Warped Kaluza-Klein reduction from string duality
NASA Astrophysics Data System (ADS)
Schulz, Michael; Tammaro, Elliott
2014-03-01
Virtually all phenomenologically relevant string theory compactifications are of warped type, in which the overall scale factor of 4D spacetime varies over the internal dimensions. However, the procedure for Kaluza-Klein (KK) reduction is more poorly understood for warped compactifications than for standard compactifications. The simplest standard compactifications are compactifications on tori, and the simplest warped compactifications differ from these by the addition of parallel D-branes and O-branes. It is astonishing that a direct derivation of the dimensionally reduced action does not exist even for these simple warped compactifications (which are T-dual to Type I), although the answer is known on supersymmetry grounds. We fill this void. We derive the procedure for the KK reduction of a simple Type IIA warped compactification with D6 branes and O6 planes, via its lift to the standard compactification of M-theory on K3. Our derivation utilizes an approximate K3 metric of Gibbons-Hawking form, which is exactly equivalent to the classical type IIA supergravity description of the warped compactification. This material is based upon work supported by the National Science Foundation under Grant Nos. PHY09-12219 and PHY11-25915.
Teleparallel conformal invariant models induced by Kaluza-Klein reduction
NASA Astrophysics Data System (ADS)
Geng, Chao-Qiang; Luo, Ling-Wei
2017-06-01
We study the extensions of teleparallism in the Kaluza-Klein (KK) scenario by writing the analogous form to the torsion scalar TNGR in terms of the corresponding antisymmetric tensors, given by TNGR = a Tijk Tijk + b Tijk Tkji + c T j{}ji Tk{}k{}i , in the four-dimensional new general relativity (NGR) with arbitrary coefficients a, b and c. After the KK dimensional reduction, the Lagrangian in the Einstein-frame can be realized by taking 2a + b + c = 0 with the ghost-free condition c≤slant0 for the one-parameter family of teleparallelism. We demonstrate that the pure conformal invariant gravity models can be constructed by the requirements of 2a + b = 0 and c = 0. In particular, the torsion vector can be identified as the conformal gauge field, while the conformal gauge theory can be obtained by 2a + b + 4c = 0 or 2a + b = 0, which is described on the Weyl-Cartan geometry Y 4 with the ghost-free conditions 2a + b + c > 0 and c\
Kaluza-Klein reduction of low-energy effective actions: geometrical approach
NASA Astrophysics Data System (ADS)
Vysoký, Jan
2017-08-01
Equations of motion of low-energy string effective actions can be conveniently described in terms of generalized geometry and Levi-Civita connections on Courant algebroids. This approach is used to propose and prove a suitable version of the Kaluza-Klein-like reduction. Necessary geometrical tools are recalled.
Next-to-leading order gravitational spin1-spin2 coupling with Kaluza-Klein reduction
Levi, Michele
2010-09-15
We use the recently proposed Kaluza-Klein (KK) reduction over the time dimension, within an effective field theory (EFT) approach, to calculate the next-to-leading order gravitational spin1-spin2 interaction between two spinning compact objects. It is shown here that to next-to-leading order in the spin1-spin2 interaction, the reduced KK action within the stationary approximation is sufficient to describe the gravitational interaction, and that it simplifies calculation substantially. We also find here that the gravitomagnetic vector field defined within the KK decomposition of the metric mostly dominates the mediation of the interaction. Our results coincide with those calculated in the Arnowitt-Deser-Misner Hamiltonian formalism, and we provide another explanation for the discrepancy with the result previously derived within the EFT approach, thus demonstrating clearly the equivalence of the Arnowitt-Deser-Misner Hamiltonian formalism and the EFT action approach.
NASA Astrophysics Data System (ADS)
Jana, Sanjib; Krishnan, Chethan
2014-05-01
We generalize the results of arXiv:1212.1875 and arXiv:1212.6919 on attraction basins and their boundaries to the case of a specific class of rotating black holes, namely the ergo-free branch of extremal black holes in Kaluza-Klein theory. We find that exact solutions that span the attraction basin can be found even in the rotating case by appealing to certain symmetries of the equations of motion. They are characterized by two asymptotic parameters that generalize those of the non-rotating case, and the boundaries of the basin are spinning versions of the (generalized) subtractor geometry. We also give examples to illustrate that the shape of the attraction basin can drastically change depending on the theory.
Klein-Gordon oscillator in Kaluza-Klein theory
NASA Astrophysics Data System (ADS)
Carvalho, Josevi; Carvalho, Alexandre M. de M.; Cavalcante, Everton; Furtado, Claudio
2016-07-01
In this contribution we study the Klein-Gordon oscillator on the curved background within the Kaluza-Klein theory. The problem of the interaction between particles coupled harmonically with topological defects in Kaluza-Klein theory is studied. We consider a series of topological defects, then we treat the Klein-Gordon oscillator coupled to this background, and we find the energy levels and corresponding eigenfunctions in these cases. We show that the energy levels depend on the global parameters characterizing these spacetimes. We also investigate a quantum particle described by the Klein-Gordon oscillator interacting with a cosmic dislocation in Som-Raychaudhuri spacetime in the presence of homogeneous magnetic field in a Kaluza-Klein theory. In this case, the energy spectrum is determined, and we observe that these energy levels represent themselves as the sum of the terms related with Aharonov-Bohm flux and of the parameter associated to the rotation of the spacetime.
NASA Astrophysics Data System (ADS)
Peng, Jun-Jin
2017-05-01
In this paper, we investigate the conserved charges of generally diffeomorphism invariant gravity theories with a wide variety of matter fields, particularly of the theories with multiple scalar fields and p -form potentials, in the context of the off-shell generalized Abbott-Deser-Tekin (ADT) formalism. We first construct a new off-shell ADT current that consists of the terms for the variation of a Killing vector and expressions of the field equations as well as the Lie derivative of a surface term with respect to the Killing vector within the framework of generally diffeomorphism invariant gravity theories involving various matter fields. After deriving the off-shell ADT potential corresponding to this current, we propose a formula of conserved charges for these theories. Next, we derive the off-shell ADT potential associated with the generic Lagrangian that describes a large range of gravity theories with a number of scalar fields and p -form potentials. Finally, the properties of the off-shell generalized ADT charges for the theory of Einstein gravity and the gravity theories with a single p -form potential are investigated by performing Kaluza-Klein dimensional reduction along a compactified direction. The results indicate that the charge contributed by all the fields in the lower-dimensional theory is equal to that of the higher-dimensional one at mathematical level with the hypothesis that the higher-dimensional spacetime allows for the existence of the compactified dimension. In order to illustrate our calculations, the mass and angular momentum for the five-dimensional rotating Kaluza-Klein black holes are explicitly evaluated as an example.
Electroweak Kaluza-Klein dark matter
Flacke, Thomas; Kang, Dong Woo; Kong, Kyoungchul; ...
2017-04-07
In models with universal extra dimensions (UED), the lightest Kaluza-Klein excitation of neutral electroweak gauge bosons is a stable, weakly interacting massive particle and thus is a candidate for dark matter thanks to Kaluza-Klein parity. We examine concrete model realizations of such dark matter in the context of non-minimal UED extensions. The boundary localized kinetic terms for the electroweak gauge bosons lead to a non-trivial mixing among the first Kaluza-Klein excitations of themore » $${\\rm SU}(2)_W$$ and $${\\rm U}(1)_Y$$ gauge bosons and the resultant low energy phenomenology is rich. We investigate implications of various experiments including low energy electroweak precision measurements, direct and indirect detection of dark matter particles and direct collider searches at the LHC. Furthermore, we show that the electroweak Kaluza-Klein dark matter can be as heavy as 2.4 TeV, which is significantly higher than $1.3$ TeV as is indicated as an upper bound in the minimal UED model.« less
Electroweak Kaluza-Klein dark matter
NASA Astrophysics Data System (ADS)
Flacke, Thomas; Kang, Dong Woo; Kong, Kyoungchul; Mohlabeng, Gopolang; Park, Seong Chan
2017-04-01
In models with universal extra dimensions (UED), the lightest Kaluza-Klein excitation of neutral electroweak gauge bosons is a stable, weakly interacting massive particle and thus is a candidate for dark matter thanks to Kaluza-Klein parity. We examine concrete model realizations of such dark matter in the context of non-minimal UED extensions. The boundary localized kinetic terms for the electroweak gauge bosons lead to a non-trivial mixing among the first Kaluza-Klein excitations of the SU(2) W and U(1) Y gauge bosons and the resultant low energy phenomenology is rich. We investigate implications of various experiments including low energy electroweak precision measurements, direct and indirect detection of dark matter particles and direct collider searches at the LHC. Notably, we show that the electroweak Kaluza-Klein dark matter can be as heavy as 2.4 TeV, which is significantly higher than 1.3 TeV as is indicated as an upper bound in the minimal UED model.
Fermions in 5D brane world models
NASA Astrophysics Data System (ADS)
Smolyakov, Mikhail
2016-10-01
In the present manuscript the fermion fields in the background of 5D brane world models with compact extra dimension are examined. It is shown that the only case that allows one to perform the Kaluza-Klein decomposition in a mathematically consistent way without unnatural fine-tunings and possible pathologies, is the one which does not admit localization of the zero mode. The report is based on the results presented in [1].
Kaluza-Klein Physics at Muon Colliders
Rizzo, Thomas G.
1999-11-04
We discuss the physics of Kaluza-Klein excitations of the Standard Model gauge bosons that can be explored by a high energy muon collider in the era after the LHC and TeV Linear Collider. We demonstrate that the muon collider is a necessary ingredient in the unraveling the properties of such states and, perhaps, proving their existence. The possibility of observing the resonances associated with the excited KK graviton states of the Randall-Sundrum model is also discussed.
Motion in Kaluza-Klein type theories
Kahil, M.E.
2006-05-15
Path and path deviation equations for charged, spinning and spinning charged objects in different versions of Kaluza-Klein (KK) theory using a modified Bazanski Lagrangian have been derived. The significance of motion in five dimensions, especially for a charged spinning object, has been examined. We have also extended the modified Bazanski approach to derive the path and path deviation equations of a test particle in a version of non-symmetric KK theory.
Kaluza-Klein reduction of massive and partially massless spin-2 fields
NASA Astrophysics Data System (ADS)
Bonifacio, James; Hinterbichler, Kurt
2017-01-01
We describe the dimensional reduction of massive and partially massless spin-2 fields on general Einstein direct product manifolds. As with massless fields, the higher-dimensional gauge symmetry of the partially massless field displays itself upon dimensional reduction as a tower of Stückelberg symmetries for the massive modes of the tower. Unlike the massless case, the zero mode of the gauge symmetry does not display itself as a lower-dimensional non-Stückelberg gauge symmetry enforcing partial masslessness on the zero mode. Partial masslessness is destroyed by the dimensional reduction and the zero-mode gauge symmetry instead serves to eliminate the radion. In addition, we study the fully nonlinear dimensional reduction of de Rham-Gabadadze-Tolley massive gravity on a circle, which results in a massive scalar-tensor-vector theory which we expect to be ghost free, and whose scalar-tensor sector is a special case of mass-varying massive gravity.
State-relevant Maxwell's equation from Kaluza-Klein theory
Luan Jing; Ma Yongge; Ma Boqiang
2007-11-15
We study a five-dimensional perfect fluid coupled with Kaluza-Klein gravity. By dimensional reduction, a modified form of Maxwell's equation is obtained, which is relevant to the equation of state of the source. Since the relativistic magnetohydrodynamics and the three-dimensional formulation are widely used to study space matter, we derive the modified Maxwell's equations and relativistic magnetohydrodynamics in 3+1 form. We then take an ideal Fermi gas as an example to study the modified effect, which can be visible under high-density or high-energy conditions, while the traditional Maxwell's equation can be regarded as a result in the low density and low temperature limit. We also indicate the possibility to test the state-relevant effect of Kaluza-Klein theory in a telluric laboratory.
An exact conformal symmetry Ansatz on Kaluza-Klein reduced TMG
NASA Astrophysics Data System (ADS)
Moutsopoulos, George; Ritter, Patricia
2011-11-01
Using a Kaluza-Klein dimensional reduction, and further imposing a conformal Killing symmetry on the reduced metric generated by the dilaton, we show an Ansatz that yields many of the known stationary axisymmetric solutions to TMG.
On the extra force in brane world scenario
NASA Astrophysics Data System (ADS)
Bejancu, Aurel; Farran, Hani Reda
2014-09-01
In the study of the dynamics in a 5D bulk from brane world scenario, an extra force with abnormal properties was detected (cf. [D. Youm, Extra force in brane worlds, Phys. Rev. D62 (2000) 084002; D. Youm, Null geodesics in brane world universe, Mod. Phys. Lett. A16 (2001) 2371; L. F. Zhang and Y. Z. Zhang, Null geodesics in brane world scenarios, Commun. Theor. Phys. (Beijing)41 (2004) 48]). In this paper, by using the Riemannian horizontal connection introduced in [A. Bejancu, A new point of view on general Kaluza-Klein theories, Progr. Theor. Phys.128 (2012) 541], we give a new definition for the extra force in a 5D bulk, and show that it does not contradict the 4D physics. In particular, we show that this force appears very rarely along geodesics in a warped 5D bulk.
Wormhole in 5D Kaluza-Klein cosmology
NASA Astrophysics Data System (ADS)
Biswas, Gargi; Modak, B.
2017-03-01
We present wormhole as a solution of Euclidean field equations as well as the solution of the Wheeler-deWitt (WD) equation satisfying Hawking-Page wormhole boundary conditions in (4 + 1)-dimensional Kaluza-Klein cosmology. The wormholes are considered in the cases of pure gravity, minimally coupled scalar (imaginary) field and with a positive cosmological constant assuming dynamical extra-dimensional space. In above cases, wormholes are allowed both from Euclidean field equations and WD equation. The dimensional reduction is possible.
Galactic entropy in extended Kaluza-Klein cosmology
NASA Astrophysics Data System (ADS)
Yanar, Hilmi; Salti, Mustafa; Aydogdu, Oktay; Acikgoz, Irfan; Yasar, Erol
2016-02-01
We use a Kaluza-Klein model with variable cosmological and gravitational terms to discuss the nature of galactic entropy function. For this purpose, we assume a universe filled with dark fluid and consider five-dimensional (5D) field equations using the Gamma law equation. We mainly discuss the validity of the first and generalized second laws of galactic thermodynamics for viable Kaluza-Klein models.
Kaluza-Klein relics from warped reheating
Berndsen, Aaron; Cline, James M.; Stoica, Horace
2008-06-15
It has been suggested that after brane-antibrane inflation in a Klebanov-Strassler (KS) warped throat, metastable Kaluza-Klein excitations can be formed due to nearly-conserved angular momenta along isometric directions in the throat. If sufficiently long lived, these relics could conflict with big bang nucleosynthesis or baryogenesis by dominating the energy density of the Universe. We make a detailed estimate of the decay rate of such relics using the low-energy effective action of type IIB string theory compactified on the throat geometry, with attention to powers of the warp factor. We find that it is necessary to turn on supersymmetry (SUSY)-breaking deformations of the KS background in order to ensure that the most dangerous relics will decay fast enough. The decay rate is found to be much larger than the naive guess based on the dimension of the operators which break the angular isometries of the throat. For an inflationary warp factor of order w{approx}10{sup -4}, we obtain the bound M{sub 3/2} > or approx. 10{sup 9} GeV on the scale of SUSY breaking to avoid cosmological problems from the relics, which is satisfied in the Kachru, Kallosh, Linde, and Trivedi construction assumed to stabilize the compactification. Given the requirement that the relics decay before nucleosynthesis or baryogenesis, we place bounds on the mass of the relic as a function of the warp factor in the throat for more general warped backgrounds.
Kaluza-Klein gravitons at LHC2
NASA Astrophysics Data System (ADS)
Dillon, Barry M.; Sanz, Veronica
2017-08-01
In this work we study constraints from new searches for heavy particles at the LHC on the allowed masses and couplings of a Kaluza-Klein (KK) graviton in a holographic composite Higgs model. Keeping new electroweak states heavy such that electroweak precision tests are satisfied, we control the mass of the lightest KK graviton using a brane kinetic term. With this we study KK graviton masses from 0.5-3 TeV. In our analysis we also employ little Randall-Sundrum (RS) models, characterized by a lower UV scale in the five-dimensional model which in turn implies modified couplings to massless bulk fields. Viewing this scenario as a strongly coupled four-dimensional theory with a composite Higgs boson, the KK graviton is interpreted as a composite spin-2 state and the varying UV scale corresponds to a varying intermediate scale between the cutoff of the low-energy effective theory and the Planck scale. We find that KK gravitons with masses in the range [500, 3000] GeV are compatible with current collider constraints, where the most promising channels for detecting these states are the diphoton and Z Z channels. A detection is more likely in the little RS models, in which the dual gauge theory has a larger number of colors than in traditional RS models.
Hawking radiation as tunneling from squashed Kaluza-Klein black hole
Matsuno, Ken; Umetsu, Koichiro
2011-03-15
We discuss Hawking radiation from a five-dimensional squashed Kaluza-Klein black hole on the basis of the tunneling mechanism. A simple method, which was recently suggested by Umetsu, may be used to extend the original derivation by Parikh and Wilczek to various black holes. That is, we use the two-dimensional effective metric, which is obtained by the dimensional reduction near the horizon, as the background metric. Using the same method, we derive both the desired result of the Hawking temperature and the effect of the backreaction associated with the radiation in the squashed Kaluza-Klein black hole background.
Charged black holes on a Kaluza-Klein bubble
Kunz, Jutta; Yazadjiev, Stoytcho
2009-01-15
We construct a solution of two black holes on a Kaluza-Klein bubble in Einstein-Maxwell-dilaton theory. We explore the consequences of the presence of charge for the properties of this solution, and obtain a generalized Smarr relation and first law.
Neutrinos from Kaluza-Klein dark matter in the Sun
Blennow, Mattias; Melbéus, Henrik; Ohlsson, Tommy E-mail: melbeus@kth.se
2010-01-01
We investigate indirect neutrino signals from annihilations of Kaluza-Klein dark matter in the Sun. Especially, we examine a five- as well as a six-dimensional model, and allow for the possibility that boundary localized terms could affect the spectrum to give different lightest Kaluza-Klein particles, which could constitute the dark matter. The dark matter candidates that are interesting for the purpose of indirect detection of neutrinos are the first Kaluza-Klein mode of the gauge boson and the neutral component of the gauge bosons. Using the DarkSUSY and WimpSim packages, we calculate muon fluxes at an Earth-based neutrino telescope, such as IceCube. For the five-dimensional model, the results that we obtained agree reasonably well with the results that have previously been presented in the literature, whereas for the six-dimensional model, we find that, at tree-level, the results are the same as for the five-dimensional model. Finally, if the first Kaluza-Klein mode of the gauge boson constitutes the dark matter, IceCube can constrain the parameter space. However, in the case that the neutral component of the gauge bosons is the LKP, the signal is too weak to be observed.
Finite temperature effective potential in a Kaluza-Klein universe
Roy, P. )
1990-01-20
The authors evaluate the finite temperature one-loop effective potential for scalar fields in Kaluza-Klein universe consisting of the product of a space with open Robertson-Walker metric and the N sphere S{sup N}. The one-loop effective potential has been computed in both high and low temperature limits.
Rotating black ring on Kaluza-Klein bubbles
Nedkova, Petya G.; Yazadjiev, Stoytcho S.
2010-08-15
We construct a new exact solution to the 5D Einstein equations describing a rotating black ring with a single angular momentum surrounded by two Kaluza-Klein bubbles. The solution is generated by two-soliton Baecklund transformation. Its physical properties are computed and analyzed. The corresponding static solution, the rotating black string, and the boosted black string are reproduced as limits.
Cosmological model of the Kaluza-Klein type
Kopczyn-ski, W.
1987-12-15
The theory of a fluid composed of multidimensional objects is joined with the Kaluza-Klein idea with the following aim: an explanation of the distinction between the internal and the external spaces. On the cosmic scale, the internal space contracts and the external space expands. A formula for the rate of decrease of the gravitational constant is discussed.
Residue theorem and summing over Kaluza-Klein excitations
Feng Taifu; Chen Jianbin; Gao Tiejun; Sun Kesheng
2011-11-01
Applying the equations of motion together with corresponding boundary conditions of bulk profiles at infrared and ultraviolet branes, we verify some lemmas on the eigenvalues of Kaluza-Klein modes in extension of the standard model with a warped extra dimension and the custodial symmetry SU(3){sub c}xSU(2){sub L}xSU(2){sub R}xU(1){sub X}xP{sub LR}. Using the lemmas and performing properly analytic extensions of bulk profiles, we present the sufficient condition for a convergent series of Kaluza-Klein excitations and sum over the series through the residue theorem. The method can also be applied to sum over the infinite series of Kaluza-Klein excitations in a universal extra dimension. Furthermore, we analyze the possible connection between the propagators in five-dimensional full theory and the product of bulk profiles with corresponding propagators of exciting Kaluza-Klein modes in four-dimensional effective theory, and recover some relations presented in the literature for warped and universal extra dimensions, respectively. As an example, we present the correction from new physics to the branching ratio of B{yields}X{sub s{gamma}} to the order O({mu}{sub EW}{sup 2}/{Lambda}{sub KK}{sup 2}) in extension of the standard model with a warped extra dimension and the custodial symmetry, where {Lambda}{sub KK} denotes the energy scale of low-lying Kaluza-Klein excitations and {mu}{sub EW} denotes the electroweak energy scale.
Topology change in Kaluza-Klein and superstring theories
NASA Astrophysics Data System (ADS)
Tipler, Frank J.
1985-12-01
It is shown that topology change-for instance, true dynamical compactification - cannot occur in classical Kaluza-Klein and superstring theories without causality violation either in the form of a breakdown in predictability (a failure of global hyperbolicity), or in the form of closed timelike curves. This implies that if causality holds, then any topological distinction between the spacetime and internal dimensions either has to be present ab initio, or else must arise in the quantum gravity regime. Permanent address.
Constraints on cosmic superstrings from Kaluza-Klein emission.
Dufaux, Jean-François
2012-07-06
Cosmic superstrings interact generically with a tower of light and/or strongly coupled Kaluza-Klein (KK) modes associated with the geometry of the internal space. We study the production of KK particles by cosmic superstring loops, and show that it is constrained by big bang nucleosynthesis. We study the resulting constraints in the parameter space of the underlying string theory model and highlight their complementarity with the regions that can be probed by current and upcoming gravitational wave experiments.
Kaluza-Klein mesons in universal extra dimensions
De Pree, Erin; Sher, Marc
2005-11-01
In models with universal extra dimensions, the isosinglet Kaluza-Klein (KK) quarks (q{sup 1}) have very narrow widths, of O(5-10) MeV, and will thus hadronize. Studies of KK quarkonia (q{sup 1}q{sup 1}) show very sharp resonances and dramatic signatures at the linear collider. In this Brief Report, we consider the possibility of detecting KK mesons (q{sup 1}q), and show that detection at a linear collider is unlikely.
Enhanced line signals from annihilating Kaluza-Klein dark matter
NASA Astrophysics Data System (ADS)
Arina, Chiara; Bringmann, Torsten; Silk, Joseph; Vollmann, Martin
2014-10-01
Monochromatic gamma ray lines have long been known to provide potential smoking-gun signals for annihilating dark matter. Here, we demonstrate that the situation is particularly interesting for Kaluza-Klein dark matter because resonant annihilation is generically expected for small, but not necessarily vanishing relative velocities of the annihilating particles. We calculate the contribution from those hitherto neglected resonances and show that the annihilation rate into monochromatic photons can be significantly enhanced, in a way that is much more pronounced than for the associated production of continuum photons. For favorable astrophysical conditions, this leads to promising prospects for the detection of TeV-scale Kaluza-Klein dark matter. We also point out that the situation may be even more interesting in the vicinity of black holes, like the supermassive black hole at the center of our Galaxy, where in principle center-of-mass energies much larger than the rest mass are available. In this case, annihilating Kaluza-Klein dark matter may show the striking and unique signature of several gamma ray lines, with an equidistant spacing corresponding to twice the compactification radius of the extra dimension.
Causal Anomalies in Kaluza-Klein Gravity Theories
NASA Astrophysics Data System (ADS)
Rebouças, M. J.; Teixeira, A. F. F.
Causal anomalies in two Kaluza-Klein gravity theories are examined, particularly as to whether these theories permit solutions in which the causality principle is violated. It is found that similarly to general relativity the field equations of the space-time-mass Kaluza-Klein (STM-KK) gravity theory do not exclude violation of causality of Gödel type, whereas the induced matter Kaluza-Klein (IM-KK) gravity rules out noncausal Gödel-type models. The induced matter version of general relativity is shown to be an efficient therapy for causal anomalies that occurs in a wide class of noncausal geometries. Perfect fluid and dust Gödel-type solutions of the STM-KK field equations are studied. It is shown that every Gödel-type perfect fluid solution is isometric to the unique dust solution of the STM-KK field equations. The question as to whether 5D Gödel-type noncausal geometries induce any physically acceptable 4D energy-momentum tensor is also addressed.
Fermions in five-dimensional brane world models
NASA Astrophysics Data System (ADS)
Smolyakov, Mikhail N.
2016-06-01
In the present paper the fermion fields, living in the background of five-dimensional warped brane world models with compact extra dimension, are thoroughly examined. The Kaluza-Klein decomposition and isolation of the physical degrees of freedom is performed for those five-dimensional fermion field Lagrangians, which admit such a decomposition to be performed in a mathematically consistent way and provide a physically reasonable four-dimensional effective theory. It is also shown that for the majority of five-dimensional fermion field Lagrangians there are no (at least rather obvious) ways to perform the Kaluza-Klein decomposition consistently. Moreover, in these cases one may expect the appearance of various pathologies in the four-dimensional effective theory. Among the cases, for which the Kaluza-Klein decomposition can be performed in a mathematically consistent way, the case, which reproduces the Standard Model by the zero Kaluza-Klein modes most closely regardless of the size of the extra dimension, is examined in detail in the background of the Randall-Sundrum model.
Asymptotic safety and Kaluza-Klein gravitons at the LHC
Gerwick, Erik; Litim, Daniel; Plehn, Tilman
2011-04-15
We study Drell-Yan production at the LHC in low-scale quantum gravity models with extra dimensions. Asymptotic safety implies that the ultraviolet behavior of gravity is dictated by a fixed point. We show how the energy dependence of Newton's coupling regularizes the gravitational amplitude using a renormalization group improvement. We study LHC predictions and find that Kaluza-Klein graviton signals are well above standard model backgrounds. This leaves a significant sensitivity to the energy scale {Lambda}{sub T} where the gravitational couplings crossover from classical to fixed point scaling.
Massless fermions and Kaluza--Klein theory with torsion
Wu, Y.; Zee, A.
1984-09-01
A pure Kaluza--Klein theory contains no massless fermion in four-dimensional theory. We investigate the effect of introducing torsion on the internal manifold and find that there are massless fermions. The hope is that given an isometry group the representation to which these fermions belong is fixed, in contrast to the situation in Yang--Mills theory. We show that this is indeed the case, but the representations do not appear to be the ones favored by current theoretical prejudice. The cases with parallelizable torsions on a group manifold as the internal manifold are analyzed in detail.
The Spacetime Between Einstein and Kaluza-Klein: Further Explorations
NASA Astrophysics Data System (ADS)
Vuille, Chris
2017-01-01
Tensor multinomials can be used to create a generalization of Einstein's general relativity that in a mathematical sense falls between Einstein's original theory in four dimensions and the Kaluza-Klein theory in five dimensions. In the extended theory there are only four physical dimensions, but the tensor multinomials are expanded operators that can accommodate other forces of nature. The equivalent Ricci tensor of this geometry yields vacuum general relativity and electromagnetism, as well as a Klein-Gordon-like quantum scalar field. With a generalization of the stress-energy tensor, an exact solution for a plane-symmetric dust can be found where the scalar portion of the field drives early universe inflation, levels off for a period, then causes a later continued universal acceleration, a possible geometric mechanism for the inflaton or dark energy. Some new explorations of the equations, the problems, and possibilities will be presented and discussed.
Kaluza-Klein Dark Matter, Electrons and Gamma Ray Telescopes
Baltz, E.
2004-12-01
Kaluza-Klein dark matter particles can annihilate efficiently into electron-positron pairs, providing a discrete feature (a sharp edge) in the cosmic e{sup +} e{sup -} spectrum at an energy equal to the particle's mass (typically several hundred GeV to one TeV). Although this feature is probably beyond the reach of satellite or balloon-based cosmic ray experiments (those that distinguish the charge and mass of the primary particle), gamma ray telescopes may provide an alternative detection method. Designed to observe very high-energy gamma-rays, ACTs also observe the diffuse flux of electron-induced electromagnetic showers. The GLAST satellite, designed for gamma ray astronomy, will also observe any high energy showers (several hundred GeV and above) in its calorimeter. We show that high-significance detections of an electron-positron feature from Kaluza-Klein dark matter annihilations are possible with GLAST, and also with ACTs such as HESS, VERITAS or MAGIC.
The classical tests in Kaluza-Klein gravity
NASA Technical Reports Server (NTRS)
Kalligas, D.; Wesson, P. S.; Everitt, C. W. F.
1995-01-01
The possible existence of extra dimensions to spacetime can be tested astrophysically using Kaluza-Klein theory, which is a natural extension of Einsteins's general relativity. In the simplest version of the theory, there is a standard class of five-dimensional solutions that are analogous to the four-dimensional Schwarzschild solution. However, even a small departure of the extra dimension from flatness affects the first or dominant part of the potential, making it possible to test for the existence of an extra dimension. Data from the solar system indicate that in our region of space the terms due to the fifth dimension are small (less than or equal to 0.1%) compared to those due to the usual for dimensions of spacetime. However, the parameters of Kaluza-Klein theory are not universal constants and can vary from place to place depending on local physics. Hence other astrophysical systems may serve as better laboratories for investigating the possible existence of extra dimensions.
Supersymmetry: Kaluza-Klein theory, anomalies, and superstrings
Aref'eva, I.Y.; Volovich, I.V.
1985-08-01
Progress in the search for a unified theory of elementary particles is reviewed. The supersymmetrical Kaluza-Klein theories are described: 11-, 10-, and 6-dimensional models of supergravity. The methods of spontaneous compactification, with whose help the four-dimensional theories are obtained, are described. The properties of the massless sector: zero modes in the Kaluza-Klein theories: and the question of the stability of vacuum solutions are discussed. An important criterion for the selection of a self-consistent theory is the absence of anomalies. The basic formulas for multidimensional chiral and gravitational anomalies are presented. The mechanism of the cancellation of the anomaly for Green and Schwarz's 10-dimensional effective field theory of superstrings with the gauge groups SO(32) and E/sub 8/ x E/sub 8/ is described. The basic concepts and the results of the theory of superstrings are presented. This theory has no divergences and is at the present time a very attractive candidate for a unified theory of elementary particles.
Vacuum Stability in Kaluza-Klein Geometric Sigma Models
NASA Astrophysics Data System (ADS)
Vasilić, M.
2002-09-01
In Kaluza-Klein geometric sigma models, the scalar fields coupled to higher-dimensional gravity are pure gauge. The gauge fixed theory contains no matter fields, and can consistently be reduced to 4 dimensions, provided the internal space is chosen in the form of a group manifold. The effective 4-dimensional theory includes standard Einstein and Yang-Mills sectors, and is free of the classical cosmological constant problem. In this paper, the stability of the internal excitations is analyzed. It is shown that the initial Lagrangian can be modified to lead to a classically stable effective 4-dimensional theory, independently of the particular group used, and retaining all the basic features of the unmodified theory.
Cosmological and coupling constants in Kaluza-Klein supergravity
NASA Astrophysics Data System (ADS)
Duff, M. J.; Pope, C. N.; Warner, N. P.
1983-10-01
Weinberg's formula, relating the Yang-Mills coupling constant, g, to the size of the extra dimensions in a Kaluza-Klein theory, requires modification when gravity is coupled to antisymmetric tensor gauge fields. In particular, in the spontaneous compactification of d = 11 supergravity on the round S7 of radius m-, the Weinberg formula g2 = 64πGm2 is changed to g2 = 16πGm2 owing to the AMNP field. Combined with the cosmological constant relation Λ = 12m2 one finds 4πGΛ = -3g2, which is precisely the relation in the gauged N = 8 supergravity of de Wit and Nicolai. Present address: Lauritsen Laboratory, Californian Institute of Technology, Pasadena, CA 91125, USA.
Universal extra dimension: Violation of Kaluza-Klein parity
Bhattacherjee, Biplob
2009-01-01
The minimal universal extra dimension (mUED) model respects the Kaluza-Klein (KK) parity (-1){sup n}, where n is the KK number. However, it is possible to have interactions located at only one of the two fixed points of the S{sub 1}/Z{sub 2} orbifold. Such asymmetric interactions violate the KK parity. This kills the cold dark matter component of UED but also removes the upper bound on the inverse compactification radius, and thus nonobservation of the KK excitations even at the Large Hadron Collider does not necessarily invalidate the model. Apart from the decay of the lightest n=1 KK excitation, this leads to collider signals which are markedly different from those in the mUED scenario. The phenomenological consequences of such KK-parity violating terms are explored.
Hawking radiation from squashed Kaluza-Klein black holes: A window to extra dimensions
Ishihara, Hideki; Soda, Jiro
2007-09-15
We explore the observability of extra dimensions through five-dimensional squashed Kaluza-Klein black holes residing in the Kaluza-Klein spacetime. With the expectation that the Hawking radiation reflects the five-dimensional nature of the squashed horizon, we study the Hawking radiation of a scalar field in the squashed black hole background. As a result, we show that the luminosity of Hawking radiation tells us the size of the extra dimension, namely, the squashed Kaluza-Klein black holes open a window to extra dimensions.
Kaluza-Klein cosmology from five-dimensional Lovelock-Cartan theory
NASA Astrophysics Data System (ADS)
Castillo-Felisola, Oscar; Corral, Cristóbal; del Pino, Simón; Ramírez, Francisca
2016-12-01
We study the Kaluza-Klein dimensional reduction of the Lovelock-Cartan theory in five-dimensional spacetime, with a compact dimension of S1 topology. We find cosmological solutions of the Friedmann-Robertson-Walker class in the reduced spacetime. The torsion and the fields arising from the dimensional reduction induce a nonvanishing energy-momentum tensor in four dimensions. We find solutions describing expanding, contracting, and bouncing universes. The model shows a dynamical compactification of the extra dimension in some regions of the parameter space.
A New Point of View on General Kaluza-Klein Theories
NASA Astrophysics Data System (ADS)
Bejancu, A.
2012-09-01
The general Kaluza-Klein theories are physical theories in which both the ``cylinder condition" and the ``compactification condition" from the classical Kaluza-Klein theory are not necessarily satisfied. Our study is developed on a general Kaluza-Klein space (overline{M} = M × K,bar{g})}, whose tangent bundle T overline{M} splits into horizontal and vertical distributions H overline{M} and V overline{M}, respectively. The main tool in our new point of view is what we call the Riemannian horizontal connection nabla on H overline{M}, which plays in a general Kaluza-Klein theory, the same role as the Levi-Civita connection on the spacetime M in the classical Kaluza-Klein theory. This connection enables us to classify the geodesics of (overline{M},bar{g}), to define the horizontal Einstein gravitational tensor field, and to write down in a covariant form, the field equations on (overline{M},bar{g}) In particular, we apply the study to both the theory of Einstein-Bergmann spaces and the theory of general Kaluza-Klein spaces with bundle-like metric.
Cosmic super-strings and Kaluza-Klein modes
Dufaux, Jean-François
2012-09-01
Cosmic super-strings interact generically with a tower of relatively light and/or strongly coupled Kaluza-Klein (KK) modes associated with the geometry of the internal space. In this paper, we study the production of spin-2 KK particles by cusps on loops of cosmic F- and D-strings. We consider cosmic super-strings localized either at the bottom of a warped throat or in a flat internal space with large volume. The total energy emitted by cusps in KK modes is comparable in both cases, although the number of produced KK modes may differ significantly. We then show that KK emission is constrained by the photo-dissociation of light elements and by observations of the diffuse gamma ray background. We show that this rules out regions of the parameter space of cosmic super-strings that are complementary to the regions that can be probed by current and upcoming gravitational wave experiments. KK modes are also expected to play an important role in the friction-dominated epoch of cosmic super-string evolution.
The abundance of Kaluza-Klein dark matter with coannihilation
Burnell, Fiona; Kribs, Graham D.
2006-01-01
In universal extra dimension models, the lightest Kaluza-Klein (KK) particle is generically the first KK excitation of the photon and can be stable, serving as particle dark matter. We calculate the thermal relic abundance of the KK photon for a general mass spectrum of KK excitations including full coannihilation effects with all (level-one) KK excitations. We find that including coannihilation can significantly change the relic abundance when the coannihilating particles are within about 20% of the mass of the KK photon. Matching the relic abundance with cosmological data, we find the mass range of the KK photon is much wider than previously found, up to about 2 TeV if the masses of the strongly interacting level-one KK particles are within 5% of the mass of the KK photon. We also find cases where several coannihilation channels compete (constructively and destructively) with one another. The lower bound on the KK photon mass, about 540 GeV when just right-handed KK leptons coannihilate with the KK photon, relaxes upward by several hundred GeV when coannihilation with electroweak KK gauge bosons of the same mass is included.
Direct detection of Kaluza-Klein particles in neutrino telescopes
Albuquerque, Ivone F. M.; Burdman, Gustavo; Krenke, Christopher A.; Nosratpour, Baran
2008-07-01
In theories with universal extra dimensions, all standard model fields propagate in the bulk and the lightest state of the first Kaluza-Klein (KK) level can be made stable by imposing a Z{sub 2} parity. We consider a framework where the lightest KK particle (LKP) is a neutral, extremely weakly interacting particle such as the first KK excitation of the graviton, while the next-to-lightest KK particle (NLKP) is the first KK mode of a charged right-handed lepton. In such a scenario, due to its very small couplings to the LKP, the NLKP is long-lived. We investigate the production of these particles from the interaction of high energy neutrinos with nucleons in the Earth and determine the rate of NLKP events in neutrino telescopes. Using the Waxman-Bahcall limit for the neutrino flux, we find that the rate can be as large as a few hundreds of events a year for realistic values of the NLKP mass.
Angular Momentum-Free of the Entropy Relations for Rotating Kaluza-Klein Black Holes
NASA Astrophysics Data System (ADS)
Liu, Hang; Meng, Xin-he
2016-11-01
Based on a mathematical lemma related to the Vandermonde determinant and two theorems derived from the first law of black hole thermodynamics, we investigate the angular momentum independence of the entropy sum as well as the entropy product of general rotating Kaluza-Klein black holes in higher dimensions. We show that for both non-charged rotating Kaluza-Klein black holes and non-charged rotating Kaluza-Klein-AdS black holes, the angular momentum of the black holes will not be present in entropy sum relation in dimensions d≥4, while the independence of angular momentum of the entropy product holds provided that the black holes possess at least one zero rotation parameter a j = 0 in higher dimensions d≥5, which means that the cosmological constant does not affect the angular momentum-free property of entropy sum and entropy product under the circumstances that charge δ=0. For the reason that the entropy relations of charged rotating Kaluza-Klein black holes as well as the non-charged rotating Kaluza-Klein black holes in asymptotically flat spacetime act the same way, it is found that the charge has no effect in the angular momentum-independence of entropy sum and product in asymptotically flat spactime.
Angular Momentum-Free of the Entropy Relations for Rotating Kaluza-Klein Black Holes
NASA Astrophysics Data System (ADS)
Liu, Hang; Meng, Xin-he
2017-02-01
Based on a mathematical lemma related to the Vandermonde determinant and two theorems derived from the first law of black hole thermodynamics, we investigate the angular momentum independence of the entropy sum as well as the entropy product of general rotating Kaluza-Klein black holes in higher dimensions. We show that for both non-charged rotating Kaluza-Klein black holes and non-charged rotating Kaluza-Klein-AdS black holes, the angular momentum of the black holes will not be present in entropy sum relation in dimensions d≥4, while the independence of angular momentum of the entropy product holds provided that the black holes possess at least one zero rotation parameter a j = 0 in higher dimensions d≥5, which means that the cosmological constant does not affect the angular momentum-free property of entropy sum and entropy product under the circumstances that charge δ=0. For the reason that the entropy relations of charged rotating Kaluza-Klein black holes as well as the non-charged rotating Kaluza-Klein black holes in asymptotically flat spacetime act the same way, it is found that the charge has no effect in the angular momentum-independence of entropy sum and product in asymptotically flat spactime.
Spectroscopy of the Rotating Kaluza-Klein Spacetime via Revisited Adiabatic Invariant Quantity
NASA Astrophysics Data System (ADS)
Yu, Li; Qi, De-Jiang
2017-07-01
In this paper, we have investigated the spectroscopy of the rotating Kaluza-Klein spacetime by applying Bohr-Sommerfeld quantization rule and the first law of thermodynamics. we derived the expression of the adiabatic invariant quantity in the dragged-Painlevé coordinate system. Then, via revisited adiabatic invariant quantity, we derive the area and entropy spectra of the spacetime. We obtained the area spectrum of the Kaluza-Klein spacetime is {Δ } A=8π {lP2}, and the entropy spectrum is Δ S = 2 π. This result is consistent with the Bekenstein's original result, which imply the entropy and horizon area are discrete and equidistant for the spacetime.
Strong gravitational lensing in a charged squashed Kaluza-Klein Gödel black hole
NASA Astrophysics Data System (ADS)
Sadeghi, J.; Naji, J.; Vaez, H.
2014-01-01
In this Letter we investigate the strong gravitational lansing in a charged squashed Kaluza-Klein Gödel black hole. The deflection angle is considered by the logarithmic term proposed by Bozza et al. Then we study the variation of deflection angle and its parameters abar and bbar. We suppose that the supermassive black hole in the galaxy center can be considered by a charged squashed Kaluza-Klein black hole in a Gödel background. Then by the relations between lensing parameters and observables, we estimate the observables for different values of charge, extra dimension and Gödel parameters.
Kaluza-Klein consistency, Killing vectors and Kähler spaces
NASA Astrophysics Data System (ADS)
Hoxha, P.; Martinez-Acosta, R. R.; Pope, C. N.
2000-10-01
We make a detailed investigation of all spaces Qn1...nNq1...qN of the form of U(1) bundles over arbitrary products ∏iCPni of complex projective spaces, with arbitrary winding numbers qi over each factor in the base. Special cases, including Q1111 (sometimes known as T11), Q111111 and Q2132, are relevant for compactifications of type IIB and D = 11 supergravity. Remarkable `conspiracies' allow consistent Kaluza-Klein S5, S4 and S7 sphere reductions of these theories that retain all the Yang-Mills fields of the isometry group in a massless truncation. We prove that such conspiracies do not occur for the reductions on the Qn1...nNq1...qN spaces, and that it is inconsistent to make a massless truncation in which the non-Abelian SU(ni + 1) factors in their isometry groups are retained. In the course of proving this we derive many properties of the spaces Qn1...nNq1...qN of more general utility. In particular, we show that they always admit Einstein metrics, and that the spaces where qi = (ni + 1)/l all admit two Killing spinors. We also obtain an iterative construction for real metrics on CPn, and construct the Killing vectors on Qn1...nNq1...qN in terms of scalar eigenfunctions on CPni. We derive bounds that allow us to prove that certain Killing-vector identities on spheres, necessary for consistent Kaluza-Klein reductions, are never satisfied on Qn1...nNq1...qN.
On Hamiltonians with position-dependent mass from Kaluza-Klein compactifications
NASA Astrophysics Data System (ADS)
Ballesteros, Ángel; Gutiérrez-Sagredo, Iván; Naranjo, Pedro
2017-02-01
In a recent paper (Morris (2015) [1]), an inhomogeneous compactification of the extra dimension of a five-dimensional Kaluza-Klein metric has been shown to generate a position-dependent mass (PDM) in the corresponding four-dimensional system. As an application of this dimensional reduction mechanism, a specific static dilatonic scalar field has been connected with a PDM Lagrangian describing a well-known nonlinear PDM oscillator. Here we present more instances of this construction that lead to PDM systems with radial symmetry, and the properties of their corresponding inhomogeneous extra dimensions are compared with the ones in the nonlinear oscillator model. Moreover, it is also shown how the compactification introduced in this type of models can alternatively be interpreted as a novel mechanism for the dynamical generation of curvature.
Model of Decaying Dark Energy Based on the Kaluza-Klein Theory
NASA Astrophysics Data System (ADS)
Zakirov, U. N.
2017-08-01
On the basis of a scalar potential associated with Beltrami's geometry - manifolds of constant negative curvature, the Klein-Gordon problem has been solved, making it possible, under the assumption of a physical structure of the fifth dimension (presumably a rich form of matter), to model on the basis of the Kaluza-Klein theory the hypothesis of decaying dark energy configuring the rates of expansion of the Universe.
Bohr-Sommerfeld Quantization of Hydrogen-Like Atoms in Kaluza-Klein Theory
NASA Astrophysics Data System (ADS)
Wilson, Weldon J.
1984-12-01
A low energy phenomenon in quantum theories with extra dimensions is studied. The method of Bohr and Sommerfeld is used to compute the relativistic bound state energy spectrum for hydrogen-like atoms in the flat, five-dimensional Kaluza-Klein model.
Z boson decay to photon plus Kaluza Klein graviton: large extra dimensional bounds
NASA Astrophysics Data System (ADS)
Allanach, B. C.; Skittrall, J. P.
2008-05-01
We consider the phenomenology of the decay of a Z boson into a photon and a Kaluza Klein excitation of the graviton in the ADD model. Using LEP data, we obtain an upper bound on the branching ratio corresponding to this process of ˜10-11. We also investigate energy profiles of the process.
On Pauli's Invention of Non-Abelian Kaluza-Klein Theory in 1953
NASA Astrophysics Data System (ADS)
Straumann, N.
2002-12-01
There are documents which show that Wolfgang Pauli developed in 1953 the first consistent generalization of the five-dimensional theory of Kaluza, Klein, Fock and others to a higher dimensional internal space. Because he saw no way to give masses to the gauge bosons, he refrained from publishing his results formally.
Hawking radiation in a rotating Kaluza-Klein black hole with squashed horizons
Chen Songbai; Wang Bin; Su Rukeng
2008-01-15
We explore the signature of the extra dimension in the Hawking radiation in a rotating Kaluza-Klein black hole with squashed horizons. Comparing with the spherical case, we find that the rotating parameter brings richer physics. We obtain the appropriate size of the extra dimension which can enhance the Hawking radiation and may open a window to detect the extra dimensions.
Deformed phase space Kaluza-Klein cosmology and late time acceleration
NASA Astrophysics Data System (ADS)
Sabido, M.; Yee-Romero, C.
2016-06-01
The effects of phase space deformations on Kaluza-Klein cosmology are studied. The deformation is introduced by modifying the symplectic structure of the minisuperspace variables. In the deformed model, we find an accelerating scale factor and therefore infer the existence of an effective cosmological constant from the phase space deformation parameter β.
Hoop conjecture and the horizon formation cross section in Kaluza-Klein spacetimes
Yoo, Chul-Moon; Ishihara, Hideki; Kimura, Masashi; Tanzawa, Sugure
2010-01-15
We analyze momentarily static initial data sets of the gravitational field produced by two-point sources in five-dimensional Kaluza-Klein spacetimes. These initial data sets are characterized by the mass, the separation of sources and the size of an extra dimension. Using these initial data sets, we discuss the condition for black hole formation, and propose a new conjecture which is a hybrid of the four-dimensional hoop conjecture and the five-dimensional hyperhoop conjecture. By using the new conjecture, we estimate the cross section of black hole formation due to collisions of particles in Kaluza-Klein spacetimes. We show that the mass dependence of the cross section gives us information about the size and the number of the compactified extra dimensions.
Uniqueness theorem for Kaluza-Klein black holes in five-dimensional minimal supergravity
Tomizawa, Shinya
2010-11-15
We show a uniqueness theorem for Kaluza-Klein black holes in the bosonic sector of five-dimensional minimal supergravity. More precisely, under the assumptions of the existence of two commuting axial isometries and a nondegenerate connected event horizon of the cross-section topology S{sup 3}, or lens space, we prove that a stationary charged rotating Kaluza-Klein black hole in five-dimensional minimal supergravity is uniquely characterized by its mass, two independent angular momenta, electric charge, magnetic flux, and nut charge, provided that there exists neither a nut nor a bolt (a bubble) in the domain of outer communication. We also show that under the assumptions of the same symmetry, same asymptotics, and the horizon cross section of S{sup 1}xS{sup 2}, a black ring within the same theory--if it exists--is uniquely determined by its dipole charge and rod intervals besides the charges and magnetic flux.
Harrison transformation and charged black objects in Kaluza-Klein theory
NASA Astrophysics Data System (ADS)
Kleihaus, Burkhard; Kunz, Jutta; Radu, Eugen; Stelea, Cristian
2009-09-01
We generate charged black brane solutions in D-dimensions in a theory of gravity coupled to a dilaton and an antisymmetric form, by using a Harrison-type transformation. The seed vacuum solutions that we use correspond to uplifted Kaluza-Klein black strings and black holes in (D-p)-dimensions. A generalization of the Marolf-Mann quasilocal formalism to the Kaluza-Klein theory is also presented, the global charges of the black objects being computed in this way. We argue that the thermodynamics of the charged solutions can be derived from that of the vacuum configurations. Our results show that all charged Kaluza-Klein solutions constructed by means of Harrison transformations are thermodynamically unstable in a grand canonical ensemble. The general formalism is applied to the case of nonuniform black strings and caged black hole solutions in D = 5,6 Einstein-Maxwell-dilaton gravity, whose geometrical properties and thermodynamics are discussed. We argue that the topology changing transition scenario, which was previously proposed in the vacuum case, also holds in this case. Spinning generalizations of the charged black strings are constructed in six dimensions in the slowly rotating limit. We find that the gyromagnetic ratio of these solutions possesses a nontrivial dependence on the nonuniformity parameter.
Testing a possible way of geometrization of the strong interaction by a Kaluza-Klein star
NASA Astrophysics Data System (ADS)
Karsai, Szilvia; Pósfay, Péter; Barnaföldi, Gergely Gábor; Lukács, Béla
2016-10-01
Geometrization of the fundamental interactions has been extensively studied during the century. The idea of introducing compactified spatial dimensions originated by Kaluza and Klein. Following their approach, several model were built representing quantum numbers (e.g. charges) as compactified space-time dimensions. Such geometrized theoretical descriptions of the fundamental interactions might lead us to get closer to the unification of the principle theories. Here, we apply a 3 + 1C + 1 dimensional theory, which contains one extra compactified spatial dimension 1C in connection with the flavor quantum number in Quantum Chromodynamics. Within our model the size of the 1C dimension is proportional to the inverse mass-difference of the first low-mass baryon states. We used this phenomena to apply in a compact star model — a natural laboratory for testing the theory of strong interaction and the gravitational theory in parallel. Our aim is to test the modification of the measurable macroscopical parameters of a compact Kaluza-Klein star by varying the size of the compactified extra dimension. Since larger the RC the smaller the mass difference between the first spokes of the Kaluza-Klein ladder resulting smaller-mass stars. Using the Tolman-Oppenheimer-Volkov equation, we investigate the M-R diagram and the dependence of the maximum mass of compact stars. Besides testing the validity of our model we compare our results to the existing observational data of pulsar properties for constraints.
Testing a Possible way of Geometrization of the Strong Interaction by a Kaluza -- Klein Star
NASA Astrophysics Data System (ADS)
Karsai, Szilvia; Pósfay, Péter Barnaföldi, Gergely Gábor Lukács, Béla
Geometrization of the fundamental interactions has been extensively studied during the century. The idea of introducing compactified spatial dimensions originated by Kaluza and Klein. Following their approach, several model were built representing quantum numbers (e.g. charges) as compactified space-time dimensions. Such geometrized theoretical descriptions of the fundamental interactions might lead us to get closer to the unification of the principle theories. Here, we apply a 3 + 1C + 1 dimensional theory, which contains one extra compactified spatial dimension 1C in connection with the flavor quantum number in Quantum Chromodynamics. Within our model the size of the 1C dimension is proportional to the inverse mass-difference of the first low-mass baryon states. We used this phenomena to apply in a compact star model -- a natural laboratory for testing the theory of strong interaction and the gravitational theory in parallel. Our aim is to test the modification of the measurable oscopical parameters of a compact Kaluza -- Klein star by varying the size of the compactified extra dimension. Since larger the RC the smaller the mass difference between the first spokes of the Kaluza -- Klein ladder resulting smaller-mass stars. Using the Tolman -- Oppenheimer -- Volkov equation, we investigate the M-R diagram and the dependence of the maximum mass of compact stars. Besides testing the validity of our model we compare our results to the existing observational data of pulsar properties for constraints.
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.
NASA Astrophysics Data System (ADS)
García-Jiménez, I.; Novales-Sánchez, H.; Toscano, J. J.
