Three-body force for baryons from the D0-D4/D8 brane matrix model
NASA Astrophysics Data System (ADS)
Li, Si-wen; Jia, Tuo
2016-03-01
This is an extensive work to our previous paper [S. Li and T. Jia, Matrix model and holographic baryons in the D0-D4 background, Phys. Rev. D 92, 046007 (2015)] that studied the D0-D4/D8 holographic system. We compute the three-body force for baryons with the D0-D4/D8 matrix model derived in [S. Li and T. Jia, Matrix model and holographic baryons in the D0-D4 background, Phys. Rev. D 92, 046007 (2015)] with considering the nonzero QCD vacuum. We obtain the three-body force at short distances but modified by the appearance of the smeared D0-branes, i.e., considering the effects from the nontrivial QCD vacuum. We first test our matrix model in the case of 't Hooft instanton and then in two more realistic cases: (1) three-neutrons with averaged spins and (2) proton-proton-neutron (or proton-neutron-proton). The three-body potential vanishes in the former case while in the two latter cases it is positive, i.e., repulsive and makes sense only if the constraint for stable baryonic state is satisfied. We require all the baryons in our computation aligned on a line. These may indicate that the cases in dense states of neutrons such as in neutron stars, Helium-3 or Tritium nucleus all with the nontrivial QCD vacuum.
Holographic model with a Neveu-Schwarz-Neveu-Schwarz field
Seo, Yunseok; Sin, Sang-jin; Xu, Wei-shui
2009-11-15
We consider a holographic model constructed using the D4/D8-D8 brane configuration with a Neveu-Schwarz-Neveu-Schwarz background field. We study some properties of the effective field theory in this intersecting brane construction and calculate the effects of this Neveu-Schwarz-Neveu-Schwarz background field on some underlying dynamics. We also discuss some other general brane configurations.
Dynamical D4-D8 and D3-D7 branes in supergravity
Binetruy, Pierre; Sasaki, Misao; Uzawa, Kunihito
2009-07-15
We present a class of dynamical solutions for intersecting D4-D8 and D3-D7 brane systems in ten-dimensional type IIA and IIB supergravity. We discuss if these solutions can be recovered in lower-dimensional effective theories for the warped compactification of a general p-brane system. It is found that an effective p+1-dimensional description is not possible in general due to the entanglement of the transverse coordinates and the p+1-dimensional coordinates in the metric components. For the D4-D8 brane system, the dynamical solutions reduces to a static warped AdS{sub 6}xS{sup 4} geometry in a certain spacetime region. For the D3-D7 brane system, we find a dynamical solution whose metric form is similar to that of a D3-brane solution. The main difference is the existence of a nontrivial dilaton configuration in the D3-D7 solution. Then we discuss cosmology of these solutions. We find that they behave like a Kasner-type cosmological solution at {tau}{yields}{infinity}, while it reduces to a warped static solution at {tau}{yields}0, where {tau} is the cosmic time.
Dynamical D4-D8 and D3-D7 branes in supergravity
NASA Astrophysics Data System (ADS)
Binetruy, Pierre; Sasaki, Misao; Uzawa, Kunihito
2009-07-01
We present a class of dynamical solutions for intersecting D4-D8 and D3-D7 brane systems in ten-dimensional type IIA and IIB supergravity. We discuss if these solutions can be recovered in lower-dimensional effective theories for the warped compactification of a general p-brane system. It is found that an effective p+1-dimensional description is not possible in general due to the entanglement of the transverse coordinates and the p+1-dimensional coordinates in the metric components. For the D4-D8 brane system, the dynamical solutions reduces to a static warped AdS6×S4 geometry in a certain spacetime region. For the D3-D7 brane system, we find a dynamical solution whose metric form is similar to that of a D3-brane solution. The main difference is the existence of a nontrivial dilaton configuration in the D3-D7 solution. Then we discuss cosmology of these solutions. We find that they behave like a Kasner-type cosmological solution at τ→∞, while it reduces to a warped static solution at τ→0, where τ is the cosmic time.
