational characteristics, and noise of the JT9D-7 engine relative to the current 4.6 AR Bill-of-Material fan. The 3.8 AR fan provides increased fan efficiency due to a more advanced blade airfoil with increased chord, eliminating one part span shroud and reducing the number of fan blades and fan exit guide vanes. Engine testing at simulated cruise conditions demonstrated the predicted 1.3 percent improvement in specific fuel consumption with the redesigned 3.8 AR fan. Flight testing and sea level stand engine testing demonstrated exhaust gas temperature margins, fan and low pressure compressor stability, operational suitability, and noise levels comparable to the Bill-of-Material fan.

  16. 26 CFR 301.6511(d)-7 - Overpayment of income tax on account of work incentive program credit carryback.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... or refund related to an overpayment of income tax attributable to a work incentive program (WIN... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Overpayment of income tax on account of work incentive program credit carryback. 301.6511(d)-7 Section 301.6511(d)-7 Internal Revenue INTERNAL REVENUE...

  17. Lutte contre la mortalité maternelle en milieu rural: décentralisation de l’offre des soins obstétricaux d’urgence au Burkina Faso

    PubMed Central

    Kaboré, Souleymane; Méda, Clément Ziemlé; Sombié, Issiaka; Savadogo, Léon Blaise; Karama, Robert; Bakouan, Koabié; Ouédraogo, Djénéba Sanon; Coulibaly, Norbert; Kargougou, Robert Lucien; Lankoandé, Emanuel; Sawadogo, Ramatou windsouri; Gosch, Karen

    2017-01-01

    Introduction Pour combler la pénurie en sages-femmes (SF) dans le district sanitaire de Tougan au Burkina Faso, il a été conçu une stratégie de décentralisation de l'offre des soins obstétricaux d'urgence basée sur des interventions ponctuelles de prise en charge des complications obstétricales au niveau des centres de santé (CS) en milieu rural par des SF. La présente étude a eu pour objectif de décrire cette expérience et d'analyser ses résultats. Méthodes Il s'agit d'une étude intervention de type transversal analytique basée sur une revue des données routinières de l'ensemble des parturientes prises en charge de 2013 à 2015. La collecte des données s'est déroulée du 5 au 20 janvier 2016. Un test Chi2, des rapports de cotes (OR) et leurs intervalles de confiance à 95% ont été calculés. Résultats Au total 416 parturientes présentant des complications obstétricales ont été prises en charge par les SF de zone. L'âge moyen des parturientes était de 26.4 ans. La distance médiane parcourue pour prendre en charge les parturientes était de quinze km pour un délai moyen d'intervention de 21.1 minutes (déviation standard = 7.13 minutes). Les dystocies représentaient la moitié (50.7%, IC95% = 45.8-55.6) des complications prises en charge suivies des hémorragies (26.4%, IC95% = 22.3%-31.0%). Plus de 77% des interventions avaient abouti à la résolution locale des complications obstétricales. Enfin, le résultat de l'intervention était fonction de la pathologie prise en charge (OR = 5.88; p < 0.001). Conclusion Cette stratégie a permis d'apporter une réplique à l'absence de SF dans les CS périphériques du district sanitaire de Tougan. Dans ce contexte particulier, cette intervention pourrait apporter une solution alternative au manque de ressources humaines en santé en milieu rural. PMID:28979638

  18. Reflection states in Ding-Iohara-Miki algebra and brane-web for D-type quiver

    NASA Astrophysics Data System (ADS)

    Bourgine, J.-E.; Fukuda, M.; Matsuo, Y.; Zhu, R.-D.

    2017-12-01

    Reflection states are introduced in the vertical and horizontal modules of the Ding-Iohara-Miki (DIM) algebra (quantum toroidal gl_1 ). Webs of DIM representations are in correspondence with ( p, q)-web diagrams of type IIB string theory, under the identification of the algebraic intertwiner of Awata, Feigin and Shiraishi with the refined topological vertex. Extending the correspondence to the vertical reflection states, it is possible to engineer the N=1 quiver gauge theory of D-type (with unitary gauge groups). In this way, the Nekrasov instanton partition function is reproduced from the evaluation of expectation values of intertwiners. This computation leads to the identification of the vertical reflection state with the orientifold plane of string theory. We also provide a translation of this construction in the Iqbal-Kozcaz-Vafa refined topological vertex formalism.

  19. Holographic duals of 3d S-fold CFTs

    NASA Astrophysics Data System (ADS)

    Assel, Benjamin; Tomasiello, Alessandro

    2018-06-01

    We construct non-geometric AdS4 solutions of IIB string theory where the fields in overlapping patches are glued by elements of the S-duality group. We obtain them by suitable quotients of compact and non-compact geometric solutions. The quotient procedure suggests CFT duals as quiver theories with links involving the so-called T [U( N)] theory. We test the validity of the non-geometric solutions (and of our proposed holographic duality) by computing the three-sphere partition function Z of the CFTs. A first class of solutions is obtained by an S-duality quotient of Janus-type non-compact solutions and is dual to 3d N=4 SCFTs; for these we manage to compute Z of the dual CFT at finite N, and it agrees perfectly with the supergravity result in the large N limit. A second class has five-branes, it is obtained by a Möbius-like S-quotient of ordinary compact solutions and is dual to 3d N=3 SCFTs. For these, Z agrees with the supergravity result if one chooses the limit carefully so that the effect of the fivebranes does not backreact on the entire geometry. Other limits suggest the existence of IIA duals.

  20. From Planck Constant to Isomorphicity Through Justice Paradox

    NASA Astrophysics Data System (ADS)

    Hidajatullah-Maksoed, Widastra

    2015-05-01

    Robert E. Scott in his ``Chaos theory and the Justice Paradox'', William & Mary Law Review, v 35, I 1, 329 (1993) wrotes''...As we approach the 21-st Century, the signs of social disarray are everywhere. Social critics observe the breakdown of core structure - the nuclear family, schools, neighborhoods & political groups''. For completions for ``soliton'' first coined by Morikazu TODA, comparing the ``Soliton on Scott-Russell aqueduct on the Union Canal near Heriot-WATT University, July 12, 1995 to Michael Stock works: ``a Fine WATT-Balance: Determination of Planck constant & Redefinition of Kilogram'', January 2011, we can concludes the inherencies between `chaos' & `soliton'. Further through ``string theory'' from Michio KAKU sought statements from Peter Mayr: Stringy world brane & Exponential hierarchy'', JHEP 11 (2000): ``if the 5-brane is embedded in flat 10-D space time, the 6-D Planck mass on the brane is infinite'' who also describes the relation of isomorphicity & ``string theory'', from whom denotes the smart city. Replace this text with your abstract body. Incredible acknowledgments to HE. Mr. Drs. P. SWANTORO & HE. Mr. Dr-HC Jakob OETAMA.