2016-05-01
One-loop Standard Model observables produced by virtual heavy Kaluza-Klein fields play a prominent role in the minimal model of universal extra dimensions. Motivated by this aspect, we integrate out all the Kaluza-Klein heavy modes coming from the Yang-Mills theory set on a spacetime with an arbitrary number, n , of compact extra dimensions. After fixing the gauge with respect to the Kaluza-Klein heavy gauge modes in a covariant manner, we calculate a gauge-independent effective Lagrangian expansion containing multiple Kaluza-Klein sums that entail a bad divergent behavior. We use the Epstein-zeta function to regularize and characterize discrete divergences within such multiple sums, and then we discuss the interplay between the number of extra dimensions and the degree of accuracy of effective Lagrangians to generate or not divergent terms of discrete origin. We find that nonrenormalizable terms with mass dimension k are finite as long as k >4 +n . Multiple Kaluza-Klein sums of nondecoupling logarithmic terms, not treatable by Epstein-zeta regularization, are produced by four-dimensional momentum integration. On the grounds of standard renormalization, we argue that such effects are unobservable.
De Sitter brane-world, localization of gravity, and the cosmological constant
Neupane, Ishwaree P.
2011-04-15
Cosmological models with a de Sitter 3-brane embedded in a 5-dimensional de Sitter spacetime (dS{sub 5}) give rise to a finite 4D Planck mass similar to that in Randall-Sundrum (RS) brane-world models in anti-de Sitter 5-dimensional spacetime(AdS{sub 5}). Yet, there arise a few important differences as compared to the results with a flat 3-brane or 4D Minkowski spacetime. For example, the mass reduction formula (MRF) M{sub Pl}{sup 2}=M{sub (5)}{sup 3}l{sub AdS} as well as the relationship M{sub Pl}{sup 2}=M{sub Pl(4+n)}{sup n+2}L{sup n} (with L being the average size or the radius of the n extra dimensions) expected in models of product-space (or Kaluza-Klein) compactifications get modified in cosmological backgrounds. In an expanding universe, a physically relevant MRF encodes information upon the 4-dimensional Hubble expansion parameter, in addition to the length and mass parameters L, M{sub Pl}, and M{sub Pl(4+n)}. If a bulk cosmological constant is present in the solution, then the reduction formula is further modified. With these new insights, we show that the localization of a massless 4D graviton as well as the mass hierarchy between M{sub Pl} and M{sub Pl(4+n)} can be explained in cosmological brane-world models. A notable advantage of having a 5D de Sitter bulk is that in this case the zero-mass wave function is normalizable, which is not necessarily the case if the bulk spacetime is anti-de Sitter. In spacetime dimensions D{>=}7, however, the bulk cosmological constant {Lambda}{sub b} can take either sign ({Lambda}{sub b}<0, =0, or >0). The D=6 case is rather inconclusive, in which case {Lambda}{sub b} may be introduced together with 2-form gauge field (or flux). We obtain some interesting classical gravity solutions that compactify higher-dimensional spacetime to produce a Robertson-Walker universe with de Sitter-type expansion plus one extra noncompact direction. We also show that such models can admit both an effective 4-dimensional Newton constant
Einstein-Yang-Mills-Dirac systems from the discretized Kaluza-Klein theory
NASA Astrophysics Data System (ADS)
Wali, Kameshwar; Viet, Nguyen Ali
2017-01-01
A unified theory of the non-Abelian gauge interactions with gravity in the framework of a discretized Kaluza-Klein theory is constructed with a modified Dirac operator and wedge product. All the couplings of chiral spinors to the non-Abelian gauge fields emerge naturally as components of the coupling of the chiral spinors in the generalized gravity together with some new interactions. In particular, the currently prevailing gravity-QCD quark and gravity-electroweak-quark and lepton models are shown to follow as special cases of the general framework.
Hawking Radiation via Damour-Ruffini Method in Squashed Charged Rotating Kaluza-Klein Black Holes
NASA Astrophysics Data System (ADS)
Hu, Ji-Wan; Wu, Jing-He; Liu, Xian-Ming
2016-12-01
Using the Damour-Ruffini method, Hawking radiation of charged particles from squashed charged rotating five-dimensional Kaluza-Klein black holes is investigated extensively. Under the generalized tortoise coordinate transformation, Hawking temperature of the black holes is calculated by using charged scalar particles and Dirac fermions respectively. We find that the obtained Hawking temperature for charged Dirac fermions is the same as for charged scalar particles. What's more, the spectrum of Hawking radiation contains the information of the size of the extra dimension, which could provide insight for further investigation of large extra dimensions in the future.
Hawking Radiation via Damour-Ruffini Method in Squashed Charged Rotating Kaluza-Klein Black Holes
NASA Astrophysics Data System (ADS)
Hu, Ji-Wan; Wu, Jing-He; Liu, Xian-Ming
2017-02-01
Using the Damour-Ruffini method, Hawking radiation of charged particles from squashed charged rotating five-dimensional Kaluza-Klein black holes is investigated extensively. Under the generalized tortoise coordinate transformation, Hawking temperature of the black holes is calculated by using charged scalar particles and Dirac fermions respectively. We find that the obtained Hawking temperature for charged Dirac fermions is the same as for charged scalar particles. What's more, the spectrum of Hawking radiation contains the information of the size of the extra dimension, which could provide insight for further investigation of large extra dimensions in the future.
Hawking Radiation of the Charged Particle via Tunneling from the Kaluza-Klein Black Hole
NASA Astrophysics Data System (ADS)
Pu, Jin; Han, Yan
2016-12-01
In this paper, by applying the Lagrangian analysis on the action, we first redefine the geodesic equation of the charged massive particle. Then, basing on the new definition of the geodesic equation, we revisit the Hawking radiation of the charged massive particle via tunneling from the event horizon of the Kaluza-Klein black hole. In our treatment, the geodesic equation of the charged massive particle is defined uniformly with that of the massless particle, which overcomes the shortcomings of its previous definition, and is more suitable for the tunneling mechanism. The highlight of our work is a new and important development for the Parikh-Wilczek's tunneling method.
Non-Abelian gauge fields as components of gravity in the discretized Kaluza-Klein theory
NASA Astrophysics Data System (ADS)
Nguyen, Ai Viet; Pham, Tien Du
2017-06-01
Discretized Kaluza-Klein theory in ℳ2 × Z 2 spacetime can be constructed based on the concepts of noncommutative geometry. In this paper, we show that it is possible to incorporate the non-Abelian gauge fields in this framework. The generalized Hilbert-Einstein action is gauge invariant only in two cases. In the first case, the gauge group must be Abelian on one sheet of spacetime and non-Abelian on the other one. In the second case, the gauge group must be the same on two sheets of spacetime. Actually, the theories of electroweak and strong interactions can fit into these two cases.
New Kaluza-Klein instantons and the decay of AdS vacua
NASA Astrophysics Data System (ADS)
Ooguri, Hirosi; Spodyneiko, Lev
2017-07-01
We construct a generalization of Witten's Kaluza-Klein instanton, where a higher-dimensional sphere (rather than a circle as in Witten's instanton) collapses to zero size and the geometry terminates at a bubble of nothing, in a low energy effective theory of M theory. We use the solution to exhibit the instability of nonsupersymmetric AdS5 vacua in M theory compactified on positive Kähler-Einstein spaces, providing further evidence for the recent conjecture that any nonsupersymmetric anti-de Sitter vacuum supported by fluxes must be unstable.
Graviton Kaluza-Klein modes in nonflat branes with stabilized modulus
NASA Astrophysics Data System (ADS)
Paul, Tanmoy; SenGupta, Soumitra
2016-04-01
We consider a generalized two brane Randall-Sundrum model where the branes are endowed with nonzero cosmological constant. In this scenario, we re-examine the modulus stabilization mechanism and the nature of Kaluza-Klein (KK) graviton modes. Our result reveals that while the KK mode graviton masses may change significantly with the brane cosmological constant, the Goldberger-Wise stabilization mechanism, which assumes a negligible backreaction on the background metric, continues to hold even when the branes have a large cosmological constant. The possibility of having a global minimum for the modulus is also discussed. Our results also include an analysis for the radion mass in this nonflat brane scenario.
Compact hyperbolic extra dimensions: branes, kaluza-klein modes, and cosmology
Kaloper; March-Russell; Starkman; Trodden
2000-07-31
We reconsider theories with low gravitational (or string) scale M(*) where Newton's constant is generated via new large-volume spatial dimensions, while standard model states are localized to a 3-brane. Utilizing compact hyperbolic manifolds we show that the spectrum of Kaluza-Klein modes is radically altered. This allows the early Universe to evolve normally up to substantial temperatures, and completely negates the astrophysical constraints on M(*). Furthermore, an exponential hierarchy between the usual Planck scale and the true fundamental scale of physics can emerge with only O(1) coefficients. The linear size of the internal space remains small. The proposal has striking testable signatures.
Schwinger pair creation of Kaluza-Klein particles: Pair creation without tunneling
Friedmann, Tamar; Verlinde, Herman
2005-03-15
We study Schwinger pair creation of charged Kaluza-Klein (KK) particles from a static KK electric field. We find that the gravitational backreaction of the electric field on the geometry--which is incorporated via the electric KK-Melvin solution--prevents the electrostatic potential from overcoming the rest mass of the KK particles, thus impeding the tunneling mechanism which is often thought of as responsible for the pair creation. However, we find that pair creation still occurs with a finite rate formally similar to the classic Schwinger result, but via an apparently different mechanism, involving a combination of the Unruh effect and vacuum polarization due to the E-field.
Cross sections for production of closed superstrings at high energy colliders in brane world models
Chialva, Diego; Iengo, Roberto; Russo, Jorge G.
2005-05-15
In brane world string models with large extra dimensions, there are processes where fermion and antifermion (or two gluons) can annihilate producing a light particle (e.g. gluon) carrying transverse momentum and a Kaluza-Klein graviton or an excited closed string that propagates in the extra dimensions. In high energy colliders, this process gives a missing-momentum signature. We compute the total cross section for this process within the context of type II superstring theory in the presence of a D-brane. This includes all missing-energy sources for this string-theory model up to s=8M{sub s}{sup 2}, and it can be used to put new limits on the string scale M{sub s}.
Consistent Kaluza-Klein truncations via exceptional field theory
NASA Astrophysics Data System (ADS)
Hohm, Olaf; Samtleben, Henning
2015-01-01
We present the generalized Scherk-Schwarz reduction ansatz for the full supersymmetric exceptional field theory in terms of group valued twist matrices subject to consistency equations. With this ansatz the field equations precisely reduce to those of lower-dimensional gauged supergravity parametrized by an embedding tensor. We explicitly construct a family of twist matrices as solutions of the consistency equations. They induce gauged supergravities with gauge groups SO( p, q) and CSO( p, q, r). Geometrically, they describe compactifications on internal spaces given by spheres and (warped) hyperboloides H p,q , thus extending the applicability of generalized Scherk-Schwarz reductions beyond homogeneous spaces. Together with the dictionary that relates exceptional field theory to D = 11 and IIB supergravity, respectively, the construction defines an entire new family of consistent truncations of the original theories. These include not only compactifications on spheres of different dimensions (such as AdS5 × S 5), but also various hyperboloid compactifications giving rise to a higher-dimensional embedding of supergravities with non-compact and non-semisimple gauge groups.
Light Kaluza Klein States in Randall-Sundrum Models with Custodial SU(2)
Carena, Marcela; Ponton, Eduardo; Santiago, Jose; Wagner, Carlos E.M.; /Argonne /Chicago U., EFI /KICP, Chicago
2006-07-01
We consider Randall-Sundrum scenarios based on SU(2){sub L} x SU(2){sub R} and a discrete parity exchanging L with R. The custodial and parity symmetries can be used to make the tree level contribution to the T parameter and the anomalous couplings of the bottom quark to the Z very small. We show that the resulting quantum numbers typically induce a negative T parameter at one loop that, together with the positive value of the S parameter, restrict considerably these models. There are nevertheless regions of parameter space that successfully reproduce the fit to electroweak precision observables with light Kaluza-Klein excitations accessible at colliders. We consider models of gauge-Higgs unification that implement the custodial and parity symmetries and find that the electroweak data singles out a very well defined region in parameter space. In this region one typically finds light gauge boson Kaluza-Klein excitations as well as light SU(2){sub L} singlet, and sometimes also doublet, fermionic states, that mix with the top quark, and that may yield interesting signatures at future colliders.
Born-Infeld action and Chern-Simons term from Kaluza-Klein monopole in M-theory
NASA Astrophysics Data System (ADS)
Imamura, Yosuke
1997-11-01
We investigate the zero modes of the Kaluza-Klein monopole in M-theory and show that the Born-Infeld action and the Chern-Simons term of a D6-brane are reproduced to quadratic order in the field strength of the U(1) field on the brane.
Supersymmetric and Kaluza-Klein Particles Multiple Scattering in the Earth
Albuquerque, Ivone; Klein, Spencer
2009-05-19
Neutrino telescopes with cubic kilometer volume have the potential to discover new particles. Among them are next to lightest supersymmetric (NLSPs) and next to lightest Kaluza-Klein (NLKPs) particles. Two NLSPs or NLKPs will transverse the detector simultaneously producing parallel charged tracks. The track separation inside the detector can be a few hundred meters. As these particles might propagate a few thousand kilometers before reaching the detector, multiple scattering could enhance the pair separation at the detector. We find that the multiple scattering will alter the separation distribution enough to increase the number of NLKP pairs separated by more than 100 meters (a reasonable experimental cut) by up to 46% depending on the NLKP mass. Vertical upcoming NLSPs will have their separation increased by 24% due to multiple scattering.
Kaluza-Klein masses in nonprime orbifolds: Z{sub 12-I} compactification and threshold correction
Kim, Jihn E.; Kyae, Bumseok
2008-05-15
Analyzing the one-loop partition function, we discuss possible Kaluza-Klein (KK) states in the orbifold compactification of the heterotic string theory, toward the application to the threshold correction. The KK massive states associated with (relatively) large extra dimensions can arise only in nonprime orbifolds. The Gliozzi-Scherk-Olive (GSO) projection condition by a shift vector V{sup I} is somewhat relaxed above the compactification scale 1/R. We also present the other condition on Wilson line W, P{center_dot}W=integer. With the knowledge of the partition function, we obtain the threshold corrections to gauge couplings, which include the Wilson line effects. We point out the differences in string and field theoretic orbifolds.
Kaluza-Klein/Z's Differentiation at the LHC and Linear Collider
Rizzo, Thomas G.
2003-05-06
We explore the capabilities of the LHC and the Linear Collider (LC) to distinguish the production of Kaluza-Klein (KK) excitations from an ordinary Z{prime} within the context of theories with TeV scale extra dimensions. At the LHC, these states are directly produced in the Drell-Yan channel while at the LC the effects of their exchanges are indirectly felt as new contact interactions in processes such as e{sup +}e{sup -} {yields} f{bar f}. While we demonstrate that the LC is somewhat more capable at KK/Z{prime} differentiation than is the LHC, the simplest LC analysis relies upon the LHC data for the resonance mass as an important necessary input.
Constraints on the size of the extra dimension from Kaluza-Klein gravitino decay
Gherson, David
2007-08-15
We study the consequences of the gravitino decay into dark matter. We suppose that the lightest neutralino is the main component of dark matter. In our framework the gravitino is heavy enough to decay before big bang nucleosynthesis starts. We consider a model coming from a five dimensional supergravity compactified on S{sup 1}/Z{sub 2} with gravity in the bulk and matter localized on tensionless branes at the orbifold fixed points. We require that the dark matter, which is produced thermally and in the decay of Kaluza-Klein modes of the gravitino, has an abundance compatible with observation. We deduce from our model that there are curves of constraints between the size of the extra dimension and the reheating temperature of the Universe after inflation.
Das, Prasanta Kumar; Satheeshkumar, V. H.; Suresh, P. K.
2008-09-15
In the large extra dimensional Kaluza-Klein (KK) scenario, where the usual standard model (SM) matter is confined to a 3+1-dimensional hypersurface called the 3-brane and gravity can propagate to the bulk (D=4+d, d being the number of extra spatial dimensions), the light graviton KK modes can be produced inside the supernova core due to the usual nucleon-nucleon bremstrahlung, electron-positron, and photon-photon annihilations. This photon inside the supernova becomes a plasmon due to the plasma effect. In this paper, we study the energy-loss rate of SN 1987A due to the KK gravitons produced from the plasmon-plasmon annihilation. We find that the SN 1987A cooling rate leads to the conservative bound M{sub D}>22.9 TeV and 1.38 TeV for the case of two and three spacelike extra dimensions.
Significant effects of second Kaluza-Klein particles on dark matter physics
Kakizaki, Mitsuru; Senami, Masato; Matsumoto, Shigeki; Sato, Yoshio
2005-06-15
We point out that Kaluza-Klein (KK) dark matter physics is drastically affected by second KK particles. In this work various interesting phenomena caused by the second KK modes are discussed. In particular, we reevaluate the annihilation cross section relevant to the thermal relic density of KK dark matter in universal extra dimension models. In these models, the first KK mode of a B boson is a viable dark matter candidate by virtue of KK parity. We demonstrate that the KK dark matter annihilation cross section can be enhanced, compared with the tree-level cross section mediated only by first KK particles. The mass of the first KK mode of the B boson consistent with the Wilkinson Microwave Anisotropy Probe observation is increased.
New supernova limit on large extra dimensions: bounds on Kaluza-Klein graviton production.
Hannestad, S; Raffelt, G G
2001-07-30
If large extra dimensions exist in nature, supernova (SN) cores will emit large fluxes of Kaluza-Klein gravitons, producing a cosmic background of these particles with energies and masses up to about 100 MeV. Radiative decays then give rise to a diffuse cosmic gamma-ray background with E(gamma) approximately less than 100 MeV which is well in excess of the observations if more than 0.5%-1% of the SN energy is emitted into the new channel. For two extra dimensions we derive a conservative bound on their radius of R approximately less than 0.9 x 10(-4) mm; for three extra dimensions it is R approximately less than 1.9 x 10(-7) mm.
Kaluza-Klein Effects on Higgs Physics in Universal Extra Dimensions
Petriello, Frank J
2002-04-05
We examine the virtual effects of Kaluza-Klein (KK) states on Higgs physics in universal extra dimension models. We study the partial widths {Lambda}{sub h{yields}gg}, {Lambda}{sub h{yields}{gamma}{gamma}}, and {Lambda}{sub h{yields}{gamma}Z}, which are relevant for Higgs production and detection in future collider experiments. These interactions occur at one loop in the Standard Model, as do the KK contributions. We find that the deviations induced by the KK exchanges can be significant; for one extra dimension, the gg {yields} h production rate is increased by 10% - 85% for the mass of the first KK state in the range 500 {approx}> m{sub 1} {approx}> 1500 GeV, a region untested by current direct search and precision measurement constraints. The h {yields} {gamma}{gamma} decay width is decreased by {approx}< 20% in the same mass range. For two or more universal extra dimensions the results are cutoff dependent, and can only be qualitatively estimated. We comment on the detectability of these shifts at the LHC and at future e{sup +}e{sup -} and {gamma}{gamma} colliders.
Kaluza-Klein gluon + jets associated production at the Large Hadron Collider
NASA Astrophysics Data System (ADS)
Iyer, A. M.; Mahmoudi, F.; Manglani, N.; Sridhar, K.
2016-08-01
The Kaluza-Klein excitations of gluons offer the exciting possibility of probing bulk Randall-Sundrum (RS) models. In these bulk models either a custodial symmetry or a deformation of the metric away from AdS is invoked in order to deal with electroweak precision tests. Addressing both these models, we suggest a new channel in which to study the production of KK-gluons (gKK): one where it is produced in association with one or more hard jets. The cross-section for the gKK + jets channel is significant because of several contributing sub-processes. In particular, the 1-jet and the 2-jet associated processes are important because at these orders in QCD the qg and the gg initial states respectively come into play. We have performed a hadron-level simulation of the signal and present strategies to effectively extract the signal from what could potentially be a huge background. We present results for the kinematic reach of the LHC Run-II for different gKK masses in bulk-RS models.
Observability of gamma-ray spectral feature from Kaluza-Klein dark matter
NASA Astrophysics Data System (ADS)
Tsuchida, Satoshi; Mori, Masaki
2017-01-01
The theory of universal extra dimensions involves Kaluza-Klein (KK) particles. The lightest KK particle (LKP) is one of the good candidates for cold dark matter. Annihilation of LKP dark matter in the Galactic halo produces high-energy gamma-rays. The gamma-ray spectrum shows a characteristic peak structure around the LKP mass. This paper investigates the observability of this peak structure by present and near-future detectors taking account of their energy resolution, and calculates the expected count spectrum of the gamma-ray signal. Then, the maximum likelihood analysis is employed to judge whether the count spectrum contains the LKP signal. In the case where the signal is not detected, we set some constraints on the boost factor which is a product of the annihilation cross section relative to the thermal one and an uncertain factor dependent on the substructure of the LKP distribution in the Galactic halo. The constraints can be regarded as comparable with the results of analysis based on the HESS data. The observational data for the TeV or higher energy region are still limited, and the possible LKP signal is not conclusive. Thus, we expect near-future missions with better sensitivity will clarify whether the LKP dark matter should exist or not.
Kaluza-Klein Dark Matter: Direct Detection vis-a-vis LHC
Arrenberg, Sebastian; Baudis, Laura; Kong, Kyoungchul; Matchev, Konstantin T.; Yoo, Jonghee; /Fermilab
2008-11-01
We explore the phenomenology of Kaluza-Klein (KK) dark matter in very general models with universal extra dimensions (UEDs), emphasizing the complementarity between high-energy colliders and dark matter direct detection experiments. In models with relatively small mass splittings between the dark matter candidate and the rest of the (colored) spectrum, the collider sensitivity is diminished, but direct detection rates are enhanced. UEDs provide a natural framework for such mass degeneracies. We consider both 5-dimensional and 6-dimensional non-minimal UED models, and discuss the detection prospects for various KK dark matter candidates: the KK photon {gamma}{sub 1} (5D) the KK Z-boson Z{sub 1} (5D) and the spinless KK photon {gamma}{sub H} (6D). We combine collider limits such as electroweak precision data and expected LHC reach, with cosmological constraints from WMAP and the sensitivity of current or planned direct detection experiments. Allowing for general mass splittings, we show that neither colliders, nor direct detection experiments by themselves can explore all of the relevant KK dark matter parameter space. Nevertheless, they probe different parameter space regions and the combination of the two types of constraints can be quite powerful. For example, in the case of {gamma}{sub 1} in 5D UEDs the relevant parameter space will be almost completely covered by the combined LHC and direct detection sensitivities expected in the near future.
Improved generating technique for D=5 supergravities and squashed Kaluza-Klein black holes
Gal'tsov, Dmitri V.; Scherbluk, Nikolai G.
2009-03-15
Recently we suggested a solution-generating technique for five-dimensional supergravity with three Abelian vector fields based on the hidden SO(4,4) symmetry of the three-dimensionally reduced theory. This technique generalizes the G{sub 2(2)} generating technique developed earlier for minimal five-dimensional supergravity (A. Bouchareb, G. Clement, C-M. Chen, D. V. Gal'tsov, N. G. Scherbluk, and Th. Wolf, Phys. Rev. D 76, 104032 (2007)) and provides a new matrix representation for cosets forming the corresponding sigma-models in both cases. Here we further improve these methods introducing a matrix-valued dualization procedure which helps to avoid difficulties associated with solving the dualization equations in the component form. This new approach is used to generate a five-parametric rotating charged Kaluza-Klein black hole with the squashed horizon adding one parameter more to the recent solution by Tomizawa, Yasui, and Morisawa, which was constructed using the previous version of the G{sub 2(2)} generating technique.
Search for Kaluza-Klein gravitons in extra dimension models via forward detectors at the LHC
NASA Astrophysics Data System (ADS)
Cho, Gi-Chol; Kono, Takanori; Mawatari, Kentarou; Yamashita, Kimiko
2015-06-01
We investigate contributions of Kaluza-Klein (KK) graviton in extra dimension models to the process p p →p γ p →p γ j X , where a proton emits a quasireal photon and is detected by using the very forward detectors planned at the LHC. In addition to the γ q initial state as in the Compton scattering in the standard model, the γ g scattering contributes through the t -channel exchange of KK gravitons. Taking account of pileup contributions to the background and examining viable kinematical cuts, constraints on the parameter space of both the ADD (Arkani-Hamed, Dimopoulos and Dvali) model and the RS (Randall and Sundrum) model are studied. With 200 fb-1 data at a center-of-mass energy of 14 TeV, the expected lower bound on the cutoff scale for the ADD model is 6.3 TeV at 95% confidence level, while a lower limit of 2.0 (0.5) TeV is set on the mass of the first excited graviton with the coupling parameter k /M¯ Pl=0.1 (0.01 ) for the RS model.
Lightest Kaluza-Klein graviton mode in a back-reacted Randall-Sundrum scenario
NASA Astrophysics Data System (ADS)
Das, Ashmita; SenGupta, Soumitra
2016-08-01
In search of the extra dimensions in the ongoing LHC experiments, the signatures of the Randall-Sundrum (RS) lightest KK graviton have been in the main focus in recent years. The recent data from the dilepton decay channel at the LHC has determined the experimental lower bound on the mass of the RS lightest Kaluza-Klein (KK) graviton for different choices of the underlying parameters of the theory. In this work we explore the effects of the back-reaction of the bulk scalar field, which is employed to stabilise the RS model, in modifying the couplings of the lightest KK graviton with the standard model matter fields located on the visible brane. In such a modified background geometry we show that the coupling of the lightest KK graviton with the SM matter fields gets a significant suppression due to the inclusion of the back-reaction of the bulk stabilising scalar field. This implies that the back-reaction parameter weakens the signals from the RS scenario in collider experiments, which in turn explains the non-visibility of KK graviton in colliders. Thus we show that the modulus stabilisation plays a crucial role in the search of warped extra dimensions in collider experiments.
Gravitational Kaluza-Klein modes in the string-cigar braneworld
NASA Astrophysics Data System (ADS)
Veras, D. F. S.; Silva, J. E. G.; Cruz, W. T.; Almeida, C. A. S.
2015-03-01
In this work we analyze the properties of the gravitational Kaluza-Klein (KK) modes in two stringlike braneworlds, the thin Gherghetta-Shaposhnikov (GS) model and the thick string-cigar model. The string-cigar model is a smooth generalization of the GS model that undergoes a Ricci geometrical flow. We find a new massless mode in both models satisfying the respective Schrödinger equations. By means of a numerical analysis, we obtain the complete graviton spectrum and its respective eigenfunctions. The KK spectrum exhibits the usual linear regime for large discrete index n and we find a new decreasing regime for small n . Moreover, there is an asymmetric mass gap between the massless mode and the massive KK tower. The mass gap in the GS model is bigger than in the string-cigar model. In addition, the mass gap remains invariant upon the geometrical flow. It turns out that in the string-cigar model the brane structure smoothes and amplifies the KK modes near the brane core. The presence of a potential well in the string-cigar scenario allows the existence of resonant massive gravitons for small masses.
Kaluza-Klein dark matter: Direct detection vis-a-vis CERN LHC
Arrenberg, Sebastian; Baudis, Laura; Kong, Kyoungchul; Matchev, Konstantin T.; Yoo, Jonghee
2008-09-01
We explore the phenomenology of Kaluza-Klein (KK) dark matter in very general models with universal extra dimensions (UEDs), emphasizing the complementarity between high-energy colliders and dark matter direct detection experiments. In models with relatively small mass splittings between the dark matter candidate and the rest of the (colored) spectrum, the collider sensitivity is diminished, but direct detection rates are enhanced. UEDs provide a natural framework for such mass degeneracies. We consider both five-dimensional and six-dimensional nonminimal UED models, and discuss the detection prospects for various KK dark matter candidates: the KK photon {gamma}{sub 1}, the KK Z boson Z{sub 1}, the KK Higgs boson H{sub 1}, and the spinless KK photon {gamma}{sub H}. We combine collider limits, such as electroweak precision data and expected LHC reach, with cosmological constraints from WMAP, and the sensitivity of current or planned direct detection experiments. Allowing for general mass splittings, we show that neither colliders nor direct detection experiments by themselves can explore all of the relevant KK dark matter parameter space. Nevertheless, they probe different parameter space regions, and the combination of the two types of constraints can be quite powerful. For example, in the case of {gamma}{sub 1} in 5D UEDs the relevant parameter space will be almost completely covered by the combined CERN LHC and direct detection sensitivities expected in the near future.
Testing extra dimensions below the production threshold of Kaluza-Klein excitations
Boos, Edward E.; Bunichev, Viacheslav E.; Smolyakov, Mikhail N.; Volobuev, Igor P.
2009-05-15
We consider a stabilized Randall Sundrum 1 model in the energy range below the direct production of Kaluza-Klein (KK) states. In this range, we work out the effective Lagrangian due to exchange of heavy KK tensor graviton and scalar radion states and compute explicitly the corresponding effective coupling constants. As an example, the Drell-Yan lepton pair production at the Tevatron and the LHC is analyzed in two situations, when the first KK resonance is too heavy to be directly detected at the colliders, and when the first KK resonance is visible, but other states are still too heavy. It is shown that in both cases the contribution from the KK invisible tower leads to a modification of final particles distributions. In particular, for the second case a nontrivial interference between the first KK mode and the rest KK tower takes place. Expected 95% C.L. limits for model parameters for the Tevatron and the LHC are given. In the Appendix, useful formulas for the cross sections and distributions of various new 2{yields}2 processes via heavy KK tower exchange are presented, the new formulas containing nonzero particle masses for final state fermions and bosons. The formulas and numerical results are obtained by means of the CompHEP code, in which all new effective interactions are implemented providing a tool for simulation of corresponding events and a more detailed analysis.
Kaluza-Klein gravitons are negative energy dust in brane cosmology
Minamitsuji, Masato; Sasaki, Misao; Langlois, David
2005-04-15
We discuss the effect of Kaluza-Klein (KK) modes of bulk metric perturbations on the second Randall-Sundrum (RS II) type brane cosmology, taking the possible backreaction in the bulk and on the brane into account. KK gravitons may be produced via quantum fluctuations during a de Sitter (dS) inflating phase of our brane universe. In an effective 4-dimensional theory in which one integrates out the extra-dimensional dependence in the action, KK gravitons are equivalent to massive gravitons on the brane with masses m>3H/2, where H represents the expansion rate of a dS brane. Thus production of even a tiny amount of KK gravitons may eventually have a significant impact on the late-time brane cosmology. As a first step to quantify the effect of KK gravitons on the brane, we calculate the effective energy density and pressure for a single KK mode. Surprisingly, we find that a KK mode behaves as cosmic dust with a negative energy density on the brane. We note that the bulk energy density of a KK mode is positive definite and there occurs no singular phenomenon in the bulk.
Dangerous angular Kaluza-Klein/glueball relics in string theory cosmology
Dufaux, J. F.; Kofman, L.; Peloso, M.
2008-07-15
The presence of Kaluza-Klein (KK) particles in the universe is a potential manifestation of string theory cosmology. In general, they can be present in the high temperature bath of the early universe. In particular examples, string theory inflation often ends with brane-antibrane annihilation followed by the energy cascading through massive closed string loops to KK modes which then decay into lighter standard model particles. However, massive KK modes in the early universe may become dangerous cosmological relics if the inner manifold contains warped throat(s) with approximate isometries. In the complimentary picture, in the AdS/CFT dual gauge theory with extra isometries, massive glueballs of various spins become the dangerous cosmological relics. The decay of these angular KK modes/glueballs, located around the tip of the throat, is caused by isometry breaking which results from gluing the throat to the compact Calabi-Yau (CY) manifold. We address the problem of these angular KK particles/glueballs, studying their interactions and decay channels, from the theory side, and the resulting cosmological constraints on the warped compactification parameters, from the phenomenology side. The abundance and decay time of the long-lived nonrelativistic angular KK modes depend strongly on the parameters of the warped geometry, so that observational constraints rule out a significant fraction of the parameter space. In particular, the coupling of the angular KK particles can be weaker than gravitational.
PAMELA and Fermi LAT signals from long-lived Kaluza-Klein dark matter
Okada, Nobuchika; Yamada, Toshifumi
2009-10-01
We propose a simple extension of the minimal universal extra dimension model by introducing a small curvature. The model is formulated as a small anti-de Sitter curvature limit of the five-dimensional standard model (SM) in the Randall-Sundrum background geometry. While the lightest Kaluza-Klein (KK) particle can be thermal relic dark matter as usual in the universal extra dimension model, the KK parity is explicitly broken in the presence of the small curvature and the KK dark matter decays into the SM fermions with a long lifetime. Couplings of the KK dark matter with SM fermion pairs in the five-dimensional bulk are controlled by fermion bulk masses. By tuning bulk masses of quarks, we can suppress KK dark matter decay into quarks. With a suitable choice of bulk masses for leptons, KK dark matter decay into leptons can account for the cosmic-ray electron/positron excesses reported by the recent PAMELA and Fermi LAT satellite experiments.
Integration of Kaluza-Klein modes in Yang-Mills theories
Novales-Sanchez, H.; Toscano, J. J.
2011-10-01
A five-dimensional pure Yang-Mills theory, with the fifth coordinate compactified on the orbifold S{sup 1}/Z{sub 2} of radius R, leads to a four-dimensional theory which is governed by two types of infinitesimal gauge transformations, namely, the well-known standard gauge transformations (SGT) dictated by the SU{sub 4}(N) group under which the zero Fourier modes A{sub {mu}}{sup (0)a} transform as gauge fields, and a set of nonstandard gauge transformations (NSGT) determining the gauge nature of the Kaluza-Klein (KK) excitations A{sub {mu}}{sup (m)a}. By using a SGT-covariant gauge-fixing procedure for removing the degeneration associated with the NSGT, we integrate out the KK excitations and obtain a low-energy effective Lagrangian expansion involving all of the independent canonical-dimension-six operators that are invariant under the SGT of the SU{sub 4}(N) group and that are constituted by light gauge fields, A{sub {mu}}{sup (0)a}, exclusively. It is shown that this effective Lagrangian is invariant under the SGT, but it depends on the gauge-fixing of the gauge KK excitations. Our result shows explicitly that the one-loop contributions of the KK excitations to light (standard) Green's functions are renormalizable.
Kaluza-Klein cosmological model in f(R, T) gravity with Λ(T)
NASA Astrophysics Data System (ADS)
Sahoo, P. K.; Mishra, B.; Tripathy, S. K.
2016-04-01
A class of Kaluza-Klein cosmological models in $f(R,T)$ theory of gravity have been investigated. In the work, we have considered the functional $f(R,T)$ to be in the form $f(R,T)=f(R)+f(T)$ with $f(R)=\\lambda R$ and $f(T)=\\lambda T$. Such a choice of the functional $f(R,T)$ leads to an evolving effective cosmological constant $\\Lambda$ which depends on the stress energy tensor. The source of the matter field is taken to be a perfect cosmic fluid. The exact solutions of the field equations are obtained by considering a constant deceleration parameter which leads two different aspects of the volumetric expansion namely a power law and an exponential volumetric expansion. Keeping an eye on the accelerating nature of the universe in the present epoch, the dynamics and physical behaviour of the models have been discussed. From statefinder diagnostic pair we found that the model with exponential volumetric expansion behaves more like a $\\Lambda$CDM model.
Hamiltonian Map to Conformal Modification of Spacetime Metric: Kaluza-Klein and TeVeS
NASA Astrophysics Data System (ADS)
Horwitz, Lawrence; Gershon, Avi; Schiffer, Marcelo
2011-01-01
It has been shown that the orbits of motion for a wide class of non-relativistic Hamiltonian systems can be described as geodesic flows on a manifold and an associated dual by means of a conformal map. This method can be applied to a four dimensional manifold of orbits in spacetime associated with a relativistic system. We show that a relativistic Hamiltonian which generates Einstein geodesics, with the addition of a world scalar field, can be put into correspondence in this way with another Hamiltonian with conformally modified metric. Such a construction could account for part of the requirements of Bekenstein for achieving the MOND theory of Milgrom in the post-Newtonian limit. The constraints on the MOND theory imposed by the galactic rotation curves, through this correspondence, would then imply constraints on the structure of the world scalar field. We then use the fact that a Hamiltonian with vector gauge fields results, through such a conformal map, in a Kaluza-Klein type theory, and indicate how the TeVeS structure of Bekenstein and Saunders can be put into this framework. We exhibit a class of infinitesimal gauge transformations on the gauge fields {mathcal{U}}_{μ}(x) which preserve the Bekenstein-Sanders condition {mathcal{U}}_{μ}{mathcal{U}}^{μ}=-1. The underlying quantum structure giving rise to these gauge fields is a Hilbert bundle, and the gauge transformations induce a non-commutative behavior to the fields, i.e. they become of Yang-Mills type. Working in the infinitesimal gauge neighborhood of the initial Abelian theory we show that in the Abelian limit the Yang-Mills field equations provide residual nonlinear terms which may avoid the caustic singularity found by Contaldi et al.
Static wormholes on the brane inspired by Kaluza-Klein gravity
Leon, J. Ponce de
2009-11-01
We use static solutions of 5-dimensional Kaluza-Klein gravity to generate several classes of static, spherically symmetric spacetimes which are analytic solutions to the equation {sup (4)}R = 0, where {sup (4)}R is the four-dimensional Ricci scalar. In the Randall and Sundrum scenario they can be interpreted as vacuum solutions on the brane. The solutions contain the Schwarzschild black hole, and generate new families of traversable Lorenzian wormholes as well as nakedly singular spacetimes. They generalize a number of previously known solutions in the literature, e.g., the temporal and spatial Schwarzschild solutions of braneworld theory as well as the class of self-dual Lorenzian wormholes. A major departure of our solutions from Lorenzian wormholes a la Morris and Thorne is that, for certain values of the parameters of the solutions, they contain three spherical surfaces (instead of one) which are extremal and have finite area. Two of them have the same size, meet the ''flare-out'' requirements, and show the typical violation of the energy conditions that characterizes a wormhole throat. The other extremal sphere is ''flaring-in'' in the sense that its sectional area is a local maximum and the weak, null and dominant energy conditions are satisfied in its neighborhood. After bouncing back at this second surface a traveler crosses into another space which is the double of the one she/he started in. Another interesting feature is that the size of the throat can be less than the Schwarzschild radius 2M, which no longer defines the horizon, i.e., to a distant observer a particle or light falling down crosses the Schwarzschild radius in a finite time.
IceCube Collaboration; Abbasi, R.; al., et
2009-10-23
A search for muon neutrinos from Kaluza-Klein dark matter annihilations in the Sun has been performed with the 22-string configuration of the IceCube neutrino detector using data collected in 104.3 days of live-time in 2007. No excess over the expected atmospheric background has been observed. Upper limits have been obtained on the annihilation rate of captured lightest Kaluza-Klein particle (LKP) WIMPs in the Sun and converted to limits on the LKP-proton cross-sections for LKP masses in the range 250 - 3000 GeV. These results are the most stringent limits to date on LKP annihilation in the Sun.
NASA Astrophysics Data System (ADS)
Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bissok, M.; Blaufuss, E.; Boersma, D. J.; Bohm, C.; Bolmont, J.; Botner, O.; Bradley, L.; Braun, J.; Breder, D.; Carson, M.; Castermans, T.; Chirkin, D.; Christy, B.; Clem, J.; Cohen, S.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; Day, C. T.; de Clercq, C.; Demirörs, L.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; Deyoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Edwards, W. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Ganugapati, R.; Gerhardt, L.; Gladstone, L.; Goldschmidt, A.; Goodman, J. A.; Gozzini, R.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gunasingha, R. M.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Hasegawa, Y.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Homeier, A.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Imlay, R. L.; Inaba, M.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kelley, J. L.; Kemming, N.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Knops, S.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Krings, T.; Kroll, G.; Kuehn, K.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Lauer, R.; Lehmann, R.; Lennarz, D.; Lucke, A.; Lundberg, J.; Lünemann, J.; Madsen, J.; Majumdar, P.; Maruyama, R.; Mase, K.; Matis, H. S.; McParland, C. P.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Middell, E.; Milke, N.; Miyamoto, H.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; Ono, M.; Panknin, S.; Patton, S.; Paul, L.; Pérez de Los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Pohl, A. C.; Porrata, R.; Potthoff, N.; Price, P. B.; Prikockis, M.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Roucelle, C.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Sarkar, S.; Schatto, K.; Schlenstedt, S.; Schmidt, T.; Schneider, D.; Schukraft, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stoufer, M. C.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sulanke, K.-H.; Sullivan, G. W.; Swillens, Q.; Taboada, I.; Tamburro, A.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Terranova, C.; Tilav, S.; Toale, P. A.; Tooker, J.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; van Overloop, A.; van Santen, J.; Voigt, B.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Wiedemann, A.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Xu, C.; Xu, X. W.; Yodh, G.; Yoshida, S.; IceCube Collaboration
2010-03-01
A search for muon neutrinos from Kaluza-Klein dark matter annihilations in the Sun has been performed with the 22-string configuration of the IceCube neutrino detector using data collected in 104.3 days of live time in 2007. No excess over the expected atmospheric background has been observed. Upper limits have been obtained on the annihilation rate of captured lightest Kaluza-Klein particle (LKP) WIMPs in the Sun and converted to limits on the LKP-proton cross sections for LKP masses in the range 250-3000 GeV. These results are the most stringent limits to date on LKP annihilation in the Sun.
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).
Uniqueness theorem for black holes with Kaluza-Klein asymptotic in 5D Einstein-Maxwell gravity
Yazadjiev, Stoytcho
2010-07-15
In the present paper, we prove a uniqueness theorem for stationary multi-black hole configurations with Kaluza-Klein asymptotic in a certain sector of 5D Einstein-Maxwell gravity. As a part of the technical assumptions in the theorem, we assume that the Killing vector associated with the compact dimension is orthogonal to the other Killing vectors and that it is also hypersurface orthogonal. About the Maxwell field, we assume that it is invariant under the Killing symmetries and has a nonzero component only along the Killing vector associated with the compact dimension. We show that such multi-black hole configurations are uniquely specified by the interval structure, angular momenta of the horizons, magnetic charges, and the magnetic flux. A straightforward generalization of the uniqueness theorem for 5D Einstein-Maxwell-dilaton gravity is also given.
Thermodynamics of rotating Kaluza-Klein black holes in gravity's rainbow
NASA Astrophysics Data System (ADS)
Alsaleh, Salwa
2017-04-01
In this paper, a four-dimensional rotating Kaluza Klien (K-K) black hole was deformed using rainbow functions derived from loop quantum gravity and non-commutative geometry. We studied the thermodynamic properties and critical phenomena of this deformed black hole. The deformed temperature and entropy showed the existence of a Planckian remnant. The calculation of Gibbs free energy G for the ordinary and deformed black holes showed that both share a similar critical behaviour.
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2004-03-26
We report on a search for direct Kaluza-Klein graviton production in a data sample of 84 pb(-1) of ppmacr; collisions at sqrt[s]=1.8 TeV, recorded by the Collider Detector at Fermilab. We investigate the final state of large missing transverse energy and one or two high energy jets. We compare the data with the predictions from a (3+1+n)-dimensional Kaluza-Klein scenario in which gravity becomes strong at the TeV scale. At 95% confidence level (C.L.) for n=2, 4, and 6 we exclude an effective Planck scale below 1.0, 0.77, and 0.71 TeV, respectively.
Evolution of perturbations of squashed Kaluza-Klein black holes: Escape from instability
Ishihara, Hideki; Kimura, Masashi; Konoplya, Roman A.; Murata, Keiju; Soda, Jiro; Zhidenko, Alexander
2008-04-15
The squashed Kaluza-Klien (KK) black holes differ from the Schwarzschild black holes with asymptotic flatness or the black strings even at energies for which the KK modes are not excited yet, so that squashed KK black holes open a window in higher dimensions. Another important feature is that the squashed KK black holes are apparently stable and, thereby, let us avoid the Gregory-Laflamme instability. In the present paper, the evolution of scalar and gravitational perturbations in time and frequency domains is considered for these squashed KK black holes. The scalar field perturbations are analyzed for general rotating squashed KK black holes. Gravitational perturbations for the so-called zero mode are shown to be decayed for nonrotating black holes, in concordance with the stability of the squashed KK black holes. The correlation of quasinormal frequencies with the size of extra dimension is discussed.
NASA Astrophysics Data System (ADS)
Kubota, Hirohisa; Nojiri, Mihoko
2013-04-01
In this paper we study the Higgs(h)-radion(r) system of the Randall-Sundum model where matter fermions and gauge fields live in the bulk while the Higgs boson resides on the infrared brane. We take into account the Kaluza-Klein loop correction to the hVV and rVV couplings where V=g, γ. Inspired by the LHC data in 2011 in which a hint of the Higgs boson has been seen at 125 GeV, we fix one of the mass eigenstates of the Higgs-radion mixed state at 125 GeV and scan over all the other parameters that have not been excluded by the 2011 Higgs search data. We find the regions of parameter space where the scalar particle at 125 GeV has a signal rate significantly larger or smaller than that of the Standard Model (SM) Higgs boson. The signal ratio Br(ZZ)/Br(γγ) also may deviate from that of the SM Higgs boson.
Matsumoto, Shigeki; Sato, Joe; Yamanaka, Masato; Senami, Masato
2009-09-01
We calculate the production rates of the second Kaluza-Klein (KK) photon {gamma}{sup (2)} and Z boson Z{sup (2)} at the LHC including all significant processes in the minimal universal extra dimension (MUED) model. For discrimination of the MUED model from other TeV scale models at the LHC, {gamma}{sup (2)} and Z{sup (2)} play a crucial role. In order to discuss the discrimination and calculate their production rates, we derive KK number violating operators including the contribution of the top Yukawa coupling. Using these operators, we accurately calculate branching ratios of second KK particles. In addition we find that these KK number violating operators provide new processes for {gamma}{sup (2)} and Z{sup (2)} productions, such as cascade decay from second KK quarks produced through these operators. They have large contributions to their total production rates. In particular, these production processes give the dominant contribution for {gamma}{sup (2)} production for 1/R > or approx. 800 GeV. As a result, with an integrated luminosity of 100 fb{sup -1}, the number of produced {gamma}{sup (2)} and Z{sup (2)} are estimated as 10{sup 6}-10{sup 2} for the compactification scale between 400 and 2000 GeV.
NASA Astrophysics Data System (ADS)
Dienes, Keith R.; Kost, Jeff; Thomas, Brooks
2017-06-01
We study the early-universe cosmology of a Kaluza-Klein (KK) tower of scalar fields in the presence of a mass-generating phase transition, focusing on the time development of the total tower energy density (or relic abundance) as well as its distribution across the different KK modes. We find that both of these features are extremely sensitive to the details of the phase transition and can behave in a variety of ways significant for late-time cosmology. In particular, we find that the interplay between the temporal properties of the phase transition and the mixing it generates are responsible for both enhancements and suppressions in the late-time abundances, sometimes by many orders of magnitude. We map out the complete model parameter space and determine where traditional analytical approximations are valid and where they fail. In the latter cases we also provide new analytical approximations which successfully model our results. Finally, we apply this machinery to the example of an axion-like field in the bulk, mapping these phenomena over an enlarged axion parameter space that extends beyond that accessible to standard treatments. An important by-product of our analysis is the development of an alternate "UV-based" effective truncation of KK theories which has a number of interesting theoretical properties that distinguish it from the more traditional "IR-based" truncation typically used in the extra-dimension literature.
NASA Astrophysics Data System (ADS)
Ebert, Dietmar; Plefka, Jan; Rodigast, Andreas
2009-02-01
We study the question of a modification of the running gauge coupling of Yang-Mills theories due to quantum gravitational effects in a compact large extra dimensional brane world scenario with a low energy quantum gravity scale. The ADD scenario is applied for a D = d+δ dimensional space-time in which gravitons freely propagate, whereas the non-abelian gauge fields are confined to a d-dimensional brane. The extra dimensions are taken to be toroidal and the transverse fluctuation modes (branons) of the brane are taken into account. On this basis we have calculated the one-loop corrections due to virtual Kaluza-Klein graviton and branon modes for the gluon two- and three-point functions in an effective field theory treatment. Applying momentum cut-off regularization we find that for a d = 4 brane the leading gravitational divergencies cancel irrespective of the number of extra dimensions δ, generalizing previous results in the absence of extra-dimensions. Hence, again the Yang-Mills β-function receives no gravitational corrections at one-loop. This is no longer true in a `universal' extra dimensional scenario with a d > 4 dimensional brane. Moreover, the subleading power-law gravitational divergencies induce higher-dimensional counterterms, which we establish in our scheme. Interestingly, for d = 4 these gravitationally induced counterterms are of the form recently considered in non-abelian Lee-Wick extensions of the standard model—now with a possible mass scale in the TeV range due to the presence of large extra dimensions.
Energy scales in a stabilized brane world
Boos, Edward E.; Mikhailov, Yuri S.; Smolyakov, Mikhail N.; Volobuev, Igor P.; /SINP, Moscow
2004-12-01
Brane world gravity looks different for observers on positive and negative tension branes. First we consider the well-known RS1 model with two branes embedded into the AdS5 space-time and recall the results on the relations between the energy scales for an observer on the negative tension brane, which is supposed to be ''our'' brane. Then from the point of view of this observer we study energy scales and masses for the radion and graviton excitations in a stabilized brane world model. We argue that there may be several possibilities leading to scales of the order 1-10 TeV or even less for new physics effects on our brane. In particular, an interesting scenario can arise in the case of a ''symmetric'' brane world with a nontrivial warp factor in the bulk, which however takes equal values on both branes.
de Sitter and double asymmetric brane worlds
Guerrero, Rommel; Rodriguez, R. Omar; Torrealba, Rafael
2005-12-15
Asymmetric brane worlds with dS expansion and static double kink topology are obtained from a recently proposed method and their properties are analyzed. These domain walls interpolate between two spacetimes with different cosmological constants. In the dynamic case, the vacua correspond to dS and AdS geometry, unlike the static case where they correspond to AdS background. We show that it is possible to confine gravity on such branes. In particular, the double-brane world hosts two different walls, so that the gravity is localized on one of them.
Davis, Stephen C.; Brechet, Sylvain
2005-05-15
The bubble nucleation rate for a first order phase transition occurring on a brane world is calculated. Both the Coleman-de Luccia thin wall instanton and the Hawking-Moss instanton are considered. The results are compared with the corresponding nucleation rates for standard four-dimensional gravity.
Conformal symmetry of brane world effective actions
McFadden, Paul L.; Turok, Neil
2005-01-15
A simple derivation of the low-energy effective action for brane worlds is given, highlighting the role of conformal invariance. We show how to improve the effective action for a positive- and negative-tension brane pair using the AdS/CFT correspondence.
Motion in Brane World Models: The Bazanski Approach
Kahil, M.E.
2007-11-20
Recently, path equations have been obtained for charged and spinning objects in brane world models, using a modified Bazanski Lagrangian. In this study, path deviation equations of extended objects are derived. The significance of moving extended objects in brane world models is examined. Motion in non-symmetric brane world models is also considered.
Savina, M. V.
2015-06-15
A survey of the results of the Compact Muon Solenoid (CMS) experiment that concern searches for massive Kaluza-Klein graviton excitations and microscopic black holes, quantum black holes, and string balls within models of low-energy multidimensional gravity is presented on behalf of the CMS Collaboration. The analysis in question is performed on the basis of a complete sample of data accumulated for proton-proton collisions at the c.m. energies of 7 and 8 TeV at the Large Hadron Collider (LHC) over the period spanning 2010 and 2012.
Brane-World Cosmology and Varying G
NASA Astrophysics Data System (ADS)
Amarilla, Leonardo; Vucetich, Héctor
We consider a brane-world cosmological model coupled to a bulk scalar field. Since the brane tension turns out to be proportional to Newton's coupling G, in such a model a time variation of G naturally occurs. By resorting to available bounds on the variation of G, the parameters of the model are constrained. The constraints coming from nucleosynthesis and CMB result to be the severest ones.
Brane-world cosmology with black strings
NASA Astrophysics Data System (ADS)
Gergely, László Á.
2006-07-01
We consider the simplest scenario when black strings/cigars penetrate the cosmological brane. As a result, the brane has a Swiss-cheese structure, with Schwarzschild black holes immersed in a Friedmann-Lemaître-Robertson-Walker brane. There is no dark radiation in the model, the cosmological regions of the brane are characterized by a cosmological constant Λ and flat spatial sections. Regardless of the value of Λ, these brane-world universes forever expand and forever decelerate. The totality of source terms in the modified Einstein equation sum up to a dust, establishing a formal equivalence with the general relativistic Einstein-Straus model. However in this brane-world scenario with black strings the evolution of the cosmological fluid strongly depends on Λ. For Λ≤0 it has positive energy density ρ and negative pressure p and at late times it behaves as in the Einstein-Straus model. For (not too high) positive values of Λ the cosmological evolution begins with positive ρ and negative p, but this is followed by an epoch with both ρ and p positive. Eventually, ρ becomes negative, while p stays positive. A similar evolution is present for high positive values of Λ, however in this case the evolution ends in a pressure singularity, accompanied by a regular behavior of the cosmic acceleration. This is a novel type of singularity appearing in brane-worlds.
D-dimensional torus as compact manifold and Kaluza-Klein cosmological model.