Yi Piljin
2011-10-21
We overview a holographic QCD based on the D4-D8 string theory model, with emphasis on baryons and nucleon-meson interactions thereof. Baryons are realized as holographic images of Skyrmions, but with much qualitative changes. This allows us to derive, without adjustable parameters, couplings of baryons to the entire tower of spin one mesons and also to pseudoscalar mesons. We find some surprisingly good match against empirical values for nucleons, in particular. Tensor couplings to all axial-vectors and iso-singlet vectors all vanish, while, for {rho} mesons, tensor couplings are found to be dominant. We close with various cautionary comments and speculations.
NASA Astrophysics Data System (ADS)
Yi, Piljin
2011-10-01
We overview a holographic QCD based on the D4-D8 string theory model, with emphasis on baryons and nucleon-meson interactions thereof. Baryons are realized as holographic images of Skyrmions, but with much qualitative changes. This allows us to derive, without adjustable parameters, couplings of baryons to the entire tower of spin one mesons and also to pseudoscalar mesons. We find some surprisingly good match against empirical values for nucleons, in particular. Tensor couplings to all axial-vectors and iso-singlet vectors all vanish, while, for ρ mesons, tensor couplings are found to be dominant. We close with various cautionary comments and speculations.
Geller, Michael; Telem, Ofri
2015-05-15
We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at m_{KK}, naturally allowing for m_{KK} beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider. PMID:26024160
Holographic equations of state and astrophysical compact objects
NASA Astrophysics Data System (ADS)
Kim, Youngman; Lee, Chang-Hwan; Shin, Ik Jae; Wan, Mew-Bing
2011-10-01
We solve the Tolman-Oppenheimer-Volkoff equation using an equation of state (EoS) calculated in holographic QCD. The aim is to use compact astrophysical objects like neutron stars as an indicator to test holographic equations of state. We first try an EoS from a dense D4/D8/D8 model. In this case, however, we could not find a stable compact star, a star satisfying pressure-zero condition with a radius R, p( R) = 0, within a reasonable value of the radius. This means that the EoS from the D4/D8/D8 model may not support any stable compact stars or may support one whose radius is very large. This might be due to a deficit of attractive force from a scalar field or two-pion exchange in the D4/D8/D8 model. Then, we consider D4/D6 type models with different number of quark flavors, N f = 1 , 2 , 3. Though the mass and radius of a holographic star is larger than those of normal neutron stars, the D4/D6 type EoS renders a stable compact star.
Holographic model of hadronization.
Evans, Nick; Tedder, Andrew
2008-04-25
We study hadronization of the final state in a particle-antiparticle annihilation using a holographic gravity dual description of QCD. At the point of hadronization we match the events to a simple (Gaussian) energy distribution in the five dimensional theory. The final state multiplicities are then modeled by calculating the overlap between the Gaussian and a set of functions in the fifth dimension which represent each hadron. We compare our results to those measured in e(+)e(-) collisions. Hadron production numbers over a range of 4 orders of magnitude are reproduced well. PMID:18518189
Holographic Model of Hadronization
Evans, Nick; Tedder, Andrew
2008-04-25
We study hadronization of the final state in a particle-antiparticle annihilation using a holographic gravity dual description of QCD. At the point of hadronization we match the events to a simple (Gaussian) energy distribution in the five dimensional theory. The final state multiplicities are then modeled by calculating the overlap between the Gaussian and a set of functions in the fifth dimension which represent each hadron. We compare our results to those measured in e{sup +}e{sup -} collisions. Hadron production numbers over a range of 4 orders of magnitude are reproduced well.
Adventures in Holographic Dimer Models
Kachru, Shamit; Karch, Andreas; Yaida, Sho; /Stanford U., Phys. Dept.
2011-08-12
We abstract the essential features of holographic dimer models, and develop several new applications of these models. Firstly, semi-holographically coupling free band fermions to holographic dimers, we uncover novel phase transitions between conventional Fermi liquids and non-Fermi liquids, accompanied by a change in the structure of the Fermi surface. Secondly, we make dimer vibrations propagate through the whole crystal by way of double trace deformations, obtaining nontrivial band structure. In a simple toy model, the topology of the band structure experiences an interesting reorganization as we vary the strength of the double trace deformations. Finally, we develop tools that would allow one to build, in a bottom-up fashion, a holographic avatar of the Hubbard model.