NASA Astrophysics Data System (ADS)
Srivastava, S. K.
1992-09-01
Singularity-free solutions of higher-dimensional Einstein field equations are obtained in the background of M4×TD manifold (M4 is a usual four-dimensional Friedmann- Robertson-Walker model and TD is a D-dimensional torus). Moreover, through dimensional reduction and one-loop quantum correction to scalar field, time-dependent cosmological constant Λ, effective gravitational constant Geff, and a fine-structure constant e/4π are derived in the effective four-dimensional theory using solutions of Einstein's equations. It is found that at late times Λ ≍ 0.
Gauge invariance, quantization and integration of heavy modes in a gauge Kaluza-Klein theory
NASA Astrophysics Data System (ADS)
Novales-Sánchez, H.
This dissertation examines topics at the intersection of environmental and energy economics. The first two chapters explore how policies can induce more efficient use of the energy sources available for generating electricity. The electricity sector is a major source of a wide variety of harmful pollutants. To mitigate the environmental impacts of electricity production, a variety of policies are being implemented to increase the quantity of generation from clean, renewable energy sources. The first chapter identifies the short-run reductions in emissions caused by generation from a particular renewable technology; wind turbines. Using the estimates of the pollution offset by the renewable production, I explore the efficiency of the incentives created by the current set of renewable energy policies. The second chapter examines the impact adding bulk electricity storage capacity will have on the full social costs of generating electricity. The third chapter explores the impact of various gasoline tax structures on both retail price volatility and state revenue volatility.
NASA Astrophysics Data System (ADS)
Lukman, Dragan; Borštnik, Norma Susana Mankoč
2017-04-01
It is shown that in the spin-charge-family theory (Mankoč Borštnik in arXiv:1607.01618v2 Phys Rev D 91:065004 (2016). 1409.7791, Mod Phys 6:2244 (205). 10.4236/jmp.2015.615230 (2015). arxiv.org/abs/1409.4981 (2016), J Mod Phys 4:823. 10.4236/jmp.2013.46113. arxiv:1312.1542 (2013) arxiv:1409.4981 (2014), as well as in all the Kaluza-Klein like theories (Blagojević in Gravitation and gauge symmetries, IoP Publishing, Bristol, 2002, An introduction to Kaluza-Klein theories, World Scientific, Singapore, 1983), vielbeins and spin connections manifest in d=(3+1) space equivalent vector gauge fields, when space with d\\ge 5 has a large enough symmetry. The authors demonstrate this equivalence in spaces with the symmetry of the metric tensor in the space out of d=(3+1)-g^{σ τ } = η ^{σ τ } f2 - for any scalar function f of the coordinates x^{σ }, where x^{σ } denotes the coordinates of space out of d=(3+1). Also the connection between vielbeins and scalar gauge fields in d=(3+1) (offering the explanation for the Higgs scalar) is discussed.
NASA Astrophysics Data System (ADS)
Wu, Shuang-Qing; Wang, He
2015-05-01
In a previous paper [S. Q. Wu, Phys. Rev. D 83, 121502(R) (2011)], a new kind of metric ansatz was found to fairly describe all already-known black hole solutions in the ungauged Kaluza-Klein (KK) supergravity theories. That metric ansatz somewhat resembles the famous Kerr-Schild (KS) form, but it is different from the KS one in two distinct aspects. That is, apart from a global conformal factor, the metric ansatz can be written as a vacuum background spacetime plus a "perturbation" modification term, the latter of which is associated with a timelike geodesic vector field rather than a null geodesic congruence in the usual KS ansatz. Replacing the flat vacuum background metric by the (anti-)de Sitter [(A)dS] spacetime, the general rotating charged KK-(A)dS black hole solutions in all higher dimensions have been successfully constructed and put into a unified form. In this paper, we shall study this novel metric ansatz in detail, aiming at achieving some inspiration as to the construction of rotating charged AdS black holes with multiple charges in other gauged supergravity theories. We find that the traditional perturbation expansion method often successfully used in the KS form is no longer useful in our new ansatz, since here no good parameter can be chosen as a suitable perturbation indicator. In order to investigate the metric properties of the general KK-AdS solutions, in this paper we devise a new effective method, dubbed the background metric expansion method, which can be thought of as a generalization of the perturbation expansion method, to deal with the Lagrangian and all equations of motion. In addition to two previously known conditions, namely the timelike and geodesic properties of the vector, we get three additional constraints via contracting the Maxwell and Einstein equations once or twice with this timelike geodesic vector. In particular, we find that these are a simpler set of sufficient conditions to determine the vector and the dilaton scalar
Christiansen, H. R.; Cunha, M. S.; Tahim, M. O.
2010-10-15
We analytically find the exact propagation modes of the electromagnetic and the Kalb-Ramond fields together in a five-dimensional curved space-time. The existence and localization of gauge particles into our four-dimensional world (4D) is studied in detail on a brane-world scenario in which two gauge fields interact with a dilaton and a gravitational background. The coupling to the dilaton is different in each case causing the splitting between gauge spectra. The gauge-field zero-modes and an infinite tower of Kaluza-Klein massive states are analytically obtained. Relevant conditions on the dilaton coupling constant are found in order to identify with precision every finite tensor and vector eigenstate in the theory. An exact quantization condition on the whole mass spectrum, depending on the dilaton coupling constant and the bulk Planck mass, is inherited from the extra-dimension. This allows finding an exact rule to prevent tachyons in the theory and, by the same token, predicting a possible tensor zero-mode in 4D world. We also show that KK massive-modes contributions onto 4D physics are strongly suppressed.
Gauge unification in supersymmetric intersecting brane worlds
NASA Astrophysics Data System (ADS)
Blumenhagen, Ralph; Lüst, Dieter; Stieberger, Stephan
2003-07-01
We show that contrary to first expectations realistic three generation supersymmetric intersecting brane world models give rise to phenomenologically interesting predictions about gauge coupling unification. Assuming the most economical way of realizing the matter content of the MSSM via intersecting branes we obtain a model independent relation among the three gauge coupling constants at the string scale. In order to correctly reproduce the experimentally known values of sin2[thetaW(Mz)] and alphas(Mz) this relation leads to natural gauge coupling unification at a string scale close to the standard GUT scale 2 x 1016 GeV. Additional vector-like matter can push the unification scale up to the Planck scale.
Gravity on codimension 2 brane worlds
Navarro, Ignacio; Santiago, Jose; /Durham U., IPPP /Fermilab
2004-11-01
The authors compute the matching conditions for a general thick codimension 2 brane, a necessary previous step towards the investigation of gravitational phenomena in co-dimension 2 braneworlds. They show that, provided the brane is weakly curved, they are specified by the integral in the extra dimensions of the brane energy-momentum, independently of its detailed internal structure. These general matching conditions can then be used as boundary conditions for the bulk solution. By evaluating Einstein equations at the brane boundary they are able to write an evolution equation for the induced metric on the brane depending only on physical brane parameters and the bulk energy-momentum tensor. They particularize to a cosmological metric and show that a realistic cosmology can be obtained in the simplest case of having just a non-zero cosmological constant in the bulk. They point out several parallelisms between this case and the codimension 1 brane worlds in an AdS space.
Clustering of galaxies in brane world models
NASA Astrophysics Data System (ADS)
Hameeda, Mir; Faizal, Mir; Ali, Ahmed Farag
2016-04-01
In this paper, we analyze the clustering of galaxies using a modified Newtonian potential. This modification of the Newtonian potential occurs due to the existence of extra dimensions in brane world models. We will analyze a system of galaxies interacting with each other through this modified Newtonian potential. The partition function for this system of galaxies will be calculated, and this partition function will be used to calculate the free energy of this system of galaxies. The entropy and the chemical potential for this system will also be calculated. We will derive explicit expression for the clustering parameter for this system. This parameter will determine the behavior of this system, and we will be able to express various thermodynamic quantities using this clustering parameter. Thus, we will be able to explicitly analyze the effect that modifying the Newtonian potential can have on the clustering of galaxies. We also analyse the effect of extra dimensions on the two-point functions between galaxies.
Asymmetric Swiss-cheese brane-worlds
NASA Astrophysics Data System (ADS)
Gergely, László Á.; Képíró, Ibolya
2007-07-01
We study a brane-world cosmological scenario with local inhomogeneities represented by black holes. The brane is asymmetrically embedded into the bulk. The black strings/cigars penetrating the Friedmann brane generate a Swiss-cheese-type structure. This universe forever expands and decelerates, as its general relativistic analogue. The evolution of the cosmological fluid, however, can proceed along four branches, two allowed to have positive energy density, and one of them having the symmetric embedding limit. On this branch a future pressure singularity can arise for either (a) a difference in the cosmological constants of the cosmological and black hole brane regions or (b) a difference in the left and right bulk cosmological constants. While behaviour (a) can be avoided by a redefinition of the fluid variables, (b) establishes a critical value of the asymmetry over which the pressure singularity occurs. We introduce the pressure singularity censorship which bounds the degree of asymmetry in the bulk cosmological constant. We also show as a model-independent generic feature that the asymmetry source term due to the bulk cosmological constant increases in the early universe. In order to obey the nucleosynthesis constraints, the brane tension should be constrained therefore both from below and from above. With the maximal degree of asymmetry obeying the pressure singularity censorship, the higher limit is ten times the lower limit. The degree of asymmetry allowed by present cosmological observations is, however, much less, pushing the upper limit to infinity.
NASA Astrophysics Data System (ADS)
Pasqua, Antonio; Chattopadhyay, Surajit; Assaf, Khudhair A.; Salako, Ines G.
2016-06-01
In this paper, we study the properties of the Holographic Dark Energy (HDE) model in the context of Kaluza-Klein (KK) cosmology with infrared cut-off given by the recently proposed by Granda-Oliveros cut-off, which contains a term proportional to the time derivative of the Hubble parameter and one proportional to the Hubble parameter squared. Moreover, this cut-off is characterized by two free parameters which are the proportional constants of the two terms of the cut-off. We derive the expression of the Equation of State (EoS) parameter ωD and of the deceleration parameter q for both non-interacting and interacting Dark Sectors and in the limiting case of a flat Dark Dominated Universe. Moreover, we study the squared speed of the sound vs2 and the statefinder diagnostic \\{r,s\\} in order to understand the cosmological properties of the model considered. We also develop a correspondence between the model considered and three scalar field models: the tachyon, the k-essence and the quintessence ones.
Photo-production of a 750 GeV di-photon resonance mediated by Kaluza-Klein leptons in the loop
NASA Astrophysics Data System (ADS)
Abel, Steven; Khoze, Valentin V.
2016-05-01
We consider the phenomenology of a 750 GeV resonance X which can be produced at the LHC by only photon fusion and subsequently decay into di-photons. We propose that the spin-zero state X is coupled to a heavy lepton that lives in the bulk of a higher-dimensional theory and interacts only with the photons of the Standard Model. We compute the di-photon rate in these models with two and more compact extra dimensions and demonstrate that they allow for a compelling explanation of the di-photon excess recently observed by the ATLAS and CMS collaborations. The central role in our approach is played by the summation over the Kaluza-Klein modes of the new leptons, thus providing a significant enhancement of the X → γγ loops for the production and decay subprocesses. It is expected that the jet activity accompanying these purely electromagnetic (at the partonic level) processes is numerically suppressed by factors such as {α}_{em}^2{{C}}_{qoverline{q}}/{{C}}_{γ γ}˜ 1{0}^{-3}.
Chang, W.-F.; Ng, John N.; Wu, Jackson M. S.
2009-03-01
We continue our previous study on what are the allowed forms of quark mass matrices in the Randall-Sundrum framework that can reproduce the experimentally observed quark mass spectrum and the pattern of Cabibbo-Kobayashi-Maskawa mixing. We study the constraints the {delta}F=2 processes in the neutral meson sector placed on the admissible forms found there, and we found only the asymmetrical type of quark mass matrices arising from anarchical Yukawa structures remain viable at the few TeV scale reachable at the LHC. We study also the decay of the first Kaluza-Klein (KK) excitation of the gluon. We give the decay branching ratios of the first KK gluon into quark pairs, and we point out that measurements of the decay width and just one of the quark spins in the dominant tt decays can be used to extract the effective coupling of the first KK gluon to top quarks for both chiralities. This provides a further probe into the flavor structure of the Randall-Sundrum framework.
Simple brane-world inflationary models — An update
NASA Astrophysics Data System (ADS)
Okada, Nobuchika; Okada, Satomi
2016-05-01
In the light of the Planck 2015 results, we update simple inflationary models based on the quadratic, quartic, Higgs and Coleman-Weinberg potentials in the context of the Randall-Sundrum brane-world cosmology. Brane-world cosmological effect alters the inflationary predictions of the spectral index (ns) and the tensor-to-scalar ratio (r) from those obtained in the standard cosmology. In particular, the tensor-to-scalar ratio is enhanced in the presence of the 5th dimension. In order to maintain the consistency with the Planck 2015 results for the inflationary predictions in the standard cosmology, we find a lower bound on the five-dimensional Planck mass (M5). On the other hand, the inflationary predictions laying outside of the Planck allowed region can be pushed into the allowed region by the brane-world cosmological effect with a suitable choice of M5.
Abundance of Asymmetric Dark Matter in Brane World Cosmology
NASA Astrophysics Data System (ADS)
Abdusattar, Haximjan; Iminniyaz, Hoernisa
2016-09-01
Relic abundance of asymmetric Dark Matter particles in brane world cosmological scenario is investigated in this article. Hubble expansion rate is enhanced in brane world cosmology and it affects the relic abundance of asymmetric Dark Matter particles. We analyze how the relic abundance of asymmetric Dark Matter is changed in this model. We show that in such kind of nonstandard cosmological scenario, indirect detection of asymmetric Dark Matter is possible if the cross section is small enough which let the anti-particle abundance kept in the same amount with the particle. We show the indirect detection signal constraints can be used to such model only when the cross section and the 5-dimensional Planck mass scale are in appropriate values. Supported by the National Natural Science Foundation of China under Grant No. 11365022
Signals from the brane-world black hole
Shen Jianyong; Wang Bin; Su Rukeng
2006-08-15
We have studied the wave dynamics and the Hawking radiation for a scalar field as well as a brane-localized gravitational field in the background of a brane-world black hole with a tidal charge containing information on the extra dimension. Comparing with four-dimensional black holes, we have observed the signature of the tidal charge which presents the signals of the extra dimension both in the wave dynamics and the Hawking radiation.
Gravity Mediation in 6d Brane-World Supergravity
Lee, Hyun Min
2005-12-02
We consider the gravity-mediated SUSY breaking within the effective theory of six-dimensional brane-world supergravity. We construct the supersymmetric bulk-brane action by Noether method and find the nontrivial moduli coupling of the brane F- and D-terms. We find that the low energy Kaehler potential is not of sequestered form, so gravity mediation may occur at tree level. In moduli stabilization with anomaly effects included, the scalar soft mass squared can be positive at tree level and it can be comparable to the anomaly mediation.
Effective theory approach to brane world black holes
McFadden, Paul L.; Turok, Neil
2005-04-15
We derive static spherically symmetric vacuum solutions of the low-energy effective action for the two brane Randall-Sundrum model. The solutions with nontrivial radion belong to a one-parameter family describing traversable wormholes between the branes and a black hole, and were first discovered in the context of Einstein gravity with a conformally coupled scalar field. From a brane world perspective, a distinctive feature of all the solutions with nontrivial radion is a brane intersection about which the bulk geometry is conical but the induced metrics on the branes are regular. Contrary to earlier claims in the literature, we show these solutions are stable under monopole perturbations.
Classical and quantum aspects of brane-world cosmology
Cordero, Ruben; Rojas, Efrain
2011-10-14
We give a brief overview of several models in brane-world cosmology. In particular, we focus on the asymmetric DGP and Regge-Teiltelboim models. We present the associated equations of motion governing the dynamics of the brane and their corresponding Friedmann-like equations. In order to develop the quantum Regge-Teiltelboim type cosmology we construct its Ostrogradski Hamiltonian formalism which naturally leads to the corresponding Wheeler-DeWitt equation. In addition, we comment on possible generalizations for these models including second order derivative geometrical terms.
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.
Topics in brane world and quantum field theory
NASA Astrophysics Data System (ADS)
Corradini, Olindo
In the first part of the thesis we study various issues in the Brane World scenario with particular emphasis on gravity and the cosmological constant problem. First, we study localization of gravity on smooth domain-wall solutions of gravity coupled to a scalar field. In this context we discuss how the aforementioned localization is affected by including higher curvature terms in the theory, pointing out among other things that, general combinations of such terms lead to delocalization of gravity with the only exception of the Gauss-Bonnet combination (and its higher dimensional counterparts). We then find a solitonic 3-brane solution in 6D bulk in the Einstein-Hilbert-Gauss-Bonnet theory of gravity. Near to the brane the metric is that for a product of the 4D flat Minkowski space with a 2D wedge whose deficit angle is proportional to the brane tension. Consistency tests imposed on such backgrounds appear to require the localized matter on the brane to be conformal. We then move onto infinite volume extra dimension Brane World scenarios where we study gravity in a codimension-2 model, generalizing the work of Dvali, Gabadadze and Porrati to tensionful branes. We point out that, in the presence of the bulk Gauss-Bonnet combination, the Einstein-Hilbert term is induced on the brane already at the classical level. Consistency tests are presented here as well. To conclude we discuss, using String Theory, an interesting class of large-N gauge theories which have vanishing energy density even though these theories are non-covariant and non-supersymmetric. In the second part of the thesis we study a formulation of Quantum Mechanical Path Integrals in curved space. Such Path Integrals present superficial divergences which need to be regulated. We perform a three-loop calculation in mode regularization as a nontrivial check of the non-covariant counterterms required by such scheme. We discover that dimensional regularization can be successfully adopted to evaluate the
Brane-world stars with a solid crust and vacuum exterior
NASA Astrophysics Data System (ADS)
Ovalle, Jorge; Gergely, László Á.; Casadio, Roberto
2015-02-01
The minimal geometric deformation approach is employed to show the existence of brane-world stellar distributions with a vacuum Schwarzschild exterior, thus without energy leaking from the exterior of the brane-world star into the extra dimension. The interior satisfies all the elementary criteria of physical acceptability for a stellar solution, namely, it is regular at the origin, the pressure and density are positive and decrease monotonically with increasing radius, and all energy conditions are fulfilled. A very thin solid crust with negative radial pressure separates the interior from the exterior, having a thickness Δ inversely proportional to both the brane tension σ and the radius R of the star, i.e. {{Δ }-1}˜ Rσ . This brane-world star with Schwarzschild exterior would appear only thermally radiating to a distant observer and be fully compatible with the stringent constraints imposed on stellar parameters by observations of gravitational lensing, orbital evolutions or properties of accretion disks.
Brane-world stars from minimal geometric deformation, and black holes
NASA Astrophysics Data System (ADS)
Casadio, Roberto; Ovalle, Jorge
2014-02-01
Using the effective four-dimensional Einstein field equations, we build analytical models of spherically symmetric stars in the brane-world, in which the external space-time contains both an ADM mass and a tidal charge. In order to determine the interior geometry, we apply the principle of minimal geometric deformation, which allows one to map general relativistic solutions to solutions of the effective four-dimensional brane-world equations. We further restrict our analysis to stars with a radius linearly related to the total general relativistic mass, and obtain a general relation between the latter, the brane-world ADM mass and the tidal charge. In these models, the value of the star's radius can then be taken to zero smoothly, thus obtaining brane-world black hole metrics with a tidal charge solely determined by the mass of the source and the brane tension. We find configurations which entail a partial screening of the gravitational mass, and general conclusions regarding the minimum mass for semiclassical black holes are also drawn.
Effective contact interactions in a stabilized RS1 brane world model
Boos, E. E. Bunichev, V. E. Smolyakov, M. N. Volobuev, I. P.
2010-06-15
We consider the effective Lagrangian due to the exchange of heavy Kaluza-Klein (KK) tensor graviton and scalar radion states in a stabilized Randall-Sundrum model (RS1) and compute explicitly the corresponding effective coupling constants. The Drell-Yan lepton pair production at the Tevatron and the LHC is analyzed in two situations, when the first KK resonance is too heavy to be directly detected at the colliders, and when the first KK resonance is visible but other states are still too heavy. In the first case the effective Lagrangian reduces to a contact interaction of Standard Model (SM) particles, whereas in the second case it includes a coupling of SM particles to the first KK mode and a contact interaction due to the exchange of all the heavier modes. It is shown that in both cases the contribution from the invisible KK tower leads to a modification of final particles distributions. In particular, for the second case a nontrivial interference between the first KK mode and the rest KK tower takes place. Expected 95% C.L. limits for model parameters for the Tevatron and the LHC are given. The numerical results are obtained by means of the CompHEP code, in which all new effective interactions are implemented providing a tool for simulation of corresponding events and a more detailed analysis.
Particle creation in Kaluza-Klein cosmology.
NASA Astrophysics Data System (ADS)
Wunghong, Huang
1989-10-01
The author exactly calculates the particle number N of scalar fields which are created from an initial vacuum in certain higher-dimensional cosmological models. The spacetimes in these models are the four-dimensional Chitre-Hartle or radiation-dominated universe with extra spaces which are static or power-law contracting. Except for some models in which no particles could be produced, the distribution of created particles shows a thermal behavior, at least in the limit of high three-dimensional "momentum" k. In some models, N does not depend on the magnitude of the extra-dimensional "momentum" kc if kc is nonvanishing. A cutoff momentum kc may emerge in some models, and particles with k ≤ kc could not be produced. The author discusses these results.
Noncommutative brane-world, (Anti) de Sitter vacua and extra dimensions
NASA Astrophysics Data System (ADS)
Kar, Supriya
2006-10-01
We investigate a curved brane-world, inspired by a noncommutative D3-brane, in a type IIB string theory. We obtain, an axially symmetric and a spherically symmetric, (anti) de Sitter black holes in 4D. The event horizons of these black holes possess a constant curvature and may be seen to be governed by different topologies. The extremal geometries are explored, using the noncommutative scaling in the theory, to reassure the attractor behavior at the black hole event horizon. The emerging two dimensional, semi-classical, black hole is analyzed to provide evidence for the extra dimensions in a curved brane-world. It is argued that the gauge nonlinearity in the theory may be redefined by a potential in a moduli space. As a result, D = 11 and D = 12 dimensional geometries may be obtained at the stable extrema of the potential.
Decay of massive Dirac hair on a brane-world black hole
Gibbons, Gary W.; Rogatko, Marek; Szyplowska, Agnieszka
2008-03-15
We investigate the intermediate and late-time behavior of the massive Dirac spinor field in the background of static spherically symmetric brane-world black hole solutions. The intermediate asymptotic behavior of the massive spinor field exhibits a dependence on the field's parameter mass as well as the multiple number of the wave mode. On the other hand, the late-time behavior power-law decay has a rate which is independent of those factors.
Limits on brane-world and particle dark radiation from big bang nucleosynthesis and the CMB
NASA Astrophysics Data System (ADS)
Sasankan, N.; Gangopadhyay, Mayukh R.; Mathews, G. J.; Kusakabe, M.
The term dark radiation is used both to describe a noninteracting neutrino species and as a correction to the Friedmann Equation in the simplest five-dimensional (5D) RS-II brane-world cosmology. In this paper, we consider the constraints on both the meanings of dark radiation-based upon the newest results for light-element nuclear reaction rates, observed light-element abundances and the power spectrum of the Cosmic Microwave Background (CMB). Adding dark radiation during big bang nucleosynthesis (BBN) alters the Friedmann expansion rate causing the nuclear reactions to freeze out at a different temperature. This changes the final light element abundances at the end of BBN. Its influence on the CMB is to change the effective expansion rate at the surface of the last scattering. We find that the BBN constraint reduces the allowed range for both types of dark radiation at 10Mev to between ‑ 12.1% and + 6.2% of the total background energy density at 10Mev. Combining this result with fits to the CMB power spectrum, produces different results for particle versus brane-world dark radiation. In the brane-world, the range decreases from + 6.2% to ‑ 6.0%. Thus, we find that the ratio of dark radiation to the background total relativistic mass energy density ρDR/ρ is consistent with zero although there remains a very slight preference for a positive (rather than negative) contribution.
Possibility of catastrophic black hole growth in the warped brane-world scenario at the LHC
Casadio, Roberto; Fabi, Sergio; Harms, Benjamin
2009-10-15
In this paper, we present the results of our analysis of the growth and decay of black holes possibly produced at the Large Hadron Collider, based on our previous study of black holes in the context of the warped brane-world scenario. The black hole mass accretion and decay is obtained as a function of time, and the maximum black hole mass are obtained as a function of a critical mass parameter. The latter occurs in our expression for the luminosity and is related to the size of extra-dimensional corrections to Newton's law. Based on this analysis, we argue against the possibility of catastrophic black hole growth at the LHC.
Casimir force for a scalar field in a single brane world
Linares, R.; Morales-Tecotl, H. A.; Pedraza, O.
2010-02-10
Vacuum force is an interesting low energy test for brane worlds due to its dependence on field's modes and its role in submillimeter gravity experiments. In this contribution we obtain the scalar field vacuum force between two parallel plates lying in the brane of a Randall-Sundrum scenario extended by p compact dimensions (RSII-{sub p}). We obtain the force using the Green's function technique and we compare our results with the ones obtained by using the zeta function regularization method. As a result we obtain agreement in the expression for the force independently of the method used, thus we solve a previous discrepancy between the two approaches.
How a Randall-Sundrum Brane-World Effective Potential Influences Inflation Physics
Beckwith, A. W.
2007-01-30
In string theory, even when there are ten to the thousand power vacuum states, does inflation produce overwhelmingly one preferred type of vacuum state? We respond affirmatively to questions whether existence of graviton production is confirmable using present detector methodology. We use an explicit Randall-Sundrum brane-world effective potential as congruent with an inflationary quadratic potential start. This occurs after Bogomolnyi inequality eliminates need for ad hoc assumption of axion wall mass high temperature related disappearing. Graviton production has explicit links with a five-dimensional brane-world negative cosmological constant and a four-dimensional positive valued cosmological constant, whose temperature dependence permits an early universe graviton production activity burst. We show how di quarks, wave functions, and various forms tie into the Wheeler-De Witt equation. This permits investigating a discretized quantum bounce and a possible link to the initial phases of present universe's evolution with a prior universe's collapse to the bounce point--the initial starting point to inflationary expansion. This opens a possibility of realistically investigating gravitons as part of a space propulsion system and dealing with problems from a beam of gravity waves, which would create a g-force because the geodestic structure is near field. It can be applied to existing and to new space propulsion concepts.
Casimir force in brane worlds: Coinciding results from Green's and zeta function approaches
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 the 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.
Cosmological tests of generalized RS brane-worlds with Weyl fluid
NASA Astrophysics Data System (ADS)
Gergely, László Á.; Keresztes, Zoltán; Szabó, Gyula M.
2007-11-01
A class of generalized Randall-Sundrum type II (RS) brane-world models with Weyl fluid are confronted with the Gold supernovae data set and BBN constraints. We consider three models with different evolutionary history of the Weyl fluid, characterized by the parameter α. For α = 0 the Weyl curvature of the bulk appears as dark radiation on the brane, while for α = 2 and 3 the brane radiates, leaving a Weyl fluid on the brane with energy density decreasing slower than that of (dark) matter. In each case the contribution Ωd of the Weyl fluid represents but a few percent of the energy content of the Universe. All models fit reasonably well the Gold2006 data. The best fit model for α = 0 is for Ωd = 0.04. In order to obey BBN constraints in this model however, the brane had to radiate at earlier times.
Probing topologically charged black holes on brane worlds in f({R}) bulk
NASA Astrophysics Data System (ADS)
Kuerten, André M.; da Rocha, Roldão
2016-07-01
The perihelion precession, the deflection of light and the radar echo delay are classical tests of General Relativity here used to probe brane-world topologically charged black holes in a f(R) bulk. Moreover, such tests are used to constrain the parameter that arises from the Shiromizu-Maeda-Sasaki procedure applied to a f(R) bulk. Observational data constrain the possible values of the tidal charge parameter and the effective cosmological constant in this context. We show that the observational/experimental data for both perihelion precession and radar echo delay make the black hole parameters to be more strict than the ones for the DMPR black hole. Moreover, the deflection of light constrains the tidal charge parameter similarly as the DMPR black holes, due to a peculiarity in the equation of motion.
Brane-world and loop cosmology from a gravity-matter coupling perspective
NASA Astrophysics Data System (ADS)
Olmo, Gonzalo J.; Rubiera-Garcia, D.
2015-01-01
We show that the effective brane-world and the loop quantum cosmology background expansion histories can be reproduced from a modified gravity perspective in terms of an f (R) gravity action plus a g (R) term non-minimally coupled with the matter Lagrangian. The reconstruction algorithm that we provide depends on a free function of the matter density that must be specified in each case and allows to obtain analytical solutions always. In the simplest cases, the function f (R) is quadratic in the Ricci scalar, R, whereas g (R) is linear. Our approach is compared with recent results in the literature. We show that working in the Palatini formalism there is no need to impose any constraint that keeps the equations second-order, which is a key requirement for the successful implementation of the reconstruction algorithm.
Haunted Kaluza universe with four-dimensional Lorentzian flat, Kerr, and Taub NUT slices
NASA Astrophysics Data System (ADS)
Ivanov, Rossen I.; Prodanov, Emil M.
2005-03-01
The duality between the original Kaluza's theory and Klein's subsequent modification is duality between slicing and threading decomposition of the five-dimensional spacetime. The field equations of the original Kaluza's theory lead to the interpretation of the four-dimensional Lorentzian Kerr and Taub-NUT solutions as resulting from static electric and magnetic charges and dipoles in the presence of ghost matter and constant dilaton, which models Newton's constant.
Low-Energy Brane-World Effective Actions and Partial Supersymmetry Breaking
Klein, Matthias
2003-03-18
As part of a programme for the general study of the low-energy implications of supersymmetry breaking in brane-world scenarios, we study the nonlinear realization of supersymmetry which occurs when breaking N = 2 to N = 1 supergravity. We consider three explicit realizations of this supersymmetry breaking pattern, which correspond to breaking by one brane, by one antibrane or by two (or more) parallel branes. We derive the minimal field content, the effective action and supersymmetry transformation rules for the resulting N = 1 theory perturbatively in powers of {kappa} = 1/M{sub Planck}. We show that the way the massive gravitino and spin-1 fields assemble into N = 1 multiplets implies the existence of direct brane-brane contact interactions at order {Omicron}({kappa}). This result is contrary to the {Omicron}({kappa}{sup 2}) predicted by the sequestering scenario but in agreement with recent work of Anisimov et al. Our low-energy approach is model independent and is a first step towards determining the low-energy implications of more realistic brane models which completely break all supersymmetries.
Kaluza-Klein magnetized cylindrical wormhole and its gravitational lensing
NASA Astrophysics Data System (ADS)
Hashemi, S. Sedigheh; Riazi, Nematollah
2016-10-01
A new exact vacuum solution in five dimensions, which describes a magnetized cylindrical wormhole in 3+1 dimensions is presented. The magnetic field lines are stretched along the wormhole throat and are concentrated near to it. We study the motion of neutral and charged test particles under the influence of the magnetized wormhole. The effective potential for a neutral test particle around and across the magnetized wormhole has a repulsive character. The gravitational lensing for the magnetized wormhole for various lens parameters are calculated and compared. The total magnetic flux on either side of the wormhole is obtained. We present analytic expressions which show regions in which the null energy condition is violated.
Geodesic motion in a Kaluza-Klein bubble spacetime
NASA Astrophysics Data System (ADS)
Brill, D. R.; Matlin, M. D.
1989-05-01
The motion of massive and massless test particles in the geometry of the five-dimensional ``Witten bubble'' spacetime is explored by obtaining the effective radial potential governing this motion. It is found that massive particles are always in bound orbits. Massless particle orbits have a turning point near the bubble wall, but extend to infinity. These results are consistent with the conception of the bubble wall as a perfectly reflecting, expanding sphere whose expansion rate increases with time.
NASA Astrophysics Data System (ADS)
Fischer-Hjalmars, Inga; Laurent, Bertel
2014-03-01
Oskar Klein died on the fifth of February 1977 at the age of eighty-two. One of the most prominent Swedish physicists ever and an outstanding personality in the field of culture had passed away. He was a man whose interests knew no limits and as a scientist he greatly enriched our understanding of Nature. All those who knew him were astounded by his profound thinking, wealth of ideas, extensive insight and humanism, qualities that obviously had been stimulated by the spirit in his parents' home. His father, rabbi and professor in Stockholm, was deeply engaged in theological and humanitarian issues...
Bouhmadi-Lopez, Mariam; Ferrera, Antonio E-mail: a.ferrera.pardo@gmail.com
2008-10-15
We construct a new brane-world model composed of a bulk with a dilatonic field, plus a brane with brane tension coupled to the dilaton, cold dark matter and an induced gravity term. It is possible to show that, depending on the nature of the coupling between the brane tension and the dilaton, this model can describe the late time acceleration of the brane expansion (for the normal branch) as it moves within the bulk. The acceleration is produced together with a mimicry of the crossing of the cosmological constant line (w = -1) on the brane, although this crossing of the phantom divide is obtained without invoking any phantom matter either on the brane or in the bulk. The role of dark energy is played by the brane tension, which reaches a maximum positive value along the cosmological expansion of the brane. It is precisely at that maximum that the crossing of the phantom divide takes place. We also show that these results remain valid when the induced gravity term on the brane is switched off.
Brane world corrections to the scalar vacuum force in the Randall-Sundrum II-p scenario
Linares, Roman; Morales-Tecotl, Hugo A.; Pedraza, Omar
2008-09-15
Vacuum force is an interesting low energy test for brane worlds due to its dependence on field's modes and its role in submillimeter gravity experiments. In this work, we generalize a previous model example: the scalar field vacuum force between two parallel plates lying in the brane of a Randall-Sundrum scenario extended by p compact dimensions (RSII-p). Upon use of Green's function technique, for the massless scalar field, the 4D force is obtained from a zero mode while leading order corrections due to the noncompact dimension turn out attractive and depend on the separation between plates as l{sup -(6+p)}. For the massive scalar field, a quasilocalized mode yields the 4D force with attractive corrections behaving like l{sup -(10+p)}. Corrections are negligible with respect to 4D force for anti-de Sitter (AdS{sub (5+p)}) radius much less than {approx}10{sup -6} m. In the massless case we also determined, numerically, the corrections due to compact dimensions. To avoid conflict with experimental data we get R{<=}0.4 {mu}m, 0.3 {mu}m for the cases p=1, 2, respectively. Although the p=0 case is not physically viable due to the different behavior in regard to localization for the massless scalar and electromagnetic fields it yields a useful comparison between the dimensional regularization and Green's function techniques as we describe in the discussion.
Kinetic approach to Kaluza's magnetohydrodynamics
NASA Astrophysics Data System (ADS)
Sandoval-Villalbazo, A.; Garcia-Colin, L. S.
2011-11-01
Ten years ago we presented a formalism by means of which the basic tenets of relativistic magnetohydrodynamics were derived using Kaluza's ideas about unifying fields in terms of the corresponding space time curvature for a given metric. In this work we present an attempt to obtain the thermodynamic properties of a charged fluid using using Boltzmann's equation for a dilute system adapted to kaluza's formalism. The main results that we obtain are analytical expressions for the main currents and corresponding forces, within the formalism of linear irreversible thermodynamics. We also indicate how transport coefficients can be calculated. Other relevant results are also mentioned. A. Sandoval-Villalbazo and L.S. Garcia-Colin; Phys. of Plasmas 7, 4823 (2000).
NASA Astrophysics Data System (ADS)
Yi, Piljin
2005-12-01
We consider reheating processes at the end of string theory inflation involving unstable D-brane systems. Nucleosynthesis restricts how much of reheating energy may be present in the nonstandard matter sector, such as gravitons and gravitinos, introducing some constraints on reheating process. In string theory setting, these may not be avoided ad hoc by fine-tuning and provide a useful tool in weeding out unrealistic scenarios. In this talk, we how the energy gets deposited into various light degrees of freedom in open and closed strings sectors. We show that a viable reheating is possible in a single throat case of KKLMMT type inflation model. Depending on details of the geometry, however, a potential problem with long-lived KK relic is present. For multi-throat case, this problem of KK relic is typically more severe and generic.
Tabak de Bianchedi, Elizabeth; Etchegoyen, R Horacio; Ungar de Moreno, Virginia; Nemas de Urman, Clara; Zysman, Samuel
2003-12-01
Erna was one of the child patients treated by Melanie Klein in Berlin, employing her recently discovered play technique. Since Erna died in Chile, the authors considered the IPA Congress in Santiago an opportunity to present a paper as a homage both to Erna and, especially, to Klein. She learned much from that very disturbed child, which she later used to sustain the ongoing development of her theories. The paper explores biographic data relevant to understanding both the case and the theories. It analyses the case material to follow Klein in the discovery and the handling of the child's transference and the harsh expressions of hate, jealousy and envy, which are brought in, with sad consequences, by strong persecutory feelings. Klein's comparison of this case with that of Freud's Wolf-man is also considered, mostly to show that the similarities were less than originally claimed, and that Klein, perhaps, was introducing a theoretic shift which led her technique to gradually change from 'Nachträglichkeit' to the 'signification-resignification' pair, akin to Strachey's concept of the mutative interpretation. Lastly, the comprehension of Erna's strong psychotic traits and the links with later developments of the theory on psychosis are studied.
Exceptional generalised geometry for massive IIA and consistent reductions
NASA Astrophysics Data System (ADS)
Cassani, Davide; de Felice, Oscar; Petrini, Michela; Strickland-Constable, Charles; Waldram, Daniel
2016-08-01
We develop an exceptional generalised geometry formalism for massive type IIA supergravity. In particular, we construct a deformation of the generalised Lie derivative, which generates the type IIA gauge transformations as modified by the Romans mass. We apply this new framework to consistent Kaluza-Klein reductions preserving maximal supersymmetry. We find a generalised parallelisation of the exceptional tangent bundle on S 6, and from this reproduce the consistent truncation ansatz and embedding tensor leading to dyonically gauged ISO(7) supergravity in four dimensions. We also discuss closely related hyperboloid reductions, yielding a dyonic ISO( p, 7 - p) gauging. Finally, while for vanishing Romans mass we find a generalised parallelisation on S d , d = 4 , 3 , 2, leading to a maximally supersymmetric reduction with gauge group SO( d + 1) (or larger), we provide evidence that an analogous reduction does not exist in the massive theory.
Winnicott's response to Klein.
Ehrlich, Robert
2004-04-01
The author suggests that, although Donald Winnicott presented some important criticisms of Melanie Klein's work, at times he tried to advance his perspectives too definitively without adequately considering her own. Because of this, he failed to acknowledge sufficiently that he was offering a model of human nature and development that could be revised. The fact that his differences with Klein arose in the context of a complex relationship in which each played numerous roles for the other, especially in the context of their affiliation with the British Psychoanalytical Society, periodically made it difficult for him to present his ideas more carefully and in his more characteristically open manner.
On the kinetic foundations of Kaluza's magnetohydrodynamics
NASA Astrophysics Data System (ADS)
Sandoval-Villalbazo, Alfredo; Sagaceta-Mejía, Alma R.; García-Perciante, Ana L.
2015-06-01
Recent work has shown the existence of a relativistic effect present in a single component non-equilibrium fluid, corresponding to a heat flux due to an electric field [J. Non-Equilib. Thermodyn. 38 (2013), 141-151]. The treatment in that work was limited to a four-dimensional Minkowski space-time in which the Boltzmann equation was treated in a special relativistic approach. The more complete framework of general relativity can be introduced to kinetic theory in order to describe transport processes associated to electromagnetic fields. In this context, the original Kaluza's formalism is a promising approach [Sitz. Ber. Preuss. Akad. Wiss. (1921), 966-972; Gen. Rel. Grav. 39 (2007), 1287-1296; Phys. Plasmas 7 (2000), 4823-4830]. The present work contains a kinetic theory basis for Kaluza's magnetohydrodynamics and gives a novel description for the establishment of thermodynamic forces beyond the special relativistic description.
Generalized Klein-Kramers equations.
Fa, Kwok Sau
2012-12-21
A generalized Klein-Kramers equation for a particle interacting with an external field is proposed. The equation generalizes the fractional Klein-Kramers equation introduced by Barkai and Silbey [J. Phys. Chem. B 104, 3866 (2000)]. Besides, the generalized Klein-Kramers equation can also recover the integro-differential Klein-Kramers equation for continuous-time random walk; this means that it can describe the subdiffusive and superdiffusive regimes in the long-time limit. Moreover, analytic solutions for first two moments both in velocity and displacement (for force-free case) are obtained, and their dynamic behaviors are investigated.
Klein bottles and simple currents
NASA Astrophysics Data System (ADS)
Huiszoon, L. R.; Schellekens, A. N.
1999-12-01
The standard Klein bottle coefficient in the construction of open descendants is shown to equal the Frobenius-Schur indicator of a conformal field theory. Other consistent Klein bottle projections are shown to correspond to simple currents. These observations enable us to generalize the standard open string construction from C-diagonal parent theories to include non-standard Klein bottles. Using (generalizations of) the Frobenius-Schur indicator we prove positivity and integrality of the resulting open and closed string state multiplicities for standard as well as non-standard Klein bottles.
Kaluza-Klein Dark Matter: Direct Detection vis-a-vis LHC (2013 update)
Arrenberg, Sebastian; Baudis, Laura; Kong, Kyoungchul; Matchev, Konstantin T.; Yoo, Jonghee
2013-07-24
We present updated results on the complementarity between high-energy colliders and dark matter direct detection experiments in the context of Universal Extra Dimensions (UED). In models with relatively small mass splittings between the dark matter candidate and the rest of the (colored) spectrum, the collider sensitivity is diminished, but direct detection rates are enhanced. UED provide a natural framework to study such mass degeneracies. We discuss the detection prospects for the KK photon $\\gamma_1$ and the KK $Z$-boson $Z_1$, combining the expected LHC reach with cosmological constraints from WMAP/Planck, and the sensitivity of current or planned direct detection experiments. Allowing for general mass splittings, neither colliders, nor direct detection experiments by themselves can explore all of the relevant KK dark matter parameter space. Nevertheless, they probe different parameter space regions, and the combination of the two types of constraints can be quite powerful.
Kaluza-Klein type of cosmological models and its astrophysical significances.
NASA Astrophysics Data System (ADS)
Chatterjee, S.
Postulating homogeneity in matter content the author has obtained exact solutions for cosmological models in higher dimensions under different symmetries. Depending on the form of the metric the models are either uniquely Robertson-Walker in higher dimensions or differ significantly from the latter in the sense that the geometry is spatially inhomogeneous.
Cosmological compactification in Kaluza-Klein model and time-dependent cosmological term
NASA Astrophysics Data System (ADS)
Srivastava, S. K.
1992-12-01
Einstein's equations for the generalized (4+ D)-dimensional Robertson-Walker model are solved taking the conformally invariant action for the matter field. Compactification of this model is discussed and the compactification time/compactification mass scale for different values of D is calculated. The resulting 4-dimensional action for gravity is obtained. It is found that a time-dependent cosmological constant is induced which is very large when the cosmic time is small and very small when the cosmic time is large.
Microstates of the D1-D5-Kaluza-Klein monopole system
Bena, Iosif; Kraus, Per
2005-07-15
We find supergravity solutions corresponding to all U(1)xU(1) invariant chiral primaries of the D1-D5-KK system. These solutions are 1/8 BPS, carry angular momentum, and are asymptotically flat in the 3+1 dimensional sense. They can be thought of as representing the ground states of the four-dimensional black hole constructed from the D1-D5-KK-P system. Demanding the absence of unphysical singularities in our solutions determines all free parameters, and gives precise agreement with the quantum numbers expected from the CFT point of view. The physical mechanism behind the smoothness of the solutions is that the D1 branes and D5 branes expand into a KK-monopole supertube in the transverse space of the original KK monopole.
Hyperbolic Kac-Moody algebras and chaos in Kaluza-Klein models
NASA Astrophysics Data System (ADS)
Damour, T.; Henneaux, M.; Julia, B.; Nicolai, H.
2001-06-01
Some time ago, it was found that the never-ending oscillatory chaotic behaviour discovered by Belinskii, Khalatnikov and Lifshitz (BKL) for the generic solution of the vacuum Einstein equations in the vicinity of a spacelike (``cosmological'') singularity disappears in spacetime dimensions /D≡d+1>10. Recently, a study of the generalization of the BKL chaotic behaviour to the superstring effective Lagrangians has revealed that this chaos is rooted in the structure of the fundamental Weyl chamber of some underlying hyperbolic Kac-Moody algebra. In this Letter we show that the same connection applies to pure gravity in any spacetime dimension />=4, where the relevant algebras are AEd. In this way the disappearance of chaos in pure gravity models in /D>=11 dimensions becomes linked to the fact that the Kac-Moody algebras AEd are no longer hyperbolic for /d>=10.
On the statistical foundations of Kaluza's magnetohydrodynamics
NASA Astrophysics Data System (ADS)
Sagaceta-Mejía, A. R.; Sandoval-Villalbazo, A.
2016-11-01
The introduction of electromagnetic fields into the Boltzmann equation following a 5D general relativistic approach is considered in order to establish the transport equations for dilute charged fluids in the presence of a weak electromagnetic field. The conserved 5D stress-energy tensor is evaluated using the Jüttner function for non-degenerate relativistic gases in local equilibrium, and the evolution equations for the local thermodynamic variables are established by means of relativistic kinetic theory. An outline of the possibilities offered by the Kaluza-type approach to MHD is also included.
Brane worlds in critical gravity
NASA Astrophysics Data System (ADS)
Chen, Feng-Wei; Liu, Yu-Xiao; Zhong, Yuan; Wang, Yong-Qiang; Wu, Shao-Feng
2013-11-01
Recently, Lü and Pope proposed critical gravities in [Phys. Rev. Lett. 106, 181302 (2011)]. In this paper we construct analytic brane solutions in critical gravity with matter. The Gibbons-Hawking surface term and junction condition are investigated, and the thin and thick brane solutions are obtained. All these branes are embedded in five-dimensional anti-de Sitter spacetimes. Our solutions are stable against scalar perturbations, and the zero modes of scalar perturbations cannot be localized on the branes.
NASA Technical Reports Server (NTRS)
Klein, Gary
2004-01-01
Gary Klein, PH.D., is chief scientist of Klein Associates, Inc., a company he founded in 1978 to better understand how to improve decision making in individuals and teams. The company has 30 employees working on projects for both government and commercial clients. Dr. Klein is one of the founders of the field of naturalistic decision making. His work on recognitional decision making has been influential for the design of new systems and interfaces, and for the development of decision training programs. He has extended his work on decision making to describe problem detection, opinion generation, sense making, and planning.
Klein's programme and quantum mechanics
NASA Astrophysics Data System (ADS)
Clemente-Gallardo, Jesús; Marmo, Giuseppe
2015-04-01
We review the geometrical formulation of quantum mechanics to identify, according to Klein's programme, the corresponding group of transformations. For closed systems, it is the unitary group. For open quantum systems, the semigroup of Kraus maps contains, as a maximal subgroup, the general linear group. The same group emerges as the exponentiation of the C*-algebra associated with the quantum system, when thought of as a Lie algebra. Thus, open quantum systems seem to identify the general linear group as associated with quantum mechanics and moreover suggest to extend the Klein programme also to groupoids. The usual unitary group emerges as a maximal compact subgroup of the general linear group.
NASA Astrophysics Data System (ADS)
Ekspong, Gösta
2014-03-01
During the 1920's the Compton effect was very much at the centre of interest among physicists due to its demonstration of the inadequacy of the classical theory for light when trying to account for the scattering of X-rays. The angular intensity distribution of scattered X-rays had not been successfully described by theory until Oskar Klein and Yoshio Nishina in 1928 solved the problem using the then new Dirac theory for the electron. The present paper gives an account of the collaboration in the summer of 1928 between the two physicists -- one a theorist, the other an experimentalist -- when both were visitors at the Niels Bohr Institute in Copenhagen.
The Lorentz gas in Kaluza's MHD: Transport equations
NASA Astrophysics Data System (ADS)
Sandoval-Villalbazo, Alfredo; Sagaceta-Mejia, Alma Rocio; Mondragon-Suarez, Jose Humberto
2016-11-01
Relativistic kinetic theory is applied to the study of the transport processes present in a Lorentz gas, using a geometric five-dimensional space-time. While the conventional transport equations are recovered in the Newtonian limit, it is shown that relativistic corrections to the conduction and diffusion fluxes arise within this formalism. A brief review of the conceptual advantages of the Kaluza-type approach to magnetohydrodynamics is also given. The authors acknowledge support from CONACyT through Grant CB2011/167563.
Minerals at Rocknest and John Klein
2013-03-12
These images, made from data obtained by Curiosity CheMin, show the patterns obtained from a drift of windblown dust and sand called Rocknest and from a powdered rock sample drilled from the John Klein bedrock.
Homology class of a Lagrangian Klein bottle
NASA Astrophysics Data System (ADS)
Nemirovski, Stefan Yu
2009-08-01
It is shown that an embedded Lagrangian Klein bottle realises a non-zero mod 2 homology class in a compact symplectic four-manifold (X,\\omega) such that c_1(X,\\omega)\\cdot \\lbrack \\omega \\rbrack > 0.
Zeta functions in brane world cosmology
NASA Astrophysics Data System (ADS)
Flachi, Antonino; Knapman, Alan; Naylor, Wade; Sasaki, Misao
2004-12-01
We present a calculation of the zeta function and of the functional determinant for a Laplace-type differential operator, corresponding to a scalar field in a higher-dimensional deSitter brane background, which consists of a higher-dimensional anti deSitter bulk spacetime bounded by a deSitter section, representing a brane. Contrary to the existing examples, which all make use of conformal transformations, we evaluate the zeta function working directly with the higher-dimensional wave operator. We also consider a generic mass term and coupling to curvature, generalizing previous results. The massless, conformally coupled case is obtained as a limit of the general result and compared with known calculations. In the limit of large anti deSitter radius, the zeta determinant for the ball is recovered in perfect agreement with known expressions, providing an interesting check of our result and an alternative way of obtaining the ball determinant.
Warped brane worlds in critical gravity
NASA Astrophysics Data System (ADS)
Zhong, Yi; Chen, Feng-Wei; Xie, Qun-Ying; Liu, Yu-Xiao
2014-12-01
We investigate the brane models in arbitrary dimensional critical gravity presented in Lu and Pope (Phys Rev Lett 106:181302, 2011). For the models of the thin branes with codimension one, the Gibbons-Hawking surface term and the junction conditions are derived, with which the analytical solutions for the flat, AdS, and dS branes are obtained at the critical point of the critical gravity. It is found that all these branes are embedded in an AdS spacetime, but, in general, the effective cosmological constant of the AdS spacetime is not equal to the naked one in the critical gravity, which can be positive, zero, and negative. Another interesting result is that the brane tension can also be positive, zero, or negative, depending on the symmetry of the thin brane and the values of the parameters of the theory, which is very different from the case in general relativity. It is shown that the mass hierarchy problem can be solved in the braneworld model in the higher-derivative critical gravity. We also study the thick brane model and find analytical and numerical solutions of the flat, AdS, and dS branes. It is found that some branes will have inner structure when some parameters of the theory are larger than their critical values, which may result in resonant KK modes for some bulk matter fields. The flat branes with positive energy density and AdS branes with negative energy density are embedded in an -dimensional AdS spacetime, while the dS branes with positive energy density are embedded in an -dimensional Minkowski one.
Gauge field localization on brane worlds
Guerrero, Rommel; Rodriguez, R. Omar; Melfo, Alejandra; Pantoja, Nelson
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 electromagnetism 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.
Higgs-radion phenomenology in stabilized RS models
NASA Astrophysics Data System (ADS)
Boos, Eduard; Bunichev, Viacheslav; Keizerov, Sergey; Perfilov, Maxim; Rakhmetov, Eduard; Smolyakov, Mikhail; Svirina, Kseniia; Volobuev, Igor
2016-10-01
An important general prediction of stabilized brane world models is the existence of a bulk scalar radion field, whose lowest Kaluza-Klein (KK) mode is the scalar particle called the radion. This field comes from the fluctuations of the metric in the extra dimension and the radion mass can be smaller than that of all the massive KK modes of the other particles propagating in the multidimensional bulk. Due to its origin, the radion and its KK tower couple to the trace of the energy-momentum tensor of the Standard Model. These fields have the same quantum numbers as the neutral Higgs field and can mix with the latter, if they are coupled. We present a short review of some aspects of Higgs-radion phenomenology in stabilized brane-world models. In particular, we discuss the possibility of explaining the 750 GeV excess by the production of a radion-dominated state.
Influence of graviton on top-antitop production at the LHC
NASA Astrophysics Data System (ADS)
Smolek, K.; Arai, M.; Okada, N.; Šimák, V.
2008-05-01
We examine the top quark production in the brane world scenario. We study two typical models - the model proposed by Arkani-Hamed, Dimopoulos and Dvali (ADD) and the model of Randall and Sundrum (RS). In addition to the Standard Model processes, there is a new contribution to the top-antitop pair production process mediated by graviton Kaluza-Klein modes in the s-channel. We calculated the density matrix for the top-antitop pair production including the new contribution. With a reasonable parameter choice, we find a sizable deviation of the top-antitop quark spin correlations from those in the Standard Model.
Bulk antisymmetric tensor fields coupled to a dilaton in a Randall-Sundrum model
Alencar, G.; Tahim, M. O.; Landim, R. R.; Muniz, C. R.
2010-11-15
A string-inspired three-form-dilaton-gravity model is studied in a Randall-Sundrum brane world scenario. As expected, the rank-3 antisymmetric field is exponentially suppressed. For each mass level, the mass spectrum is bigger than the one for the Kalb-Ramond field. The coupling between the dilaton and the massless Kaluza-Klein mode of the three-form is calculated, and the coupling constant of the cubic interactions is obtained numerically. This coupling are of the order of Tev{sup -1}; therefore, there exists a possibility to find some signal of it at Tev scale.
Field Equations for Space-Time Theory
NASA Astrophysics Data System (ADS)
Bejancu, Aurel
2013-05-01
In the present paper we obtain, in a covariant form, and in their full generality, the field equations in a relativistic general Kaluza-Klein space. This is done by using the Riemannian horizontal connection defined in [3], and some 4D horizontal tensor fields, as for instance: horizontal Ricci tensor, horizontal Einstein gravitational tensor field, horizontal electromagnetic energy-momentum tensor field, etc. Also, we present some inter-relations between STM theory and brane-world theory. This enables us to introduce in brane theory some electromagnetic potentials constructed by means of the warp function.
General self-tuning solutions and no-go theorem
Förste, Stefan; Kim, Jihn E.; Lee, Hyun Min E-mail: jihnekim@gmail.com
2013-03-01
We consider brane world models with one extra dimension. In the bulk there is in addition to gravity a three form gauge potential or equivalently a scalar (by generalisation of electric magnetic duality). We find classical solutions for which the 4d effective cosmological constant is adjusted by choice of integration constants. No go theorems for such self-tuning mechanism are circumvented by unorthodox Lagrangians for the three form respectively the scalar. It is argued that the corresponding effective 4d theory always includes tachyonic Kaluza-Klein excitations or ghosts. Known no go theorems are extended to a general class of models with unorthodox Lagrangians.
Annihilation cross section of Kaluza Klien dark matter
Sharma, Rakesh; Upadhyaya, G. K. Sharma, S.
2015-07-31
The question as to how this universe came into being and as to how it has evolved to its present stage, is an old question. The answer to this question unfolds many secrets regarding fundamental particles and forces between them. Theodor Kaluza proposed the concept that the universe is composed of more than four space-time dimensions. In his work, electromagnetism is united with gravity. Various extra dimension formulations have been proposed to solve a variety of problems. Recently, the idea of more than four space time dimensions is applied to the search for particle identity of dark matter (DM). Signature of dark matter can be revealed by analysis of very high energy electrons which are coming from outer space. We investigate recent advancement in the field of dark matter search with reference to very high energy electrons from outer space [1-8].
Dimer statistics on the Klein bottle
NASA Astrophysics Data System (ADS)
Lu, Fuliang; Zhang, Lianzhu; Lin, Fenggen
2011-06-01
The problem of enumerating close-packed dimers, or perfect matchings, on a quadratic lattice embedded on the Klein bottle is considered. Thomassen [C. Thomassen, Tilings of the torus and the Klein Bottle and vertex-transitive graphs on a fixed surface, Trans. Amer. Math. Soc. 323(2) (1991) 605-635] characterized that there are six quadrilateral lattices embedded on the Klein bottle. Lu and Wu [W. T. Lu and F. Y. Wu, Close-packed dimers on nonorientable surfaces, Phys. Lett. A 293 (2002) 235-246] had obtained a expression for the number of close-packed dimers on one of them. In this paper we investigate four other embeddings and obtain explicit expressions of the numbers of close-packed dimers and free energy per dimer by enumerating Pfaffians.
Melanie Klein on mourning: Its relation to pastoral care.
Hart, C W
1991-09-01
This paper connects the work of Melanie Klein on mourning to the pastor's work with the grief sufferer. Klein holds that mourning is an illness of manic depressive character rooted in infantile development. Klein's description of manic defenses in the face of loss has adult behavioral analogues with which the pastor must deal to bring mourning to resolution.
Location of John Klein Drill Site
2013-03-12
This false-color map shows the area within Gale Crater on Mars, where NASA Curiosity rover landed on Aug. 5, 2012 PDT Aug. 6, 2012 EDT and the location where Curiosity collected its first drilled sample at the John Klein rock.
1885 Cholera Controversy: Klein versus Koch.
Atalic, Bruno
2010-06-01
This paper will try to give new insight into the Cholera Controversy, which occurred 125 years ago. The majority of papers already written on the topic have emphasised the role of Robert Koch who described the comma bacillus as the cause of cholera epidemics. At the same time they have marginalised the role of Emanuel Edward Klein by stating that he was wrong when he objected to Robert Koch's statement, because as an employee of the British government he was politically motivated. Moreover, they have paid barely any attention to Klein's writings on the subject. In this paper I will try to approach his attitudes from the scientific, not political, perspective and try to explain the reasons why he challenged Koch.
Klein, Ferenczi and the clinical diary.
Hernandez-Halton, Isabel
2015-03-01
The aim of this article is to revisit Ferenczi's Clinical Diary (1932) to investigate the influence he had on Melanie Klein's work. It starts from the position that insufficient recognition has been given to Ferenczi's contribution to Klein's body of work and her professional development. Her analysis with Ferenczi lasted 5 years, a relatively long analysis for the period. It explores his influence in three specific areas: the importance of raw and early emotion in the maternal bond, the importance of freedom and authenticity in the analytic relationship, and finally the use of transference and countertransference feelings. Ferenczi's ill-fated experiment with mutual analysis will be discussed as it opened up a route to explore the analytic relationship, with important consequences for the future development of psychoanalysis.
Kleine-Levin Syndrome Treated With Clarithromycin
Rezvanian, Elham; Watson, Nathaniel F.
2013-01-01
Kleine-Levin syndrome (KLS) is a rare sleep disorder characterized by periodic hypersomnia and various degrees of cognitive and behavioral disturbance, hyperphagia, and hypersexuality. Effective treatment is challenging. Stimulants marginally address sleepiness, but may increase irritability and do not improve cognitive and behavioral disturbances. Modafinil may shorten the symptomatic period but not the recurrence rate. Lithium and carbamazepine are beneficial in some cases, possibly related to similarities between KLS and affective disorders. Currently, no single medication is consistently successful in treating the syndrome. Here we report the short-term effect of clarithromycin in a patient with KLS. Citation: Rezvanian E; Watson NF. Kleine-Levin syndrome treated with clarithromycin. J Clin Sleep Med 2013;9(11):1211-1212. PMID:24235906
Martin J. Klein: From Physicist to Historian
NASA Astrophysics Data System (ADS)
Hu, Danian
2012-12-01
To his friends, colleagues, and students, Martin Klein was a gentle and modest man of extraordinary integrity whose stellar accomplishments garnered him many honors. I sketch his life and career, in which he transformed himself from a theoretical physicist at Columbia University, the Massachusetts Institute of Technology, and the Case Institute of Technology into a historian of physics while on leave at the Dublin Institute for Advanced Study and the University of Leiden and then pursued this field full time at Yale University.
Primary mental expression: freud, klein, and beyond.
Robbins, Michael
2008-03-01
Freud formulated the primary process model, describing mental activity that creates the illusion of an actual experience in lieu of reflective thought, at the very start of his career. In this, his initial formulation of unconscious mental activity, he was attempting to account for the nature of dreaming, by inference for the mind of infancy and, more speculatively, for adult psychosis. He never revised the model in light of his later formulations of the structural model and the death instinct, nor did he elaborate on his speculation that it could serve as a model for psychosis, and there has been little subsequent effort to employ the model outside the context of dreaming. A small number of analysts, including Klein, Bion, and Matte-Blanco, have constructed theories of psychosis in idiosyncratic conceptual languages that seem to be describing phenomena similar to those from which Freud constructed his model. Although Klein's model of positions, which has become the most widely accepted theory of psychosis, is generally considered a fundamental departure from Freud, both accounts have remarkable similarity and both tend to confuse primary mental expression with mature thought and normal infancy with psychosis. Contributions by cognitive-developmental psychologists including Werner and Piaget suggest ways to clarify some of the confusion and to supplement and amplify Freud's and Klein's description of some of the salient features of primary mental expression. Findings from neuroimaging studies of dreaming and of schizophrenia support the proposition that primary mental activity is a qualitatively distinctive form of mental expression.
Bronnikov, K. A.; Meierovich, B. E.
2008-02-15
We consider (d{sub 0} + 2)-dimensional configurations with global strings in two extra dimensions and a flat metric in d{sub 0} dimensions, endowed with a warp factor e{sup 2{gamma}} depending on the distance l from the string center. All possible regular solutions of the field equations are classified by the behavior of the warp factor and the extradimensional circular radius r(l). Solutions with r {sup {yields}} {infinity} and r {sup {yields}} const > 0 as l {sup {yields}} {infinity} are interpreted in terms of thick brane-world models. Solutions with r {sup {yields}} 0 as l {sup {yields}} l{sub c} > 0, i.e., those with a second center, are interpreted as either multibrane systems (which are appropriate for large enough distances l{sub c} between the centers) or as Kaluza-Klein-type configurations with extra dimensions invisible due to their smallness. In the case of the Mexican-hat symmetry-breaking potential, we build the full map of regular solutions on the ({epsilon}, {gamma}) parameter plane, where {epsilon} acts as an effective cosmological constant and {gamma} characterizes the gravitational field strength. The trapping properties of candidate brane worlds for test scalar fields are discussed. Good trapping properties for massive fields are found for models with increasing warp factors. Kaluza-Klein-type models are shown to have nontrivial warp factor behaviors, leading to matter particle mass spectra that seem promising from the standpoint of hierarchy problems.
Bronnikov, K. A.; Meierovich, B. E.
2008-02-15
We consider (d{sub 0} + 2)-dimensional configurations with global strings in two extra dimensions and a flat metric in d{sub 0} dimensions, endowed with a warp factor e{sup 2{gamma}} depending on the distance l from the string center. All possible regular solutions of the field equations are classified by the behavior of the warp factor and the extradimensional circular radius r(l). Solutions with r {yields} {infinity} and r {yields} const > 0 as l {yields} {infinity} are interpreted in terms of thick brane-world models. Solutions with r {yields} 0 as l {yields} l{sub c} > 0, i.e., those with a second center, are interpreted as either multibrane systems (which are appropriate for large enough distances l{sub c} between the centers) or as Kaluza-Klein-type configurations with extra dimensions invisible due to their smallness. In the case of the Mexican-hat symmetry-breaking potential, we build the full map of regular solutions on the ({epsilon}, {Gamma}) parameter plane, where {epsilon} acts as an effective cosmological constant and {Gamma} characterizes the gravitational field strength. The trapping properties of candidate brane worlds for test scalar fields are discussed. Good trapping properties for massive fields are found for models with increasing warp factors. Kaluza-Klein-type models are shown to have nontrivial warp factor behaviors, leading to matter particle mass spectra that seem promising from the standpoint of hierarchy problems.
Adrian Stokes and the portrait of Melanie Klein.
Sayers, Janet
2015-08-01
This paper focuses on the offer by the art writer Adrian Stokes to commission and pay for a portrait of the psychoanalyst Melanie Klein by the artist William Coldstream. It details some of the precursors of this offer in Stokes's preceding involvement first with Klein and then with Coldstream; her response to this offer; and its outcome and aftermath in Stokes's subsequent writing about Klein and Coldstream. Copyright © 2015 Institute of Psychoanalysis.
A Disorder Unique to Adolescence? The Kleine-Levin Syndrome.
ERIC Educational Resources Information Center
Cawthorn, Paul
1990-01-01
Describes Kleine-Levin syndrome, rare disorder characterized by excessive sleep and abnormal hunger. Notes that, in its pure form, disorder can only be diagnosed in adolescent males. Presents case study of 15-year-old male with disease. Presents evidence which suggests link between Kleine-Levin syndrome and cyclic affective disorders. (Author/ABL)
Spanning trees of lattices embedded on the Klein bottle.
Lu, Fuliang
2014-01-01
The problem of enumerating spanning trees in lattices with Klein bottle boundary condition is considered here. The exact closed-form expressions of the numbers of spanning trees for 4.8.8 lattice, hexagonal lattice, and 3(3) · 4(2) lattice on the Klein bottle are presented.
A Disorder Unique to Adolescence? The Kleine-Levin Syndrome.
ERIC Educational Resources Information Center
Cawthorn, Paul
1990-01-01
Describes Kleine-Levin syndrome, rare disorder characterized by excessive sleep and abnormal hunger. Notes that, in its pure form, disorder can only be diagnosed in adolescent males. Presents case study of 15-year-old male with disease. Presents evidence which suggests link between Kleine-Levin syndrome and cyclic affective disorders. (Author/ABL)
Obituary: Michael John Klein, 1940-2005
NASA Astrophysics Data System (ADS)
Gulkis, Samuel
2006-12-01
Michael John Klein died on 14 May 2005 at home in South Pasadena, California. The cause of death was tongue cancer that metastasized to the lungs. He was a non-smoker. Mike was a passionate radio astronomer, a trusted astronomical observer, an educator and a family man. Mike was born on 19 January 1940 in Ames, Iowa, the son of Florence Marie (Graf) and Fred Michael Klein. His mother was a homemaker, and his father was a banker. Mike had two older sisters, Lois Jean (Klein) Flauher and Marilyn June (Klein) Griffin. In 1962, Mike married his high school sweetheart Barbara Dahlberg, who survives him along with their three children, Kristin Marie (Klein) Shields, Michael John Klein Jr., Timothy Joel Klein, and six grandchildren. Mike developed a love for astronomy early in his life, and credited an early morning, newspaper-delivery route that he had at age twelve, which took him outside well before sunrise. He told family members that as he walked along his route, he stared into the sky and wondered what everything was. He studied sky charts, located stars, and began to understand how the planets shifted their positions relative to the stars each day. Another big influence in Mike's life was his brother in-law, Jim Griffin. Jim helped Mike understand that his passion for science did not have to remain a hobby, but could and should become a career. Jim's encouragement led Mike to attend Iowa State University in Ames, where he earned a BS in electrical engineering in 1962. Mike then started graduate school in electrical engineering at Michigan State, but after one semester transferred to the University of Michigan, Ann Arbor, where he earned an MS (1966) and PhD (1968) in astronomy. His doctoral dissertation, under the direction of Professor Fred Haddock, was based on extensive observations of the planets and examined the physical and thermal properties of planetary atmospheres and surfaces. Mike was awarded a Resident Research Associate position at JPL by the National
The Klein-Gordon Operator on Möbius Strip Domains and the Klein Bottle in ℝ n
NASA Astrophysics Data System (ADS)
Kraußhar, Rolf Sören
2013-12-01
In this paper we present explicit formulas for the fundamental solution to the Klein-Gordon operator on some higher dimensional generalizations of the Möbius strip and the Klein bottle with values in distinct pinor bundles. The fundamental solution is described in terms of generalizations of the Weierstraß -function that are adapted to the context of these geometries. The explicit formulas for the kernel then allow us to express all solutions to the homogeneous and inhomogeneous Klein-Gordon problem with given boundary data in the context of these manifolds. In the case of the Klein bottle we are able to describe all null solutions of the Klein-Gordon equation in terms of finite linear combinations of the fundamental solution and its partial derivatives.
Cassullo, Gabriele
2016-03-01
Compared to the impact of the work of Melanie Klein on the history of psychoanalysis, the contributions of her daughter, Melitta Schmideberg, passed almost unnoticed. At present, Schmideberg is solely remembered for having harshly attacked her mother at the start of the Controversial Discussions of the British Psycho-Analytical Society and for having coined the fitting expression "stable instability" in order to describe borderline and asocial personality disorders. However, the author discusses how the early groundbreaking discoveries of Klein with regards to primitive anxieties were the result of the joint work and thinking of Melanie and Melitta. Moreover, he argues that the conflict between the two, along with the subsequent polarization of their views, did not facilitate the development of psychoanalysis, neither did it help the analytic community to recognize the value of Melitta's contributions to psychoanalysis.
The ego according to Klein: return to Freud and beyond.
Blass, Rachel B
2012-02-01
This paper explores fundamental dimensions of Melanie Klein's concept of the ego through a detailed study of the writings of Klein and her early colleagues (Paula Heimann, Susan Isaacs and Joan Riviere). The study examines three central issues: (a) the basic theoretical framework for Klein's conceptualization of the ego, and specifically how her conceptualization builds on Freud's structural and dual instinct models; (b) the processes involved in the development of the ego and its capacities (including the development from id to ego and from ego to superego); and (c) the view of the ego as an object of phantasy. Through this examination, the study demonstrates that Klein's conceptualization of the ego is firmly grounded both in Freud's formulations about the ego and in his theoretical and metapsychological approach to thinking about the ego. This counters the prevalent view that Klein was only focused on clinical understandings, unconcerned with theory and fuzzy in her abstract thinking. More specifically, it counters the view that Klein did not really have a concept of the ego in any well-structured sense of the term (Britton, 2003; Hinshelwood, 1994; Segal, 2001). The study considers the sources of these misconceived views. Finally, it argues that discarding such views allows us to appreciate better the richness of Klein's thinking, her theoretical affinities to Freud, and the role of theory in the development and justification of psychoanalysis. Copyright © 2011 Institute of Psychoanalysis.
Melanie Klein and countertransference: a note on some archival material.
Hinshelwood, R D
2008-01-01
Five pages of notes were found in the Melanie Klein Archives at the Wellcome Library that concern her views on countertransference in 1953. Because of the paucity of references to countertransference in Klein's published writings these Notes fill in out knowledge. Her views were provoked by the work her students were doing in their experimental analyses of schizophrenic patients. Apocryphal stories suggest that Klein remained aligned with Freud's view of countertransference as simply interference. The Notes confirm that, whilst there is some truth to that, she did have a more sophisticated and nuanced view of the unconscious relations between analyst and analysand.
[An unpublished contribution of Melanie Klein "On Reassurance"].
Frank, Claudia; Klein, Melanie
2005-01-01
Melanie Klein's unpublished paper on reassurance is presented in German translation. The author shows that it was a contribution to Glover's investigation on psychoanalytic technique in the 1930s. The paper is discussed against the background of the technical discussions conducted in London at that time (e. g. M. Schmideberg, J. Strachey) and of Klein's relevant publications. Although Klein consistently considered "correct" interpretation to be the most effective means of reassurance, she occasionally also accepted a non-interpreting approach. In this respect the paper presented here goes further than any other of her writings.
Curiosity Rover Self Portrait at John Klein Drilling Site
2013-02-07
The rover is positioned at a patch of flat outcrop called John Klein, which was selected as the site for the first rock-drilling activities by NASA Curiosity. This self-portrait was acquired to document the drilling site.
Observing other universes through ringholes and Klein-bottle holes
NASA Astrophysics Data System (ADS)
Alonso-Serrano, Ana; Gonzalez-Díaz, Pedro F.
2012-07-01
It is argued that, unlike wormholes and ringholes, the signature produced by gravitational lensing effects for Klein-bottle holes cannot be attributed to any other single or composite astronomical object and could prove the possible existence of other universes.
The conflict and process theory of Melanie Klein.
Kavaler-Adler, S
1993-09-01
This article depicts the theory of Melanie Klein in both its conflict and process dimensions. In addition, it outlines Klein's strategic place in psychoanalytic history and in psychoanalytic theory formation. Her major contributions are seen in light of their clinical imperatives, and aspects of her metapsychology that seem negligible are differentiated from these clinical imperatives. Klein's role as a dialectical fulcrum between drive and object relations theories is explicated. Within the conflict theory, drive derivatives of sex and aggression are reformulated as object-related passions of love and hate. The process dimensions of Klein's theory are outlined in terms of dialectical increments of depressive position process as it alternates with regressive paranoid-schizoid-position mental phenomenology. The mourning process as a developmental process is particularly high-lighted in terms of self-integrative progression within the working through of the depressive position.
5. Historic American Buildings Survey, William C. Kleine, Photographer February ...
5. Historic American Buildings Survey, William C. Kleine, Photographer February 10, 1934 SOUTH ELEVATION OF STORE. - Francis Louis des Mazieres Store Building & House, Martinez & South Alamo Streets, San Antonio, Bexar County, TX
4. Historic American Buildings Survey, William C. Kleine, Photographer February ...
4. Historic American Buildings Survey, William C. Kleine, Photographer February 10, 1934 SOUTH ELEVATION OF RESIDENCE. - Francis Louis des Mazieres Store Building & House, Martinez & South Alamo Streets, San Antonio, Bexar County, TX
Sleeping beauty: kleine-levin syndrome.
Mudgal, Soumiya; Jiloha, R C; Kandpal, Manish; Das, Aparna
2014-07-01
Kleine-Levin syndrome (KLS) alias sleeping beauty syndrome, is a rare sleep disorder. Clinically presenting as episodes of hypersomnolence, behavioral and cognitive disturbances, hyperphagia and hypersexuality. KLS may have an idiopathic onset or may be precipitated by neurological event or infection. Until date, no definite underlying cause is established and neither there are any definitive management guidelines. It remains a diagnosis of exclusion after other psychiatric and neurological causes have been ruled out. Coloring of presentation with behavioral and mood elements makes it important for a psychiatrist to be well-informed about the condition to avoid the erroneous diagnosis. KLS is a devastating illness, which robs the patient of time, experiences, and relationships. An early diagnosis and effective management can help patient escape from the morbidity caused by this disorder. Armodafinil and oxcarbamazepine have found to be effective in two of the case. The emphasis of this report is to add to the existing clinical knowledge of neurologists, psychiatrists and physicians. In the future, research is needed on genetic etiology and management of this disorder.
Relativistic superfluidity and vorticity from the nonlinear Klein-Gordon equation
NASA Astrophysics Data System (ADS)
Xiong, Chi; Good, Michael R. R.; Guo, Yulong; Liu, Xiaopei; Huang, Kerson
2014-12-01
We investigate superfluidity, and the mechanism for creation of quantized vortices, in the relativistic regime. The general framework is a nonlinear Klein-Gordon equation in curved spacetime for a complex scalar field, whose phase dynamics gives rise to superfluidity. The mechanisms discussed are local inertial forces (Coriolis and centrifugal), and current-current interaction with an external source. The primary application is to cosmology, but we also discuss the reduction to the nonrelativistic nonlinear Schrödinger equation, which is widely used in describing superfluidity and vorticity in liquid helium and cold-trapped atomic gases.
Melanie Klein's letters addressed to Marcelle Spira (1955-1960).
Quinodoz, Jean-Michel
2009-12-01
Between 1955 and 1960, Melanie Klein wrote some 45 hitherto unpublished letters to Marcelle Spira, the Swiss psychoanalyst living at that time in Geneva. In 2006, after Spira's death, these letters were deposited with the Raymond de Saussure Psychoanalysis Centre in Geneva. They are the only known letters that Klein addressed to her psychoanalyst colleagues. Several topics are mentioned in them: (1) the meetings between the two women in Geneva and London; (2) Spira's contribution to Boulanger's translation into French of The Psychoanalysis of Children, which Klein herself carefully revised; (3) the papers that Klein was at that time working on, including Envy and Gratitude; (4) Spira's own work; (5) the difficulties that Spira, a Kleinian psychoanalyst who trained in Buenos Aires, was encountering in her attempt to be admitted to the Swiss Psychoanalytical Society; and (6) a few items of personal and family news. In addition to the invaluable historical information that these letters provide, they offer us a very moving epistolary self-portrait of Melanie Klein, enabling us to discover her personality in the final years of her life - she died in September 1960, just two months after writing her last letter to Spira.
A new look at the theory of Melanie Klein.
Stein, R
1990-01-01
This paper tried to show that Melanie Klein's theory can very profitably be viewed as a descriptive theory of strong emotions rather than an instinct or developmental theory. Furthermore, since in Klein's thinking feelings 'create' objects, the primacy of feelings in this theory is central. The paper contains a short chronological study of Klein's formulations of psychic phenomena in terms of affects. It is also maintained that the paranoid-schizoid and the depressive positions are constellations of affects and of reactions to them; that psychic development is essentially in terms of the capacity to tolerate feelings, and that the basic conflict in mental life is between feelings of love and hate and associated feelings. Such a view solves many of the conceptual difficulties of Kleinian theory and in addition promises rewarding insights into the world of feelings.
Klein tunneling in driven-dissipative photonic graphene
NASA Astrophysics Data System (ADS)
Ozawa, Tomoki; Amo, Alberto; Bloch, Jacqueline; Carusotto, Iacopo
2017-07-01
We theoretically investigate Klein tunneling processes in photonic artificial graphene. Klein tunneling is a phenomenon in which a particle with Dirac dispersion going through a potential step shows a characteristic angle- and energy-dependent transmission. We consider a generic photonic system consisting of a honeycomb-shaped array of sites with losses, illuminated by coherent monochromatic light. We show how the transmission and reflection coefficients can be obtained from the steady-state field profile of the driven-dissipative system. Despite the presence of photonic losses, we recover the main scattering features predicted by the general theory of Klein tunneling. Signatures of negative refraction and the orientation dependence of the intervalley scattering are also highlighted. Our results will stimulate the experimental study of intricate transport phenomena using driven-dissipative photonic simulators.
Quadratic nonlinear Klein-Gordon equation in one dimension
NASA Astrophysics Data System (ADS)
Hayashi, Nakao; Naumkin, Pavel I.
2012-10-01
We study the initial value problem for the quadratic nonlinear Klein-Gordon equation vtt + v - vxx = λv2, t ∈ R, x ∈ R, with initial conditions v(0, x) = v0(x), vt(0, x) = v1(x), x ∈ R, where v0 and v1 are real-valued functions, λ ∈ R. Using the method of normal forms of Shatah ["Normal forms and quadratic nonlinear Klein-Gordon equations," Commun. Pure Appl. Math. 38, 685-696 (1985)], we obtain a sharp asymptotic behavior of small solutions without the condition of a compact support on the initial data, which was assumed in the previous work of J.-M. Delort ["Existence globale et comportement asymptotique pour l'équation de Klein-Gordon quasi-linéaire á données petites en dimension 1," Ann. Sci. Ec. Normale Super. 34(4), 1-61 (2001)].
Some technical implications of Klein's concept of 'premature ego development'.
Mitrani, Judith L
2007-08-01
In this paper, the author revisits the problem of 'premature ego development' first introduced by Melanie Klein in 1930. She also highlights several developments in post-Kleinian thinking since the publication of that paper, which can be seen as offshoots of or complements to Klein's work. The author proposes a link between this category of precocious development and the absence of the experience of what Bion termed the 'containing object.' She puts forward several technical considerations relevant to analytic work with patients who suffer as a result of early developmental failures and presents various clinical vignettes in order to demonstrate the ways in which these considerations take shape in the analytic setting.
Generalized Klein-Kramers equation: solution and application
NASA Astrophysics Data System (ADS)
Sau Fa, Kwok; Wang, K. G.
2013-09-01
A generalized Klein-Kramers equation based on the continuous time random walk model is investigated. The equation generalizes the ordinary and fractional Klein-Kramers equations. Analytic solutions for the probability density and first two moments (for the force-free case) are obtained, and their dynamic behaviors are investigated in detail. The model is used to describe the cell migration of two migrating transformed renal epithelial Madin-Darby canine kidney (MDCK-F) cell strains: wild-type (NHE+) and NHE-deficient (NHE-) cells. Our theoretical predictions are in good agreement with experimental work in the paper (Dieterich et al 2008 Proc. Nat. Acad. Sci. USA 105 459).
Considerations on the hyperbolic complex Klein-Gordon equation
Ulrych, S.
2010-06-15
This article summarizes and consolidates investigations on hyperbolic complex numbers with respect to the Klein-Gordon equation for fermions and bosons. The hyperbolic complex numbers are applied in the sense that complex extensions of groups and algebras are performed not with the complex unit, but with the product of complex and hyperbolic unit. The modified complexification is the key ingredient for the theory. The Klein-Gordon equation is represented in this framework in the form of the first invariant of the Poincare group, the mass operator, in order to emphasize its geometric origin. The possibility of new interactions arising from hyperbolic complex gauge transformations is discussed.
Veselago lens and Klein collimator in disordered graphene
NASA Astrophysics Data System (ADS)
Libisch, F.; Hisch, T.; Glattauer, R.; Chizhova, L. A.; Burgdörfer, J.
2017-03-01
We simulate electron transport through graphene nanoribbons of realistic size containing a p–n junction patterned by electrostatic gates. For a sharp p–n interface, Klein tunneling leads to refocusing of a divergent beam forming a Veselago lens. Wider transition regions allow only electrons with near-perpendicular incidence to pass the junction, forming a Klein collimator. Using a third nearest neighbor tight binding description we explore the influence of interface roughness and bulk disorder on guiding properties. We provide bounds on disorder amplitudes and p–n junction properties to be satisfied in order to experimentally observe the focusing effect and compare our predictions to very recent realizations.
Dissociating Word Frequency and Age of Acquisition: The Klein Effect Revived (and Reversed)
ERIC Educational Resources Information Center
Dewhurst, Stephen A.; Barry, Christopher
2006-01-01
The Klein effect (G. S. Klein, 1964) refers to the finding that high-frequency words produce greater interference in a color-naming task than low-frequency words. The present study used the Klein effect to investigate the relationship between frequency and age of acquisition (AoA) by measuring their influence on color naming. Two experiments…
Dissociating Word Frequency and Age of Acquisition: The Klein Effect Revived (and Reversed)
ERIC Educational Resources Information Center
Dewhurst, Stephen A.; Barry, Christopher
2006-01-01
The Klein effect (G. S. Klein, 1964) refers to the finding that high-frequency words produce greater interference in a color-naming task than low-frequency words. The present study used the Klein effect to investigate the relationship between frequency and age of acquisition (AoA) by measuring their influence on color naming. Two experiments…
On Realistic Brane Worlds from Type i Strings
NASA Astrophysics Data System (ADS)
Aldazabal, Gerardo; IbÁñez, Luis E.; Quevedo, Fernando
We review recent progress in constructing realistic brane models from type I string vacua. Explicit models with three families of the standard model gauge group and its l-right generalizations are presented with supersymmetry broken at the string scale of order Ms ~ 1010-12
Particle Physics of Brane Worlds and Extra Dimensions
NASA Astrophysics Data System (ADS)
Raychaudhuri, Sreerup; Sridhar, K.
2016-06-01
Preface; 1. Dimensional dreams; 2. The Standard Model and beyond; 3. The birth of compact dimensions; 4. String theory: a review; 5. Effective theories; 6. Large extra dimensions; 7. Visible towers of invisible gravitons; 8. Making black holes; 9. Universal extra dimensions; 10. Warped compactifications; 11. Graviton resonances; 12. Stability of warped Worlds; 13. Exploring the bulk; 14. Epilogue; Appendix A. General relativity in a nutshell; Appendix B. Testing the inverse square law; Index.
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.
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.
Spontaneous symmetry breaking in general relativity: Brane world concept
Meierovich, Boris E.
2009-05-15
Gravitational properties of a hedgehog-type topological defect in two extra dimensions are considered in general relativity employing a vector as the order parameter. The developed macroscopic theory of phase transitions with spontaneous symmetry breaking is applied to the analysis of possible ''thick'' brane structures. The previous considerations were done using the order parameter in the form of a multiplet in a target space of scalar fields. The difference of these two approaches is analyzed and demonstrated in detail. There are two different symmetries of regular solutions of Einstein equations for a hedgehog-type vector order parameter. Both solutions are analyzed in parallel analytically and numerically. Regular configurations in cases of a vector order parameter have one more free parameter in comparison with the scalar multiplet solutions. It is shown that the existence of a negative cosmological constant is sufficient for the spontaneous symmetry breaking of the initially plain bulk. Regular configurations have a growing gravitational potential and are able to trap the matter to the brane. Among others there are solutions with the gravitational potential having several points of minimum such as being identical in the uniform bulk spinless particles, being trapped within separate points of minimum, acquiring different masses, and appearing to an observer within the brane as different particles with integer spins.
Casimir force for a scalar field in warped brane worlds
Linares, Roman; Morales-Tecotl, Hugo A.; Pedraza, Omar
2008-03-15
In looking for imprints of extra dimensions in braneworld models one usually builds these so that they are compatible with known low energy physics and thus focuses on high energy effects. Nevertheless, just as submillimeter Newton's law tests probe the mode structure of gravity other low energy tests might apply to matter. As a model example, in this work we determine the 4D Casimir force corresponding to a scalar field subject to Dirichlet boundary conditions on two parallel planes lying within the single brane of a Randall-Sundrum scenario extended by one compact extra dimension. Using the Green's function method such a force picks the contribution of each field mode as if it acted individually but with a weight given by the square of the mode wave functions on the brane. In the low energy regime one regains the standard 4D Casimir force that is associated to a zero mode in the massless case or to a quasilocalized or resonant mode in the massive one while the effect of the extra dimensions gets encoded as an additional term.
Establishment of the thermoelectric effect in Kaluza's MHD through the kinetic theory
NASA Astrophysics Data System (ADS)
Sagaceta-Mejia, A. R.; Garcia-Perciante, A. L.; Sandoval-Villalbazo, A.
2015-11-01
The study of the behavior of charged gases in curved space-times is an active research area in which cross effects, such as thermoelectricity, have not been studied in depth. In our kinetic description of transport theory the electric charge is introduced into the fifth component of the particle velocity, following the idea first proposed by Kaluza in 1919. Using Chapman-Enskog's method, the first order in the gradients correction to the gas distribution function is established, noticing that some of the thermodynamic forces present in the system are associated with the space-time curvature. It is shown that with this distribution function, it is possible to obtain the well-known expressions that relate the heat flux with the electric field in a dilute gas, without resorting to the steady state approximation. This formalism corresponds to an extension of the result obtained for the case of the direct effect between the particle flux and the electric field within Kaluza's MHD (A. Sandoval-Villalbazo, A. R. Sagaceta-Mejía, A. L. García- Perciante; Journal of Non-Equilibrium Thermodynamics, 2015, Vol. 40, pp. 93-101.) The authors acknowledge support from CONACyT through grant CB2011/167563.
Visualizing Klein tunneling in graphene at the atomic limit
NASA Astrophysics Data System (ADS)
Gutierrez, Christopher; Brown, Lola; Lochocki, Edward B.; Kim, Cheol-Joo; Shen, Kyle M.; Park, Jiwoong; Pasupathy, Abhay N.
Graphene has attracted much attention from both the solid-state and high-energy scientific communities because its elementary excitations mimic relativistic chiral fermions. This has allowed graphene to act as a table-top testbed for verifying certain longstanding theoretical predictions dating back to the very first formulation of relativistic quantum mechanics. One such prediction is Klein tunneling, the ability of chiral electrons to transmit perfectly through arbitrarily high potential barriers. Previous transport and point-spectroscopic studies confirmed Klein behavior of graphene electrons but lacked real-space resolution. Here we use scanning tunneling microscopy and spectroscopy (STM/STS) measurements to present the first real-space atomic images of Klein tunneling in graphene. In these CVD-grown samples, quasi-circular regions of the copper substrate underneath graphene act as potential barriers that can scatter and transmit electrons. At certain energies, the relativistic chiral fermions that Klein scatter from these barriers are shown to fulfill resonance conditions such that the transmitted electrons become trapped and form standing waves. These resonant modes are visualized with detailed spectroscopic images with atomic resolution that agree well with theoretical calculations. The trapping time is shown to depend critically on both the angular momenta quantum number of the resonant state and the radius of the trapping potential.
Exploring Klein Bottles through Pottery: A STEAM Investigation
ERIC Educational Resources Information Center
Smith, Christopher E.; Paré, Jana N.
2016-01-01
While one author was reading "The Simpsons and Their Mathematical Secrets by Simon Singh" (2013) in preparation for a presentation, the second author asked what in the book would be interesting to discuss. The topic of Klein bottles was on the first author's mind at that moment, so he tried to describe and explain the form to her--a real…
Exploring Klein Bottles through Pottery: A STEAM Investigation
ERIC Educational Resources Information Center
Smith, Christopher E.; Paré, Jana N.
2016-01-01
While one author was reading "The Simpsons and Their Mathematical Secrets by Simon Singh" (2013) in preparation for a presentation, the second author asked what in the book would be interesting to discuss. The topic of Klein bottles was on the first author's mind at that moment, so he tried to describe and explain the form to her--a real…
Tori and Klein bottles in four-dimensional chaotic flows
NASA Astrophysics Data System (ADS)
Mindlin, G. B.; Solari, H. G.
1997-02-01
We have analyzed the local structure of the flow in the neighborhood of the unstable periodic orbits within the chaotic solution of a four-dimensional vector field. Surfaces within the invariant manifolds of the orbits are found and characterized: they are either Klein bottles or tori.
ERIC Educational Resources Information Center
Tucker, Lauren R.
1998-01-01
Deconstructs the "kiddie porn" media frame used by the industry and mainstream media to characterize Klein's ad campaign. Extends scholarship on the construction of youth in the media, showing how the kiddie-porn frame produces and reproduces common-sense beliefs about the nature of youth. Suggests a metadiscourse encompassing the…
ERIC Educational Resources Information Center
Tucker, Lauren R.
1998-01-01
Deconstructs the "kiddie porn" media frame used by the industry and mainstream media to characterize Klein's ad campaign. Extends scholarship on the construction of youth in the media, showing how the kiddie-porn frame produces and reproduces common-sense beliefs about the nature of youth. Suggests a metadiscourse encompassing the…
The potential for very high-frequency gravitational wave detection
NASA Astrophysics Data System (ADS)
Cruise, A. M.
2012-05-01
The science case for observing gravitational waves at frequencies in the millihertz-kilohertz range using LIGO, VIRGO, GEO600 or LISA is very strong and the first results are expected at these frequencies. However, as gravitational wave astronomy progresses beyond the first detections, other frequency bands may be worth exploring. Early predictions of gravitational wave emission from discrete sources at very much higher frequencies (megahertz and above) have been published and more recent studies of cosmological signals from inflation, Kaluza-Klein modes from gravitational interactions in brane worlds and plasma instabilities surrounding violent astrophysical events, are all possible sources. This communication examines current observational possibilities and the detector technology required to make meaningful observations at these frequencies.
Aguayo, Joseph
2002-10-01
The author investigates the clinical affinity between Klein and Winnicott (1935-46) asa way to historically situate Winnicott 's later criticism of Klein's 'temperamental' inability to understand the impact of the environment on the infant's development. By setting out Klein s theories at the time when Winnicott began supervision with her in 1935, a context is established for the analysis of an unpublished 1937 manuscript by Klein ('Notes on baby'). The author argues that this direct and extensive infant observation demonstrates Klein's sensitivity to the familial environment. While Winnicott as a paediatrician showed enthusiasm for Klein s ideas, he also demonstrated a difference of opinion in emphasising the maternal environment of provision after his wartime evacuation experiences with London children. The factors leading to their mutual distancing are outlined as follows: (1) the post-Controversial Discussion atmosphere of the British Psycho-Analytical Society in 1944. The new non-aligned psychoanalytic 'middle group' allowed Winnicott to take a pick and choose attitude towards available analytic theories; (2) Winnicott us new clinical practices and theory differed from Klein 's, leading to a widening gap between 1946 and 1951. Winnicott's new theory and practice simultaneously represented his technical marginalisation of Klein s emphasis on the direct analysis of the patient s destructiveness by the time he delivered the 'Transitional objects' paper in 1951.
Klein tunneling in the α -T3 model
NASA Astrophysics Data System (ADS)
Illes, E.; Nicol, E. J.
2017-06-01
We investigate Klein tunneling for the α -T3 model, which interpolates between graphene and the dice lattice via parameter α . We study transmission across two types of electrostatic interfaces: sharp potential steps and sharp potential barriers. We find both interfaces to be perfectly transparent for normal incidence for the full range of the parameter α for both interfaces. For other angles of incidence, we find that transmission is enhanced with increasing α . For the dice lattice, we find perfect, all-angle transmission across a potential step for incoming electrons with energy equal to half of the height of the potential step. This is analogous to the "super", all-angle transmission reported for the dice lattice for Klein tunneling across a potential barrier.
Dimers on two types of lattices on the Klein bottle
NASA Astrophysics Data System (ADS)
Lu, Fuliang; Zhang, Lianzhu
2012-12-01
The problem of enumerating close-packed dimers, or perfect matchings, on two types of lattices (the so-called 8.8.4 and 8.8.6 lattices) embedded on the Klein bottle is considered, and we obtain the explicit expression of the number of close-packed dimers and entropy. Our results imply that 8.8.4 lattices have the same entropy under three different boundary conditions (cylindrical, toroidal and Klein bottle) and 8.8.6 lattices have the same property. This article is part of ‘Lattice models and integrability’, a special issue of Journal of Physics A: Mathematical and Theoretical in honour of F Y Wu's 80th birthday.
Treatment of Kleine-Levin Syndrome with Acetazolamide
Kapson, Blaire; Nayar, Sumiti; Spiegel, Rebecca
2014-01-01
Kleine-Levin syndrome (KLS) is a rare and disabling disorder characterized by recurrent episodes of hypersomnia as well as cognitive and behavioral abnormalities. Sadly, the treatment options are very limited and often ineffective. To our knowledge, there have been no reports in the literature for the use of acetazolamide as a treatment for this disorder. We report the case of a 26-year-old female patient with KLS in whom acetazolamide was used to treat recurrent hypersomnia and cognitive abnormalities. The patient had a dramatic improvement on acetazolamide in both the frequency and severity of her symptoms. The symptoms recurred when acetazolamide was stopped on two occasions and improved with resumption of the drug, leading us to conclude that its therapeutic effect was significant. Citation: Kapson B, Nayar S, Spiegel R. Treatment of Kleine-Levin syndrome with acetazolamide. J Clin Sleep Med 2014;10(10):1153-1154. PMID:25317098
Thalamic Activation in the Kleine-Levin Syndrome
Engström, Maria; Karlsson, Thomas; Landtblom, Anne-Marie
2014-01-01
Study Objectives: The objective of this study was to investigate if combined measures of activation in the thalamus and working memory capacity could guide the diagnosis of Kleine-Levin Syndrome (KLS). A second objective was to obtain more insight into the neurobiological causes of KLS. Design: Matched group and consecutive recruitment. Setting: University hospital neurology department and imaging center. Patients or Participants: Eighteen patients with KLS diagnosed according to the International Classification of Sleep Disorders and 26 healthy controls were included. Interventions: N/A. Measurements and Results: Working memory capacity was assessed by the listening span task. A version of this task (reading span) was presented to the participants during functional magnetic resonance imaging (fMRI). Activation in the thalamus was measured in a region of interest analysis. A combination of the working memory capacity and the thalamic activation measures resulted in 80% prediction accuracy, 81% sensitivity, and 78% specificity regarding the ability to separate KLS patients from healthy controls. The controls had an inverse relation between working memory capacity and thalamic activation; higher performing participants had lower thalamic activation (r = -0.41). KLS patients showed the opposite relationship; higher performing participants had a tendency to higher thalamic activation (r = -0.35). Conclusions: This study shows that functional neuroimaging of the thalamus combined with neuropsychological assessment of working memory function provides a means to guide diagnosis of Kleine-Levin Syndrome. Results in this study also indicate that imaging of brain function and evaluation of cognitive capacity can give insights into the neurobiological mechanisms of Kleine-Levin Syndrome. Citation: Engström M; Karlsson T; Landtblom AM. Thalamic activation in the Kleine-Levin Syndrome. SLEEP 2014;37(2):379-386. PMID:24497666
Global bifurcations on a Klein bottle. The general case
NASA Astrophysics Data System (ADS)
Borisyuk, A. R.
2005-04-01
A one-parameter family of smooth vector fields in a space of a high dimension is considered such that for some critical parameter value the corresponding field has a saddle-node cycle (a periodic orbit). The case when the union of the cycle and its homoclinic orbits form a smooth Klein bottle is discussed. The problem consists in the description of the behaviour of the orbit set under the variation of the parameter.
The torus and the Klein bottle amplitude of permutation orbifolds
NASA Astrophysics Data System (ADS)
Kadar, Z.
2000-07-01
The torus and the Klein bottle amplitude coefficients are computed in permutation orbifolds of RCFT's in terms of the same quantities in the original theory and the twist group. An explicit expression is presented for the number of self conjugate primaries in the orbifold as a polynomial of the total number of primaries and the number of self conjugate ones in the parent theory. The formulae in the Z2 orbifold illustrate the general results.
Klein's theorem and the proof of E0 = mc2
NASA Astrophysics Data System (ADS)
Ohanian, Hans C.
2012-12-01
Despite repeated attempts, Einstein failed to give us a general and rigorous proof of his E0=mc2 relation. A completely general proof emerged in 1918 from a theorem on the four-vector character of energy-momentum of extended systems by the mathematician Felix Klein, but this proof is not well known, rarely seen in textbooks, and sometimes misunderstood. A simple version of this proof is presented here, with discussion of the crucial role of the energy-momentum tensor.
Resolution of the Klein Paradox within Relativistic Quantum Mechanics
Alhaidari, A. D.
2011-10-27
We present a resolution of the Klein paradox within the framework of one-particle relativistic quantum mechanics (no pair production). Not only reflection becomes total but the vacuum remains neutral as well. This is accomplished by replacing the pair production process with virtual negative energy ''incidence'' within the barrier in a process analogous to the introduction of image charges in electrostatic and virtual sources in optics.
Modeling Klein tunneling and caustics of electron waves in graphene
NASA Astrophysics Data System (ADS)
Logemann, R.; Reijnders, K. J. A.; Tudorovskiy, T.; Katsnelson, M. I.; Yuan, Shengjun
2015-01-01
We employ the tight-binding propagation method to study Klein tunneling and quantum interference in large graphene systems. With this efficient numerical scheme, we model the propagation of a wave packet through a potential barrier and determine the tunneling probability for different incidence angles. We consider both sharp and smooth potential barriers in n-p-n and n -n' junctions and find good agreement with analytical and semiclassical predictions. When we go outside the Dirac regime, we observe that sharp n -p junctions no longer show Klein tunneling because of intervalley scattering. However, this effect can be suppressed by considering a smooth potential. Klein tunneling holds for potentials changing on the scale much larger than the interatomic distance. When the energies of both the electrons and holes are above the Van Hove singularity, we observe total reflection for both sharp and smooth potential barriers. Furthermore, we consider caustic formation by a two-dimensional Gaussian potential. For sufficiently broad potentials we find a good agreement between the simulated wave density and the classical electron trajectories.
Collapse threshold for a cosmological Klein-Gordon field
NASA Astrophysics Data System (ADS)
Hidalgo, Juan Carlos; De Santiago, Josué; German, Gabriel; Barbosa-Cendejas, Nandinii; Ruiz-Luna, Waldemar
2017-09-01
Oscillating scalar fields are useful to model a variety of matter components in the Universe. One or more scalar fields participate in the reheating process after inflation, while at much lower energies scalar fields are robust dark matter candidates. Pertaining to structure formation in these models, it is well known that inhomogeneities of the Klein-Gordon field are unstable above the characteristic de Broglie wavelength. In this paper we show that such instability implies the existence of a threshold amplitude for the collapse of primordial fluctuations. We use this threshold to correctly predict the cutoff scale of the matter power spectrum in the scalar field dark matter model. Furthermore, for a Klein-Gordon field during reheating we show that this same threshold allows for abundant production of structure (oscillons but not necessarily black holes). Looking at the production of primordial black holes (PBHs) in this scenario we note that the sphericity condition yields a much lower probability of PBH formation at the end of inflation. Remarkably, even after meeting a such stringent condition, we find that PBHs may be overproduced during reheating. We finally constrain the epochs at which an oscillating Klein-Gordon field could dominate the early universe.
Fractional Klein-Gordon Equations and Related Stochastic Processes
NASA Astrophysics Data System (ADS)
Garra, Roberto; Orsingher, Enzo; Polito, Federico
2014-03-01
This paper presents finite-velocity random motions driven by fractional Klein-Gordon equations of order α in (0,1] . A key tool in the analysis is played by the McBride's theory which converts fractional hyper-Bessel operators into Erdélyi-Kober integral operators. Special attention is payed to the fractional telegraph process whose space-dependent distribution solves a non-homogeneous fractional Klein-Gordon equation. The distribution of the fractional telegraph process for α = 1 coincides with that of the classical telegraph process and its driving equation converts into the homogeneous Klein-Gordon equation. Fractional planar random motions at finite velocity are also investigated, the corresponding distributions obtained as well as the explicit form of the governing equations. Fractionality is reflected into the underlying random motion because in each time interval a binomial number of deviations B(n,α ) (with uniformly-distributed orientation) are considered. The parameter n of B(n,α ) is itself a random variable with fractional Poisson distribution, so that fractionality acts as a subsampling of the changes of direction. Finally the behaviour of each coordinate of the planar motion is examined and the corresponding densities obtained. Extensions to N -dimensional fractional random flights are envisaged as well as the fractional counterpart of the Euler-Poisson-Darboux equation to which our theory applies.
Super-Klein tunneling of massive pseudospin-one particles
NASA Astrophysics Data System (ADS)
Betancur-Ocampo, Y.; Cordourier-Maruri, G.; Gupta, V.; de Coss, R.
2017-07-01
The transmission properties of massive particles with pseudospin-one through homogeneous and heterogeneous junctions are studied from an effective spin-orbit Hamiltonian. The addition of a mass term in the Hamiltonian creates an energy band gap with a flat band inside the gap. There are three possible scenarios for the location of the flat band: at the top of the valence band, at the bottom of the conduction band, and at the center of the energy band gap. We have studied how the position of the flat band affects the transmission through a general type of junction. We found that omnidirectional perfect transmission, called super-Klein tunneling, occurs even for massive particles with specific symmetrical conditions in the junction. In all other cases, an angular independent transmission is obtained, which can be considered as an attenuated super-Klein tunnelling. These effects emerge when the junction operates as a Veselago lens under the generalized focusing condition. Furthermore, we found that Klein tunneling is restored in the massless limit. The present findings may have important implications in the development of electronic devices based on quantum optics with massive pseudospin-one particles.
Freud and Klein on the concept of phantasy.
Spillius, E B
2001-04-01
In summary, I think Freud's idea is that the prime mover of psychic life is the unconscious wish, not phantasy. The 'work' of making phantasies and the 'work' of making dreams are parallel processes in which forbidden unconscious wishes achieve disguised expression and partial fulfilment. For Freud himself, especially in his central usage, and even more for his immediate followers, phantasies are conceived as imagined fulfilments of frustrated wishes. Whether they originate in the system conscious or the system preconscious, they are an activity of the ego and are formed according to the principles of the secondary process. That is not the whole story, however, because phantasies may get repressed into the system unconscious, where they become associated with the instinctual wishes, become subject to the laws of the primary process, and may find their way into dreams and many other derivatives. For Freud and for French psychoanalysts particularly, there are the primal phantasies, 'unconscious all along', of the primal scene, castration and seduction, also capable of being directly incorporated into dreams and expressed through other derivatives. For Klein phantasy is an even more central concept than for Freud and it has continued to be used by her successors with only minor changes. In Klein's thinking unconscious phantasies play the part that Freud assigned to the unconscious wish. They underlie dreams rather than being parallel to them--a much more inclusive definition of phantasy than Freud's. The earliest and most deeply unconscious phantasies are bodily, and only gradually, with maturation and developing experience through introjection and projection do some of them come to take a verbal form. Freud's central usage, the wish-fulfilling definition of phantasy, is a particular type of phantasy within Klein's more inclusive definition. And, as in Freud's formulation, conscious phantasies may be repressed, but in Klein's formulation this is not the only or even
Klein tunneling and Dirac potentials in trapped ions
Casanova, J.; Garcia-Ripoll, J. J.; Gerritsma, R.; Roos, C. F.; Solano, E.
2010-08-15
We propose the quantum simulation of the Dirac equation with potentials, allowing the study of relativistic scattering and Klein tunneling. This quantum relativistic effect permits a positive-energy Dirac particle to propagate through a repulsive potential via the population transfer to negative-energy components. We show how to engineer scalar, pseudoscalar, and other potentials in the 1+1 Dirac equation by manipulating two trapped ions. The Dirac spinor is represented by the internal states of one ion, while its position and momentum are described by those of a collective motional mode. The second ion is used to build the desired potentials with high spatial resolution.
Kleine-levin syndrome and idiopathic hypersomnia: spectrum disorders.
Gupta, Ravi; Lahan, Vivekananda; Srivastava, Malini
2011-07-01
Kleine-Levin syndrome (KLS) and idiopathic hypersomnia (IH) are primary sleep disorders of unknown etiologies, which often run a chronic course. The common core symptoms of these syndromes are hypersomnolence and sleep drunkenness, with periodic hypersomnolence and hyperphagia being the prominent symptoms of KLS. Psychiatric manifestations are common to both and include irritability, depression, apathy, inattention and poor concentration. Both disorders are diagnosed clinically and no specific laboratory investigation is available to confirm the diagnosis. We present a case highlighting the overlapping of the symptoms of KLS and IH, producing a complex clinical picture.