Matrix model and holographic baryons in the D0-D4 background
NASA Astrophysics Data System (ADS)
Li, Si-wen; Jia, Tuo
2015-08-01
We study the spectrum and short-distance two-body force of holographic baryons by the matrix model, which is derived from the Sakai-Sugimoto model in the D0-D4 background (D0-D4/D8 system). The matrix model is derived by using the standard technique in string theory, and it can describe multibaryon systems. We rederive the action of the matrix model from open string theory on the baryon vertex, which is embedded in the D0-D4/D8 system. The matrix model offers a more systematic approach to the dynamics of the baryons at short distances. In our system, we find that the matrix model describes stable baryonic states only if ζ =UQ0 3/UKK 3<2 , where UQ0 3 is related to the number density of smeared D0-branes. This result in our paper is exactly the same as some previous results studied in this system, presented in [W. Cai, C. Wu, and Z. Xiao, Phys. Rev. D 90, 106001 (2014)]. We also compute the baryon spectrum (k =1 case) and short-distance two-body force of baryons (k =2 case). The baryon spectrum is modified and could be able to fit the experimental data if we choose a suitable value for ζ . And the short-distance two-body force of baryons is also modified by the appearance of smeared D0-branes from the original Sakai-Sugimoto model. If ζ >2 , we find that the baryon spectrum will be totally complex and an attractive force will appear in the short-distance interaction of baryons, which may consistently correspond to the existence of unstable baryonic states.
Four-nucleon contact interactions from holographic QCD
NASA Astrophysics Data System (ADS)
Kim, Youngman; Yi, Deokhyun; Yi, Piljin
2012-01-01
We calculate the low energy constants of four-nucleon interactions in an effective chiral Lagrangian in holographic QCD. We start with a D4-D8 model to obtain meson-nucleon interactions and then integrate out massive mesons to obtain the four-nucleon interactions in 4D. We end up with two low energy constants at the leading order and seven of them at the next leading order, which is consistent with the effective chiral Lagrangian. The values of the low energy constants are evaluated with the first five Kaluza-Klein resonances.
Exploring holographic Composite Higgs models
NASA Astrophysics Data System (ADS)
Croon, Djuna; Dillon, Barry M.; Huber, Stephan J.; Sanz, Veronica
2016-07-01
Simple Composite Higgs models predict new vector-like fermions not too far from the electroweak scale, yet LHC limits are now sensitive to the TeV scale. Motivated by this tension, we explore the holographic dual of the minimal model, MCHM5, to try and alleviate this tension without increasing the fine-tuning in the Higgs potential. Interestingly, we find that lowering the UV cutoff in the 5D picture allows for heavier top partners and less fine-tuning. In the 4D dual this corresponds to increasing the number of "colours" N , thus increasing the decay constant of the Goldstone Higgs. This is essentially a `Little Randall-Sundrum Model', which are known to reduce some flavour and electroweak constraints. Furthermore, in anticipation of the ongoing efforts at the LHC to put bounds on the top Yukawa, we demonstrate that deviations from the SM can be suppressed or enhanced with respect to what is expected from mere symmetry arguments in 4D. We conclude that the 5D holographic realisation of the MCHM5 with a small UV cutoff is not in tension with the current experimental data.
G-corrected holographic dark energy model
NASA Astrophysics Data System (ADS)
Malekjani, M.; Honari-Jafarpour, M.
2013-08-01
Here we investigate the holographic dark energy model in the framework of FRW cosmology where the Newtonian gravitational constant, G, is varying with cosmic time. Using the complementary astronomical data which support the time dependency of G, the evolutionary treatment of EoS parameter and energy density of dark energy model are calculated in the presence of time variation of G. It has been shown that in this case, the phantom regime can be achieved at the present time. We also calculate the evolution of G-corrected deceleration parameter for holographic dark energy model and show that the dependency of G on the comic time can influence on the transition epoch from decelerated expansion to the accelerated phase. Finally we perform the statefinder analysis for G-corrected holographic model and show that this model has a shorter distance from the observational point in s- r plane compare with original holographic dark energy model.