Felix Klein and the NCTM's Standards: A Mathematician Considers Mathematics Education.
ERIC Educational Resources Information Center
McComas, Kim Krusen
2000-01-01
Discusses the parallels between Klein's position at the forefront of a movement to reform mathematics education and that of the National Council of Teachers of Mathematics' (NCTM) Standards. Draws a picture of Klein as an important historical figure who saw equal importance in studying pure mathematics, applying mathematics, and teaching…
Lefschetz pencils, Morse functions, and Lagrangian embeddings of the Klein bottle
NASA Astrophysics Data System (ADS)
Nemirovski, Stefan Yu
2002-02-01
It is shown that the mod 2 homology class represented by a Lagrangian Klein bottle in a complex algebraic surface is non-zero. In particular, the Klein bottle does not admit a Lagrangian embedding into the standard symplectic four-space.
Graphene Klein tunnel transistors for high speed analog RF applications.
Tan, Yaohua; Elahi, Mirza M; Tsao, Han-Yu; Habib, K M Masum; Barker, N Scott; Ghosh, Avik W
2017-08-29
We propose Graphene Klein tunnel transistors (GKTFET) as a way to enforce current saturation while maintaining large mobility for high speed radio frequency (RF) applications. The GKTFET consists of a sequence of angled graphene p-n junctions (GPNJs). Klein tunneling creates a collimation of electrons across each GPNJ, so that the lack of substantial overlap between transmission lobes across successive junctions creates a gate-tunable transport gap without significantly compromising the on-current. Electron scattering at the device edge tends to bleed parasitic states into the gap, but the resulting pseudogap is still sufficient to create a saturated output (I D -V D ) characteristic and a high output resistance. The modulated density of states generates a higher transconductance (g m ) and unity current gain cut-off frequency (f T ) than GFETs. More significantly the high output resistance makes the unity power gain cut-off frequency (f max ) of GKTFETs considerably larger than GFETs, making analog GKTFET potentially useful for RF electronics. Our estimation shows the f T /f max of a GKTFET with 1 μm channel reaches 33 GHz/17 GHz, and scale up to 350 GHz/53 GHz for 100 nm channel (assuming a single, scalable trapezoidal gate). The f max of a GKTFET is 10 times higher than a GFET with the same channel length.
Observing another universe through ringholes and Klein-bottle holes
NASA Astrophysics Data System (ADS)
González-Díaz, Pedro F.; Alonso-Serrano, Ana
2011-07-01
It is argued that whereas the Shatskiy single rings produced by the gravitational inner field of a spherically symmetric wormhole and the concentric double Einstein rings generated by a toroidal ringhole could not be used without some uncertainty to identify the presence of such tunnelings in the universe or the existence of a parallel universe, the image which the inner gravitational field of a nonorientable Klein-bottle hole tunneling would leave by lensing a single luminous source is that of a truncated double spiral, which is a signature that cannot be attributed to any other single or composite astronomical object in whichever universe it may be placed. In this report we argue some more reasons to predict that such a signature would imply the discovery of one such nonorientable tunneling in our or other universe. After all, a nonorientable Klein-bottle hole is also a perfectly valid solution to the Einstein equations, and the stuff which would make it feasible is becoming more and more familiar in cosmology.
Extended Klein-Gordon action, gravity and nonrelativistic fluid
Hassaiene, Mokhtar
2006-03-15
We consider a scalar field action for which the Lagrangian density is a power of the massless Klein-Gordon Lagrangian. The coupling of gravity to this matter action is considered. In this case, we show the existence of nontrivial scalar field configurations with vanishing energy-momentum tensor on any static, spherically symmetric vacuum solutions of the Einstein equations. These configurations in spite of being coupled to gravity do not affect the curvature of space-time. The properties of this particular matter action are also analyzed. For a particular value of the exponent, the extended Klein-Gordon action is shown to exhibit a conformal invariance without requiring the introduction of a nonminimal coupling. We also establish a correspondence between this action and a nonrelativistic isentropic fluid in one fewer dimension. This fluid can be identified with the (generalized) Chaplygin gas for a particular value of the power. It is also shown that the nonrelativistic fluid admits, apart from the Galileo symmetry, an additional symmetry whose action is a rescaling of the time.
Some developments from the work of Melanie Klein.
Spillius, E B
1983-01-01
This paper discusses four areas of work in which several followers of Melanie Klein in Britain have developed some of the discoveries and ideas she initiated. First, extension of her concept of projective identification is briefly described, with emphasis on Bion's and Rosenfeld's stress on its communicative as well as its pathological aspects. Second, the extension of Klein's ideas about the epistemophilic instinct, on symbolism, and about projective identification is described in the work of Segal, Bion, Money-Kyrle, and Bick on the development of the capacity to think. Third, certain developments in Kleinian technique are described, with emphasis on the use of the concept of projective identification in analysing transference, and on the analysis of acting out in the transference, a trend contributed to by many Kleinian analysts but perhaps most closely associated with Betty Joseph. Finally, continued refinements in the analysis of the death instinct are briefly described, together with discussion of the changes these refinements have led to in ideas about the organization and relations of parts of the self and internal objects.
Numerical computation of travelling breathers in Klein Gordon chains
NASA Astrophysics Data System (ADS)
Sire, Yannick; James, Guillaume
2005-05-01
We numerically study the existence of travelling breathers in Klein-Gordon chains, which consist of one-dimensional networks of nonlinear oscillators in an anharmonic on-site potential, linearly coupled to their nearest neighbors. Travelling breathers are spatially localized solutions having the property of being exactly translated by p sites along the chain after a fixed propagation time T (these solutions generalize the concept of solitary waves for which p=1). In the case of even on-site potentials, the existence of small amplitude travelling breathers superposed on a small oscillatory tail has been proved recently [G. James, Y. Sire, Travelling breathers with exponentially small tails in a chain of nonlinear oscillators, Commun. Math. Phys., 2005, in press (available online at http://www.springerlink.com)], the tail being exponentially small with respect to the central oscillation size. In this paper, we compute these solutions numerically and continue them into the large amplitude regime for different types of even potentials. We find that Klein-Gordon chains can support highly localized travelling breather solutions superposed on an oscillatory tail. We provide examples where the tail can be made very small and is difficult to detect at the scale of central oscillations. In addition, we numerically observe the existence of these solutions in the case of non-even potentials.
Dissipative effects in nonlinear Klein-Gordon dynamics
NASA Astrophysics Data System (ADS)
Plastino, A. R.; Tsallis, C.
2016-03-01
We consider dissipation in a recently proposed nonlinear Klein-Gordon dynamics that admits exact time-dependent solutions of the power-law form e_qi(kx-wt) , involving the q-exponential function naturally arising within the nonextensive thermostatistics (e_qz \\equiv [1+(1-q)z]1/(1-q) , with e_1^z=ez ). These basic solutions behave like free particles, complying, for all values of q, with the de Broglie-Einstein relations p=\\hbar k , E=\\hbar ω and satisfying a dispersion law corresponding to the relativistic energy-momentum relation E2 = c^2p2 + m^2c4 . The dissipative effects explored here are described by an evolution equation that can be regarded as a nonlinear generalization of the celebrated telegraph equation, unifying within one single theoretical framework the nonlinear Klein-Gordon equation, a nonlinear Schrödinger equation, and the power-law diffusion (porous-media) equation. The associated dynamics exhibits physically appealing traveling solutions of the q-plane wave form with a complex frequency ω and a q-Gaussian square modulus profile.
Little, Reginald B; McClary, Felicia; Rice, Bria; Jackman, Corine; Mitchell, James W
2012-12-14
The recent observation of the explosive oxidation of graphene with enhancement for decreasing temperature and the requirements for synchronizing oxidants for collective oxidation-reduction (redox) reactions presented a chemical scenario for the thermal harvesting by the magnetic spin Hall Effect. More experimental data are presented to demonstrate such spin Hall Effect by determining the influence of spins of so-called spectator fermionic cations. Furthermore, the so-called spectator bosonic cations are discovered to cause a Klein tunneling effect during the redox reaction of graphene. The Na(+) and K(+), fermionic cations and the Mg(2+) and Ca(2+), bosonic cations were observed and compared under a variety of experimental conditions: adiabatic reactions with initial temperatures (18-22 °C); reactions toward infinite dilution; isothermal reactions under nonadiabatic conditions at low temperature of 18 °C; reactions under paramagnetic O(2) or diamagnetic N(2) atmospheres of different permeabilities; reactions in applied and no applied external magnetic field; and reactions toward excess concentrations of common and uncommon Na(+) and Mg(2+) cations. The observed reaction kinetics and dynamics under these various, diverse conditions are consistent with the spin Hall mechanism, energy harvesting and short time violation of Second Law of Thermodynamics for redox reactions of graphene by the Na(+)K(+) mixture and are consistent with the Klein tunnel mechanism for the redox reactions of graphene by the Mg(2+)Ca(2+) mixture. Mixed spin Hall and Klein tunnel mechanisms are discovered to slow and modulate explosive redox reactions. Such spin Hall Effect also gives explanation of recent tunneling of electrons through boron nitride.
Quantum Simulation of the Klein Paradox with Trapped Ions
Gerritsma, R.; Lanyon, B. P.; Kirchmair, G.; Zaehringer, F.; Hempel, C.; Blatt, R.; Roos, C. F.; Casanova, J.; Garcia-Ripoll, J. J.; Solano, E.
2011-02-11
We report on quantum simulations of relativistic scattering dynamics using trapped ions. The simulated state of a scattering particle is encoded in both the electronic and vibrational state of an ion, representing the discrete and continuous components of relativistic wave functions. Multiple laser fields and an auxiliary ion simulate the dynamics generated by the Dirac equation in the presence of a scattering potential. Measurement and reconstruction of the particle wave packet enables a frame-by-frame visualization of the scattering processes. By precisely engineering a range of external potentials we are able to simulate text book relativistic scattering experiments and study Klein tunneling in an analogue quantum simulator. We describe extensions to solve problems that are beyond current classical computing capabilities.
Klein Tunneling in the Presence of Random Impurities
NASA Astrophysics Data System (ADS)
Palpacelli, S.; Mendoza, M.; Herrmann, H. J.; Succi, S.
2012-11-01
In this paper, we study Klein tunneling in random media. To this purpose, we simulate the propagation of a relativistic Gaussian wave packet through a disordered medium with randomly distributed potential barriers (impurities). The simulations, based on a relativistic quantum lattice Boltzmann (QLB) method, permit to compute the transmission coefficient across the sample, thereby providing an estimate for the conductivity (or permeability) as a function of impurity concentration and strength of the potentials. It is found that the conductivity loss due to impurities is significantly higher for wave packets of massive particles, as compared to massless ones. A general expression for the loss of conductivity as a function of the impurity percentage is presented and successfully compared with the Kozeny-Carman law for disordered media in classical fluid-dynamics.
Conservative difference methods for the Klein-Gordon-Zakharov equations
NASA Astrophysics Data System (ADS)
Wang, Tingchun; Chen, Juan; Zhang, Luming
2007-08-01
Firstly an implicit conservative finite difference scheme is presented for the initial-boundary problem of the one space dimensional Klein-Gordon-Zakharov (KGZ) equations. The existence of the difference solution is proved by Leray-Schauder fixed point theorem. It is proved by the discrete energy method that the scheme is uniquely solvable, unconditionally stable and second order convergent for U in l[infinity] norm, and for N in l2 norm on the basis of the priori estimates. Then an explicit difference scheme is proposed for the KGZ equations, on the basis of priori estimates and two important inequalities about norms, convergence of the difference solutions is proved. Because it is explicit and not coupled it can be computed by a parallel method. Numerical experiments with the two schemes are done for several test cases. Computational results demonstrate that the two schemes are accurate and efficient.
Long-Term Cognitive Impairment in Kleine-Levin Syndrome
Uguccioni, Ginevra; Lavault, Sophie; Chaumereuil, Charlotte; Golmard, Jean-Louis; Gagnon, Jean-François; Arnulf, Isabelle
2016-01-01
Study Objectives: In Kleine-Levin syndrome (KLS), episodes of hypersomnia, cognitive, and behavioral disturbances alternate with asymptomatic periods. Because 50% of patients report decreased academic performances, we evaluated their cognitive status during asymptomatic periods, determinants of deficits, and changes during follow-up. Methods: The cognitive assessment during asymptomatic periods in all consecutive patients with typical KLS and healthy controls included the non-verbal intelligence quotient (Raven Progressive Matrices), the Trail Making Test, the Stroop Color-Word Test, the Wechsler Memory Test, verbal fluencies, the Free and Cued Learning Memory Test, and the Rey-Osterreith Complex Figure. Cognitive status was reevaluated after 0.5 to 2 y in 44 patients. Results: At baseline, compared with the 42 controls, the 122 patients with KLS exhibited lower non-verbal intelligence quotient, speed of processing, attention, and reduced retrieval strategies in episodic memory. Higher episode frequency, shorter episode duration, shorter time since last episode, deeper sleep, and megaphagia during episodes predicted impaired memory. The visuoconstructional abilities and non-verbal memory were intact. After a mean follow-up of 1.7 ± 1.0 y, the episode frequency decreased from 4.6 ± 4.8 to 1.7 ± 1.9/y. The logical reasoning and attention improved, the processing speed remained low, and the retrieval strategies in verbal memory further worsened. Conclusions: In this field study, one-third of patients with KLS have long-term cognitive deficits affecting retrieval and processing speed. Cognitive function should be systematically tested in patients with KLS, which appears important to help patients in their academic studies. Citation: Uguccioni G, Lavault S, Chaumereuil C, Golmard JL, Gagnon JF, Arnulf I. Long-term cognitive impairment in kleine-levin syndrome. SLEEP 2016;39(2):429–438. PMID:26414895
Vicious circles of punishment: a reading of Melanie Klein's Envy and gratitude.
Smith, Henry F
2008-01-01
Staged as a moral drama, Melanie Klein's Envy and Gratitude (1957) straddles two eras: one reflecting a simpler more concrete, historical method, and the other an approach of greater complexity, focused on the transferential moment. Embedded within the transference are the vicious circles of envy and punishment that are the hallmark of Klein's text. Punishment itself which is always punishment of both self and other, creates its own vicious circle, set in motion by a single act. In the sadomasochistic enactments that result, the moral force of Klein's categories fuels the countertransference. A detailed clinical hour is presented.
PHYTOCHEMICAL OBSERVATION OF WHOLE PLANT OF PHYLLANTHUS DEBILIS KLEIN .EX.WILLD
Chandrashekar, K. S.; Joshi, A. B.; Satyanarayana, D.; Pai, P.
2005-01-01
Phytochemical studies of whole plant of Phyllanthus debilis Klein.ex.willd (Euphorbiaceae) reveals the presence of phytosterols, lignans, glycosides and absence of saponin, triterpenoids, tannins and alkaloids have been reported in this plant for the first time. PMID:22557187
["Is it an animal inside? "Melanie Klein's unpublished Don Juan Paper (1939)].
Frank, Claudia
2008-01-01
Klein had been asked to contribute an article to the birthday number of the International Journal for Jones. The author outlines how she hurriedly wrote a text about Don Juan which, however, was rejected by the editor. Essential parts of it are presented in German translation. The manuscript is discussed in the context of Klein's published work as well as of the relevant contemporary literature. In Klein's view, Don Juan's genitality is determined by oral impulses and fears. By his manic acting out he attempts to ward off a depressive break-down. The paper ends with some reflections about why Klein--ontrary to her intention--failed to revise her manuscript for later publication.
Continuum percolation on nonorientable surfaces: the problem of permeable disks on a Klein bottle
NASA Astrophysics Data System (ADS)
Borman, V. D.; Grekhov, A. M.; Tronin, V. N.; Tronin, I. V.
2015-11-01
The percolation threshold and wrapping probability (R ∞) for the two-dimensional problem of continuum percolation on the surface of a Klein bottle have been calculated by the Monte Carlo method with the Newman-Ziff algorithm for completely permeable disks. It has been shown that the percolation threshold of disks on the Klein bottle coincides with the percolation threshold of disks on the surface of a torus, indicating that this threshold is topologically invariant. The scaling exponents determining corrections to the wrapping probability and critical concentration owing to the finite-size effects are also topologically invariant. At the same time, the quantities R ∞ are different for percolation on the torus and Klein bottle and are apparently determined by the topology of the surface. Furthermore, the difference between the R ∞ values for the torus and Klein bottle means that at least one of the percolation clusters is degenerate.
On the statistical properties of Klein polyhedra in three-dimensional lattices
Illarionov, A A
2013-06-30
We obtain asymptotic formulae for the average values of the number of faces of a fixed type and of vertices of Klein polyhedra of three-dimensional integer lattices with a given determinant. Bibliography: 20 titles.
Approximate symmetry and solutions of the nonlinear Klein-Gordon equation with a small parameter
NASA Astrophysics Data System (ADS)
Rahimian, Mohammad; Toomanian, Megerdich; Nadjafikhah, Mehdi
In this paper, the Lie approximate symmetry analysis is applied to investigate new solutions of the nonlinear Klein-Gordon equation with a small parameter. The nonlinear Klein-Gordon equation is used to model many nonlinear phenomena. The hyperbolic function method and Riccati equation method are employed to solve some of the obtained reduced ordinary differential equations. We construct new analytical solutions with a small parameter which is effectively obtained by the proposed method.
A not so short note on the Klein Gordon equation at second order
NASA Astrophysics Data System (ADS)
Malik, Karim A.
2007-03-01
We give the governing equations for multiple scalar fields in a flat Friedmann Robertson Walker (FRW) background spacetime on all scales, allowing for metric and field perturbations up to second order. We then derive the Klein Gordon equation at second order in closed form in terms of gauge-invariant perturbations of the fields in the uniform curvature gauge. We also give a simplified form of the Klein Gordon equation using the slow-roll approximation.
Kleine-Levin syndrome in a 14-year-old girl: CSF hypocretin-1 measurements.
Podestá, Claudio; Ferreras, Mónica; Mozzi, Marcela; Bassetti, Claudio; Dauvilliers, Yves; Billiard, Michel
2006-12-01
CSF hypocretin-1 measurements were performed during a period of hypersomnia and during an asymptomatic interval in a 14-year-old girl affected with severe Kleine-Levin syndrome. A twofold decrease in hypocretin-1 was evidenced during the period of hypersomnia in comparison with the asymptomatic interval. Together with previous data, this result is in favour of recurrent dysfunction at the hypothalamic level in Kleine-Levin syndrome.
Familial Kleine-Levin Syndrome: A Specific Entity?
Nguyen, Quang Tuan Remy; Groos, Elisabeth; Leclair-Visonneau, Laurène; Monaca-Charley, Christelle; Rico, Tom; Farber, Neal; Mignot, Emmanuel; Arnulf, Isabelle
2016-01-01
Study Objectives: Kleine-Levin syndrome (KLS) is a rare, mostly sporadic disorder, characterized by intermittent episodes of hypersomnia plus cognitive and behavior disorders. Although its cause is unknown, multiplex families have been described. We contrasted the clinical and biological features of familial versus sporadic KLS. Methods: Two samples of patients with KLS from the United States and France (n = 260) were studied using clinical interviews and human leukocyte antigen (HLA) genotyping. A multiplex family contained two or more first- or second-degree affected relatives (familial cases). Results: Twenty-one patients from 10 multiplex families (siblings: n = 12, including two pairs of monozygotic twins; parent-child: n = 4; cousins: n = 2; uncle-nephews: n = 3) and 239 patients with sporadic KLS were identified, yielding to 4% multiplex families and 8% familial cases. The simplex and multiplex families did not differ for autoimmune, neurological, and psychiatric disorders. Age, sex ratio, ethnicity, HLA typing, karyotyping, disease course, frequency, and duration of KLS episodes did not differ between groups. Episodes were less frequent in familial versus sporadic KLS (2.3 ± 1.8/y versus 3.8 ± 3.7/y, P = 0.004). Menses triggered more frequently KLS onset in the nine girls with familial KLS (relative risk, RR = 4.12, P = 0.03), but not subsequent episodes. Familial cases had less disinhibited speech (RR = 3.44, P = 0.049), less combined hypophagia/hyperphagia (RR = 4.38, P = 0.006), more abrupt termination of episodes (RR = 1.45, P = 0.04) and less postepisode insomnia (RR = 2.16, P = 0.008). There was similar HLA DQB1 distribution in familial versus sporadic cases and no abnormal karyotypes. Conclusion: Familial KLS is mostly present in the same generation, and is clinically similar to but slightly less severe than sporadic KLS. Citation: Nguyen QT, Groos E, Leclair-Visonneau L, Monaca-Charley C, Rico T, Farber N, Mignot E, Arnulf I. Familial Kleine
Melanie Klein in Buenos Aires: beginnings and developments.
Etchegoyen, R Horacio; Zysman, Samuel
2005-06-01
In the first decades of the 20th century, Freud was known and quoted in Latin America by an elite of enlightened minds. In the 1940s a convergence took place in Buenos Aires of European exiles with local pioneers, and thus the Argentine Psychoanalytical Association was founded in 1942. Since then psychoanalysis has grown steadily and has spread into hospitals and universities, influencing culture at large. The socioeconomic situation of that time permitted this phenomenon to develop, to the astonishment of observers. In this paper the authors study the strong influence of Kleinian thought during the first 30 years of this development. The original works of local thinkers constitute the intellectual capital that sustains the idea of an 'Argentine psychoanalytic school'. During the 1970s, both society and psychoanalysis endured deep and complex changes. Lacan's teachings gained support and Klein's influence began to decline. At present the Buenos Aires Kleinians keep working, while their relationship with Lacanians and other schools is calmer. Respectful discussions became thus possible, oriented to strictly scientific differences.
Revisiting the Freud-Klein controversies fifty years later.
Baudry, F
1994-04-01
This paper examines the contribution to the study of psychoanalytic controversy made possible by the publication of the Freud-Klein Controversies. The availability of the complete minutes allows us as never before to dissect a historical, scientific controversy immersed in passion and intertwined with issues of power, economics and educational control. For the first time in the analytic literature we are able to follow closely how each side conceptualised the nature of preverbal development, and how and where and with what consequences polemics and artificial polarisation contaminated the dialogue. The problematic relation between theory and data is illustrated very sharply and many of the methodological issues encountered are highly relevant to current disagreements within our field. A careful reading shows at which points opportunities for bridging gaps were scuttled, and how ensuing developments in our field were coloured by the failure of a true resolution. Particularly remarkable are the 'Memoranda on Technique' written by a number of participants. These very moving, brief essays document the process of acquiring a personal approach to analytic work. The section by Brierley deserves a special mention for its excellence, clarity and modesty.
Emanuel Edward Klein's book on diseases of birds.
Atalić, Bruno
2015-01-01
Emanuel Edward Klein (1844 - 1925) was a British microbiologist of Croatian origin. He was born in Osijek in what is currently the Republic of Croatia and which was then part of the Habsburg Monarchy, he completed his medical studies in Vienna in 1869, and went on to spend his entire career in London. Although trained as an anatomist, embryologist and histologist, his main area of research was microbiology. Due to the fact that back then it was a new and fast developing discipline, he was able to pursue his interests in many directions and make significant discoveries, such as the identification of the 'Bacillus enteritidis sporogenes' as a cause of summer hospital diarrhoeas. Although the overwhelming majority of his researches dealt with bacteria which attacked humans, in 1892 he published a book entitled The Etiology and Pathology of Grouse Disease, Fowl Enteritis, and Some Other Diseases Affecting Birds, which revealed the results of his experiments on the bacteria which affected birds. In the context of the general development of the microbiology, this paper tries to give an objective evaluation of this until now widely neglected book.
Long-Term Cognitive Impairment in Kleine-Levin Syndrome.
Uguccioni, Ginevra; Lavault, Sophie; Chaumereuil, Charlotte; Golmard, Jean-Louis; Gagnon, Jean-François; Arnulf, Isabelle
2016-02-01
In Kleine-Levin syndrome (KLS), episodes of hypersomnia, cognitive, and behavioral disturbances alternate with asymptomatic periods. Because 50% of patients report decreased academic performances, we evaluated their cognitive status during asymptomatic periods, determinants of deficits, and changes during follow-up. The cognitive assessment during asymptomatic periods in all consecutive patients with typical KLS and healthy controls included the non-verbal intelligence quotient (Raven Progressive Matrices), the Trail Making Test, the Stroop Color-Word Test, the Wechsler Memory Test, verbal fluencies, the Free and Cued Learning Memory Test, and the Rey-Osterreith Complex Figure. Cognitive status was reevaluated after 0.5 to 2 y in 44 patients. At baseline, compared with the 42 controls, the 122 patients with KLS exhibited lower non-verbal intelligence quotient, speed of processing, attention, and reduced retrieval strategies in episodic memory. Higher episode frequency, shorter episode duration, shorter time since last episode, deeper sleep, and megaphagia during episodes predicted impaired memory. The visuoconstructional abilities and non-verbal memory were intact. After a mean follow-up of 1.7 ± 1.0 y, the episode frequency decreased from 4.6 ± 4.8 to 1.7 ± 1.9/y. The logical reasoning and attention improved, the processing speed remained low, and the retrieval strategies in verbal memory further worsened. In this field study, one-third of patients with KLS have long-term cognitive deficits affecting retrieval and processing speed. Cognitive function should be systematically tested in patients with KLS, which appears important to help patients in their academic studies. © 2016 Associated Professional Sleep Societies, LLC.
Numerical solution of linear Klein-Gordon equation using FDAM scheme
NASA Astrophysics Data System (ADS)
Kasron, Noraini; Suharto, Erni Suryani; Deraman, Ros Fadilah; Othman, Khairil Iskandar; Nasir, Mohd Agos Salim
2017-05-01
Many scientific areas appear in a hyperbolic partial differential equation like the Klien-Gordon equation. The analytical solutions of the Klein-Gordon equation have been approximated by the suggested numerical approaches. However, the arithmetic mean (AM) method has not been studied on the Klein-Gordon equation. In this study, a new proposed scheme has utilized central finite difference formula in time and space (CTCS) incorporated with AM formula averaging of functional values for approximating the solutions of the Klein-Gordon equation. Three-point AM is considered to a linear inhomogeneous Klein-Gordon equation. The theoretical aspects of the numerical scheme for the Klein-Gordon equation are also considered. The stability analysis is analyzed by using von Neumann stability analysis and Miller Norm Lemma. Graphical results verify the necessary conditions of Miller Norm Lemma. Good results obtained relate to the theoretical aspects of the numerical scheme. The numerical experiments are examined to verify the theoretical analysis. Comparative study shows the new CTCS scheme incorporated with three-point AM method produced better accuracy and shown its reliable and efficient over the standard CTCS scheme.
Frank, C; Weiss, H
1996-12-01
Using the example of the analysis of 6-year-old Erna, which extended over more than two years and was the longest treatment conducted by Melanie Klein in her Berlin years, the authors demonstrate the importance of her early child analyses for the development of some of her concepts and hence for a decisive advance in psychoanalysis itself. For this purpose they adduce unpublished original documents found among Klein's papers in London, which include autobiographical material, the text of her Würzburg lecture on her obsessional-neurotic little patient, handwritten session notes, and drawings by Erna herself. Although in the author's view Klein attempted to accommodate her findings within Freud's theoretical framework, her clinical experience of the psychic reality of the relational world of early oedipality eventually called for the introduction of new concepts. The combined parent figure, primary sadism, the paranoid-schizoid position, splitting, the relevance of the death drive to the superego, and later formulations on reparation, envy and gratitude are all shown to be foreshadowed in Klein's account of the treatment of Erna. After some retrospective considerations of Erna's analysis and a fleeting glimpse of Erna as an adult, the authors conclude by emphasising the significance of Klein's emigration to England for the subsequent flowering of her work.
Melanie Klein and Repression: an examination of some unpublished Notes of 1934.
Hinshelwood, R D
2006-01-01
Fifteen pages of unpublished Notes were found in the Melanie Klein Archives dating from early 1934, a crucial moment in Klein's development. She was at this time, 1934, moving away from child analysis, whilst also rethinking and revising her allegiance to Karl Abraham's theory of the phases of libidinal development. These Notes, entitled "Early Repression Mechanism," show Klein struggling to develop what became her characteristic theories of the depressive position and the paranoid-schizoid position. Although these Notes are precursors of the paper Klein gave later to the IPA Congress in 1934, they also show the origins of the emphasis she and her followers eventually gave to "splitting" rather than repression. The Notes give us an insight into the way that she worked clinically at the time. We see Klein's confidence develop as she diverged from the classical theories and technique. Her ideas were based on close attention to the detail of her clinical material, rather than attacking theoretical problems directly. The Notes show her method of struggling to her own conclusions, and they offer us a chance to grasp the roots of the subsequent controversy over Kleinian thought.
Rocamora, Rodrigo; Gil-Nagel, Antonio; Franch, Oriol; Vela-Bueno, Antonio
2010-11-01
Kleine-Levin syndrome and menstrual-related hypersomnia are rare idiopathic sleep disorders occurring primarily in adolescence. They are characterized by intermittent periods of excessive sleepiness, cognitive disturbances, and behavioral abnormalities. In both, the etiology remains unknown but autoinmune, hormonal, infectious, and inflammatory mechanisms have been proposed. The authors describe, for the first time, the association of Kleine-Levin syndrome and menstrual-related hypersomnia in 2 adolescent siblings who shared the human leukocyte antigen (HLA) loci DQB1*0501. The same haplotype has been associated with sleepwalking and with rapid eye movement (REM) sleep behavior disorder. This gender differences in the manifestation of a probably genetic influenced sleep disorder suggests that hormonal mechanisms could be implicated in the phenotypical expression of this sleep disorder. The male sibling with Kleine-Levin syndrome was easily controlled with carbamazepine in low doses, but his sister could be only efficaciously treated with oral contraceptives.
NASA Astrophysics Data System (ADS)
Bao, Zhi-qiang; Shi, Jun-jie; Zhang, Min
2013-05-01
The electronic structure and magnetic characteristics of Klein graphene nanoribbons (KGNRs), as observed by Suenaga and Koshino [K. Suenaga and M. Koshino, Nature 468, 1088 (2010)], are investigated using first-principles calculations. We find three new characteristics induced by the Klein boundary. First, the localized edge states in the KGNRs have a ferromagnetic coupling rather than the antiferromagnetic coupling of the zigzag graphene nanoribbons (ZGNRs). Lieb's theorem is no longer applicable in the KGNRs. Second, the marginal single carbon adatom of the ZGNRs can destroy the edge states nearby. The edge states can recover if the length of the zigzag chains is equal to or greater than five times that of the lattice constant. Finally, we show that the pentagon-heptagon edge can be induced from the Klein boundary.
Melanie Klein and Anna Freud: the discourse of the early dispute.
Viner, R
1996-01-01
Divisions in the field of the psychoanalysis of children can be traced to a dispute over the infantile super-ego between the theorists Melanie Klein and Anna Freud beginning in 1927. These divisions are understood within the analytic world as the result of scientific disputation between alternative valid theories. An examination of the language, claims, and epistemology of Klein's and Freud's publications in 1927 that marked the public commencement of the conflict, reveals a personalized discourse in which authority was derived from the allegiance, experience, and personal analytic standing of the contestants as much as from theoretical insight. The structure and rhetoric of the debate suggest that, rather than terminating the dispute, the publications of 1927 served to encourage professionalization in child analysis and establish Anna Freud and Melanie Klein as authoritative alternative theorists.
Chain recurrence in flows on the Klein bottle
NASA Astrophysics Data System (ADS)
Alexellis, Athanassios; Athanassopoulos, Konstantin
1999-07-01
In the classical Poincaré-Bendixson theory the object of study are the limit sets of a continuous flow on the 2-sphere S2 and the behaviour of the orbits near them (see [7, 9]). In [2] the second author proved that an assertion similar to the Poincaré-Bendixson theorem is true in the wider class of the 1-dimensional invariant (internally) chain recurrent continua of flows on S2. On the other hand, it is known that among the closed 2-manifolds, the 2-sphere S2, the projective plane RP2 and the Klein bottle K2 are the only ones for which the Poincaré-Bendixson theorem is true (see [1, 8, 11]).The motivation of the present paper was to examine to what extent the main results of [2] carry over to flows on RP2 and K2. A first attempt to study chain recurrent sets of flows on closed 2-manifolds other than the 2-sphere was [3]. As one expects, the results of [2] carry over easily to RP2, since chain recurrence behaves well with respect to regular covering maps of compact manifolds, as we show in Section 3. The situation with K2 is quite different, since it is doubly covered by the 2-torus T2, where we have no Poincaré-Bendixson theorem. Actually, the Poincaré-Bendixson theorem for 1-dimensional invariant chain recurrent continua of flows on K2 is not true. For example, identifying suitably the boundary periodic orbits of a 2-dimensional Reeb flow on a closed annulus (see [7, chapter III, 2·6]) we get a flow on K2 with a 1-dimensional invariant chain recurrent continuum consisting of the unique periodic orbit and another orbit, which spirals against it in positive and negative time. As we prove in Theorem 4·4, this situation, or concatenations of it, is the only one where the Poincaré-Bendixson theorem for 1-dimensional invariant chain recurrent continua of flows on K2 is not true. Then, we are concerned with the topological structure of the 1-dimensional chain components of a flow on K2 with finitely many singularities. In Proposition 4·6 we find when such a set
Group invariant transformations for the Klein-Gordon equation in three dimensional flat spaces
NASA Astrophysics Data System (ADS)
Jamal, Sameerah; Paliathanasis, Andronikos
2017-07-01
We perform the complete symmetry classification of the Klein-Gordon equation in maximal symmetric spacetimes. The central idea is to find all possible potential functions V(t , x , y) that admit Lie and Noether symmetries. This is done by using the relation between the symmetry vectors of the differential equations and the elements of the conformal algebra of the underlying geometry. For some of the potentials, we use the admitted Lie algebras to determine corresponding invariant solutions to the Klein-Gordon equation. An integral part of this analysis is the problem of the classification of Lie and Noether point symmetries of the wave equation.
Hydrodynamic representation of the Klein-Gordon-Einstein equations in the weak field limit
NASA Astrophysics Data System (ADS)
Suárez, Abril; Chavanis, Pierre-Henri
2015-11-01
Using a generalization of the Madelung transformation, we derive the hydrodynamic representation of the Klein-Gordon-Einstein equations in the weak field limit. We consider a complex self-interacting scalar field with an arbitrary potential of the form V(|ϕ|2). We compare the results with simplified models in which the gravitational potential is introduced by hand in the Klein-Gordon equation, and assumed to satisfy a (generalized) Poisson equation. Nonrelativistic hydrodynamic equations based on the Schrodinger-Poisson equations or on the Gross-Pitaevskii-Poisson equations are recovered in the limit c → +∞.
Dimer statistics of honeycomb lattices on Klein bottle, Möbius strip and cylinder
NASA Astrophysics Data System (ADS)
Li, Wei; Zhang, Heping
2012-08-01
Dimer statistics is a central problem in statistical physics. In this paper the enumerations of close-packed dimers of honeycomb lattices on Klein bottle, Möbius strip and cylinder are considered. By establishing a Pfaffian orientation or a crossing orientation, and then computing the determinants of the skew-symmetric matrices of the resulting orientation graphs, we obtain explicit expressions of the number of close-packed dimers of the Klein-bottle polyhex, the Möbius polyhex and the cylindrical polyhex.
Abelian Yang-Mills Theory on Real Tori and Theta Divisors of Klein Surfaces
NASA Astrophysics Data System (ADS)
Okonek, Christian; Teleman, Andrei
2013-11-01
The purpose of this paper is to compute determinant index bundles of certain families of Real Dirac type operators on Klein surfaces as elements in the corresponding Grothendieck group of Real line bundles in the sense of Atiyah. On a Klein surface these determinant index bundles have a natural holomorphic description as theta line bundles. In particular we compute the first Stiefel-Whitney classes of the corresponding fixed point bundles on the real part of the Picard torus. The computation of these classes is important, because they control to a large extent the orientability of certain moduli spaces in Real gauge theory and Real algebraic geometry.
Between practice and theory: Melanie Klein, Anna Freud and the development of child analysis.
Donaldson, G
1996-04-01
An examination of the early history of child analysis in the writings of Melanie Klein and Anna Freud reveals how two different and opposing approaches to child analysis arose at the same time. The two methods of child analysis are rooted in a differential emphasis on psychoanalytic theory and practice. The Kleinian method derives from the application of technique while the Anna Freudian method is driven by theory. Furthermore, by holding to the Freudian theory of child development Anna Freud was forced to limit the scope of child analysis, while Klein's application of Freudian practice has led to new discoveries about the development of the infant psyche.
Verification of Compton Collision and Klein-Nishina Formulas--An Undergraduate Laboratory Experiment
ERIC Educational Resources Information Center
Singhal, R. P.; Burns, A. J.
1978-01-01
Describes an experiment to verify the Compton collision formula and the angular dependance of the Klein-Nishina formula. Equipment used is a 1-mCi(137)Cs source, 2x2 in. NaI detector and a multichannel analyzer. Suitable for honor undergraduates. (Author/GA)
On 'the fear of death' as the primary anxiety: how and why Klein differs from Freud.
Blass, Rachel B
2014-08-01
It is well known that Melanie Klein held the view that 'fear of death' is the primary source of anxiety and that her position is explicitly opposed to that of Sigmund Freud, who maintained that that fear cannot in any way or form be a source of anxiety. In a previous article on Freud's Inhibitions, Symptoms and Anxiety (Blass, 2013), the author argued that, counter to what is commonly portrayed in the literature, Freud's considerations for rejecting the fear of death as a source of anxiety were based on relational and experiential factors that are usually associated with Kleinian psychoanalysis. In light of this affinity of Freud with Klein a question arises as to the actual source of their differences in this context. The present paper offers an answer to this question. The author first presents some of her earlier findings on what led Freud to reject the fear of death as a source of anxiety and then turns to investigate Klein's considerations for accepting it. This takes us beyond her explicit statements on this matter and sheds new light on the relationship of her views regarding death and anxiety and those of Freud. In turn this deepens the understanding of the relationship of Freud and Klein's conceptualizations of the psyche and its internal object relations, pointing to both surprising common ground and foundational differences. Copyright © 2014 Institute of Psychoanalysis.
Verification of Compton Collision and Klein-Nishina Formulas--An Undergraduate Laboratory Experiment
ERIC Educational Resources Information Center
Singhal, R. P.; Burns, A. J.
1978-01-01
Describes an experiment to verify the Compton collision formula and the angular dependance of the Klein-Nishina formula. Equipment used is a 1-mCi(137)Cs source, 2x2 in. NaI detector and a multichannel analyzer. Suitable for honor undergraduates. (Author/GA)
Noncommutative Integrability of the Klein-Gordon and Dirac Equations in (2+1)-Dimensional Spacetime
NASA Astrophysics Data System (ADS)
Breev, A. I.; Shapovalov, A. V.
2017-03-01
Noncommutative integration of the Klein-Gordon and Dirac relativistic wave equations in (2+1)-dimensional Minkowski space is considered. It is shown that for all non-Abelian subalgebras of the (2+1)-dimensional Poincaré algebra the condition of noncommutative integrability is satisfied.
Migraine with brainstem aura presenting as recurrent hypersomnia (Kleine-Levin syndrome).
Nesbitt, Alexander D; Leschziner, Guy D
2016-10-01
Recurrent hypersomnia, or Kleine-Levin syndrome, is rare and frequently causes substantial diagnostic anxiety and delay. Patients often undergo multiple investigations to rule out other causes of encephalopathy. The treatment options are unsatisfactory. Migraine with brainstem aura has not previously been widely considered in the medical literature as a differential diagnosis. We describe two patients referred to a tertiary sleep neurology service with a putative diagnosis of Kleine-Levin syndrome. Each described attacks of hypersomnia with elements of migraine with brainstem aura, in addition to having a history of migraine with aura. Simple acute migraine treatment clearly attenuated further attacks. These cases generate discussion as to the common features and potential mechanisms underlying both disorders. Furthermore, they highlight a hitherto underexplored alternative diagnosis of Kleine-Levin syndrome. This provides scope for offering established and effective migraine treatment options to patients who with a potential misdiagnosis of Kleine-Levin syndrome, providing scope for offering established and effective migraine treatment to some patients originally diagnosed with a rare condition for which there is no current consistently effective therapeutic options. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
All but Her Life: Holocaust Survivor Gerda Klein Shares with Learners
ERIC Educational Resources Information Center
Lincoln, Margaret
2007-01-01
During the 2006-2007 school year, students from Battle Creek, Michigan, high school joined numerous others from across the state in reading holocaust survivor Gerda Klein's memoir, "All But My Life." Published in 57 editions and still in print after 50 years, the book is the inspiring account of a remarkable individual who endured unspeakable…
What Do Klein et al. Tell Us about Test Scores in Texas?
ERIC Educational Resources Information Center
Toenjes, Laurence A.
2005-01-01
A paper appearing in this journal by Klein, Hamilton, McCaffrey and Stecher (2000) attempted to raise serious questions about the validity of the gains in student performance as measured by Texas' standardized test, the Texas Assessment of Academic Skills (TAAS). Part of their analysis was based on the results of three tests which they…
All but Her Life: Holocaust Survivor Gerda Klein Shares with Learners
ERIC Educational Resources Information Center
Lincoln, Margaret
2007-01-01
During the 2006-2007 school year, students from Battle Creek, Michigan, high school joined numerous others from across the state in reading holocaust survivor Gerda Klein's memoir, "All But My Life." Published in 57 editions and still in print after 50 years, the book is the inspiring account of a remarkable individual who endured unspeakable…
Stability of Schwarzschild-AdS for the Spherically Symmetric Einstein-Klein-Gordon System
NASA Astrophysics Data System (ADS)
Holzegel, Gustav; Smulevici, Jacques
2013-01-01
In this paper, we study the global behavior of solutions to the spherically symmetric coupled Einstein-Klein-Gordon (EKG) system in the presence of a negative cosmological constant. For the Klein-Gordon mass-squared satisfying a ≥ -1 (the Breitenlohner-Freedman bound being a > -9/8), we prove that the Schwarzschild-AdS spacetimes are asymptotically stable: Small perturbations of Schwarzschild-AdS initial data again lead to regular black holes, with the metric on the black hole exterior approaching, at an exponential rate, a Schwarzschild-AdS spacetime. The main difficulties in the proof arise from the lack of monotonicity for the Hawking mass and the asymptotically AdS boundary conditions, which render even (part of) the orbital stability intricate. These issues are resolved in a bootstrap argument on the black hole exterior, with the redshift effect and weighted Hardy inequalities playing the fundamental role in the analysis. Both integrated decay and pointwise decay estimates are obtained. As a corollary of our estimates on the Klein-Gordon field, one obtains in particular exponential decay in time of spherically-symmetric solutions to the linear Klein-Gordon equation on Schwarzschild-AdS.
Response to "What Do Klein et al. Tell Us about Test Scores in Texas?"
ERIC Educational Resources Information Center
Klein, Stephen P.; Hamilton, Laura S.; McCaffrey, Daniel F.; Stecher, Brian M.
2005-01-01
The authors reviewed the article "What Do Klein et al. Tell Us About Test Scores in Texas?" by Toenjes. A summary of their responses is presented. First, Toenjes incorrectly describes the focus of the authors' study. Second, Toenjes appears to have misunderstood the purpose of their 20-schools analysis. Third, Toenjes misunderstands the…
The statistical properties of Klein-Gordon oscillator in noncommutative space
Hassanabadi, H. Hosseini, S. S.; Boumali, A.; Zarrinkamar, S.
2014-03-15
We study the relativistic spin-zero bosons influenced by the Klein-Gordon oscillator and an external magnetic field in noncommutative formulation. The problem is considered in two dimensions and is solved in an exact analytical manner. Having found the spectrum of the system, the statistical properties of an N-boson system are reported.
Group classification and conservation laws of the generalized Klein-Gordon-Fock equation
NASA Astrophysics Data System (ADS)
Muatjetjeja, B.
2016-08-01
In the present paper, we perform Lie and Noether symmetries of the generalized Klein-Gordon-Fock equation. It is shown that the principal Lie algebra, which is one-dimensional, has several possible extensions. It is further shown that several cases arise for which Noether symmetries exist. Exact solutions for some cases are also obtained from the invariant solutions of the investigated equation.
Scattering theory for the Klein-Gordon equation with nondecreasing potentials
Cruz, Maximino; Arredondo R, Juan H.
2008-11-15
The Klein-Gordon equation is considered in the case of nondecreasing potentials. The energy inner product is nonpositive on a subspace of infinite dimension, not consisting entirely of eigenvectors of the associated operator. A scattering theory for this case is developed and asymptotic completeness for generalized Moeller operators is proven.
The statistical properties of Klein-Gordon oscillator in noncommutative space
Hassanabadi, H. Hosseini, S. S.; Boumali, A.; Zarrinkamar, S.
2014-03-15
We study the relativistic spin-zero bosons influenced by the Klein-Gordon oscillator and an external magnetic field in noncommutative formulation. The problem is considered in two dimensions and is solved in an exact analytical manner. Having found the spectrum of the system, the statistical properties of an N-boson system are reported.
Patronage in the dispute over child analysis between Melanie Klein and Anna Freud--1927-1932.
Aguayo, J
2000-08-01
The author investigates the role of patrons and advocates for Melanie Klein's clinical ideas at the British Psycho-Analytical Society against the backdrop of her theoretical and technical differences with Anna Freud from 1927 to 1932. He also outlines the development of Klein and Anna Freud's theories and techniques within the nascent discipline of child psychoanalysis. The London and Viennese patrons/advocates contributed to polarising what initially were clinical differences about how to analyse pre-latency and latency-age children and which technical processes might best facilitate successful treatment. While the author speculates that a diversity of motivations and agendas may have driven the London group's support for Klein--personal and politicised enthusiasm (Jones), genuine conviction (Riviere) and attempts at theoretical rapprochement between the London and Vienna schools (Glover)--he also argues that Freud's diagnosis with cancer in 1923 and suspicion of patricidal son-successors necessitated the choice of a female successor with unquestioning loyalty to his doctrines. From 1932, when Klein's clinical authority was established, her first group of English supporters began to splinter, as she went on to become a training analyst, mentor and patron in her own right to a succeeding generation of adherents who defended her views during the Controversial Discussions.
Potential magnetic properties of nanotubes ( n, 0) with Klein and Fujita edges
NASA Astrophysics Data System (ADS)
Luhavaya, H. M.; Pavlov, M. V.; Ermilov, A. Yu.; Stepanov, N. F.
2012-08-01
Analytical solutions for localized states of zigzag-type nanotube (NT) fragments with various combinations of Klein and Fujita borders are considered using the Hückel approach. It is shown that the equations for determining molecular orbitals (MOs) in systems with two Klein edges are similar to equations for systems with two Fujita edges. An analytical formula for the energies of all π MOs is obtained for systems that have a Klein edge on one side and a Fujita edge on the other. It is established that these systems have n orbitals with energy α that are localized on the Fujita and Klein edges in dependence on the MO symmetry. The degeneracy of edge orbitals indicates that there is a tendency toward single occupancy of them and to the appearance of spin (magnetic) properties. In addition, the energies of the states of different multiplicity for NT fragments (8, 0) are calculated using the CASSCF approach. It is shown that the ground state has a multiplicity of 9, as was also indicated by estimates obtained using the density functional method (B3LYP). It is concluded that zigzag-type NTs with asymmetric edges have a tendency to exhibit spin properties. It is noted that the construction of nanoscale magnetic materials based on them is very promising.
Chacko, Z.; Graesser, M.L.; Grojean, C.; Pilo, L.
2003-12-11
At present no theory of a massive graviton is known that is consistent with experiments at both long and short distances. The problem is that consistency with long distance experiments requires the graviton mass to be very small. Such a small graviton mass however implies an ultraviolet cutoff for the theory at length scales far larger than the millimeter scale at which gravity has already been measured. In this paper we attempt to construct a model which avoids this problem. We consider a brane world setup in warped AdS spacetime and we investigate the consequences of writing a mass term for the graviton on a the infrared brane where the local cutoff is of order a large (galactic) distance scale. The advantage of this setup is that the low cutoff for physics on the infrared brane does not significantly affect the predictivity of the theory for observers localized on the ultraviolet brane. For such observers the predictions of this theory agree with general relativity at distances smaller than the infrared scale but go over to those of a theory of massive gravity at longer distances. A careful analysis of the graviton two-point function, however, reveals the presence of a ghost in the low energy spectrum. A mode decomposition of the higher dimensional theory reveals that the ghost corresponds to the radion field. We also investigate the theory with a brane localized mass for the graviton on the ultraviolet brane, and show that the physics of this case is similar to that of a conventional four dimensional theory with a massive graviton, but with one important difference: when the infrared brane decouples and the would-be massive graviton gets heavier than the regular Kaluza-Klein modes, it becomes unstable and it has a finite width to decay off the brane into the continuum of Kaluza-Klein states.
Kovalyov, Mikhail
2010-06-15
In this article the sets of solutions of the sine-Gordon equation and its linearization the Klein-Gordon equation are discussed and compared. It is shown that the set of solutions of the sine-Gordon equation possesses a richer structure which partly disappears during linearization. Just like the solutions of the Klein-Gordon equation satisfy the linear superposition principle, the solutions of the sine-Gordon equation satisfy a nonlinear superposition principle.
NASA Astrophysics Data System (ADS)
Zhang, Jinliang; Hu, Wuqiang; Ma, Yu
2016-12-01
In this paper, the famous Klein-Gordon-Zakharov equations are firstly generalized, the new special types of Klein-Gordon-Zakharov equations with the positive fractional power terms (gKGZE) are presented. In order to derive the exact solutions of new special gKGZE, the subsidiary higher order ordinary differential equations (sub-ODEs) with the positive fractional power terms are introduced, and with the aids of the Sub-ODE, the exact solutions of three special types of the gKGZE are derived, which are the bell-type solitary wave solution, the algebraic solitary wave solution, the kink-type solitary wave solution and the sinusoidal traveling wave solution, provided that the coefficients of gKGZE satisfy certain constraint conditions.
Modification to the Klein-Nishina cross section for Ge electrons at high statistics limit
Wang, T.F.
1995-11-03
Modification factors for the Klein-Nishina cross-sections for gamma-ray with energies between 50 keV and 250 keV incident on Ge electrons have been obtained at the high statistics limit. In this limit, the Ge electrons can then be treated as they are obtained from the self-consistent augmented plane wave calculations, without considering the orientation of crystal lattice with respect to incident photons. The kinematics corrections (i.e. outgoing momenta), on the other hand, have to be taken into account on an event by event basis. Even so, the computing time has been reduced dramatically since the relativistic calculation of the modifications to the Klein-Nishina cross sections is the most tedious one. The modification factors are almost linear with respect to incident photon energy in the interesting energy range with respect to a given photon outgoing angle.
Inhibiting Klein Tunneling in a Graphene p -n Junction without an External Magnetic Field
NASA Astrophysics Data System (ADS)
Oh, Hyungju; Coh, Sinisa; Son, Young-Woo; Cohen, Marvin L.
2016-07-01
We study by first-principles calculations a densely packed island of organic molecules (F4TCNQ ) adsorbed on graphene. We find that with electron doping the island naturally forms a p -n junction in the graphene sheet. For example, a doping level of ˜3 ×1013 electrons per cm2 results in a p -n junction with an 800 meV electrostatic potential barrier. Unlike in a conventional p -n junction in graphene, in the case of the junction formed by an adsorbed organic molecular island we expect that the Klein tunneling is inhibited, even without an applied external magnetic field. Here Klein tunneling is inhibited by the ferromagnetic order that spontaneously occurs in the molecular island upon doping. We estimate that the magnetic barrier in the graphene sheet is around 10 mT.
Klein's Fundamental 2-Form of Second Kind for the Cab Curves
NASA Astrophysics Data System (ADS)
Suzuki, Joe
2017-03-01
In this paper, we derive the exact formula of Klein's fundamental 2-form of second kind for the so-called C_{ab} curves. The problem was initially solved by Klein in the 19th century for the hyper-elliptic curves, but little progress had been seen for its extension for more than 100 years. Recently, it has been addressed by several authors, and was solved for subclasses of the C_{ab} curves whereas they found a way to find its individual solution numerically. The formula gives a standard cohomological basis for the curves, and has many applications in algebraic geometry, physics, and applied mathematics, not just analyzing sigma functions in a general way.
Klein tunnelling and electron trapping in nanometre-scale graphene quantum dots
NASA Astrophysics Data System (ADS)
Gutiérrez, Christopher; Brown, Lola; Kim, Cheol-Joo; Park, Jiwoong; Pasupathy, Abhay N.
2016-11-01
Relativistic fermions that are incident on a high potential barrier can pass through unimpeded, a striking phenomenon termed the `Klein paradox’ in quantum electrodynamics. Electrostatic potential barriers in graphene provide a solid-state analogue to realize this phenomenon. Here, we use scanning tunnelling microscopy to directly probe the transmission of electrons through sharp circular potential wells in graphene created by substrate engineering. We find that electrons in this geometry display quasi-bound states where the electron is trapped for a finite time before escaping via Klein tunnelling. We show that the continuum Dirac equation can be successfully used to model the energies and wavefunctions of these quasi-bound states down to atomic dimensions. We demonstrate that by tuning the geometry of the barrier it is possible to trap particular energies and angular momentum states with increased efficiency, showing that atomic-scale electrostatic potentials can be used to engineer quantum transport through graphene.
Dirac and Klein-Gordon particles in one-dimensional periodic potentials
NASA Astrophysics Data System (ADS)
Barbier, Michaël; Peeters, F. M.; Vasilopoulos, P.; Pereira, J. Milton, Jr.
2008-03-01
We evaluate the dispersion relation for massless fermions, described by the Dirac equation, and for zero-spin bosons, described by the Klein-Gordon equation, moving in two dimensions and in the presence of a one-dimensional periodic potential. For massless fermions, the dispersion relation shows a zero gap for carriers with zero momentum in the direction parallel to the barriers in agreement with the well-known “Klein paradox.” Numerical results for the energy spectrum and the density of states are presented. Those for fermions are appropriate to graphene in which carriers behave relativistically with the “light speed” replaced by the Fermi velocity. In addition, we evaluate the transmission through a finite number of barriers for fermions and zero-spin bosons and relate it with that through a superlattice.
Theories on anxiety in Freud and Melanie Klein. Their metapsychological status.
De Bianchedi, E T; Scalozub De Boschan, L; De Cortiñas, L P; De Piccolo, E G
1988-01-01
This paper presents a comparative study of the theories on anxiety formulated by Freud and Melanie Klein, with particular emphasis on the questions of its origin, its meaning for the individual and its function in both theoretical systems. The purpose of this comparative analysis is to offer an instrument which helps frame the theoretical discussions in psychoanalysis in an epistemological context. The authors hold that for Freud anxiety is considered as one more amongst the various manifestations of mental life, which his general theories try to explain, whereas for Melanie Klein anxiety and its destinies occupies a central place in her theories on mental functioning. The differences in both theories, which the authors of this paper describe, especially as to origin, function and meaning of anxiety, respond partially to the different metapsychological points of view with which both authors focus mental life--points of view which they have themselves investigated in a previous paper.
Nonlinear self-adjointness and conservation laws of Klein-Gordon-Fock equation with central symmetry
NASA Astrophysics Data System (ADS)
Abdulwahhab, Muhammad Alim
2015-05-01
The concept of nonlinear self-adjointness, introduced by Ibragimov, has significantly extends approaches to constructing conservation laws associated with symmetries since it incorporates the strict self-adjointness, the quasi self-adjointness as well as the usual linear self-adjointness. Using this concept, the nonlinear self-adjointness condition for the Klein-Gordon-Fock equation was established and subsequently used to construct simplified but infinitely many nontrivial and independent conserved vectors. The Noether's theorem was further applied to the Klein-Gordon-Fock equation to explore more distinct first integrals, result shows that conservation laws constructed through this approach are exactly the same as those obtained under strict self-adjointness of Ibragimov's method.
Post, Gloria B; Stern, Alan H
2006-10-01
The recent article by Costa and Klein (2006) contains several inaccuracies about the federal drinking water standard for chromium. The federal drinking water standard for chromium is 100 ppb, not 50 ppb as stated by Costa and Klein, and it is based on non-carcinogenic effects, not a one in one million cancer risk level. The question of whether or not hexavalent chromium is carcinogenic via the oral route is the focus of much current interest and has major implications for regulation of chromium in drinking water and soil. The chronic drinking water study of hexavalent chromium currently being conducted by the National Toxicology Program will provide further information that will be useful in addressing this question.
Dark soliton solutions of Klein-Gordon-Zakharov equation in (1+2) dimensions
NASA Astrophysics Data System (ADS)
Demiray, Seyma Tuluce; Bulut, Hasan
2017-01-01
This study base on dark soliton solutions of Klein-Gordon-Zakharov (KGZ) equation in (1+2) dimensions. The generalized Kudryashov method (GKM) which is one of the analytical methods has been handled for finding exact solutions of KGZ equation in (1+2) dimensions. By using this method, dark soliton solutions of this equation have been obtained. Also, by using Mathematica Release 9, some graphical simulations were done to see the behavior of these solutions.
Deep-water sponges (Porifera) from Bonaire and Klein Curaçao, Southern Caribbean.
Van Soest, Rob W M; Meesters, Erik H W G; Becking, Leontine E
2014-10-29
Four submersible dives off the coast of Bonaire (Caribbean Netherlands) and Klein Curaçao (Curaçao) to depths of 99.5-242 m, covering lower mesophotic and upper dysphotic zones, yielded 52 sponge specimens belonging to 31 species. Among these we identified 13 species as new to science. These are Plakinastrella stinapa n. sp., Pachastrella pacoi n. sp., Characella pachastrelloides n. sp., Geodia curacaoensis n. sp., Caminus carmabi n. sp., Discodermia adhaerens n. sp., Clathria (Microciona) acarnoides n. sp., Antho (Acarnia) pellita n. sp., Parahigginsia strongylifera n. sp., Calyx magnoculata n. sp., Neopetrosia dutchi n. sp., Neopetrosia ovata n. sp. and Neopetrosia eurystomata n. sp. We also report an euretid hexactinellid, which belongs to the rare genus Verrucocoeloidea, recently described (2014) as V. liberatorii Reiswig & Dohrmann. The remaining 18 already known species are all illustrated by photos of the habit, either in situ or 'on deck', but only briefly characterized in an annotated table to confirm their occurrence in the Southern Caribbean. The habitat investigated-steep limestone rocks, likely representing Pleistocene fossil reefs--is similar to deep-water fossil reefs at Barbados of which the sponges were sampled and studied by Van Soest and Stentoft (1988). A comparison is made between the two localities, showing a high degree of similarity in sponge composition: 53% of the present Bonaire-Klein Curaçao species were also retrieved at Barbados. At the level of higher taxa (genera, families) Bonaire-Klein Curaçao shared approximately 80% of its lower mesophotic and upper dysphotic sponge fauna with Barbados, despite a distance between them of 1000 km, indicating high faunal homogeneity. We also preliminarily compared the shallow-water (euphotic) sponge fauna of Curaçao with the combined data available for the Barbados, Bonaire and Klein Curaçao mesophotic and upper dysphotic sponges, which resulted in the conclusion that the two faunas show only
Generalized Klein-Gordon and Dirac Equations from Nonlocal Kinetic Approach
NASA Astrophysics Data System (ADS)
El-Nabulsi, Rami Ahmad
2016-09-01
In this note, I generalized the Klein-Gordon and the Dirac equations by using Suykens's nonlocal-in-time kinetic energy approach, which is motivated from Feynman's kinetic energy functional formalism where the position differences are shifted with respect to one another. I proved that these generalized equations are similar to those obtained in literature in the presence of minimal length based on the Quesne-Tkachuk algebra.
Statistical aspects of the Klein-Gordon oscillator in the frame work of GUP
NASA Astrophysics Data System (ADS)
Khosropour, B.
2017-07-01
Investigation in perturbative string theory and quantum gravity suggest that there is a measurable minimal length in nature. In this work, according to generalized uncertainty principle, we study the statistical characteristics of Klein-Gordon Oscillator (KLO). The modified energy spectrum of the KLO are obtained. The generalized thermodynamical quantities of the KLO such as partition function, mean energy and entropy are calculated by using the modified energy spectrum.
Solutions to the 1d Klein Gordon equation with cut-off Coulomb potentials
NASA Astrophysics Data System (ADS)
Hall, Richard L.
2007-12-01
In a recent paper by Barton [G. Barton, J. Phys. A: Math. Gen. 40 (2007) 1011], the 1-dimensional Klein Gordon equation was solved analytically for the non-singular Coulomb-like potential V(|x|)=-α/(|x|+a). In the present Letter, these results are completely confirmed by a numerical formulation that also allows a solution for an alternative cut-off Coulomb potential V(|x|)=-α/|x|, |x|>a, and otherwise V(|x|)=-α/a.
Klein-Gordon equations for energy-momentum of the relativistic particle in rapidity space
Yamaleev, R. M.
2013-10-15
The notion of four-rapidity is defined as a four-vector with one time-like and three space-like coordinates. It is proved, the energy and momentum defined in the space of four-rapidity obey Klein-Gordon equations constrained by the classical trajectory of a relativistic particle. It is shown, for small values of a proper mass influence of the constraint is weakened and the classical motion gains features of a wave motion.
Klein tunneling in carbon nanostructures: A free-particle dynamics in disguise
Jakubsky, Vit; Nieto, Luis-Miguel; Plyushchay, Mikhail S.
2011-02-15
The absence of backscattering in metallic nanotubes as well as perfect Klein tunneling in potential barriers in graphene are the prominent electronic characteristics of carbon nanostructures. We show that the phenomena can be explained by a peculiar supersymmetry generated by a first order Hamiltonian and zero-order supercharge operators. Like the supersymmetry associated with second order reflectionless finite-gap systems, it relates here the low-energy behavior of the charge carriers with the free-particle dynamics.
Kramers' escape problem for fractional Klein-Kramers equation with tempered α-stable waiting times.
Gajda, Janusz; Magdziarz, Marcin
2011-08-01
In this paper we extend the subdiffusive Klein-Kramers model, in which the waiting times are modeled by the α-stable laws, to the case of waiting times belonging to the class of tempered α-stable distributions. We introduce a generalized version of the Klein-Kramers equation, in which the fractional Riemman-Liouville derivative is replaced with a more general integro-differential operator. This allows a transition from the initial subdiffusive character of motion to the standard diffusion for long times to be modeled. Taking advantage of the corresponding Langevin equation, we study some properties of the tempered dynamics, in particular, we approximate solutions of the tempered Klein-Kramers equation via Monte Carlo methods. Also, we study the distribution of the escape time from the potential well and compare it to the classical results in the Kramers escape theory. Finally, we derive the analytical formula for the first-passage-time distribution for the case of free particles. We show that the well-known Sparre Andersen scaling holds also for the tempered subdiffusion.
The "new" democratic woman of modernity: Georgia O'Keeffe and Melanie Klein.
Gadt, J C
1994-06-01
O'Keeffe put into visual language the psychic splitting that had occurred between the sexes in the United States, attempting to integrate what had formerly been separated as feminine and masculine into the female psyche. In her most important contribution, she explored presence rather than absence and opened up possibilities for thinking about openings. The concept of the female opening in particular had heretofore been assigned a negative meaning, signifying more often than not a gaping wound rather than a space and place of possibilities. Klein's complex and evocative understanding of some of the earliest mental processes of life enabled researchers to delve into the meanings made of the presence of the mother and father and baby, in the context of the baby's body-mind. Klein's female or male baby desires to know from the beginning. She discovered splitting and projective identification, the development of anxiety and guilt under the aegis of these mental processes, the multiple meanings of aggression, and, significantly, she permitted the female baby's body to have its own language. The answers provided by O'Keeffe and Klein bequeathed new possibilities for women's self-invention and remain pivot points for female identity throughout the century, to be confronted again by the second wave of feminism beginning in the late 1960s, by "postfeminist" debates, and by a challenged psychoanalysis. A more careful probing of these issues may help us to better understand our past so as to have greater resources for a more comprehensive reading of our present.
The life and work of Melanie Klein in the British Psycho-Analytical Society.
King, P H
1983-01-01
This paper describes certain aspects of the life and work of Melanie Klein in the British Psycho-Analytical Society. It attempts to highlight the reciprocity of the relationship between Melanie Klein and other members of that Society by showing how the climate of psychoanalytical opinion that was prevalent among members of that Society during the first decade of her stay in London, and which encouraged discussion of clinical work and interest in psychoanalytical discovery, provided a congenial setting for her to become firmly established as an active member of the British Society and to continue her contributions to psychoanalytic theory and clinical expertise. The paper also traces the development of Melanie Klein's main theoretical contributions, together with relevant criticisms of them as they emerged, against the background of the history of the British Psycho-Analytical Society. It describes the controversies that arose as to whether or not her ideas could properly be viewed within the framework of psychoanalytic theory, as formulated by Freud, and the attempted resolution of these controversies, together with some comments on the repercussions of these theoretical disagreements on relationships within the Society. An extensive list of references is included to facilitate a more detailed study of the subject.
NASA Astrophysics Data System (ADS)
Encinas, A. H.; Gayoso-Martínez, V.; Martín Del Rey, A.; Martín-Vaquero, J.; Queiruga-Dios, A.
2016-03-01
In this paper, we discuss the problem of solving nonlinear Klein-Gordon equations (KGEs), which are especially useful to model nonlinear phenomena. In order to obtain more exact solutions, we have derived different fourth- and sixth-order, stable explicit and implicit finite difference schemes for some of the best known nonlinear KGEs. These new higher-order methods allow a reduction in the number of nodes, which is necessary to solve multi-dimensional KGEs. Moreover, we describe how higher-order stable algorithms can be constructed in a similar way following the proposed procedures. For the considered equations, the stability and consistency of the proposed schemes are studied under certain smoothness conditions of the solutions. In addition to that, we present experimental results obtained from numerical methods that illustrate the efficiency of the new algorithms, their stability, and their convergence rate.
Black hole as a point radiator and recoil effect on the brane world.
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.
A Deconstruction Lattice Description of the D1/D5 Brane World-Volume Gauge Theory
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
Phantomlike behavior in a brane-world model with curvature effects
Bouhmadi-Lopez, Mariam; Moniz, Paulo Vargas
2008-10-15
Recent observational evidence seems to allow the possibility that our Universe may currently be under a dark energy effect of a phantom nature. A suitable effective phantom fluid behavior can emerge in brane cosmology; in particular, within the normal non-self-accelerating Dvali-Gabadadze-Porrati branch, without any exotic matter and due to curvature effects from induced gravity. The phantomlike behavior is based in defining an effective energy density that grows as the brane expands. This effective description breaks down at some point in the past when the effective energy density becomes negative and the effective equation of state parameter blows up. In this paper we investigate if the phantomlike regime can be enlarged by the inclusion of a Gauss-Bonnet (GB) term into the bulk. The motivation is that such a GB component would model additional curvature effects on the brane setting. More precisely, our aim is to determine if the GB term, dominating and modifying the early behavior of the brane universe, may eventually extend the regime of validity of the phantom mimicry on the brane. However, we show that the opposite occurs: the GB effect seems instead to induce a breakdown of the phantomlike behavior at an even smaller redshift.
Higher-dimensional bulk wormholes and their manifestations in brane worlds
Rodrigo, Enrico
2006-11-15
There is nothing to prevent a higher-dimensional anti-de Sitter bulk spacetime from containing various other branes in addition to hosting our universe, presumed to be a positive-tension 3-brane. In particular, it could contain closed, microscopic branes that form the boundary surfaces of void bubbles and thus violate the null energy condition in the bulk. The possible existence of such micro branes can be investigated by considering the properties of the ground state of a pseudo-Wheeler-DeWitt equation describing brane quantum dynamics in minisuperspace. If they exist, a concentration of these micro branes could act as a fluid of exotic matter able to support macroscopic wormholes connecting otherwise-distant regions of the bulk. Were the brane constituting our universe to expand into a region of the bulk containing such higher-dimensional macroscopic wormholes, they would likely manifest themselves in our brane as wormholes of normal dimensionality, whose spontaneous appearance and general dynamics would seem inexplicably peculiar. This encounter could also result in the formation of baby universes of a particular type.
The Dirac-ADM Quantization of the Brane-World Gravity
NASA Astrophysics Data System (ADS)
Maia, M. D.; Fernandes, M. C. B.
The ADM canonical formulation of the gravitational field is extended to four-dimensional space-times embedded in a higher-dimensional bulk space. The embedding is justified as a means to remove the ambiguity of the Riemann curvature. Using Nash's perturbative embedding theorem, we derive a simple generalization of the ADM canonical structure without breaking the diffeomorphism invariance and with a non-vanishing Hamiltonian. Nash's perturbations also allows us to define the functional derivative in Schwinger's equation, leading to a Schrödinger-like quantum equation describing the wave function of the embedded space-time.
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.
Stability of the graviton Bose-Einstein condensate in the brane-world
NASA Astrophysics Data System (ADS)
Casadio, Roberto; da Rocha, Roldão
2016-12-01
We consider a solution of the effective four-dimensional Einstein equations, obtained from the general relativistic Schwarzschild metric through the principle of Minimal Geometric Deformation (MGD). Since the brane tension can, in general, introduce new singularities on a relativistic Eötvös brane model in the MGD framework, we require the absence of observed singularities, in order to constrain the brane tension. We then study the corresponding Bose-Einstein condensate (BEC) gravitational system and determine the critical stability region of BEC MGD stellar configurations. Finally, the critical stellar densities are shown to be related with critical points of the information entropy.
NASA Astrophysics Data System (ADS)
Droz-Vincent, Philippe
2001-01-01
In order to reduce the Klein-Gordon equation (with minimal coupling), we introduce a generalization of the so-called `mode solutions' that are well known in the special case of a Robertson-Walker universe. After separation of the variables, we end up with a partial differential equation in lower dimension. A reduced version of the Gordon current arises and is conserved. When the first factor-manifold is Lorentzian, distinct modes appear as orthogonal in the sense of the sesquilinear form associated with the Gordon current. Moreover, a sesquilinear form is defined on the space of solutions to the reduced equation. Extension of this picture to curvature coupling is possible when the second factor manifold is of constant scalar curvature.
Dark energy and the hierarchy problem
NASA Astrophysics Data System (ADS)
Chen, Pisin
2009-03-01
The well-known hierarchy between the Planck scale (˜10GeV) and the TeV scale, namely a ratio of ˜10 between the two, is coincidentally repeated in a inverted order between the TeV scale and the dark energy scale at ˜10eV implied by the observations. We argue that this is not a numerical coincidence. The same brane-world setups to address the first hierarchy problem may also in principle address this second hierarchy issue. Specifically, we consider supersymmetry in the bulk and its breaking on the brane and resort to the Casimir energy induced by the bulk graviton-gravitino mass-shift on the brane as the dark energy. For the ADD model we found that our notion is sensible only if the number of extra dimension n=2. We extend our study to the Randall-Sundrum model. Invoking the chirality-flip on the boundaries for SUSY-breaking, the zero-mode gravitino contribution to the Casimir energy does give rise to the double hierarchy. Unfortunately since the higher Kaluza-Klein modes acquire relative mass-shifts at the TeV level, the zero-mode contribution to Casimir energy is overshadowed.
Dark Energy and the Hierarchy Problem
Chen, Pisin
2006-12-06
The well-known hierarchy between the Planck scale (>> 1019GeV) and the TeV scale, namely a ratio of {approx} 10{sup 16} between the two, is coincidentally repeated in a inverted order between the TeV scale and the dark energy scale at {approx} 10{sup -3} eV implied by the observations. We argue that this is not a numerical coincidence. The same brane-world setups to address the first hierarchy problem may also in principle address this second hierarchy issue. Specifically, we consider supersymmetry in the bulk and its breaking on the brane and resort to the Casimir energy induced by the bulk graviton-gravitino mass-shift on the brane as the dark energy. For the ADD model we found that our notion is sensible only if the number of extra dimension n = 2. We extend our study to the Randall-Sundrum model. Invoking the chirality-flip on the boundaries for SUSY-breaking, the zero-mode gravitino contribution to the Casimir energy does give rise to the double hierarchy. Unfortunately since the higher Kaluza-Klein modes acquire relative mass-shifts at the TeV level, the zero-mode contribution to Casimir energy is overshadowed.
The Klein-Gordon equation on the toric AdS-Schwarzschild black hole
NASA Astrophysics Data System (ADS)
Dunn, Jake; Warnick, Claude
2016-06-01
We consider the Klein-Gordon equation on the exterior of the toric anti de-Sitter Schwarzschild black hole with Dirichlet, Neumann and Robin boundary conditions at { I }. We define a non-degenerate energy for the equation which controls the renormalised H 1 norm of the field. We then establish both decay and integrated decay of this energy through vector field methods. Finally, we demonstrate the necessity of ‘losing a derivative’ in the integrated energy estimate through the construction of a Gaussian beam staying in the exterior of the event horizon for arbitrarily long coordinate time.
First Order Solutions for Klein-Gordon-Maxwell Equations in a Specific Curved Manifold Case
Murariu, Gabriel
2009-05-22
The aim of this paper is to study the SO(3,1)xU(1) gauge minimally coupled charged spinless field to a spherically symmetric curved space-time. It is derived the first order analytically approximation solution for the system of Klein-Gordon-Maxwell equations. Using these solutions, it evaluated the system electric charge density. The considered space -time manifold generalize an anterior studied one. The chosen space time configuration is of S diagonal type from the MAPLE GRTensor II metrics package.
Length scale competition in nonlinear Klein-Gordon models: A collective coordinate approach
Cuenda, Sara; Sanchez, Angel
2005-06-01
Working within the framework of nonlinear Klein-Gordon models as a paradigmatic example, we show that length scale competition, an instability of solitons subjected to perturbations of an specific length, can be understood by means of a collective coordinate approach in terms of soliton position and width. As a consequence, we provide a natural explanation of the phenomenon in much simpler terms than any previous treatment of the problem. Our technique allows us to study the existence of length scale competition in most soliton bearing nonlinear models and can be extended to coherent structures with more degrees of freedom.
The XRD Amorphous Component in John Klein Drill Fines at Yellowknife Bay, Gale Crater, Mars
NASA Technical Reports Server (NTRS)
Morris, Richard V.; Ming,, Douglas W.; Blake, David; Vaniman, David; Bish, David L; Chipera, Steve; Downs, Robert; Morrison, Shaunna; Gellert, Ralf; Campbell, Iain;
2013-01-01
Drill fines of mudstone (targets John Klein and Cumberland) from the Sheepbed unit at Yel-lowknife Bay were analyzed by MSL payload elements including the Chemistry and Mineralogy (CheMin), APXS (Alpha Particle X-Ray Spectrometer), and Sample Analysis at Mars (SAM) instruments. CheMin XRD results show a variety of crystalline phases including feldspar, pyroxene, olivine, oxides, oxyhydroxides, sulfates, sulfides, a tri-octahedral smectite, and XRD amorphous material. The drill fines are distinctly different from corresponding analyses of the global soil (target Rocknest) in that the mudstone samples contained detectable phyllosilicate. Here we focus on John Klein and combine CheMin and APXS data to calculate the chemical composition and concentration of the amorphous component. The chemical composition of the amorphous plus smectite component for John Klein was calculated by subtracting the abundance-weighted chemical composition of the individual XRD crystalline components from the bulk composition of John Kline as measured by APXS. The chemical composition of individual crystalline components was determined either by stoichiometry (e.g., hematite and magnetite) or from their unit cell parameters (e.g., feldspar, olivine, and pyroxene). The chemical composition of the amorphous + smectite component (approx 71 wt.% of bulk sample) and bulk chemical composition are similar. In order to calculate the chemical composition of the amorphous component, a chemical composition for the tri-octahedral smectite must be assumed. We selected two tri-octahedral smectites with very different MgO/(FeO + Fe2O3) ratios (34 and 1.3 for SapCa1 and Griffithite, respectively). Relative to bulk sample, the concentration of amorphous and smectite components are 40 and 29 wt.% for SapCa1 and 33 and 36 wt.% for Griffithite. The amount of smectite was calculated by requiring the MgO concentration to be approx 0 wt.% in the amorphous component. Griffithite is the preferred smectite because
Finitized Conformal Spectra of the Ising Model on the Klein Bottle and Möbius Strip
NASA Astrophysics Data System (ADS)
Chui, C. H. Otto; Pearce, Paul A.
2002-06-01
We study the conformal spectra of the critical square lattice Ising model on the Klein bottle and Möbius strip using Yang-Baxter techniques and the solution of functional equations. In particular, we obtain expressions for the finitized conformal partition functions in terms of finitized Virasoro characters. This demonstrates that Yang-Baxter techniques and functional equations can be used to study the conformal spectra of more general exactly solvable lattice models in these topologies. The results rely on certain properties of the eigenvalues which are confirmed numerically.
Dimer statistics on the Möbius strip and the Klein bottle
NASA Astrophysics Data System (ADS)
Lu, W. T.; Wu, F. Y.
1999-08-01
Closed-form expressions are obtained for the generating function of close-packed dimers on a 2 M×2 N simple quartic lattice embedded on a Möbius strip and a Klein bottle. Finite-size corrections are also analyzed and compared with those under cylindrical and free boundary conditions. Particularly, it is found that, for large lattices of the same size and with a square symmetry, the number of dimer configurations on a Möbius strip is 70.2% of that on a cylinder. We also establish two identities relating dimer generating functions for Möbius strips and cylinders.
Dispersion relation of the nonlinear Klein-Gordon equation through a variational method.
Amore, Paolo; Raya, Alfredo
2006-03-01
We derive approximate expressions for the dispersion relation of the nonlinear Klein-Gordon equation in the case of strong nonlinearities using a method based on the linear delta expansion. All the results obtained in this article are fully analytical, never involve the use of special functions, and can be used to obtain systematic approximations to the exact results to any desired degree of accuracy. We compare our findings with similar results in the literature and show that our approach leads to better and simpler results.
The XRD Amorphous Component in John Klein Drill Fines at Yellowknife Bay, Gale Crater, Mars
NASA Astrophysics Data System (ADS)
Morris, R. V.; Ming, D. W.; Blake, D.; Vaniman, D.; Bish, D. L.; Chipera, S.; Downs, R.; Morrison, S.; Gellert, R.; Campbell, I.; Treiman, A. H.; Achilles, C.; Bristow, T.; Crisp, J. A.; McAdam, A.; Archer, P. D.; Sutter, B.; Rampe, E. B.; Team, M.
2013-12-01
Drill fines of mudstone (targets John Klein and Cumberland) from the Sheepbed unit at Yel-lowknife Bay were analyzed by MSL payload elements including the Chemistry and Mineralogy (CheMin), APXS (Alpha Particle X-Ray Spectrometer), and Sample Analysis at Mars (SAM) instruments. CheMin XRD results show a variety of crystalline phases including feldspar, pyrox-ene, olivine, oxides, oxyhydroxides, sulfates, sulfides, a tri-octahedral smectite, and XRD amorphous material. The drill fines are distinctly different from corresponding analyses of the global soil (target Rocknest) in that the mudstone samples contained detectable phyllosilicate. Here we focus on John Klein and combine CheMin and APXS data to calculate the chemical composition and concentration of the amorphous component. The chemical composition of the amorphous plus smectite component for John Klein was cal-culated by subtracting the abundance-weighted chemical composition of the individual XRD crystalline components from the bulk composition of John Kline as measured by APXS. The chemical composition of individual crystalline components was determined either by stoichiome-try (e.g., hematite and magnetite) or from their unit cell parameters (e.g., feldspar, olivine, and pyroxene). The chemical composition of the amorphous + smectite component (~71 wt.% of bulk sample) and bulk chemical compositon are similar. In order to calculate the chemical composition of the amorphous component, a chemical composition for the tri-octahedral smectite must be assumed. We selected two tri-octahedral smectites with very different MgO/(FeO + Fe2O3) ratios (34 and 1.3 for SapCa1 and Griffithite, respectively). Relative to bulk sample, the concentration of amorphous and smectite components are 40 and 29 wt.% for SapCa1 and 33 and 36 wt.% for Griffithite. The amount of smectite was calculated by requiring the MgO concentration to be~0 wt.% in the amporphous component. Griffithite is the preferred smectite because the position
Using the Bem and Klein Grid Scores to Predict Health Services Usage by Men.
Reynolds, Grace L; Fisher, Dennis G; Dyo, Melissa; Huckabay, Loucine M
2016-01-01
We examined the association between scores on the Bem Sex Roles Inventory (BSRI), Klein Sexual Orientation Grid, and utilization of hospital inpatient services, emergency departments, and outpatient clinic visits in the past 12 months among 53 men (mean age 39 years). The femininity subscale score on the BSRI, ever having had gonorrhea and age were the three variables identified in a multivariate linear regression significantly predicting use of total health services. This supports the hypothesis that sex roles can assist our understanding of men's use of health services.
Differential quadrature solution of nonlinear Klein-Gordon and sine-Gordon equations
NASA Astrophysics Data System (ADS)
Pekmen, B.; Tezer-Sezgin, M.
2012-08-01
Differential quadrature method (DQM) is proposed to solve the one-dimensional quadratic and cubic Klein-Gordon equations, and two-dimensional sine-Gordon equation. We apply DQM in space direction and also blockwise in time direction. Initial and derivative boundary conditions are also approximated by DQM. DQM provides one to obtain numerical results with very good accuracy using considerably small number of grid points. Numerical solutions are obtained by using Gauss-Chebyshev-Lobatto (GCL) grid points in space intervals, and GCL grid points in each equally divided time blocks.
Dispersion estimates for one-dimensional Schrödinger and Klein-Gordon equations revisited
NASA Astrophysics Data System (ADS)
Egorova, I. E.; Kopylova, E. A.; Marchenko, V. A.; Teschl, G.
2016-06-01
It is shown that for a one-dimensional Schrödinger operator with a potential whose first moment is integrable the elements of the scattering matrix are in the unital Wiener algebra of functions with integrable Fourier transforms. This is then used to derive dispersion estimates for solutions of the associated Schrödinger and Klein-Gordon equations. In particular, the additional decay conditions are removed in the case where a resonance is present at the edge of the continuous spectrum. Bibliography: 29 titles.
NASA Astrophysics Data System (ADS)
Jamal, Sameerah
In this paper, we study the geometric properties of generators for the Klein-Gordon equation on classes of space-time homogeneous Gödel-type metrics. Our analysis complements the study involving the “Symmetries of geodesic motion in Gödel-type spacetimes” by U. Camci (J. Cosmol. Astropart. Phys., doi:10.1088/1475-7516/2014/07/002). These symmetries or Killing vectors (KVs) are used to construct potential functions admitted by the Klein-Gordon equation. The criteria for the potential function originates from three primary sources, viz. through generators that are identically the Killing algebra, or with the KV fields that are recast into linear combinations and third, real subalgebras within the Killing algebra. This leads to a classification of the (1 + 3) Klein-Gordon equation according to the catalogue of infinitesimal Lie and Noether point symmetries admitted. A comprehensive list of group invariant functions is provided and their application to analytic solutions is discussed.
NASA Astrophysics Data System (ADS)
Sandoval-Villalbazo, A.; Garcia-Perciante, A. L.; Sagaceta-Mejia, A. R.
2015-11-01
Kinetic theory is used to establish the explicit form of the particle flux associated to the Hall effect for the case of a dilute single component charged gas, using the Chapman-Enskog method and the BGK approximation for the collision Kernel. It is shown that when the system evolves towards mechanical equilibrium, the standard treatment using the concept of external force fails to describe the Hall effect. It is also shown that the use of a five-dimensional curved space-time in the description of the dynamics of the charged particle in the kinetic treatment (Kaluza's theory) formally solves the problem. The implications of this result are briefly discussed. The authors acknowledge support from CONACyT (Mexico) through grant CB2011/167563.
The ideal and the real in Klein and Milton: some observations on reading Paradise Lost.
Steiner, John
2013-10-01
Extracts from Paradise Lost (Milton 1674) are presented to illustrate some ideas of mutual interest to poets and psychoanalysts. In particular, Milton portrays the distinction between the human and the divine in terms of God's perfection and omnipotence, in contrast to man's imperfections. Recognition of this difference can open a painful gap between the self and the ideal, leading to attempts to bridge it via omnipotence. Because we imbue our objects with omnipotence, a similar gap can arise between adult and child and between patient and analyst. Klein's description of the ideal good object highlights similar issues. Both Klein and Milton present the ideal as something important to internalize as a foundation for hope, trust, and belief in goodness, and both emphasize the ideal as something that can be aspired to but not omnipotently realized. Facing this distinction requires a capacity to relinquish and mourn the loss of the good object, as well as the loss of the omnipotence that made possession of it possible.
Klein tunneling in Weyl semimetals under the influence of magnetic field
NASA Astrophysics Data System (ADS)
Yesilyurt, Can; Tan, Seng Ghee; Liang, Gengchiau; Jalil, Mansoor B. A.
2016-12-01
Klein tunneling refers to the absence of normal backscattering of electrons even under the case of high potential barriers. At the barrier interface, the perfect matching of electron and hole wavefunctions enables a unit transmission probability for normally incident electrons. It is theoretically and experimentally well understood in two-dimensional relativistic materials such as graphene. Here we investigate the Klein tunneling effect in Weyl semimetals under the influence of magnetic field induced by ferromagnetic stripes placed at barrier boundaries. Our results show that the resonance of Fermi wave vector at specific barrier lengths gives rise to perfect transmission rings, i.e., three-dimensional analogue of the so-called magic transmission angles in two-dimensional Dirac semimetals. Besides, the transmission profile can be shifted by application of magnetic field in the central region, a property which may be utilized in electro-optic applications. When the applied potential is close to the Fermi level, a particular incident vector can be selected by tuning the magnetic field, thus enabling highly selective transmission of electrons in the bulk of Weyl semimetals. Our analytical and numerical calculations obtained by considering Dirac electrons in three regions and using experimentally feasible parameters can pave the way for relativistic tunneling applications in Weyl semimetals.
Klein and Lacan meet 21st century schizoid man: fairy stories for the modern era.
Charles, Marilyn
2014-09-01
Melanie Klein invited us into the phenomenology of the schizoid dilemma through her depictions of the paranoid-schizoid position. By inserting his recursive arrows, Bion extended this conceptualization, showing us the folly of believing that we can ever entirely move beyond the frightening fantasies and realities of social exclusion and isolation. The 21st century has brought, along with the explosion of technology, an expulsion from the social order of many children who have found refuge from isolation and humiliation in the more accessible and less terrifying world of media and technological invention. What may look like narcissism can mask a terrible underlying schizoid failure to enter into the human race. This is the realm of fantasy run amok, where desire becomes alien and alienated such that one is haunted and hunted down by its very possibility. In this universe, conceptualizations from Klein, Bion, and Lacan help us to locate the individual who has become caught in a massive psychic retreat such that there is no subject because there are no objects. To illustrate, I describe my work with a young man who is living in a terrible "zombie zone" where people are not real and therefore are incomprehensible and terribly dangerous. The poignancy of his dilemma is heartbreaking. Perhaps that is one lesson we can still take from our old fairy tales: when one's heart can be broken by another's plight, then comes the possibility of a healing, an entry through that piercing of what had been impenetrable.
Efficient and accurate numerical methods for the Klein-Gordon-Schroedinger equations
Bao, Weizhu . E-mail: bao@math.nus.edu.sg; Yang, Li . E-mail: yangli@nus.edu.sg
2007-08-10
In this paper, we present efficient, unconditionally stable and accurate numerical methods for approximations of the Klein-Gordon-Schroedinger (KGS) equations with/without damping terms. The key features of our methods are based on: (i) the application of a time-splitting spectral discretization for a Schroedinger-type equation in KGS (ii) the utilization of Fourier pseudospectral discretization for spatial derivatives in the Klein-Gordon equation in KGS (iii) the adoption of solving the ordinary differential equations (ODEs) in phase space analytically under appropriate chosen transmission conditions between different time intervals or applying Crank-Nicolson/leap-frog for linear/nonlinear terms for time derivatives. The numerical methods are either explicit or implicit but can be solved explicitly, unconditionally stable, and of spectral accuracy in space and second-order accuracy in time. Moreover, they are time reversible and time transverse invariant when there is no damping terms in KGS, conserve (or keep the same decay rate of) the wave energy as that in KGS without (or with a linear) damping term, keep the same dynamics of the mean value of the meson field, and give exact results for the plane-wave solution. Extensive numerical tests are presented to confirm the above properties of our numerical methods for KGS. Finally, the methods are applied to study solitary-wave collisions in one dimension (1D), as well as dynamics of a 2D problem in KGS.
[Kleine-Levin syndrome: differential diagnosis in recurrent encephalitic syndromes in adolescence].
Duat-Rodriguez, A; Martinez-Albadalejo, I; Perez-Sebastian, I; Cantarin-Extremera, V; Hedrera-Fernandez, A; Garcia-Penas, J J
2017-04-01
Introduccion. El sindrome de Kleine-Levin es una enfermedad rara de causa desconocida que se caracteriza por episodios recurrentes autolimitados de hipersomnia acompañados de alteracion cognitiva y conductual. Entre los episodios, los pacientes tienen un patron de sueño y cognitivo normal. Casos clinicos. Se presentan tres pacientes de 14 años, dos chicos y una chica. Comenzaron tras un desencadenante (vacuna, una infeccion respiratoria por influenza B; en el caso de la chica, coincidian con la menstruacion). En el episodio agudo mostraban tendencia al sueño y en vigilia destacaba bradipsiquia, inquietud motora y gran labilidad emocional, con tendencia al llanto y necesidad de la presencia de los familiares. Presentaron una duracion aproximada de 10-15 dias y periodicidad mensual, y se mostraron asintomaticos entre los episodios. Los tres pacientes fueron valorados por pediatras, diagnosticados y tratados de encefalitis autoinmune. Solo uno cumplia la triada tipica de hipersomnia, hiperfagia e hipersexualidad, pero ninguno de los tres datos se habia recogido en la historia clinica inicial y la familia solo lo referia tras una anamnesis dirigida. Conclusiones. En el sindrome de Kleine-Levin, los sintomas neurologicos durante el cuadro agudo son aun mas frecuentes que los psiquiatricos. La tendencia al sueño y el hecho de que durante la vigilia no esten asintomaticos y se muestren lentos, apaticos, labiles e irascibles, situa en primer lugar la sospecha de sindrome encefalitico. Debemos tener presente esta entidad en encefalitis recurrentes de etiologia no filiada.
Emanuel Edward Klein, a diligent and industrious plodder or the father of British microbiology.
Atalic, Bruno; Peric, Ines Drenjancevic; Ferencic, Stella Fatovic
2010-08-01
Emanuel Edward Klein (Osijek, 1844 - Hove, 1925) was a British microbiologist of Croatian origin. He completed his medical studies in Vienna in 1869. In 1869 he was sent to England to determine terms for the translation of Samuel Stricker's manual Handbuch von den Geweben des Menchen und der Tiere. During his visit he made a good impression on John Burdon Sanderson and John Simon, which was the main reason why he was invited to London in 1871 to conduct investigations under their guidance. In 1873 Klein began his collaboration with the Saint Bartholomew's Hospital, where he was appointed as a Joint Professor of General Anatomy and Physiology. His researches were in the fields of anatomy, histology, pathology, embryology, physiology, and especially microbiology. He did a great deal to its development in Britain. He has written about 260 scientific papers on a broad range of different topics. Despite all the aforementioned facts, his work was never properly studied, and he is almost unknown outside academic circles. For that reason, attitudes towards him still range between the extremes of calling him the father of British microbiology on one side, and attributing him as a diligent and industrious plodder on the other. In this paper we will try to prove the first attitude. We will put his researches in a general context. Finally we will highlight his original achievements in the isolation of new microbes.
Klein tunneling in Weyl semimetals under the influence of magnetic field.
Yesilyurt, Can; Tan, Seng Ghee; Liang, Gengchiau; Jalil, Mansoor B A
2016-12-12
Klein tunneling refers to the absence of normal backscattering of electrons even under the case of high potential barriers. At the barrier interface, the perfect matching of electron and hole wavefunctions enables a unit transmission probability for normally incident electrons. It is theoretically and experimentally well understood in two-dimensional relativistic materials such as graphene. Here we investigate the Klein tunneling effect in Weyl semimetals under the influence of magnetic field induced by ferromagnetic stripes placed at barrier boundaries. Our results show that the resonance of Fermi wave vector at specific barrier lengths gives rise to perfect transmission rings, i.e., three-dimensional analogue of the so-called magic transmission angles in two-dimensional Dirac semimetals. Besides, the transmission profile can be shifted by application of magnetic field in the central region, a property which may be utilized in electro-optic applications. When the applied potential is close to the Fermi level, a particular incident vector can be selected by tuning the magnetic field, thus enabling highly selective transmission of electrons in the bulk of Weyl semimetals. Our analytical and numerical calculations obtained by considering Dirac electrons in three regions and using experimentally feasible parameters can pave the way for relativistic tunneling applications in Weyl semimetals.
Unstable Mode Solutions to the Klein-Gordon Equation in Kerr-anti-de Sitter Spacetimes
NASA Astrophysics Data System (ADS)
Dold, Dominic
2017-03-01
For any cosmological constant {Λ = -3/ℓ2 < 0} and any {α < 9/4}, we find a Kerr-AdS spacetime {({M}, g_{KAdS})}, in which the Klein-Gordon equation {Box_{g_{KAdS}}ψ + α/ℓ2ψ = 0} has an exponentially growing mode solution satisfying a Dirichlet boundary condition at infinity. The spacetime violates the Hawking-Reall bound {r+2 > |a|ℓ}. We obtain an analogous result for Neumann boundary conditions if {5/4 < α < 9/4}. Moreover, in the Dirichlet case, one can prove that, for any Kerr-AdS spacetime violating the Hawking-Reall bound, there exists an open family of masses {α} such that the corresponding Klein-Gordon equation permits exponentially growing mode solutions. Our result adopts methods of Shlapentokh-Rothman developed in (Commun. Math. Phys. 329:859-891, 2014) and provides the first rigorous construction of a superradiant instability for negative cosmological constant.
Klein tunneling in Weyl semimetals under the influence of magnetic field
Yesilyurt, Can; Tan, Seng Ghee; Liang, Gengchiau; Jalil, Mansoor B. A.
2016-01-01
Klein tunneling refers to the absence of normal backscattering of electrons even under the case of high potential barriers. At the barrier interface, the perfect matching of electron and hole wavefunctions enables a unit transmission probability for normally incident electrons. It is theoretically and experimentally well understood in two-dimensional relativistic materials such as graphene. Here we investigate the Klein tunneling effect in Weyl semimetals under the influence of magnetic field induced by ferromagnetic stripes placed at barrier boundaries. Our results show that the resonance of Fermi wave vector at specific barrier lengths gives rise to perfect transmission rings, i.e., three-dimensional analogue of the so-called magic transmission angles in two-dimensional Dirac semimetals. Besides, the transmission profile can be shifted by application of magnetic field in the central region, a property which may be utilized in electro-optic applications. When the applied potential is close to the Fermi level, a particular incident vector can be selected by tuning the magnetic field, thus enabling highly selective transmission of electrons in the bulk of Weyl semimetals. Our analytical and numerical calculations obtained by considering Dirac electrons in three regions and using experimentally feasible parameters can pave the way for relativistic tunneling applications in Weyl semimetals. PMID:27941894
NASA Astrophysics Data System (ADS)
Gérard, Christian; Wrochna, Michał
2017-08-01
We consider the massive Klein-Gordon equation on a class of asymptotically static spacetimes (in the long range sense) with Cauchy surface of bounded geometry. We prove the existence and Hadamard property of the in and out states constructed by scattering theory methods.
Feeling unreal: a functional imaging study in patients with Kleine-Levin syndrome.
Kas, Aurelie; Lavault, Sophie; Habert, Marie-Odile; Arnulf, Isabelle
2014-07-01
Kleine-Levin syndrome is characterized by relapsing-remitting episodes of severe hypersomnia, cognitive impairment, apathy, derealization and behavioural disturbances. Between episodes, patients have normal sleep, mood and behaviour. Functional imaging studies performed in small series of patients with Kleine-Levin syndrome with visual or semi-quantitative, uncontrolled analysis yielded equivocal brain changes. Using whole brain voxel-based group analysis, we compared brain perfusion scintigraphy during and between episodes in consecutive patients with Kleine-Levin syndrome versus healthy control subjects and correlated perfusion changes with disease severity and symptoms, focusing on less studied but disabling symptoms, such as apathy and derealization. During asymptomatic periods, 41 patients (mean age of 22.3 ± 8.1 years, 56.1% male) and 15 age- and sex-matched healthy control subjects underwent single-photon emission computed tomography scanning with technetium-99m ethyl cysteinate dimer. Eleven patients repeated the test during a symptomatic period. Compared with controls, patients during asymptomatic periods had persistent hypoperfusion in the hypothalamus, the thalamus (mainly the right posterior part), the caudate nucleus, and cortical associative areas, including the anterior cingulate, (Brodmann area 25), the orbito-frontal (Brodmann area 11) and the right superior temporal cortices (Brodmann area 22), extending to the insula (P < 0.001 in all area). Two additional hypoperfused areas emerged during symptomatic periods (P < 0.001), located in the right dorsomedial prefrontal cortex (Brodmann area 8) and the right parieto-temporal junction (Brodmann areas 22 and 39). These two areas were more affected between episodes, when the mean episode duration was longer (r = -0.53; P < 0.001). The score for the Depersonalization/Derealization Inventory during symptomatic periods strongly correlated with the hypoperfusion of the right (r = -0.74, P < 0.001) and left
Klein-Gordon equation and reflection of Alfven waves in nonuniform media
NASA Technical Reports Server (NTRS)
Musielak, Z. E.; Fontenla, J. M.; Moore, R. L.
1992-01-01
A new analytical approach is presented for assessing the reflection of linear Alfven waves in smoothly nonuniform media. The general one-dimensional case in Cartesian coordinates is treated. It is shown that the wave equations, upon transformation into the form of the Klein-Gordon equation, display a local critical frequency for reflection. At any location in the medium, reflection becomes strong as the wave frequency descends past this characteristic frequency set by the local nonuniformity of the medium. This critical frequecy is given by the transformation as an explicit function of the Alfven velocity and its first and second derivatives, and hence as an explicit spatial function. The transformation thus directly yields, without solution of the wave equations, the location in the medium at which an Alfven wave of any given frequency becomes strongly reflected and has its propagation practically cut off.
The density profile for the Klein-Kramers equation near an absorbing wall
NASA Astrophysics Data System (ADS)
Titulaer, U. M.
1984-12-01
We derive asymptotic series for the expansion coefficients of a function in terms of the Pagani functions, which occur in the boundary layer solutions of the Klein-Kramers equation. The results enable us to determine the density profile in the stationary solution of this equation near an absorbing wall from the numerically determined velocity distribution at the wall, with an accuracy of about 2%. We also obtain information about the analytic behavior of the density profile: this profile increases near the wall with the square root of the distance to the wall. Finally, the asymptotic analysis leads to an understanding of the slow convergence of variational approximations to the solution of the absorbing-wall problem and of the exponents that occur when one studies the variational approximations to various quantities of interest as functions of the number of terms in the variational ansatz. This is used to obtain a better variational estimate for the density at the wall.
Phase transition from the symmetry breaking of charged Klein-Gordon fields
NASA Astrophysics Data System (ADS)
Matos, T.; Castellanos, E.
2014-01-01
We analyze the phase transition associated with the U(1) symmetry breaking of the complex Klein-Gordon (KG) equation with a Mexican-hat scalar field potential up to one loop in perturbations immersed in a thermal bath. We show that the KG equation reduces to a Gross-Pitaevskii like-equation (GP), which also contains the entire information of the phase transition. Indeed, the thermal bath contributions, together with the corresponding U(1) local symmetry, allow us to interpret the resulting GP equation as a charged and finite temperature version of the system. Finally, we obtain the hydrodynamics and consequently, the corresponding thermodynamics, and show that breakdown of the U(1) local symmetry of the KG field into the new version of the GP equation corresponds, under certain circumstances, to a phase transition of the gas into a condensate, superfluid, and/or superconductor.
Analyses of PION-40Ca Elastic Scattering Data Using the Klein-Gordon Equation
NASA Astrophysics Data System (ADS)
Shehadeh, Zuhair F.
The elastic scattering data for incident pion energies of 130, 163.3, 180, and 230 MeV on 40Ca have been analyzed using the full Klein-Gordon equation (KGE), as opposed to its approximate form which renders it to the format of a Schrödinger equation with an energy-dependent potential (RSE). Calculated angular distributions, using KGE and RSE, for all four cases are nearly the same up to about 70° but differ significantly at larger angles. To fit the large-angle data of 163.3 MeV, the nature of the old potential determined by using RSE needs to be revised. The new potentials in four cases are presented and they are compatible with those determined from the inverse scattering theory at a fixed energy in the surface region.
Lagrangian embeddings of the Klein bottle and combinatorial properties of mapping class groups
NASA Astrophysics Data System (ADS)
Shevchishin, Vsevolod V.
2009-08-01
In this paper we prove the non-existence of Lagrangian embeddings of the Klein bottle K in \\mathbb{R}^4 and \\mathbb{C}\\mathbb{P}^2. We exploit the existence of a special embedding of K in a symplectic Lefschetz pencil \\operatorname{pr}\\colon X \\to S^2 and study its monodromy. As the main technical tool, we develop the combinatorial theory of mapping class groups. The results obtained enable us to show that in the case when the class \\lbrack K \\rbrack \\in\\mathsf{H}_2(X,\\mathbb{Z}_2) is trivial, the monodromy of \\operatorname{pr}\\colon X \\to S^2 must be of a special form. Finally, we show that such a monodromy cannot be realized in \\mathbb{C}\\mathbb{P}^2.
Hadamard States for the Klein-Gordon Equation on Lorentzian Manifolds of Bounded Geometry
NASA Astrophysics Data System (ADS)
Gérard, Christian; Oulghazi, Omar; Wrochna, Michał
2017-06-01
We consider the Klein-Gordon equation on a class of Lorentzian manifolds with Cauchy surface of bounded geometry, which is shown to include examples such as exterior Kerr, Kerr-de Sitter spacetime and the maximal globally hyperbolic extension of the Kerr outer region. In this setup, we give an approximate diagonalization and a microlocal decomposition of the Cauchy evolution using a time-dependent version of the pseudodifferential calculus on Riemannian manifolds of bounded geometry. We apply this result to construct all pure regular Hadamard states (and associated Feynman inverses), where regular refers to the state's two-point function having Cauchy data given by pseudodifferential operators. This allows us to conclude that there is a one-parameter family of elliptic pseudodifferential operators that encodes both the choice of (pure, regular) Hadamard state and the underlying spacetime metric.
Hadamard States for the Klein-Gordon Equation on Lorentzian Manifolds of Bounded Geometry
NASA Astrophysics Data System (ADS)
Gérard, Christian; Oulghazi, Omar; Wrochna, Michał
2017-03-01
We consider the Klein-Gordon equation on a class of Lorentzian manifolds with Cauchy surface of bounded geometry, which is shown to include examples such as exterior Kerr, Kerr-de Sitter spacetime and the maximal globally hyperbolic extension of the Kerr outer region. In this setup, we give an approximate diagonalization and a microlocal decomposition of the Cauchy evolution using a time-dependent version of the pseudodifferential calculus on Riemannian manifolds of bounded geometry. We apply this result to construct all pure regular Hadamard states (and associated Feynman inverses), where regular refers to the state's two-point function having Cauchy data given by pseudodifferential operators. This allows us to conclude that there is a one-parameter family of elliptic pseudodifferential operators that encodes both the choice of (pure, regular) Hadamard state and the underlying spacetime metric.
Eab, C. H.; Lim, S. C.; Teo, L. P.
2007-08-15
This paper studies the Casimir effect due to fractional massless Klein-Gordon field confined to parallel plates. A new kind of boundary condition called fractional Neumann condition which involves vanishing fractional derivatives of the field is introduced. The fractional Neumann condition allows the interpolation of Dirichlet and Neumann conditions imposed on the two plates. There exists a transition value in the difference between the orders of the fractional Neumann conditions for which the Casimir force changes from attractive to repulsive. Low and high temperature limits of Casimir energy and pressure are obtained. For sufficiently high temperature, these quantities are dominated by terms independent of the boundary conditions. Finally, validity of the temperature inversion symmetry for various boundary conditions is discussed.
Carvalho, Evanilda Souza de Santana; Araújo, Edna Maria de; Santos, Silvone Santa Bárbara da Silva; Santos, Alexandro Gesner Gomes Dos
2016-06-01
Objectives To analyze the representations of the nurse and individual in mental suffering portrayed in the photographic work by Steven Klein, in the USAnatomy exhibit held at the Museum of Sculpture (Museu da escultura) in São Paulo, in 2011. Methods Qualitative study carried out in 2012. Three photographs were submitted to iconographic analysis. The interpretation of the findings was based on theoretical frameworks of Foucault and Bourdieu on power relations. Results The nurse is represented as a sensual, insensitive person, with the power to control and torture while the person in psychological distress is represented as dirty, imprisoned and subjected to an asymmetrical relationship of power with the nurse. Final considerations Relationships of submission and symbolic dominance, in which the person in psychological distress has their body molded by discipline imposed by the nurse. Stereotypes of the image of the nurse oppose the ideology of the profession, which is to ensure the integrity of those being cared for.
On the Klein-Gordon equation using the dispersion relation of Doubly Special Relativity
NASA Astrophysics Data System (ADS)
Felipe, Yese J.
2017-01-01
The theory of Doubly Special Relativity or Deformed Special Relativity (DSR), proposes that there is a maximum energy scale and a minimum length scale that is invariant for all observers. These maximum energy and minimum length correspond to the Planck energy and the Planck length, respectively. As a consequence, the dispersion relation is modified to be E2 =p2c2 +m2c4 + λE3 + ... Previous work has been done to express Quantum Mechanics using the dispersion relation of DSR. Solutions of the free particle, the harmonic oscillator, and the Hydrogen atom have been obtained from the DSR Schrodinger equation. We explore how the DSR Klein-Gordon equation can be consistently approximated in the non-relativistic limit in order to derive the DSR Schrodinger equation.
To Wise King Ehrenfest: Humorous Writings by Oskar Klein and Others from 1930s Copenhagen
NASA Astrophysics Data System (ADS)
Halpern, Paul
2005-04-01
In the late 1920s and early 1930s, Copenhagen, the center of the development of quantum physics, was also the home of abundant humor. As a respite from the intensive and highly competitive efforts taking place to characterize fundamental interactions on an atomic scale, physicists took the time to develop satirical letters, articles, plays and other works. Written in German, English and other languages, many of these efforts were quite pointed and clever. This paper will focus on several examples of these humorous contributions, including letters exchanged between Oskar Klein and Paul Ehrenfest in 1930, articles written for the ``Journal of Jocular Physics,'' and a well-known parody of Faust. We'll show how these pieces reflect the political and scientific climate of the era, and attempt to characterize the personal styles of the some of the researchers involved.
Three-dimensional Einstein-Klein-Gordon system in characteristic numerical relativity
Barreto, W.; Silva, A. da; Lehner, L.; Gomez, R.; Rosales, L.; Winicour, J.
2005-03-15
We incorporate a massless scalar field into a three-dimensional code for the characteristic evolution of the gravitational field. The extended three-dimensional code for the Einstein-Klein-Gordon system is calibrated to be second-order convergent. It provides an accurate calculation of the gravitational and scalar radiation at infinity. As an application, we simulate the fully nonlinear evolution of an asymmetric scalar pulse of ingoing radiation propagating toward an interior Schwarzschild black hole and compute the backscattered scalar and gravitational outgoing radiation patterns. The amplitudes of the scalar and gravitational outgoing radiation modes exhibit the predicted power law scaling with respect to the amplitude of the initial data. For the scattering of an axisymmetric scalar field, the final ring down matches the complex frequency calculated perturbatively for the l=2 quasinormal mode.
Cerebrospinal Fluid Orexin A Levels and Autonomic Function in Kleine-Levin Syndrome
Wang, Jing Yu; Han, Fang; Dong, Song X.; Li, Jing; An, Pei; Zhang, Xiao Zhe; Chang, Yuan; Zhao, Long; Zhang, Xue Li; Liu, Ya Nan; Yan, Han; Li, Qing Hua; Hu, Yan; Lv, Chang Jun; Gao, Zhan Cheng; Strohl, Kingman P.
2016-01-01
Study Objectives: Kleine-Levin syndrome (KLS) is a rare disorder of relapsing sleepiness. The hypothesis was that the syndrome is related to a change in the vigilance peptide orexin A. Methods: From 2002 to 2013, 57 patients with relapsing hypersomnolence were clinically assessed in a referral academic center in Beijing, China, and 44 (28 males and 16 females; mean age 18.3 ± 8.9 y (mean ± standard deviation, range 9–57 y) were determined to have clinical and behavioral criteria consistent with KLS. Cerebrospinal fluid orexin A levels and diurnal blood pressure were measured in relapse versus remission in a subgroup of patients. Results: Presenting symptoms included relapsing or remitting excessive sleepiness–associated parallel complaints of cognitive changes (82%), eating disorders (84%); depression (45%); irritability (36%); hypersexuality (18%); and compulsions (11%). Episodes were 8.2 ± 3.3 days in duration. In relapse, diurnal values for blood pressure and heart rate were lower (P < 0.001). In a subgroup (n = 34), cerebrospinal fluid orexin A levels were ∼31% lower in a relapse versus remission (215.7 ± 81.5 versus 319.2 ± 95.92 pg/ml, P < 0.001); in three patients a pattern of lower levels during subsequent relapses was documented. Conclusions: There are lower orexin A levels in the symptomatic phase than in remission and a fall and rise in blood pressure and heart rate, suggesting a role for orexin dysregulation in KLS pathophysiology. Citation: Wang JY, Han F, Dong SX, Li J, An P, Zhang XZ, Chang Y, Zhao L, Zhang XL, Liu YN, Yan H, Li QH, Hu Y, Lv CJ, Gao ZC, Strohl KP. Cerebrospinal fluid orexin A levels and autonomic function in Kleine-Levin syndrome. SLEEP 2016;39(4):855–860. PMID:26943469
Prevalence and Mimics of Kleine-Levin Syndrome: A Survey in French-Speaking Switzerland
Habra, Oussama; Heinzer, Raphaël; Haba-Rubio, Jose; Rossetti, Andrea O.
2016-01-01
Study Objective: Kleine-Levin syndrome (KLS) is a rare disease of unknown etiology, the diagnosis of which can be challenging. We aimed to estimate KLS prevalence in French-speaking Switzerland, and assess differences with mimicking conditions. Methods: In this cross-sectional study, KLS patients were identified through a population-based approach, including at our hospital and contacting all sleep-certified facilities and neurologists in French-speaking Switzerland. Furthermore, we identified patients referred to our center for suspected KLS that received other diagnoses. Relevant clinical data of these two groups was compared. Results: We identified 7 patients with diagnosed KLS (6 since 2009), leading to a prevalence estimation of 3.19 per million (95% confidence interval: 1.55–6.59). Median age at diagnosis was 17 years (range: 12–19), 71.4% of them were men, and mean diagnosis delay after the first episode was 20.1 ± 10.9 months. We identified 9 mimic patients referred to our center; they differed from KLS patients by their higher age at disease onset (median: 15 [range: 12–16] vs. 19 [range: 16–64] years; p < 0.001), suspected KLS as referral reason (more frequent in mimics, p = 0.003), and the presence of precipitating factors (more frequent in KLS, p = 0.011). Among the mimic patients, 77% (versus 28% in KLS) had a psychiatric diagnosis. Conclusions: This study suggests a relatively higher KLS prevalence than previously reported. As compared to KLS, mimic patients have higher age at symptom onset, are more often initially referred for KLS suspicion, and have a higher prevalence of psychiatric disorders. Citation: Habra O, Heinzer R, Haba-Rubio J, Rossetti AO. Prevalence and mimics of Kleine-Levin syndrome: a survey in French-speaking Switzerland. J Clin Sleep Med 2016;12(8):1083–1087. PMID:27250808
Relationship between Kleine-Levin Syndrome and Upper Respiratory Infection in Taiwan
Huang, Yu-Shu; Guilleminault, Christian; Lin, Kuang-Lin; Hwang, Fang-Ming; Liu, Feng-Yuan; Kung, Yen-Ping
2012-01-01
Study Objectives: In Kleine-Levin Syndrome (KLS), new episodes of hypersomnia are often preceded by an acute flu-like syndrome or upper airway infection 3 to 5 days before onset. This study investigated the relationship between the occurrence of mild upper respiratory tract infections (URIs) in the general population and the occurrence and seasonality and hypersomnic episodes in KLS patients. Design: This investigation was a longitudinal clinical study. Based on data obtained from the National Health Research Institutes between 2006 and 2007, the timing of hypersomnic episodes in 30 KLS patients were compared with calendar reports of URI events, and the results compared with age-matched general Taiwanese population. Measurements: Clinical symptoms, physical examination, polysomnographic recording, SPECT study, and laboratory tests affirming KLS during both periods of hypersomnic attack and non-attack were collected. Every symptomatic episode was then followed up. The cross-correlation function (CCF) and bivariate correlations analysis were performed to see the relationship between KLS and URIs. Results: A positive finding of CCF analysis and significant bivariate correlations were found between KLS episodes and URI in the general population (r = 0.456*). In onset of hypersomnia, significant correlations existed among “acute upper respiratory infections” (r = 0.446*), “acute bronchitis and bronchiolitis” (r = 0.462*), and “pharyngitis and nasopharyngitis” (r = 0.548*) subtypes of infections. A positive correlation between higher reports of symptomatic hypersomnia and URI also existed in a given season. A positive nonsignificant trend for “allergic rhinitis” (r = 0.400) was also found. Conclusion: The agent behind URI or its consequence (such as fever) is associated with increased incidence of KLS episodes and may explain periodic symptomatic recurrences. Citation: Huang YS; Guilleminault C; Lin KL Hwang FM; Liu FY; Kung YP. Relationship between
Phantom black holes and sigma models
Azreg-Aienou, Mustapha; Clement, Gerard; Fabris, Julio C.; Rodrigues, Manuel E.
2011-06-15
We construct static multicenter solutions of phantom Einstein-Maxwell-dilaton theory from null geodesics of the target space, leading to regular black holes without spatial symmetry for certain discrete values of the dilaton coupling constant. We also discuss the three-dimensional gravitating sigma models obtained by reduction of phantom Einstein-Maxwell, phantom Kaluza-Klein and phantom Einstein-Maxwell-dilaton-axion theories. In each case, we generate by group transformations phantom charged black hole solutions from a neutral seed.
NASA Astrophysics Data System (ADS)
Nakao, Mitsuhiro
We prove the existence of global decaying solutions to the exterior problem for the Klein-Gordon equation with a nonlinear localized dissipation and a derivative nonlinearity. To derive the required estimates of solutions we employ a 'loan' method.
Killing superalgebra deformations of ten-dimensional supergravity backgrounds
NASA Astrophysics Data System (ADS)
Figueroa-O'Farrill, José; Vercnocke, Bert
2007-12-01
We explore Lie superalgebra deformations of the Killing superalgebras of some ten-dimensional supergravity backgrounds. We prove the rigidity of the Poincaré superalgebras in types I, IIA and IIB, as well as of the Killing superalgebra of the Freund Rubin vacuum of type IIB supergravity. We also prove rigidity of the Killing superalgebras of the NS5-, D0-, D3-, D4- and D5-branes, whereas we exhibit the possible deformations of the D1-, D2-, D6- and D7-brane Killing superalgebras, as well as of that of the type II fundamental string solutions. We relate the superalgebra deformations of the D2- and D6-branes to those of the (delocalized) M2-brane and the Kaluza Klein monopole, respectively. The good behaviour under Kaluza Klein reduction suggests that the deformed superalgebras ought to have a geometric interpretation.
Hinshelwood, R D
1996-06-01
Although the concept of "inner objects" developed by Melanie Klein is hardly a major object of discussion today, it caused a furore in the ranks of the British Psychoanalytical Society in the thirties and forties. Notably the analysts from Vienna were unable to agree to the existence of inner objects engendered via processes of internalisation. The author traces the course of these discussions of a clinical problem and the confusion they caused, placing them at the same time in a specific historical context. He sees the controversy as the expression of conflicts and fears unsettling the British Psychoanalytical Society during that period, caused on the one hand by the necessary integration of the exiled Freud family and on the other by tensions within its own ranks leading ultimately to a division of the Society and the constitution of the Klein Group.
EPR & Klein Paradoxes in Complex Hamiltonian Dynamics and Krein Space Quantization
NASA Astrophysics Data System (ADS)
Payandeh, Farrin
2015-07-01
Negative energy states are applied in Krein space quantization approach to achieve a naturally renormalized theory. For example, this theory by taking the full set of Dirac solutions, could be able to remove the propagator Green function's divergences and automatically without any normal ordering, to vanish the expected value for vacuum state energy. However, since it is a purely mathematical theory, the results are under debate and some efforts are devoted to include more physics in the concept. Whereas Krein quantization is a pure mathematical approach, complex quantum Hamiltonian dynamics is based on strong foundations of Hamilton-Jacobi (H-J) equations and therefore on classical dynamics. Based on complex quantum Hamilton-Jacobi theory, complex spacetime is a natural consequence of including quantum effects in the relativistic mechanics, and is a bridge connecting the causality in special relativity and the non-locality in quantum mechanics, i.e. extending special relativity to the complex domain leads to relativistic quantum mechanics. So that, considering both relativistic and quantum effects, the Klein-Gordon equation could be derived as a special form of the Hamilton-Jacobi equation. Characterizing the complex time involved in an entangled energy state and writing the general form of energy considering quantum potential, two sets of positive and negative energies will be realized. The new states enable us to study the spacetime in a relativistic entangled “space-time” state leading to 12 extra wave functions than the four solutions of Dirac equation for a free particle. Arguing the entanglement of particle and antiparticle leads to a contradiction with experiments. So, in order to correct the results, along with a previous investigation [1], we realize particles and antiparticles as physical entities with positive energy instead of considering antiparticles with negative energy. As an application of modified descriptions for entangled (space
NASA Astrophysics Data System (ADS)
Zhang, Qidi
2016-12-01
We show for almost every m > 0, the solution to the semi-linear Klein-Gordon equation with a quadratic potential in dimension one, exists over a longer time interval than the one given by local existence theory, using the normal form method. By using an Lp -Lq estimate for eigenfunctions of the harmonic oscillator and by carefully analysis on the nonlinearity, we improve the result obtained by the author before.
NASA Astrophysics Data System (ADS)
Arda, Altuğ; Tezcan, Cevdet; Sever, Ramazan
2017-02-01
We study some thermodynamics quantities for the Klein-Gordon equation with a linear plus inverse-linear, scalar potential. We obtain the energy eigenvalues with the help of the quantization rule from the biconfluent Heun's equation. We use a method based on the Euler-MacLaurin formula to analytically compute the thermal functions by considering only the contribution of positive part of the spectrum to the partition function.
Higher-dimensional lifts of Killing-Yano forms with torsion
NASA Astrophysics Data System (ADS)
Chow, David D. K.
2017-01-01
Using a Kaluza-Klein-type lift, it is shown how Killing-Yano forms with torsion can remain symmetries of a higher-dimensional geometry, subject to an algebraic condition between the Kaluza-Klein field strength and the Killing-Yano form. The lift condition’s significance is highlighted, and is satisfied by examples of black holes in supergravity.
NASA Astrophysics Data System (ADS)
Lucio Rapoport, Diego
2013-04-01
We present a unified principle for science that surmounts dualism, in terms of torsion fields and the non-orientable surfaces, notably the Klein Bottle and its logic, the Möbius strip and the projective plane. We apply it to the complex numbers and cosmology, to non-linear systems integrating the issue of hyperbolic divergences with the change of orientability, to the biomechanics of vision and the mammal heart, to the morphogenesis of crustal shapes on Earth in connection to the wavefronts of gravitation, elasticity and electromagnetism, to pattern recognition of artificial images and visual recognition, to neurology and the topographic maps of the sensorium, to perception, in particular of music. We develop it in terms of the fundamental 2:1 resonance inherent to the Möbius strip and the Klein Bottle, the minimal surfaces representation of the wavefronts, and the non-dual Klein Bottle logic inherent to pattern recognition, to the harmonic functions and vector fields that lay at the basis of geophysics and physics at large. We discuss the relation between the topographic maps of the sensorium, and the issue of turning inside-out of the visual world as a general principle for cognition, topological chemistry, cell biology and biological morphogenesis in particular in embryology
Clinical and Polysomnographic Features of Kleine-Levin Syndrome: Case Series
ERDEM, Murat; BOLU, Abdullah; GARİP, Beyazıt; KARAMAN, Dursun; YETKİN, Sinan
2013-01-01
Kleine-Levin Syndrome (KLS) is a rare disorder characterized intermittent hypersomnia, hyperphagia, hypersexuality, abnormal behaviors, and confusion. Patients are asymptomatic between episodes. The aim of this case series study was to determine the clinical features of patients with KLS and to compare the polysomnography (PSG) findings between symptomatic and asymptomatic periods. We compared the results of PSG investigations performed in symptomatic and asymptomatic periods in six patients diagnosed with KLS at Gulhane Military Medical Faculty Sleep Research Center between 1998 and 2005. The age at onset of KLS was approximately 18 years, the diagnosis delayed 2.67 years, hypersomnia episodes lasted approximately 11.5 days, until the correct diagnosis, the patients had experienced on average 5 episodes. Total sleep time in KLS patients during symptomatic period and stage 2 sleep percent was higher than in asymptomatic period. REM latency was shorter and stage 3 and REM percent was lower in asymptomatic period. The clinical features including the age of onset and episode duration are compatible with those from the previous studies. It was observed that the sleep architecture during symptomatic period was different from that in asymptomatic period.
One perspective on the Freud-Klein controversies 1941-45.
Schafer, R
1994-04-01
Comments on the complex relations obtaining between, on the one hand, tradition, innovations and existential perspective and, on the other, presuppositions about method, evidence and truth are prefaced by a review of the helpful and hindering attitudes and conduct of the three parties to these controversial discussions, the third group being the indigenous ('independent') British group. This group directed the process into productive channels against great odds. The subsequent history of psychoanalysis shows, in addition to increased organisational stability and tolerance in times of crisis, an evolving enrichment and refinement of theory and practice in all three groups. Those following Melanie Klein have developed further their own kind of ego-psychological emphasis, while those following Anna Freud and 'the Viennese' around her have developed a more inclusive theoretical and clinical perspective, one that makes more salient the influence of the very first years of life and early infantile aggression as well as accepting a broadening of the idea of transference to include child analysis. This history supports the view that pluralism in psychoanalysis has been of much benefit.
Huygens' principle for the Klein-Gordon equation in the de Sitter spacetime
Yagdjian, Karen
2013-09-15
In this article we prove that the Klein-Gordon equation in the de Sitter spacetime obeys the Huygens' principle only if the physical mass m of the scalar field and the dimension n⩾ 2 of the spatial variable are tied by the equation m{sup 2}= (n{sup 2}−1)/4. Moreover, we define the incomplete Huygens' principle, which is the Huygens' principle restricted to the vanishing second initial datum, and then reveals that the massless scalar field in the de Sitter spacetime obeys the incomplete Huygens' principle and does not obey the Huygens' principle, for the dimensions n= 1, 3, only. Thus, in the de Sitter spacetime the existence of two different scalar fields (in fact, with m= 0 and m{sup 2}= (n{sup 2}−1)/4), which obey incomplete Huygens' principle, is equivalent to the condition n= 3, the spatial dimension of the physical world. In fact, Paul Ehrenfest in 1917 addressed the question: “Why has our space just three dimensions?”. For n= 3 these two values of the mass are the endpoints of the so-called in quantum field theory the Higuchi bound. The value m{sup 2}= (n{sup 2}−1)/4 of the physical mass allows us also to obtain complete asymptotic expansion of the solution for the large time.
A local energy-preserving scheme for Klein-Gordon-Schrödinger equations
NASA Astrophysics Data System (ADS)
Cai, Jia-Xiang; Wang, Jia-Lin; Wang, Yu-Shun
2015-05-01
A local energy conservation law is proposed for the Klein-Gordon-Schrödinger equations, which is held in any local time-space region. The local property is independent of the boundary condition and more essential than the global energy conservation law. To develop a numerical method preserving the intrinsic properties as much as possible, we propose a local energy-preserving (LEP) scheme for the equations. The merit of the proposed scheme is that the local energy conservation law can hold exactly in any time-space region. With the periodic boundary conditions, the scheme also possesses the discrete change and global energy conservation laws. A nonlinear analysis shows that the LEP scheme converges to the exact solutions with order 𝒪(τ2 + h2). The theoretical properties are verified by numerical experiments. Project supported by the National Natural Science Foundation of China (Grant Nos. 11201169, 11271195, and 41231173) and the Project of Graduate Education Innovation of Jiangsu Province, China (Grant No. CXLX13 366).
Contact doping, Klein tunneling, and asymmetry of shot noise in suspended graphene
NASA Astrophysics Data System (ADS)
Laitinen, Antti; Paraoanu, G. S.; Oksanen, Mika; Craciun, Monica F.; Russo, Saverio; Sonin, Edouard; Hakonen, Pertti
2016-01-01
The inherent asymmetry of the electric transport in graphene is attributed to Klein tunneling across barriers defined by p n interfaces between positively and negatively charged regions. By combining conductance and shot noise experiments, we determine the main characteristics of the tunneling barrier (height and slope) in a high-quality suspended sample with Au/Cr/Au contacts. We observe an asymmetric resistance Rodd=100 -70 Ω across the Dirac point of the suspended graphene at carrier density | nG|=(0.3 -4 ) × 1011cm-2 , while the Fano factor displays a nonmonotonic asymmetry in the range Fodd˜0.03 -0.1. Our findings agree with analytical calculations based on the Dirac equation with a trapezoidal barrier. Comparison between the model and the data yields the barrier height for tunneling, an estimate of the thickness of the p n interface d <20 nm, and the contact region doping corresponding to a Fermi level offset of ˜-18 meV. The strength of pinning of the Fermi level under the metallic contact is characterized in terms of the contact capacitance Cc=19 ×10-6 F/cm2 . Additionally, we show that the gate voltage corresponding to the Dirac point is given by the difference in work functions between the backgate material and graphene.
Final state problem for the cubic nonlinear Klein-Gordon equation
Hayashi, Nakao; Naumkin, Pavel I.
2009-10-15
We study the final state problem for the nonlinear Klein-Gordon equation, u{sub tt}+u-u{sub xx}={mu}u{sup 3}, t is an element of R,x is an element of R, where {mu} is an element of R. We prove the existence of solutions in the neighborhood of the approximate solutions 2 Re U(t)w{sub +}(t), where U(t) is the free evolution group defined by U(t)=F{sup -1}e{sup -it<{xi}}{sup >}F,
A Multiple Particle System Equation Underlying the Klein-Gordon-Dirac-Schrödinger Equations
NASA Astrophysics Data System (ADS)
Froedge, D. T.
2012-03-01
The purpose of this paper is to illustrate a fundamental, multiple particle, system equation for which the Klein-Gordon-Dirac-Schrödinger equations are single particle special cases. The basic concept is that there is a broader picture, based on a more general equation that includes the entire system of particles. The first part will be to postulate an equation, and then, by modifying the methods of Path Integrals, develop a solution which describes the internal dynamics as well as particle interactions of quantum particles. The complete function has both real and imaginary, as well as timelike and spacelike parts, each of which are separable into independent expressions that define particle properties. In the same manner that eigenvalues of the Schrödinger equation represents energy levels of an atomic system, particle are eigenvalues in an interacting universe of particles. The Dirac massive and massless equation and solution will be shown as factorable independent components. A clear distinction between the classical and quantum properties of particles is made, increasing the scope of QM. Located at http://www.arxdtf.org/css/system.pdf
Dauvilliers, Y; Baumann, C.; Carlander, B; Bischof, M; Blatter, T; Lecendreux, M; Maly, F; Besset, A; Touchon, J; Billiard, M; Tafti, M; Bassetti, C
2003-01-01
Objective: To determine the role of CSF hypocretin-1 in narcolepsy with and without cataplexy, Kleine-Levin syndrome (KLS), idiopathic and other hypersomnias, and several neurological conditions. Patients: 26 narcoleptic patients with cataplexy, 9 narcoleptic patients without cataplexy, 2 patients with abnormal REM-sleep-associated hypersomnia, 7 patients with idiopathic hypersomnia, 2 patients with post-traumatic hypersomnia, 4 patients with KLS, and 88 patients with other neurological disorders. Results: 23 patients with narcolepsy-cataplexy had low CSF hypocretin-1 levels, while one patient had a normal hypocretin level (HLA-DQB1*0602 negative) and the other two had intermediate levels (familial forms). One narcoleptic patient without cataplexy had a low hypocretin level. One patient affected with post-traumatic hypersomnia had intermediate hypocretin levels. The KLS patients had normal hypocretin levels while asymptomatic, but one KLS patient (also affected with Prader-Willi syndrome) showed a twofold decrease in hypocretin levels during a symptomatic episode. Among the patients without hypersomnia, two patients with normal pressure hydrocephalus and one with unclear central vertigo had intermediate levels. Conclusion: Low CSF hypocretin-1 is highly specific (99.1%) and sensitive (88.5%) for narcolepsy with cataplexy. Hypocretin ligand deficiency appears not to be the major cause for other hypersomnias, with a possible continuum in the pathophysiology of narcolepsy without cataplexy and idiopathic hypersomnia. However, partial hypocretin lesions without low CSF hypocretin-1 consequences cannot be definitely excluded in those disorders. The existence of normal hypocretin levels in narcoleptic patients and intermediate levels in other rare aetiologies needs further investigation, especially for KLS, to establish the functional significance of hypocretin neurotransmission alterations. PMID:14638887
Atalić, Bruno; Fatović-Ferencić, Stella
2009-10-01
The new Appendix A of the European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes, which gives guidelines for accommodation and care of animals and was approved on June 15, 2006, was the main reason the authors decided to investigate the origins of the regulations of animal experiments. Although one might assume that the regulation had its origin in the United Nations conventions, the truth is that its origins are a hundred years old. The authors present a case of the nineteenth-century vivisection controversy brought about by the publication of the Handbook for the Physiological Laboratory in 1873, in which John Burdon-Sanderson, Emanuel Edward Klein, Michael Foster, and Thomas Lauder Brunton described a series of vivisection experiments they performed on animals for research purposes. It was the first case of vivisection to be examined, processed, and condemned for inhuman behavior toward animals before an official body, leading to enactment of the Cruelty to Animals Act in 1876. The case reveals a specific ethos of science in the second half of the nineteenth century, which was characterized by a deep commitment of scientists to the scientific enterprise and their strong belief that science could solve social problems, combined with an overt insensitivity to the suffering of experimental animals. The central figure in the case was Emanuel Edward Klein, a disciple of the Central European medical tradition (Vienna Medical School) and a direct follower of the experimental school of Brücke, Stricker, Magendie, and Bernard. Because of his undisguised attitudes and opinions on the use of vivisection, Klein became a paradigm of the new scientific identity, strongly influencing the stereotypic image of a scientist, and polarizing the public opinion on vivisection in England in the nineteenth century and for some considerable time afterward.
NASA Technical Reports Server (NTRS)
Hall, Dorothy K.; Bayr, Klaus J.; Schoener, Wolfgang; Bindschadler, Robert A.; Chien, Janet Y. L.
2002-01-01
The tongue of the Pasterze Glacier in the eastern Alps of Austria receded more than 1152 m from 1880 to 2001. Landsat and Ikonos satellite data from 1976 to 2001, topographic maps beginning in 1893 and ground measurements were studied. Results show that though satellite images significantly underestimate the width of the Pasterze Glacier tongue due to the presence of morainal material on the surface, they provide an excellent way to measure the recession of the exposed-ice part of the glacier tongue. The rate of change of the terminus as determined using satellite data is found to compare well with ground measurements. Between 1976 and 2001, Landsat-derived measurements show a recession of the terminus of the Pasterze Glacier of 479+/-113 m (at an average rate of 18.4 m a(exp -1) while measurements from the ground showed a recession of 428 m (at an average recession of 17.1 m a(exp -1). Ikonos satellite images from 2000 and 2001 reveal changes in the exposed ice part of the Pasterze tongue, and a decrease in area of the exposed ice part of the tongue of 22,096 sq m. GPS points and a ground survey of the glacier terminus in August 2001 were plotted on a 1-m resolution Ikonos image, and showed the actual terminus shape and location. The nearby Kleines Fleisskees glacier lost 30% of its area between 1984 and 2001, and the area of exposed ice increased by 0.44 sq km, according to Landsat satellite measurements. Recession of both the Pasterze and the Kleines Fleisskees corresponds generally to temperature and precipitation trends, especially increasing summer temperatures, as determined from meteorological data acquired from the Sonnblick Observatory, however the smaller the Kleines FleiSkees reacts more quickly to climate changes than does the Pasterze Glacier.
NASA Astrophysics Data System (ADS)
LeFloch, Philippe G.; Ma, Yue
2016-09-01
The Hyperboloidal Foliation Method (introduced by the authors in 2014) is extended here and applied to the Einstein equations of general relativity. Specifically, we establish the nonlinear stability of Minkowski spacetime for self-gravitating massive scalar fields, while existing methods only apply to massless scalar fields. First of all, by analyzing the structure of the Einstein equations in wave coordinates, we exhibit a nonlinear wave-Klein-Gordon model defined on a curved background, which is the focus of the present paper. For this model, we prove here the existence of global-in-time solutions to the Cauchy problem, when the initial data have sufficiently small Sobolev norms. A major difficulty comes from the fact that the class of conformal Killing fields of Minkowski space is significantly reduced in the presence of a massive scalar field, since the scaling vector field is not conformal Killing for the Klein-Gordon operator. Our method relies on the foliation (of the interior of the light cone) of Minkowski spacetime by hyperboloidal hypersurfaces and uses Lorentz-invariant energy norms. We introduce a frame of vector fields adapted to the hyperboloidal foliation and we establish several key properties: Sobolev and Hardy-type inequalities on hyperboloids, as well as sup-norm estimates, which correspond to the sharp time decay for the wave and the Klein-Gordon equations. These estimates allow us to control interaction terms associated with the curved geometry and the massive field by distinguishing between two levels of regularity and energy growth and by a successive use of our key estimates in order to close a bootstrap argument.
ChemCam investigation of the John Klein and Cumberland drill holes and tailings, Gale crater, Mars
NASA Astrophysics Data System (ADS)
Jackson, R. S.; Wiens, R. C.; Vaniman, D. T.; Beegle, L.; Gasnault, O.; Newsom, H. E.; Maurice, S.; Meslin, P.-Y.; Clegg, S.; Cousin, A.; Schröder, S.; Williams, J. M.
2016-10-01
The ChemCam instrument on the Mars Science Laboratory rover analyzed the rock surface, drill hole walls, tailings, and unprocessed and sieved dump piles to investigate chemical variations with depth in the first two martian drill holes and possible fractionation or segregation effects of the drilling and sample processing. The drill sites are both in Sheepbed Mudstone, the lowest exposed member of the Yellowknife Bay formation. Yellowknife Bay is composed of detrital basaltic materials in addition to clay minerals and an amorphous component. The drill tailings are a mixture of basaltic sediments and diagenetic material like calcium sulfate veins, while the shots on the drill site surface and walls of the drill holes are closer to those pure end members. The sediment dumped from the sample acquisition, processing, and handling subsystem is of similar composition to the tailings; however, due to the specifics of the drilling process the tailings and dump piles come from different depths within the hole. This allows the ChemCam instrument to analyze samples representing the bulk composition from different depths. On the pre-drill surfaces, the Cumberland site has a greater amount of CaO and evidence for calcium sulfate veins, than the John Klein site. However, John Klein has a greater amount of calcium sulfate veins below the surface, as seen in mapping, drill hole wall analysis, and observations in the drill tailings and dump pile. In addition, the Cumberland site does not have any evidence of variations in bulk composition with depth down the drill hole, while the John Klein site has evidence for a greater amount of CaO (calcium sulfates) in the top portion of the hole compared to the middle section of the hole, where the drill sample was collected.
Classical and quantum field-theoretical approach to the non-linear q-Klein-Gordon equation
NASA Astrophysics Data System (ADS)
Plastino, A.; Rocca, M. C.
2016-11-01
In the wake of efforts made Nobre and Rego-Monteiro in EPL, 97 (2012) 41001 and J. Math. Phys., 54 (2913) 103302, we extend them here by developing the conventional Lagrangian treatment of a classical field theory (FT) to the q-Klein-Gordon equation advanced in Phys. Rev. Lett., 106 (2011) 140601 and J. Math. Phys., 54 (2913) 103302 by the same authors, and the quantum theory corresponding to q=\\frac {3} {2} . This makes it possible to generate a putative conjecture regarding black matter. Our theory reduces to the usual FT for q→ 1 .
Finite-size scaling for the ising model on the Möbius strip and the klein bottle.
Kaneda, K; Okabe, Y
2001-03-05
We study the finite-size scaling properties of the Ising model on the Möbius strip and the Klein bottle. The results are compared with those of the Ising model under different boundary conditions, that is, the free, cylindrical, and toroidal boundary conditions. The difference in the magnetization distribution function p(m) for various boundary conditions is discussed in terms of the number of the percolating clusters and the cluster size. We also find interesting aspect-ratio dependence of the value of the Binder parameter at T = T(c) for various boundary conditions. We discuss the relation to the finite-size correction calculations for the dimer statistics.
Finite-Size Scaling for the Ising Model on the Möbius Strip and the Klein Bottle
NASA Astrophysics Data System (ADS)
Kaneda, Kazuhisa; Okabe, Yutaka
2001-03-01
We study the finite-size scaling properties of the Ising model on the Möbius strip and the Klein bottle. The results are compared with those of the Ising model under different boundary conditions, that is, the free, cylindrical, and toroidal boundary conditions. The difference in the magnetization distribution function p\\(m\\) for various boundary conditions is discussed in terms of the number of the percolating clusters and the cluster size. We also find interesting aspect-ratio dependence of the value of the Binder parameter at T = Tc for various boundary conditions. We discuss the relation to the finite-size correction calculations for the dimer statistics.
NASA Astrophysics Data System (ADS)
Ikot, A. N.; Lutfuoglu, B. C.; Ngwueke, M. I.; Udoh, M. E.; Zare, S.; Hassanabadi, H.
2016-12-01
In this paper we use the Nikiforov-Uvarov method to obtain the approximate solutions for the Klein-Gordon equation with the deformed five-parameter exponential-type potential (DFPEP) model. We also obtain solutions for the Schrödinger equation in the presence of DFPEP in non-relativistic limits. In addition, we calculate in the non-relativistic limits thermodynamics properties, such as vibrational mean energy U, free energy F and the specific heat capacity C. Special cases of the potential are also discussed.
Heavily fractionated noble gases in an acid residue from the Klein Glacier 98300 EH3 chondrite
NASA Astrophysics Data System (ADS)
Nakashima, Daisuke; Ott, Ulrich; El Goresy, Ahmed; Nakamura, Tomoki
2010-09-01
Noble gases were measured both in bulk samples (stepped pyrolysis and total extraction) and in a HF/HCl residue (stepped pyrolysis and combustion) from the Klein Glacier (KLE) 98300 EH3 chondrite. Like the bulk meteorite and as seen in previous studies of bulk type 3 E chondrites ("sub-Q"), the acid residue contains elementally fractionated primordial noble gases. As we show here, isotopically these are like those in phase-Q of primitive meteorites, but elementally they are heavily fractionated relative to these. The observed noble gases are different from "normal" Q noble gases also with respect to release patterns, which are similar to those of Ar-rich noble gases in anhydrous carbonaceous chondrites and unequilibrated ordinary chondrites (with also similar isotopic compositions). While we cannot completely rule out a role for parent body processes such as thermal and shock metamorphism (including a later thermal event) in creating the fractionated elemental compositions, parent body processes in general seem not be able to account for the distinct release patterns from those of normal Q noble gases. The fractionated gases may have originated from ion implantation from a nebular plasma as has been suggested for other types of primordial noble gases, including Q, Ar-rich, and ureilite noble gases. With solar starting composition, the corresponding effective electron temperature is about 5000 K. This is lower than inferred for other primordial noble gases (10,000-6000 K). Thus, if ion implantation from a solar composition reservoir was a common process for the acquisition of primordial gas, electron temperatures in the early solar system must have varied spatially or temporally between 10,000 and 5000 K. Neon and xenon isotopic ratios of the residue suggest the presence of presolar silicon carbide and diamond in abundances lower than in the Qingzhen EH3 and Indarch EH4 chondrites. Parent body processes including thermal and shock metamorphism and a late thermal
Quantum mechanics of Klein-Gordon-type fields and quantum cosmology
NASA Astrophysics Data System (ADS)
Mostafazadeh, Ali
2004-01-01
With a view to address some of the basic problems of quantum cosmology, we formulate the quantum mechanics of the solutions of a Klein-Gordon-type field equation: (∂t2+D)ψ(t)=0, where t∈R and D is a positive-definite operator acting in a Hilbert space H~. In particular, we determine all the positive-definite inner products on the space H of the solutions of such an equation and establish their physical equivalence. This specifies the Hilbert space structure of H uniquely. We use a simple realization of the latter to construct the observables of the theory explicitly. The field equation does not fix the choice of a Hamiltonian operator unless it is supplemented by an underlying classical system and a quantization scheme supported by a correspondence principle. In general, there are infinitely many choices for the Hamiltonian each leading to a different notion of time-evolution in H. Among these is a particular choice that generates t-translations in H and identifies t with time whenever D is t-independent. For a t-dependent D, we show that regardless of the choice of the inner product the t-translations do not correspond to unitary evolutions in H, and t cannot be identified with time. We apply these ideas to develop a formulation of quantum cosmology based on the Wheeler-DeWitt equation for a Friedman-Robertson-Walker model coupled to a real scalar field with an arbitrary positive confining potential. In particular, we offer a complete solution of the Hilbert space problem, construct the observables, use a position-like observable to introduce the wave functions of the universe (which differ from the Wheeler-DeWitt fields), reformulate the corresponding quantum theory in terms of the latter, reduce the problem of the identification of time to the determination of a Hamiltonian operator acting in L2(R)⊕L2(R), show that the factor-ordering problem is irrelevant for the kinematics of the quantum theory, and propose a formulation of the dynamics. Our method is
Chen, Lvyi; Mola, Mahmutjian; Deng, Xukun; Mei, Zhinan; Huang, Xianju; Shu, Guangwen; Wei, Liuhong; Hou, Xiaomin; Lan, Zhou; Lin, Qinxiong
2013-11-25
Dolichos falcata Klein (DF), a Chinese Dai ethnic medicine popularly known as "Tuoyeteng" in Yunnan province of China, has been widely used as a traditional herbal medicine for the treatment of fracture and beriberoid disease for a long time in China. The present study was carried out to investigate the anti-inflammatory activity and the bioactive chemical constituents of DF, and further to assess its possible mechanism on gouty arthritis in an animal model of the MSU crystals-induced gouty inflammation. The ethanol extract (EE) of DF at the doses of 10, 20 and 40 mg/kg was administered to the rats treated with MSU crystals to evaluate the anti-gouty arthritis effect. Subsequently, the components of EE were isolated and identified using classical methods. Phyto-chemical analysis of EE was further carried out by HPLC-DAD. Finally, the anti-inflammatory effect of EE and two isolated components were assessed using the MSU crystals-treated monocyte/macrophage cell line RAW 264.7 in vitro. EE (10, 20 and 40 mg/kg) significantly attenuated the pain threshold value, the joint swelling degree, the inflammatory cell infiltration of articular tissue and the increased levels of pro-inflammatory cytokines in MSU crystals-treated rats. Moreover, doliroside A (DA) and medicagenic acid-3-O-β-D-glucopyranoside (MG) were isolated and identified from EE. The major components of EE, including DA, MG and other triterpenoids, were well confirmed by HPLC. A further study revealed that EE, DA and MG (10, 20, 40μg/mL) exhibited stronger inhibitory effects on the production of pro-inflammatory cytokines (including interleukin-1β, interleukin-6 and tumor necrosis factor-α) in MSU crystals-treated RAW 264.7 cells. These findings indicate that the major triterpenoids present in DF have a remarkable effect on improving symptoms of acute gouty arthritis induced by MSU crystals through inhibiting the production of pro-inflammatory cytokines. © 2013 Elsevier Ireland Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Garcia, M. G.; de Castro, A. S.; Castro, L. B.; Alberto, P.
2017-03-01
New exact analytical bound-state solutions of the D-dimensional Klein-Gordon equation for a large set of couplings and potential functions are obtained via mapping onto the nonrelativistic bound-state solutions of the one-dimensional generalized Morse potential. The eigenfunctions are expressed in terms of generalized Laguerre polynomials, and the eigenenergies are expressed in terms of solutions of irrational equations at the worst. Several analytical results found in the literature, including the so-called Klein-Gordon oscillator, are obtained as particular cases of this unified approach.
NASA Astrophysics Data System (ADS)
Suárez, Abril; Chavanis, Pierre-Henri
2015-07-01
Using a generalization of the Madelung transformation, we derive the hydrodynamic representation of the Klein-Gordon-Einstein equations in the weak field limit. We consider a complex self-interacting scalar field with a λ |φ |4 potential. We study the evolution of the spatially homogeneous background in the fluid representation and derive the linearized equations describing the evolution of small perturbations in a static and in an expanding Universe. We compare the results with simplified models in which the gravitational potential is introduced by hand in the Klein-Gordon equation, and assumed to satisfy a (generalized) Poisson equation. Nonrelativistic hydrodynamic equations based on the Schrödinger-Poisson equations or on the Gross-Pitaevskii-Poisson equations are recovered in the limit c →+∞. We study the evolution of the perturbations in the matter era using the nonrelativistic limit of our formalism. Perturbations whose wavelength is below the Jeans length oscillate in time while perturbations whose wavelength is above the Jeans length grow linearly with the scale factor as in the cold dark matter model. The growth of perturbations in the scalar field model is substantially faster than in the cold dark matter model. When the wavelength of the perturbations approaches the cosmological horizon (Hubble length), a relativistic treatment is mandatory. In that case, we find that relativistic effects attenuate or even prevent the growth of perturbations. This paper exposes the general formalism and provides illustrations in simple cases. Other applications of our formalism will be considered in companion papers.
NASA Astrophysics Data System (ADS)
Hack, Thomas-Paul
2014-11-01
We quantize the linearized Einstein-Klein-Gordon system on arbitrary on-shell backgrounds in a manifestly covariant and gauge-invariant manner. For the special case of perturbations in inflation, i.e. on-shell backgrounds of Friedmann-Lemaître-Robertson-Walker type, we compare our general quantization construction with the standard approach to the quantum theory of perturbations in inflation. We find that not all local quantum observables of the linearized Einstein-Klein-Gordon system can be split into local observables of scalar and tensor type as in the standard approach. However, we argue that this subclass of observables is sufficient for measuring perturbations that vanish at spatial infinity, which is in line with standard assumptions. Finally, we comment on a recent observation that, upon standard quantization, the quantum Bardeen potentials display a non-local behaviour and argue that a similar phenomenon occurs in any local quantum field theory. It is the hope of the author that the present work may constitute a bridge between the generally applicable and thus powerful framework of algebraic quantum field theory in curved spacetimes and the standard treatment of perturbations in inflation.
NASA Astrophysics Data System (ADS)
Li, Pengcheng; Zhang, Zhongzhi
2012-07-01
In this paper, we present an extensive analytical study of continuous-time quantum walks (CTQWs) occurring on two-dimensional lattices under various boundary conditions, focusing on the M × N lattice wrapped on Möbius strips and Klein bottles, which are featured by the twisted boundary conditions. We find that the eigenvalue spectra and transport efficiency (both quantum mechanical and classical) for the two structures show comparable results with those for other well-known two-dimensional lattices, including rectangles, cylinders and tori. We also demonstrate that the behaviors of CTQWs depend on the initial node of the excitation and the network size, both on short and long timescales. In addition, we discover the asymmetric behaviors of limiting probabilities for Möbius strips and Klein bottles, which are quite different from each other and are also compared to those discovered in other two-dimensional networks. Our work provides a comprehensive understanding of recent results about CTQWs on two-dimensional lattices, and sheds light on quantum dynamics on lattices, especially those with different boundary conditions.
Quantum Gravitational Corrections to the Real Klein-Gordon Field in the Presence of a Minimal Length
NASA Astrophysics Data System (ADS)
Moayedi, S. K.; Setare, M. R.; Moayeri, H.
2010-09-01
The ( D+1)-dimensional ( β, β')-two-parameter Lorentz-covariant deformed algebra introduced by Quesne and Tkachuk (J. Phys., A Math. Gen. 39, 10909, 2006), leads to a nonzero minimal uncertainty in position (minimal length). The Klein-Gordon equation in a (3+1)-dimensional space-time described by Quesne-Tkachuk Lorentz-covariant deformed algebra is studied in the case where β'=2 β up to first order over deformation parameter β. It is shown that the modified Klein-Gordon equation which contains fourth-order derivative of the wave function describes two massive particles with different masses. We have shown that physically acceptable mass states can only exist for β<1/8m^{2c2} which leads to an isotropic minimal length in the interval 10-17 m<(Δ X i )0<10-15 m. Finally, we have shown that the above estimation of minimal length is in good agreement with the results obtained in previous investigations.
Sergyeyev, Artur; Krtous, Pavel
2008-02-15
We consider the Klein-Gordon equation in generalized higher-dimensional Kerr-NUT-(A)dS spacetime without imposing any restrictions on the functional parameters characterizing the metric. We establish commutativity of the second-order operators constructed from the Killing tensors found in [J. High Energy Phys. 02 (2007) 004] and show that these operators, along with the first-order operators originating from the Killing vectors, form a complete set of commuting symmetry operators (i.e., integrals of motion) for the Klein-Gordon equation. Moreover, we demonstrate that the separated solutions of the Klein-Gordon equation obtained in [J. High Energy Phys. 02 (2007) 005] are joint eigenfunctions for all of these operators. We also present an explicit form of the zero mode for the Klein-Gordon equation with zero mass. In the semiclassical approximation we find that the separated solutions of the Hamilton-Jacobi equation for geodesic motion are also solutions for a set of Hamilton-Jacobi-type equations which correspond to the quadratic conserved quantities arising from the above Killing tensors.
NASA Astrophysics Data System (ADS)
Hatami, N.; Setare, M. R.
2017-10-01
We present approximate analytical solutions of the Klein-Gordon equation with arbitrary l state for the Manning-Rosen potential using the Nikiforov-Uvarov method and adopting the approximation scheme for the centrifugal term. We provide the bound state energy spectrum and the wave function in terms of the hypergeometric functions.
NASA Astrophysics Data System (ADS)
Wu, Shu-Rui; Long, Zheng-Wen; Long, Chao-Yun; Wang, Bing-Quan; Liu, Yun
2017-09-01
The (2+1)-dimensional Klein-Gordon oscillator under a magnetic field in the presence of a minimal length in the noncommutative (NC) space is analyzed via the momentum space representation. Energy eigenvalue of the system is obtained by employing the Jacobi polynomials. In further steps, the special cases are discussed and the corresponding numerical results are depicted, respectively.
ERIC Educational Resources Information Center
Rothstein, Richard
2010-01-01
Joel Klein, chancellor of the New York City public school system, and Michelle Rhee, who resigned October 13 as Washington, D.C. chancellor, published a "manifesto" in the "Washington Post" claiming that the difficulty of removing incompetent teachers "has left our school districts impotent and, worse, has robbed millions…
Ising model on nonorientable surfaces: exact solution for the Möbius strip and the Klein bottle.
Lu, W T; Wu, F Y
2001-02-01
Closed-form expressions are obtained for the partition function of the Ising model on an MxN simple-quartic lattice embedded on a Möbius strip and a Klein bottle. The solutions all lead to the same bulk free energy, but for finite M and N the expressions are different depending on whether the strip width M is odd or even. Finite-size corrections at criticality are analyzed and compared with those under cylindrical and toroidal boundary conditions. Our results are consistent with the conformal field prediction of a central charge c=1/2, provided that the twisted Möbius boundary condition is regarded as a free or fixed boundary.
Ising model on nonorientable surfaces: Exact solution for the Möbius strip and the Klein bottle
NASA Astrophysics Data System (ADS)
Lu, Wentao T.; Wu, F. Y.
2001-02-01
Closed-form expressions are obtained for the partition function of the Ising model on an M×N simple-quartic lattice embedded on a Möbius strip and a Klein bottle. The solutions all lead to the same bulk free energy, but for finite M and N the expressions are different depending on whether the strip width M is odd or even. Finite-size corrections at criticality are analyzed and compared with those under cylindrical and toroidal boundary conditions. Our results are consistent with the conformal field prediction of a central charge c=1/2, provided that the twisted Möbius boundary condition is regarded as a free or fixed boundary.
NASA Astrophysics Data System (ADS)
Khodja, A.; Kadja, A.; Benamira, F.; Guechi, L.
2017-07-01
The problem of a Klein-Gordon particle moving in equal vector and scalar Rosen-Morse-type potentials is solved in the framework of Feynman's path integral approach. Explicit path integration leads to a closed form for the radial Green's function associated with different shapes of the potentials. For q≤-1 , and 1/2α ln | q|
NASA Astrophysics Data System (ADS)
Li, Zhenglu; Cao, Ting; Wu, Meng; Louie, Steven G.
2017-04-01
Artificial lattices have been employed in many two-dimensional systems, including those of electrons, atoms and photons, in a quest for massless Dirac particles with flexibility and controllability. Periodically patterned molecule assembly and electrostatic gating as well as moir\\'e pattern induced by substrate, have produced electronic states with linear dispersions from isotropic two-dimensional electron gas (2DEG). Here we demonstrate that massless Dirac fermions with tunable anisotropic characteristics can, in general, be generated in highly anisotropic 2DEG under slowly varying external periodic potentials. For patterned few-layer black phosphorus superlattices, the new chiral quasiparticles exist exclusively in an isolated energy window and inherit the strong anisotropic properties of pristine black phosphorus. These states exhibit asymmetric Klein tunneling with the direction of incidence for wave packet with perfect transmission deviating from normal incidence by more than 50{\\deg} under an appropriate barrier orientation.
Benamira, F.; Guechi, L.; Mameri, S.; Sadoun, M. A.
2010-03-15
The Green's function for a Klein-Gordon particle under the action of vector plus scalar deformed Hulthen and Woods-Saxon potentials is evaluated by exact path integration. Explicit path integration leads to the Green's function for different shapes of the potentials. From the singularities of the latter Green's function, the bound states are extracted. For q{>=}1 and (1/{alpha})ln q
2004-03-13
NASA DC-8 Mission Manager Walter Klein and Chilean Air Force Advisor Captain Saez review maps of the Antarctic Peninsula during an AirSAR 2004 mission. AirSAR 2004 is a three-week expedition in Central and South America by an international team of scientists that is using an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR), located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world are combining ground research with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. These photos are from the DC-8 aircraft while flying an AirSAR mission over Antarctica. The Antarctic Peninsula is more similar to Alaska and Patagonia than to the rest of the Antarctic continent. It is drained by fast glaciers, receives abundant precipitation, and melts significantly in the summer months. In recent decades, the Peninsula has experienced significant atmospheric warming (about 2 degrees C since 1950), which has triggered a vast and spectacular retreat of its floating ice shelves, glacier reduction, a decrease in permanent snow cover and a lengthening of the melt season. As a result, the contribution to sea level from this region could be rapid and substantial. With an area of 120,000 km, or ten times the Patagonia ice fields, the Peninsula could contribute as much as 0.4mm/yr sea level rise, which would be the largest single contribution to sea level from anywhere in the world. This region is being studied by NASA using a DC-8 equipped with the Airborne Synthetic Aperture Radar developed by scientists from NASA’s Jet Propulsion Laboratory. AirSAR will provide a baseline model and unprecedented mapping of the region. This data will make it possible to determine whether the warming trend is slowing, continuing or accelerating. AirSAR will also provide reliable information on ice shelf thickness to measure the contribution of the glaciers to sea level.
Normand, Jacques; Li, Jih-Heng; Thomson, Nicholas; Jarlais, Don Des
2014-01-01
The “Harm Reduction” session was chaired by Dr. Jacques Normand, Director of the AIDS Research Program of the U.S. National Institute on Drug Abuse. The three presenters (and their presentation topics) were: Dr. Don Des Jarlais (High Coverage Needle/Syringe Programs for People Who Inject Drugs in Low and Middle Income Countries: A Systematic Review), Dr. Nicholas Thomson (Harm Reduction History, Response, and Current Trends in Asia), and Dr. Jih-Heng Li (Harm Reduction Strategies in Taiwan). PMID:25278732
ERIC Educational Resources Information Center
Bray, Marilyn; And Others
1996-01-01
Presents activities that focus on waste reduction in the school and community. The ideas are divided into grade level categories. Sample activities include Techno-Trash, where children use tools to take apart broken appliances or car parts, then reassemble them or build new creations. Activities are suggested for areas including language arts and…
Hakky, Tariq S.; Martinez, Daniel; Yang, Christopher; Carrion, Rafael E.
2015-01-01
Objective Here we present the first video demonstration of reduction corporoplasty in the management of phallic disfigurement in a 17 year old man with a history sickle cell disease and priapism. Introduction Surgical management of aneurysmal dilation of the corpora has yet to be defined in the literature. Materials and Methods: We preformed bilateral elliptical incisions over the lateral corpora as management of aneurysmal dilation of the corpora to correct phallic disfigurement. Results The patient tolerated the procedure well and has resolution of his corporal disfigurement. Conclusions Reduction corporoplasty using bilateral lateral elliptical incisions in the management of aneurysmal dilation of the corpora is a safe an feasible operation in the management of phallic disfigurement. PMID:26005988
Dziewinski, Jacek J.; Marczak, Stanislaw
2000-01-01
Nitrates are reduced to nitrogen gas by contacting the nitrates with a metal to reduce the nitrates to nitrites which are then contacted with an amide to produce nitrogen and carbon dioxide or acid anions which can be released to the atmosphere. Minor amounts of metal catalysts can be useful in the reduction of the nitrates to nitrites. Metal salts which are formed can be treated electrochemically to recover the metals.
NASA Astrophysics Data System (ADS)
Khader, M. M.; Adel, M.
2016-09-01
In this paper, we implement the fractional complex transform method to convert the nonlinear fractional Klein-Gordon equation (FKGE) to an ordinary differential equation. We use the variational iteration method (VIM) to solve the resulting ODE. The fractional derivatives are presented in terms of the Caputo sense. Some numerical examples are presented to validate the proposed techniques. Finally, a comparison with the numerical solution using Runge-Kutta of order four is given.
2004-03-03
Airborne Science personnel Walter Klein and David Bushman at the Mission Manager's console onboard NASA's DC-8 during the AirSAR 2004 campaign. AirSAR 2004 is a three-week expedition by an international team of scientists that will use an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR), in a mission ranging from the tropical rain forests of Central America to frigid Antarctica.
NASA Astrophysics Data System (ADS)
Arya Nugraha, Dewanta; Suparmi, A.; Cari, C.; Nur Pratiwi, Beta
2017-01-01
Klein-Gordon equation for Trigonometric Pöschl-Teller Potential in D-dimensions was obtained within framework of a centrifugal term approximation. Asymptotic iteration method was used to obtain the relativistic energy spectrum and wave functions. The value of relativistic energy was calculated numerically and the results have shown that in higher dimension the energy level is increased with positive energy states. The wave functions were expressed in hypergeometric term.
NASA Astrophysics Data System (ADS)
Liu, Changying; Wu, Xinyuan
2017-07-01
In this paper we explore arbitrarily high-order Lagrange collocation-type time-stepping schemes for effectively solving high-dimensional nonlinear Klein-Gordon equations with different boundary conditions. We begin with one-dimensional periodic boundary problems and first formulate an abstract ordinary differential equation (ODE) on a suitable infinity-dimensional function space based on the operator spectrum theory. We then introduce an operator-variation-of-constants formula which is essential for the derivation of our arbitrarily high-order Lagrange collocation-type time-stepping schemes for the nonlinear abstract ODE. The nonlinear stability and convergence are rigorously analysed once the spatial differential operator is approximated by an appropriate positive semi-definite matrix under some suitable smoothness assumptions. With regard to the two dimensional Dirichlet or Neumann boundary problems, our new time-stepping schemes coupled with discrete Fast Sine / Cosine Transformation can be applied to simulate the two-dimensional nonlinear Klein-Gordon equations effectively. All essential features of the methodology are present in one-dimensional and two-dimensional cases, although the schemes to be analysed lend themselves with equal to higher-dimensional case. The numerical simulation is implemented and the numerical results clearly demonstrate the advantage and effectiveness of our new schemes in comparison with the existing numerical methods for solving nonlinear Klein-Gordon equations in the literature.
NASA Astrophysics Data System (ADS)
Chang, Shu-Chiuan; Shrock, Robert
2006-05-01
We present a method for calculating transfer matrices for the q-state Potts model partition functions Z(G,q,v), for arbitrary q and temperature variable v, on strip graphs G of the square (sq), triangular (tri), and honeycomb (hc) lattices of width Ly vertices and of arbitrarily great length Lx vertices, subject to toroidal and Klein-bottle boundary conditions. For the toroidal case we express the partition function as Z(Λ,Ly×Lx,q,v)=∑d=0Ly ∑ bj(d)(λ)m, where Λ denotes lattice type, bj(d) are specified polynomials of degree d in q, λ are eigenvalues of the transfer matrix T in the degree- d subspace, and m=Lx ( Lx/2) for Λ=sq,tri (hc), respectively. An analogous formula is given for Klein-bottle strips. We exhibit a method for calculating T for arbitrary Ly. In particular, we find some very simple formulas for the determinant det(T), and trace Tr(T). Illustrative examples of our general results are given, including new calculations of transfer matrices for Potts model partition functions on strips of the square, triangular, and honeycomb lattices with toroidal or Klein-bottle boundary conditions.
Riedel, Melanie; Speer, Karl; Stuke, Sven; Schmeer, Karl
2010-01-01
Since 2003, two new multipesticide residue methods for screening crops for a large number of pesticides, developed by Klein and Alder and Anastassiades et al. (Quick, Easy, Cheap, Effective, Rugged, and Safe; QuEChERS), have been published. Our intention was to compare these two important methods on the basis of their extraction efficiency, reproducibility, ruggedness, ease of use, and speed. In total, 70 pesticides belonging to numerous different substance classes were analyzed at two concentration levels by applying both methods, using five different representative matrixes. In the case of the QuEChERS method, the results of the three sample preparation steps (crude extract, extract after SPE, and extract after SPE and acidification) were compared with each other and with the results obtained with the Klein and Alder method. The extraction efficiencies of the QuEChERS method were far higher, and the sample preparation was much quicker when the last two steps were omitted. In most cases, the extraction efficiencies after the first step were approximately 100%. With extraction efficiencies of mostly less than 70%, the Klein and Alder method did not compare favorably. Some analytes caused problems during evaluation, mostly due to matrix influences.
NASA Astrophysics Data System (ADS)
Jamal, Sameerah; Shabbir, Ghulam
2017-02-01
We study the geometric properties of generators for the Klein-Gordon equation in Kantowski-Sachs and certain Bianchi-type spaces. Several versions of the Klein-Gordon equation are derived from its dependence on a potential function. The criteria for different versions of the (1+3) Klein-Gordon equation originates from analyzing three sources, viz. through generators that are identically the Killing algebra, or with the Killing vector fields that are recast into linear combinations and thirdly, real sub-algebras within the conformal algebra. In turn, these equations admit a catalogue of infinitesimal symmetries that are equivalent to the corresponding Killing vector fields in Kantowski-Sachs, Bianchi type III, IX, VIII, VI0 and VII0 space-times, with the exception of a linear vector W=upartialu in every case. The sheer number of results are displayed in appropriate tables. Subsequently, in application, we derive some Noetherian conservation laws and identify some exact solutions by quadratures.
NASA Astrophysics Data System (ADS)
Jafarnejad, Mona; Pfister, Michael; Franca, Mário J.; Schleiss, Anton J.
2014-05-01
Potential failure for river bank protection measures is a critical issue to be evaluated for the safety and stability assessment. Moreover, uncertainties associated to flood conditions and sediment transport in rivers, as a possible result of climate change in the future, affects the safety level of such riverbank protection structures as riprap and walls. Bank failure can lead to uncontrolled erosion and flooding with disastrous consequences in residential areas or in critical infrastructures. The probabilistic analysis of failure on different mechanisms due to possible flood events and sediment transport is a principal step to assess embankment stability in future scenarios. Herein, a probabilistic risk assessment model to define the failure risk of river bank ripraps, developed based on Monte Carlo simulation and Moment Analysis Methods, is showed. This probabilistic simulation estimates the resistance of ripraps regarding varied flood and sediment transport scenarios in future. The failure probability of ripraps is assessed by a probabilistic function of the design safety factor. The probability of failure in different mechanisms such as direct block erosion, toe scouring and overtopping is defined by taking into account the modified bed-load transport due to a probabilistic function of the design discharge. This evaluation method is applied to a Swiss river located in Canton Lucerne, the Kleine Emme. The results highlight the failure probability of riverbank riprap associated to different mechanisms individually. A risk map to represent the risk of total failure along a longitudinal profile of the river is proposed.
Li, Zhenglu; Cao, Ting; Wu, Meng; Louie, Steven G
2017-03-02
Artificial lattices have been employed in a broad range of two-dimensional systems, including those with electrons, atoms, and photons, in the quest for massless Dirac fermions with high flexibility and controllability. Establishing triangular or hexagonal symmetry, from periodically patterned molecule assembly or electrostatic gating as well as from moiré pattern induced by substrate, has produced electronic states with linear dispersions from two-dimensional electron gas (2DEG) residing in semiconductors, metals, and graphene. Different from the commonly studied isotropic host systems, here we demonstrate that massless Dirac fermions with tunable anisotropic characteristics can, in general, be generated in highly anisotropic 2DEG under slowly varying external periodic potentials. In the case of patterned few-layer black phosphorus superlattices, the new chiral quasiparticles exist exclusively in certain isolated energy window and inherit the strong anisotropic properties of pristine black phosphorus. These states exhibit asymmetric Klein tunneling, in which the transmission probability of the wave packets with normal incidence is no longer unity and can be tuned and controlled. In general, the direction of wave packet incidence for perfect transmission and that of the normal incidence are different, and the difference can reach more than 50° under an appropriate barrier orientation in black phosphorus superlattices. Our findings provide insight into the understanding and possible utilization of these novel emergent chiral quasiparticles.
Grotstein, J S
1997-10-01
The ancient Greek myth linking the images of the labyrinth and the Minotaur provides an allegory for Melanie Klein's conception of the archaic Oedipus complex as well as a vivid illustration of Winnicott's notions of object usage and the 'subjective object'. The labyrinth is suggestive of mother's body as the first area for an infant's exploration and putative sadistic conquest. The Minotaur, in turn, suggests the infant's unconscious phantasies about the content of mother's body, namely such projective identifications onto that body as the paternal penis and the 'internal babies'. Further, the heroic dynamic personified by Theseus in the myth of the labyrinth metaphorically signifies what is here proposed as a developmental line that involves the courage to do a number of things, including to become, to create, to seek, to explore, to do, to challenge, to undertake risks, to accept, to rescue, to initiate, to think, to know and to realize. The Minotaur can thus be thought to serve as a universal subjective signifier for an 'Object of Challenge', which, if not successfully dealt with by the ego-development of the infant, transforms that default into the 'Object of Nemesis'. Ultimately, this myth of mastery speaks to the psychoanalytic process itself as well as casting light on the transformative aspects of sexual intercourse as a personal healing ritual.
NASA Astrophysics Data System (ADS)
Moreno, Carlos
1980-06-01
In a space-time (V n × R;g) with Vn closed ( n ≠ 2) satisfying certain global conditions, we can write the Klein-Gordon equation, relative to a suitable class of atlases, in the evolution form du/ dt = T-1( t) u, on Sobolev spaces Kl( Vn) = Hl( Vn) × Hl-1 ( Vn), where the spectrum of T-1( t) is imaginary. Following papers by T. Kato and J. Kisyński we prove the existence of the evolution operator for this equation. The space K {1}/{2}(V n) has a natural strongly-symplectic structure ω. We determine the explicit form of complex-structure-positive operators of this structure. We prove that any two such operators, say J1, J2, are symplectically equivalent, (i.e. there is a symplectic transformation S such that J2 = SJ1S-1). Spaces of positive and negative frequency solutions are then unique modulo symplectic equivalence. Each operator J determines a regular kernel on space-time which satisfies the properties of the kernel postulated by A. Lichnérowich in his program of quantization of fields in curved space-times. We carry out explicit calculations in the case of Robertson-Walker space-times. If an additional condition is satisfied by the given space-time, a unique complex-structure-positive operator can be selected in a natural way. This condition is satisfied by globally stationary space-times.
Several solutions of the Klein-Gordon equation in Kerr-Newman spacetime and the BSW effect
NASA Astrophysics Data System (ADS)
Yumisaki, Hikaru
2017-06-01
We investigate the radial part of the charged massive Klein-Gordon equation in Kerr-Newman spacetime, and in several specific situations, obtain exact solutions by means of essentially hypergeometric functions or their confluent types. Using these global solutions and generally obtained local solutions, we calculate a sort of intensity of the collision of two field excitations, which is a slight generalization of the trace of the stress tensor. We find that when the black hole is nonextremal, the intensity of the collision of two ingoing modes is bounded. However, in the extremal limit, more precisely \\hbar \\kappa_H \\rArr 0, the upper bound grows so that when the frequency of one of the two modes satisfies the critical relation, the intensity of the collision at the horizon becomes unboundedly large. Furthermore, the intensity of the collision of ingoing and outgoing modes is always unbounded, as well as in the classical particle theory. Our results suggest that the BSW effect is inherited by the quantum theory.
Prado de Oliveira, L E
1995-01-01
Starting from The Freud-Klein Controversies, the author explores the historical reality of these controversies and their transformations into myth which give them the appearance of titanic fights. The verification of the different periods, the description of the variations in themes and style of intervention of the principal actors of these debates show aspects of the way a psychoanalytic institute works and of the theoretical elaboration in psychoanalysis: these appear very different from what the myth suggests. The major function of myth is, as Freud noted and Strachey reminds us, to hide very trite, even shameful realities. History and myth, theoritical effort and institutional life are all organized from and around transference, a major axis of psychoanalytic thought. When we organize our psychoanalytic lives in societies, we have the pride or the vanity of participating in a great historical movement. This goes back to the work of transference in institutional life that involves primal objects in the crudeness of their sexuality. Such is the constraining strength of transference. Being fully conscious of it, like Stratchey or Balint show us, enables to alleviate its violence and stimulate creativity.
The elusive concept of 'internal objects' (1934-1943). Its role in the formation of the Klein Group.
Hinshelwood, R D
1997-10-01
The author traces a debate about the concept of 'internal objects' that took place between 1937 and 1943 at a time when a group of British analysts was forming around Melanie Klein. The debate is set within a complex of personal, group and organisational dynamics, which the paper makes a start on unravelling. The history of the British Psycho-Analytical Society at this time exemplifies Bion's notion of group schism. The events in the Society's history demonstrate defensive aspects of the interaction between the opposed groups, which support members against various anxieties. These include the stress of the work of analysis, but also in this instance the particular anxieties deriving from the collapse of psychoanalysis in Europe, the state of war of the country as a whole, and the death of Freud shortly after he came to London. This psychoanalytic anxiety/defence model clarifies some aspects of the debate about internal objects, and demonstrates the way in which these various anxieties and defences become organised around a scientific debate in a scientific society.
2004-03-08
NASA Dryden Mission Manager Walter Klein poses with school children that visited the airport during AirSAR 2004. In spanish, he explained to them the mission of the DC-8 AirSAR 2004 Mesoamerican campaign in Costa Rica. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that uses an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central America with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. The radar, developed by NASA's Jet Propulsion Laboratory, can penetrate clouds and also collect data at night. Its high-resolution sensors operate at multiple wavelengths and modes, allowing AirSAR to see beneath treetops, through thin sand, and dry snow pack. AirSAR's 2004 campaign is a collaboration of many U.S. and Central American institutions and scientists, including NASA; the National Science Foundation; the Smithsonian Institution; National Geographic; Conservation International; the Organization of Tropical Studies; the Central American Commission for Environment and Development; and the Inter-American Development Bank.
Next-to-leading-order QCD corrections to graviton production at hadron colliders
Karg, Stefan; Kraemer, Michael; Li, Qiang; Zeppenfeld, Dieter
2010-05-01
Models with large extra dimensions predict the existence of Kaluza-Klein graviton resonances. We compute the next-to-leading-order QCD corrections to graviton plus jet hadro-production, which is an important channel for graviton searches at the Tevatron and the LHC. The QCD corrections are sizable and lead to a significant reduction of the scale dependence. We present numerical results for cross sections and distributions, and discuss the uncertainty from parton distribution functions and the ultraviolet sensitivity of the theoretical prediction.
Vector boson production in association with KK modes of the ADD model to NLO in QCD at the LHC
NASA Astrophysics Data System (ADS)
Kumar, M. C.; Mathews, Prakash; Ravindran, V.; Seth, Satyajit
2011-05-01
Next-to-leading order (NLO) QCD corrections to the associated production of the vector boson (Z/W±) with the Kaluza-Klein (KK) modes of the graviton in large extra-dimensional model at the Large Hadron Collider (LHC) are presented. We have obtained various kinematic distributions using a Monte Carlo code which is based on the two-cutoff phase space slicing method that handles soft and collinear singularities appearing at the NLO level. We estimate the impact of the QCD corrections on various observables and find that they are significant. We also show the reduction in factorization scale uncertainty when QCD corrections are included.
Dual technicolor with hidden local symmetry
Belitsky, A. V.
2010-08-15
We consider a dual description of the technicolor-like gauge theory within the D4/D8-brane configuration with varying confinement and electroweak symmetry breaking scales. Constructing an effective truncated model valid below a certain cutoff, we identify the particle spectrum with Kaluza-Klein modes of the model in a manner consistent with the hidden local symmetry. Integrating out heavy states, we find that the low-energy action receives nontrivial corrections stemming from the mixing between standard model and heavy gauge bosons, which results in reduction of oblique parameters.
Completeness of inextensible electromagnetic trajectories in a stationary spacetime
NASA Astrophysics Data System (ADS)
de la Fuente, Daniel; Romero, Alfonso
2017-07-01
A new technique is introduced to study the completeness of inextensible electromagnetic trajectories in an n(≥ 2) -dimensional stationary spacetime. Sufficient conditions on an electromagnetic field on a stationary spacetime are imposed to ensure that the associated (n + 1) -dimensional Kaluza-Klein bundle spacetime is itself stationary. The problem is then reduced to the geodesic completeness of the corresponding Kaluza-Klein bundle spacetime. Applications are given specially to the case of a standard static spacetime.
Gallet, Basile; Nazarenko, Sergey; Dubrulle, Bérengère
2015-07-01
In field theory, particles are waves or excitations that propagate on the fundamental state. In experiments or cosmological models, one typically wants to compute the out-of-equilibrium evolution of a given initial distribution of such waves. Wave turbulence deals with out-of-equilibrium ensembles of weakly nonlinear waves, and is therefore well suited to address this problem. As an example, we consider the complex Klein-Gordon equation with a Mexican-hat potential. This simple equation displays two kinds of excitations around the fundamental state: massive particles and massless Goldstone bosons. The former are waves with a nonzero frequency for vanishing wave number, whereas the latter obey an acoustic dispersion relation. Using wave-turbulence theory, we derive wave kinetic equations that govern the coupled evolution of the spectra of massive and massless waves. We first consider the thermodynamic solutions to these equations and study the wave condensation transition, which is the classical equivalent of Bose-Einstein condensation. We then focus on nonlocal interactions in wave-number space: we study the decay of an ensemble of massive particles into massless ones. Under rather general conditions, these massless particles accumulate at low wave number. We study the dynamics of waves coexisting with such a strong condensate, and we compute rigorously a nonlocal Kolmogorov-Zakharov solution, where particles are transferred nonlocally to the condensate, while energy cascades towards large wave numbers through local interactions. This nonlocal cascading state constitutes the intermediate asymptotics between the initial distribution of waves and the thermodynamic state reached in the long-time limit.
Weinrich, James D; Klein, Fritz; McCutchan, J Allen; Grant, Igor
2014-01-01
We used a cluster analysis to empirically address whether sexual orientation is a continuum or can usefully be divided into categories such as heterosexual, homosexual, and bisexual using scores on the Klein Sexual Orientation Grid (KSOG) in three samples: groups of men and women recruited through bisexual groups and the Internet (Main Study men; Main Study women), and men recruited for a clinical study of HIV and the nervous system (HIV Study men). A five-cluster classification was chosen for the Main Study men (n = 212), a four-cluster classification for the Main Study women (n = 120), and a five-cluster classification for the HIV Study men (n = 620). We calculated means and standard deviations of these 14 clusters on the 21 variables composing the KSOG. Generally, the KSOG's overtly erotic items (Sexual Fantasies, Sexual Behavior, and Sexual Attraction), as well as the Self Identification items, tended to be more uniform within groups than the more social items were (Emotional Preference, Socialize with, and Lifestyle). The result is a set of objectively identified subgroups of bisexual men and women along with characterizations of the extent to which their KSOG scores describe and differentiate them. The Bisexual group identified by the cluster analysis of the HIV sample was distinctly different from any of the bisexual groups identified by the clustering process in the Main Sample. Simply put, the HIV sample's bisexuality is not like bisexuality in general, and attempts to generalize (even cautiously) from this clinical Bisexual group to a larger population would be doomed to failure. This underscores the importance of recruiting non-clinical samples if one wants insight into the nature of bisexuality in the population at large. Although the importance of non-clinical sampling in studies of sexual orientation has been widely and justly asserted, it has rarely been demonstrated by direct comparisons of the type conducted in the present study.
Weiss, Heinz
2017-02-17
Starting with Freud's discovery of unconscious phantasy as a means of accessing his patients' internal world, the author discusses the evolution of the concept in the work of Melanie Klein and some of her successors. Whereas Freud sees phantasy as a wish fulfilling imagination, dominated by primary process functioning and kept apart from reality testing, Klein understands phantasies as a structural function and organizer of mental life. From their very beginnings they involve object relations and gradually evolve from primitive body-near experiences to images and symbolic representations. With her concept of projective identification in particular, Klein anticipates the communicative function of unconscious phantasies. They are at the basis of processes of symbolization, but may also be put into the service of complex defensive operations. The author traces the further evolution of the concept from the contributions of S. Isaacs, the theories of thinking proposed by W.R. Bion and R. Money-Kyrle, Hanna Segal's ideas on symbolization and reparation all the way to the latest approaches by R. Britton, J. Steiner and others, including the understanding of transference and counter-transference as a 'total situation'. Points of contact with Freud are to be found particularly in connection with his concept of 'primal phantasies'. In the author's view, the idea of the transmission and communicative potential of unconscious phantasies enabled these authors to overcome the solipsistic origins of drive theory in favour of a notion in which unconscious phantasies both set down the coordinates of the inner world and form and reflect the matrix of inter-subjective relations.
Song, Ming; Ahmed, Bouthina S; Zerrad, Essaid; Biswas, Anjan
2013-09-01
This paper studies the Klein-Gordon Zakharov equation with power law nonlinearity in (1+2)-dimensions. The ansatz method will be applied to obtain the 1-soliton solution, also known as domain wall solution, along with several constraint conditions that naturally fall out. Subsequently, the bifurcation analysis is carried out where the phase portrait is given. Additionally, this analysis leads to several solutions to the equation with the traveling wave scheme. This gives soliton solution as well as singular periodic solutions. Finally, the numerical simulations for the domain wall solution were obtained where the finite difference scheme is applied.
Hakim Shoushtari, Mitra; Ghalebandi, Mirfarhad; Tavasoli, Azita; Pourshams, Maryam
2015-01-01
Objective Kleine-Levin syndrome (KLS) is a rare disorder with an unknown etiology. Autism spectrum disorder is characterized by various degrees of impairment in social communication, repetitive behavior and restricted interests. Only four patients of KLS with autistic spectrum disorder (ASD) have been reported so far. This report presents an 8-year-old girl with history of autistic disorder and epilepsy that superimposed KLS. Because of the rarity of KLS and related studies did not address whether autism accounts for a primary or secondary cause, the area required attention further studies.
2004-03-03
Dr. Tom Mace, NASA DFRC Director of Airborne Sciences, and Walter Klein(far right), NASA DFRC Airborne Science Mission Manager, brief John Danilovich, US Ambassador to Costa Rica, and NASA Administrator Sean O'Keefe onboard NASA's DC-8 during a stop-off on the AirSAR 2004 Mesoamerica campaign. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that will use an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR), in a mission ranging from the tropical rain forests of Central America to frigid Antarctica.
NASA Astrophysics Data System (ADS)
Kraniotis, G. V.
2016-11-01
Exact solutions of the Klein-Gordon-Fock (KGF) general relativistic equation that describe the dynamics of a massive, electrically charged scalar particle in the curved spacetime geometry of an electrically charged, rotating Kerr-Newman-(anti) de Sitter black hole are investigated. In the general case of a rotating, charged, cosmological black hole the solution of the KGF equation with the method of separation of variables results in Fuchsian differential equations for the radial and angular parts which for most of the parameter space contain more than three finite singularities and thereby generalise the Heun differential equations. For particular values of the physical parameters (i.e. mass of the scalar particle) these Fuchsian equations reduce to the case of the Heun equation and the closed form analytic solutions we derive are expressed in terms of Heun functions. For other values of the parameters some of the extra singular points are false singular points. We derive the conditions on the coefficients of the generalised Fuchsian equation such that a singular point is a false point. In such a case the exact solution of the Fuchsian equation can in principle be simplified and expressed in terms of Heun functions. This is the generalisation of the case of a Heun equation with a false singular point in which the exact solution of Heun’s differential equation is expressed in terms of Gauß hypergeometric function. We also derive the exact solutions of the radial and angular equations for a charged massive scalar particle in the Kerr-Newman spacetime. The analytic solutions are expressed in terms of confluent Heun functions. Moreover, we derived the constraints on the parameters of the theory such that the solution simplifies and expressed in terms of confluent Kummer hypergeometric functions. We also investigate the radial solutions in the KN case in the regions near the event horizon and far from the black hole. Finally, we construct several expansions of the
... Cerebral Atrophy Information Page Cerebral Palsy Information Page Cerebro-Oculo-Facio-Skeletal Syndrome (COFS) Information Page Charcot- ... Cerebral Atrophy Information Page Cerebral Palsy Information Page Cerebro-Oculo-Facio-Skeletal Syndrome (COFS) Information Page Charcot- ...
NASA Astrophysics Data System (ADS)
Rapoport, Diego L.
2011-01-01
In this transdisciplinary article which stems from philosophical considerations (that depart from phenomenology—after Merleau-Ponty, Heidegger and Rosen—and Hegelian dialectics), we develop a conception based on topological (the Moebius surface and the Klein bottle) and geometrical considerations (based on torsion and non-orientability of manifolds), and multivalued logics which we develop into a unified world conception that surmounts the Cartesian cut and Aristotelian logic. The role of torsion appears in a self-referential construction of space and time, which will be further related to the commutator of the True and False operators of matrix logic, still with a quantum superposed state related to a Moebius surface, and as the physical field at the basis of Spencer-Brown's primitive distinction in the protologic of the calculus of distinction. In this setting, paradox, self-reference, depth, time and space, higher-order non-dual logic, perception, spin and a time operator, the Klein bottle, hypernumbers due to Musès which include non-trivial square roots of ±1 and in particular non-trivial nilpotents, quantum field operators, the transformation of cognition to spin for two-state quantum systems, are found to be keenly interwoven in a world conception compatible with the philosophical approach taken for basis of this article. The Klein bottle is found not only to be the topological in-formation for self-reference and paradox whose logical counterpart in the calculus of indications are the paradoxical imaginary time waves, but also a classical-quantum transformer (Hadamard's gate in quantum computation) which is indispensable to be able to obtain a complete multivalued logical system, and still to generate the matrix extension of classical connective Boolean logic. We further find that the multivalued logic that stems from considering the paradoxical equation in the calculus of distinctions, and in particular, the imaginary solutions to this equation
... considering breast reduction surgery, consult a board-certified plastic surgeon. It's important to understand what breast reduction ... risk of complications from breast reduction surgery. Your plastic surgeon will likely: Evaluate your medical history and ...
NASA Astrophysics Data System (ADS)
Li, Jibin
In this paper, we consider the exact explicit solutions for the famous generalized Hénon-Heiles (H-H) system. Corresponding to the three integrable cases, on the basis of the investigation of the dynamical behavior and level curves of the planar dynamical systems, we find all possible explicit exact parametric representations of solutions in the invariant manifolds of equilibrium points in the four-dimensional phase space. These solutions contain quasi-periodic solutions, homoclinic solutions, periodic solutions as well as blow-up solutions. Therefore, we answer the question: what are the flows in the center manifolds and homoclinic manifolds of the generalized Hénon-Heiles (H-H) system. As an application of the above results, we consider the traveling wave solutions for the coupled (n + 1)-dimensional Klein-Gordon-Schrödinger Equations with quadratic power nonlinearity.
NASA Astrophysics Data System (ADS)
Aggoun, L.; Benamira, F.; Guechi, L.; Sadoun, M. A.
2016-04-01
The Green's function associated with a Klein-Gordon particle moving in a D-dimensional space under the action of vector plus scalar q-deformed Hulthén potentials is constructed by path integration for {q ≥ 1} and {1/α ln q < r < infty}. An appropriate approximation of the centrifugal potential term and the technique of space-time transformation are used to reduce the path integral for the generalized Hulthén potentials into a path integral for q-deformed Rosen-Morse potential. Explicit path integration leads to the radial Green's function for any l state in closed form. The energy spectrum and the correctly normalized wave functions, for a state of orbital quantum number {l ≥ 0}, are obtained. Eventually, the vector q-deformed Hulthén potential and the Coulomb potentials in D dimensions are considered as special cases.
Reductive dissolution of goethite by phenolic reductants
LaKind, J.S.; Stone, A.T. )
1989-05-01
The reductive dissolution of goethite ({alpha}-FeOOH) and hematite ({alpha}-Fe{sub 2}O{sub 3}) by phenolic reductants has been examined in order to improve the understanding of iron transformations in soils, sediments and aquifers. Rates of goethite reductive dissolution by hydroquinone increased as the pH was increased from pH 1.8 to 4.65, and the following reaction stoichiometry was obeyed: 2{alpha}-FeOOH + QH{sub 2} = 2Fe{sup 2+} + Q + 4OH{sup {minus}}. As the pH was increased from pH 4.5 to 6.0, the reductive dissolution rate decreased to below the detection limit. At pH 3.4, the reductive dissolution of hematite was two orders of magnitude slower than goethite. The relationship between structure and reactivity was examined for a series of mono-, di-, and tri-hydroxybenzene reductants. Rates of reductive dissolution decreased in the following order: catechol {approx equal} hydroquinone > 3,4-dihydroxybenzoic acid > resorcinol-phenol-4-hydroxybenzoic acid.
NASA Astrophysics Data System (ADS)
Rosaler, Joshua
2015-05-01
A conventional wisdom about the progress of physics holds that successive theories wholly encompass the domains of their predecessors through a process that is often called "reduction." While certain influential accounts of inter-theory reduction in physics take reduction to require a single "global" derivation of one theory's laws from those of another, I show that global reductions are not available in all cases where the conventional wisdom requires reduction to hold. However, I argue that a weaker "local" form of reduction, which defines reduction between theories in terms of a more fundamental notion of reduction between models of a single fixed system, is available in such cases and moreover suffices to uphold the conventional wisdom. To illustrate the sort of fixed-system, inter-model reduction that grounds inter-theoretic reduction on this picture, I specialize to a particular class of cases in which both models are dynamical systems. I show that reduction in these cases is underwritten by a mathematical relationship that follows a certain liberalized construal of Nagel/Schaffner reduction, and support this claim with several examples. Moreover, I show that this broadly Nagelian analysis of inter-model reduction encompasses several cases that are sometimes cited as instances of the "physicist's" limit-based notion of reduction.
Reduction Mechanisms in Manganese Ore Reduction
NASA Astrophysics Data System (ADS)
Coetsee, Theresa; Reinke, Christian; Nell, Johannes; Pistorius, Petrus Christiaan
2015-12-01
Manganese ores are highly heterogeneous and contain various minerals with different levels of contained manganese and iron and therefore the ore reduction behavior is not uniform. Both phase chemistry and phase morphology at the reaction interface, at micron scale, must be investigated to understand the reaction mechanism effects in manganese ore reduction. This approach is applied here to reacted material mixture samples taken from the AlloyStream pilot plant furnace over a period of 4 months. The mineralogical features are reported and discussed. Deductions are made on the likely dominant reduction mechanism in this reaction system, given the phase morphology observations presented.
Breast reduction (mammoplasty) - slideshow
... page: //medlineplus.gov/ency/presentations/100189.htm Breast reduction (mammoplasty) - series—Indications To use the sharing features ... to slide 4 out of 4 Overview Breast reduction is usually performed for enlarged breasts (macromastia), but ...
ERIC Educational Resources Information Center
Armoni, Michal; Gal-Ezer, Judith; Tirosh, Dina
2005-01-01
Solving problems by reduction is an important issue in mathematics and science education in general (both in high school and in college or university) and particularly in computer science education. Developing reductive thinking patterns is an important goal in any scientific discipline, yet reduction is not an easy subject to cope with. Still,…
NASA Astrophysics Data System (ADS)
Zaghou, N.; Benamira, F.; Guechi, L.
2017-01-01
Rigorous use of the SUSYQM approach applied for the Klein-Gordon equation with scalar and vector potentials is discussed. The method is applied to solve exactly, for bound states, two models with position-dependent masses and PT-symmetric vector potentials, depending on some parameters. The necessary conditions on the parameters to get physical solutions are described. Some special cases are also derived by adjusting the parameters of the models.
Papoutsoglou, Sofronios E; Karakatsouli, Nafsika; Papoutsoglou, Eustratios S; Vasilikos, Georgios
2010-09-01
The objective of this study was to further investigate the effects of music on fish physiology, bearing in mind available information regarding the involvement of endogenous and exogenous factors in fish farming. Therefore, Cyprinus carpio (50.5 +/- 0.36 g) were reared in a recirculating water system under 80 and 200 lux and subjected to no music at all (control, ambient noise only), 4 h of Mozart's "Eine Kleine Nachtmusik", or 4 h of anonymous "Romanza-Jeux Interdits" for 106 days. Both music treatments resulted in increased growth performance at both light intensities, with Romanza treatment at 200 lux resulting in better growth performance than Mozart treatment. Furthermore, feed efficiency for the Romanza groups was significantly better than for the control. Although no significant music effect was apparent for brain neurotransmitters, lower anterior intestine alkaline protease levels were detected for both music treatments. Taking into consideration the numerous advantages of recirculating water systems, it should be emphasised that fish response to music expresses the results of various physiological and biochemical processes, especially when fish notably respond differently when subjected to two different pieces of music.
2004-03-17
NASA DC-8 Mission Manager Walter Klein poses with a group of Chilean Students onboard the aircraft at Carlos Ibanez del Campo International Airport in Punta Arenas, Chile. AirSAR 2004 is a three-week expedition by an international team of scientists that is using an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central and South America with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. In South America and Antarctica, AirSAR will collect imagery and data to help determine the contribution of Southern Hemisphere glaciers to sea level rise due to climate change. In Patagonia, researchers found this contribution had more than doubled from 1995 to 2000, compared to the previous 25 years. AirSAR data will make it possible to determine whether that trend is decreasing, continuing or accelerating. AirSAR will also provide reliable information on ice shelf thickness to measure the contribution of the glaciers to sea level.
NASA Astrophysics Data System (ADS)
Lewis, Tiffany R.; Finke, Justin; Becker, Peter A.
2017-08-01
Blazars are a sub-class of active galactic nuclei, with a polar jet aligned along our line of sight. Emission from blazar jets is observed across the electromagnetic spectrum. In our model we assume that the emission emanates from one homogeneous zone in the jet, which is in the process of passing through the Broad Line Region (BLR). We start from first-principles to build up a particle transport model, whose solution is the electron distribution, rather than assuming a convenient functional form. Our transport model considers shock acceleration, adiabatic expansion, stochastic acceleration, Bohm diffusion, synchrotron radiation, and Klein-Nishina radiation pulling seed photons from the BLR and dusty torus. We obtain the steady-state electron distribution computationally, and calculate individual spectral contributions due to synchrotron with self-absorption, disk, synchrotron self-Compton, and external-Compton emission, using numerical integration. We compare the resulting radiation spectrum with multi-wavelength data for 3C 279, during quiescence and two flares. Our preliminary results suggest that the jet emission is produced in a region with a sub-equipartition magnetic field, and that the magnetic field in the jet decreases during flaring events, implying that reconnection may play a role in blazar flares.
2004-03-10
L to R; NASA Dryden Mission Manager Walter Klein (in tan flight suit), JPL AirSAR Scientist Tim Miller, and Mission Manager David Bushman briefing press in Santiago, Chile, for NASA's AirSAR 2004 mission. AirSAR 2004 is a three-week expedition by an international team of scientists that uses an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central and South America with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. In South America and Antarctica, AirSAR collected imagery and data to help determine the contribution of Southern Hemisphere glaciers to sea level rise due to climate change. In Patagonia, researchers found this contribution had more than doubled from 1995 to 2000, compared to the previous 25 years. AirSAR data will make it possible to determine whether that trend is continuing or accelerating. AirSAR will also provide reliable information on ice shelf thickness to measure the contribution of the glaciers to sea level.
NASA Technical Reports Server (NTRS)
Morris, R. V.; Ming, D. W.; Gellert, R.; Vaniman, D. T.; Bish, D. L.; Blake, D. F.; Chipera, S. J.; Morrison, S. M.; Downs, R. T.; Rampe, E. B.; Treiman, A. H.; Yen, A. S.; Achilles, C. N.; Archer, P. D.; Bristow, T. F.; Cavanaugh, P.; Fenrdrich, K.; Crisp, J. A.; Des Marais, D. J.; Farmer, J. D.; Grotzinger, J. P.; Mahaffy, P. R.; McAdam, A. C.; Morookian, J. M.
2015-01-01
We have previously calculated the chemical compositions of the X-ray-diffraction (XRD) amorphous component of three solid samples (Rocknest (RN) soil, John Klein (JK) drill fines, and Cumberland (CB) drill fines) using major-element chemistry (APXS), volatile-element chemistry (SAM), and crystalline- phase mineralogy (CheMin) obtained by the Curiosity rover as a part of the ongoing Mars Science Laboratory mission in Gale Crater. According to CheMin analysis, the RN and the JK and CB samples are mineralogically distinct in that RN has no detectable clay minerals and both JK and CB have significant concentrations of high-Fe saponite. The chemical composition of the XRD amorphous component is the composition remaining after mathematical removal of the compositions of crystalline components, including phyllosilicates if present. Subsequent to, we have improved the unit cell parameters for Fe-forsterite, augite, and pigeonite, resulting in revised chemical compositions for the XRD-derived crystalline component (excluding clay minerals). We update here the calculated compositions of amorphous components using these revised mineral compositions.
2004-03-10
NASA Dryden Mission Manager Walter Klein poses with school children that visited the DC-8 during AirSAR 2004 in Punta Arenas, Chile. AirSAR 2004 is a three-week expedition by an international team of scientists that uses an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central and South America with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. In South America and Antarctica, AirSAR collected imagery and data to help determine the contribution of Southern Hemisphere glaciers to sea level rise due to climate change. In Patagonia, researchers found this contribution had more than doubled from 1995 to 2000, compared to the previous 25 years. AirSAR data will make it possible to determine whether that trend is continuing or accelerating. AirSAR will also provide reliable information on ice shelf thickness to measure the contribution of the glaciers to sea level.
2004-03-10
NASA Dryden Mission Manager Walter Klein talks with school children from Punta Arenas, Chile, during a tour of the DC-8 aircraft while it was in the country supporting the AirSAR 2004 campaign. AirSAR 2004 is a three-week expedition by an international team of scientists that uses an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central and South America with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. In South America and Antarctica, AirSAR collected imagery and data to help determine the contribution of Southern Hemisphere glaciers to sea level rise due to climate change. In Patagonia, researchers found this contribution had more than doubled from 1995 to 2000, compared to the previous 25 years. AirSAR data will make it possible to determine whether that trend is continuing or accelerating. AirSAR will also provide reliable information on ice shelf thickness to measure the contribution of the glaciers to sea level.
Yang, Linlin; Li, Nianbei; Li, Baowen
2014-12-01
The temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with soft on-site potential (soft-KG) are investigated systematically. Similarly to the previously studied hard-KG lattices, the existence of renormalized phonons is also confirmed in soft-KG lattices. In particular, the temperature dependence of the renormalized phonon frequency predicted by a classical field theory is verified by detailed numerical simulations. However, the thermal conductivities of soft-KG lattices exhibit the opposite trend in temperature dependence in comparison with those of hard-KG lattices. The interesting thing is that the temperature-dependent thermal conductivities of both soft- and hard-KG lattices can be interpreted in the same framework of effective phonon theory. According to the effective phonon theory, the exponents of the power-law dependence of the thermal conductivities as a function of temperature are only determined by the exponents of the soft or hard on-site potentials. These theoretical predictions are consistently verified very well by extensive numerical simulations.
2004-03-08
NASA Dryden Mission Manager Walter Klein passes out Airborne Science stickers and lithographs to underprivileged school children that visited the airport on Monday March 8, 2004. In spanish, he explained to them the mission of the DC-8 AirSAR 2004 Mesoamerican campaign in Costa Rica. AirSAR 2004 Mesoamerica is a three-week expedition by an international team of scientists that uses an all-weather imaging tool, called the Airborne Synthetic Aperture Radar (AirSAR) which is located onboard NASA's DC-8 airborne laboratory. Scientists from many parts of the world including NASA's Jet Propulsion Laboratory are combining ground research done in several areas in Central America with NASA's AirSAR technology to improve and expand on the quality of research they are able to conduct. The radar, developed by NASA's Jet Propulsion Laboratory, can penetrate clouds and also collect data at night. Its high-resolution sensors operate at multiple wavelengths and modes, allowing AirSAR to see beneath treetops, through thin sand, and dry snow pack. AirSAR's 2004 campaign is a collaboration of many U.S. and Central American institutions and scientists, including NASA; the National Science Foundation; the Smithsonian Institution; National Geographic; Conservation International; the Organization of Tropical Studies; the Central American Commission for Environment and Development; and the Inter-American Development Bank.
NASA Technical Reports Server (NTRS)
Bushnell, D. M.; Moore, K. J.
1991-01-01
Recent studies on the drag-reducing shapes, structures, and behaviors of swimming and flying animals are reviewed, with an emphasis on potential analogs in vehicle design. Consideration is given to form drag reduction (turbulent flow, vortex generation, mass transfer, and adaptations for body-intersection regions), skin-friction drag reduction (polymers, surfactants, and bubbles as surface 'additives'), reduction of the drag due to lift, drag-reduction studies on porpoises, and drag-reducing animal behavior (e.g., leaping out of the water by porpoises). The need for further research is stressed.
NASA Technical Reports Server (NTRS)
Bushnell, D. M.; Moore, K. J.
1991-01-01
Recent studies on the drag-reducing shapes, structures, and behaviors of swimming and flying animals are reviewed, with an emphasis on potential analogs in vehicle design. Consideration is given to form drag reduction (turbulent flow, vortex generation, mass transfer, and adaptations for body-intersection regions), skin-friction drag reduction (polymers, surfactants, and bubbles as surface 'additives'), reduction of the drag due to lift, drag-reduction studies on porpoises, and drag-reducing animal behavior (e.g., leaping out of the water by porpoises). The need for further research is stressed.
CARBON DIOXIDE REDUCTION SYSTEM.
CARBON DIOXIDE , *SPACE FLIGHT, RESPIRATION, REDUCTION(CHEMISTRY), RESPIRATION, AEROSPACE MEDICINE, ELECTROLYSIS, INSTRUMENTATION, ELECTROLYTES, VOLTAGE, MANNED, YTTRIUM COMPOUNDS, ZIRCONIUM COMPOUNDS, NICKEL.
ERIC Educational Resources Information Center
Alm, Kent F.; And Others
1977-01-01
A process for the management of reductions in the number of faculty positions available to a university is described. It considers staffing by projections, the evolution of personnel planning, and the balance of reductions in faculty and administration, along with coping strategies and advice growing out of five years of enrollment decline…
Microbial reductive dehalogenation.
Mohn, W W; Tiedje, J M
1992-01-01
A wide variety of compounds can be biodegraded via reductive removal of halogen substituents. This process can degrade toxic pollutants, some of which are not known to be biodegraded by any other means. Reductive dehalogenation of aromatic compounds has been found primarily in undefined, syntrophic anaerobic communities. We discuss ecological and physiological principles which appear to be important in these communities and evaluate how widely applicable these principles are. Anaerobic communities that catalyze reductive dehalogenation appear to differ in many respects. A large number of pure cultures which catalyze reductive dehalogenation of aliphatic compounds are known, in contrast to only a few organisms which catalyze reductive dehalogenation of aromatic compounds. Desulfomonile tiedjei DCB-1 is an anaerobe which dehalogenates aromatic compounds and is physiologically and morphologically unusual in a number of respects, including the ability to exploit reductive dehalogenation for energy metabolism. When possible, we use D. tiedjei as a model to understand dehalogenating organisms in the above-mentioned undefined systems. Aerobes use reductive dehalogenation for substrates which are resistant to known mechanisms of oxidative attack. Reductive dehalogenation, especially of aliphatic compounds, has recently been found in cell-free systems. These systems give us an insight into how and why microorganisms catalyze this activity. In some cases transition metal complexes serve as catalysts, whereas in other cases, particularly with aromatic substrates, the catalysts appear to be enzymes. Images PMID:1406492
ERIC Educational Resources Information Center
Allaway, David
1992-01-01
Suggests that quantification is essential to establish the cost-effectiveness of source reduction (SR). Presents case studies of monitoring methods for seven different kinds of SR efforts: (1) packaging changes, (2) SR businesses, (3) waste exchanges, (4) individual nonresidential efforts, (5) variable garbage rates, (6) yard waste reduction, and…
ERIC Educational Resources Information Center
Allaway, David
1992-01-01
Suggests that quantification is essential to establish the cost-effectiveness of source reduction (SR). Presents case studies of monitoring methods for seven different kinds of SR efforts: (1) packaging changes, (2) SR businesses, (3) waste exchanges, (4) individual nonresidential efforts, (5) variable garbage rates, (6) yard waste reduction, and…
Bayesian supervised dimensionality reduction.
Gönen, Mehmet
2013-12-01
Dimensionality reduction is commonly used as a preprocessing step before training a supervised learner. However, coupled training of dimensionality reduction and supervised learning steps may improve the prediction performance. In this paper, we introduce a simple and novel Bayesian supervised dimensionality reduction method that combines linear dimensionality reduction and linear supervised learning in a principled way. We present both Gibbs sampling and variational approximation approaches to learn the proposed probabilistic model for multiclass classification. We also extend our formulation toward model selection using automatic relevance determination in order to find the intrinsic dimensionality. Classification experiments on three benchmark data sets show that the new model significantly outperforms seven baseline linear dimensionality reduction algorithms on very low dimensions in terms of generalization performance on test data. The proposed model also obtains the best results on an image recognition task in terms of classification and retrieval performances.
Greybody factors for Myers–Perry black holes
Boonserm, Petarpa; Chatrabhuti, Auttakit Ngampitipan, Tritos; Visser, Matt
2014-11-15
The Myers–Perry black holes are higher-dimensional generalizations of the usual (3+1)-dimensional rotating Kerr black hole. They are of considerable interest in Kaluza–Klein models, specifically within the context of brane-world versions thereof. In the present article, we shall consider the greybody factors associated with scalar field excitations of the Myers–Perry spacetimes, and develop some rigorous bounds on these greybody factors. These bounds are of relevance for characterizing both the higher-dimensional Hawking radiation, and the super-radiance, that is expected for these spacetimes.
Microbial reduction of uranium
Lovley, D.R.; Phillips, E.J.P.; Gorby, Y.A.; Landa, E.R.
1991-01-01
REDUCTION of the soluble, oxidized form of uranium, U(VI), to insoluble U(IV) is an important mechanism for the immobilization of uranium in aquatic sediments and for the formation of some uranium ores1-10. U(VI) reduction has generally been regarded as an abiological reaction in which sulphide, molecular hydrogen or organic compounds function as the reductant1,2,5,11. Microbial involvement in U(VI) reduction has been considered to be limited to indirect effects, such as microbial metabolism providing the reduced compounds for abiological U(VI) reduction and microbial cell walls providing a surface to stimulate abiological U(VI) reduction1,12,13. We report here, however, that dissimilatory Fe(III)-reducing microorganisms can obtain energy for growth by electron transport to U(VI). This novel form of microbial metabolism can be much faster than commonly cited abiological mechanisms for U(VI) reduction. Not only do these findings expand the known potential terminal electron acceptors for microbial energy transduction, they offer a likely explanation for the deposition of uranium in aquatic sediments and aquifers, and suggest a method for biological remediation of environments contaminated with uranium.
Acceleration of particles in Einstein-Maxwell-dilaton black holes
NASA Astrophysics Data System (ADS)
Mao, Pu-Jian; Li, Ran; Jia, Lin-Yu; Ren, Ji-Rong
2017-06-01
It has recently been pointed out that, under certain conditions, the energy of particles accelerated by black holes in the center-of-mass frame can become arbitrarily high. In this paper, we study the collision of two particles in the case of four-dimensional charged nonrotating, extremal charged rotating and near-extremal charged rotating Kaluza-Klein black holes as well as the naked singularity case in Einstein-Maxwell-dilaton theory. We find that the center-of-mass energy for a pair of colliding particles is unlimited at the horizon of charged nonrotating Kaluza-Klein black holes, extremal charged rotating Kaluza-Klein black holes and in the naked singularity case. Supported by NSFC (11575202, 11205048), Foundation for Young Key Teacher of Henan Normal University and Cuiying Programme of Lanzhou University (225000-582404) and Fundamental Research Fund for Physics and Mathematic of Lanzhou University (LZULL200911)
NASA Astrophysics Data System (ADS)
Johansson, Magnus
2006-04-01
We analyze certain aspects of the classical dynamics of a one-dimensional discrete nonlinear Schrödinger model with inter-site as well as on-site nonlinearities. The equation is derived from a mixed Klein-Gordon/Fermi-Pasta-Ulam chain of anharmonic oscillators coupled with anharmonic inter-site potentials, and approximates the slow dynamics of the fundamental harmonic of discrete small-amplitude modulational waves. We give explicit analytical conditions for modulational instability of travelling plane waves, and find in particular that sufficiently strong inter-site nonlinearities may change the nature of the instabilities from long-wavelength to short-wavelength perturbations. Further, we describe thermodynamic properties of the model using the grand-canonical ensemble to account for two conserved quantities: norm and Hamiltonian. The available phase space is divided into two separated parts with qualitatively different properties in thermal equilibrium: one part corresponding to a normal thermalized state with exponentially small probabilities for large-amplitude excitations, and another part typically associated with the formation of high-amplitude localized excitations, interacting with an infinite-temperature phonon bath. A modulationally unstable travelling wave may exhibit a transition from one region to the other as its amplitude is varied, and thus modulational instability is not a sufficient criterion for the creation of persistent localized modes in thermal equilibrium. For pure on-site nonlinearities the created localized excitations are typically pinned to particular lattice sites, while for significant inter-site nonlinearities they become mobile, in agreement with well-known properties of localized excitations in Fermi-Pasta-Ulam-type chains.
Reduction of astrometric plates
NASA Technical Reports Server (NTRS)
Stock, J.
1984-01-01
A rapid and accurate method for the reduction of comet or asteroid plates is described. Projection equations, scale length correction, rotation of coordinates, linearization, the search for additional reference stars, and the final solution are examined.
Reduction of astrometric plates
NASA Technical Reports Server (NTRS)
Stock, J.
1984-01-01
A rapid and accurate method for the reduction of comet or asteroid plates is described. Projection equations, scale length correction, rotation of coordinates, linearization, the search for additional reference stars, and the final solution are examined.
To help solid waste planners and organizations track/report GHG emissions reductions from various waste management practices. To assist in calculating GHG emissions of baseline and alternative waste management practices and provide the history of WARM.
NASA Technical Reports Server (NTRS)
Bingham, Cindy
1990-01-01
Viewgraphs on reduction of bone strength are presented. WEHI 231 B growth rates, experimental chambers used to apply the electric field to the cell cultures, and a mouse suspended by rotating cuff in electromagnetic field are shown.
Dissimilatory metal reduction.
Lovley, D R
1993-01-01
Microorganisms can enzymatically reduce a variety of metals in metabolic processes that are not related to metal assimilation. Some microorganisms can conserve energy to support growth by coupling the oxidation of simple organic acids and alcohols, H2, or aromatic compounds to the reduction of Fe(III) or Mn(IV). This dissimilatory Fe(III) and Mn(IV) reduction influences the organic as well as the inorganic geochemistry of anaerobic aquatic sediments and ground water. Microorganisms that use U(VI) as a terminal electron acceptor play an important role in uranium geochemistry and may be a useful tool for removing uranium from contaminated environments. Se(VI) serves as a terminal electron acceptor to support anaerobic growth of some microorganisms. Reduction of Se(VI) to Se(O) is an important mechanism for the precipitation of selenium from contaminated waters. Enzymatic reduction of Cr(VI) to the less mobile and less toxic Cr(III), and reduction of soluble Hg(II) to volatile Hg(O) may affect the fate of these compounds in the environment and might be used as a remediation strategy. Microorganisms can also enzymatically reduce other metals such as technetium, vanadium, molybdenum, gold, silver, and copper, but reduction of these metals has not been studied extensively.
NASA Astrophysics Data System (ADS)
Benamira, F.; Guechi, L.; Zouache, A.
2007-08-01
The supersymmetric quantum mechanical method employed by Gang Chen and co-workers to solve the problem of the s states of a Klein Gordon particle under the action of generalized vector plus scalar Hulthén-type potentials is shown inadequate since only one of their solutions remains valid for q⩾1 and 1αlnq
Electroweak symmetry breaking by extra dimensions
Hsin-Chia Cheng; Bogdan A. Dobrescu and Christopher T. Hill
2000-05-25
Electroweak symmetry breaking may be naturally induced by the observed quark and gauge fields in extra dimensions without a fundamental Higgs field. The authors show that a composite Higgs doublet can arise as a bound state of (t,b){sub L} and a linear combination of the Kaluza-Klein states of t{sub R}, due to QCD in extra dimensions. The top quark mass depends on the number of active t{sub R} Kaluza-Klein modes, and is consistent with the experimental value.
The cyclic reduction algorithm
NASA Astrophysics Data System (ADS)
Bini, Dario; Meini, Beatrice
2009-05-01
Cyclic reduction is an algorithm invented by G.H. Golub and R. W. Hockney in the mid 1960s for solving linear systems related to the finite differences discretization of the Poisson equation over a rectangle. Among the algorithms of Gene Golub, it is one of the most versatile and powerful ever created. Recently, it has been applied to solve different problems from different applicative areas. In this paper we survey the main features of cyclic reduction, relate it to properties of analytic functions, recall its extension to solving more general finite and infinite linear systems, and different kinds of nonlinear matrix equations, including algebraic Riccati equations, with applications to Markov chains, queueing models and transport theory. Some new results concerning the convergence properties of cyclic reduction and its applicability are proved under very weak assumptions. New formulae for overcoming breakdown are provided.