Soft wall model for a holographic superconductor
NASA Astrophysics Data System (ADS)
Afonin, S. S.; Pusenkov, I. V.
2016-06-01
We consider the soft wall holographic approach for description of the high-T_c superconductivity. In comparison with the existing bottom-up holographic superconductors, the proposed approach is more phenomenological and does not describe the superconducting phase transition. On the other hand, technically it is simpler and has more freedom for fitting the conductivity properties of the real high-T_c materials in the superconducting phase. Some examples of emerging models are analyzed.
Meson wave function from holographic models
Vega, Alfredo; Schmidt, Ivan; Branz, Tanja; Gutsche, Thomas; Lyubovitskij, Valery E.
2009-09-01
We consider the light-front wave function for the valence quark state of mesons using the AdS/CFT correspondence, as has been suggested by Brodsky and Teramond. Two kinds of wave functions, obtained in different holographic Soft-Wall models, are discussed.
Holographic models and the QCD trace anomaly
Jose L. Goity, Roberto C. Trinchero
2012-08-01
Five dimensional dilaton models are considered as possible holographic duals of the pure gauge QCD vacuum. In the framework of these models, the QCD trace anomaly equation is considered. Each quantity appearing in that equation is computed by holographic means. Two exact solutions for different dilaton potentials corresponding to perturbative and non-perturbative {beta}-functions are studied. It is shown that in the perturbative case, where the {beta}-function is the QCD one at leading order, the resulting space is not asymptotically AdS. In the non-perturbative case, the model considered presents confinement of static quarks and leads to a non-vanishing gluon condensate, although it does not correspond to an asymptotically free theory. In both cases analyses based on the trace anomaly and on Wilson loops are carried out.
A holographic model of the Kondo effect
NASA Astrophysics Data System (ADS)
Erdmenger, Johanna; Hoyos, Carlos; O'Bannon, Andy; Wu, Jackson
2013-12-01
We propose a model of the Kondo effect based on the Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence, also known as holography. The Kondo effect is the screening of a magnetic impurity coupled anti-ferromagnetically to a bath of conduction electrons at low temperatures. In a (1+1)-dimensional CFT description, the Kondo effect is a renormalization group flow triggered by a marginally relevant (0+1)-dimensional operator between two fixed points with the same Kac-Moody current algebra. In the large- N limit, with spin SU( N) and charge U(1) symmetries, the Kondo effect appears as a (0+1)-dimensional second-order mean-field transition in which the U(1) charge symmetry is spontaneously broken. Our holographic model, which combines the CFT and large- N descriptions, is a Chern-Simons gauge field in (2+1)-dimensional AdS space, AdS 3, dual to the Kac-Moody current, coupled to a holographic superconductor along an AdS 2 sub-space. Our model exhibits several characteristic features of the Kondo effect, including a dynamically generated scale, a resistivity with power-law behavior in temperature at low temperatures, and a spectral flow producing a phase shift. Our holographic Kondo model may be useful for studying many open problems involving impurities, including for example the Kondo lattice problem.
Cosmological model favored by the holographic principle
NASA Astrophysics Data System (ADS)
Dymnikova, Irina; Dobosz, Anna; Sołtysek, Bożena
2016-03-01
We present a regular spherically symmetric cosmological model of the Lemaitre class distinguished by the holographic principle as the thermodynamically stable end-point of quantum evaporation of the cosmological horizon. A source term in the Einstein equations connects smoothly two de Sitter vacua with different values of cosmological constant and corresponds to anisotropic vacuum dark fluid defined by symmetry of its stress-energy tensor which is invariant under the radial boosts. Global structure of space-time is the same as for the de Sitter space-time. Cosmological evolution goes from a big initial value of the cosmological constant towards its presently observed value.
Nawa, Kanabu; Suganuma, Hideo; Kojo, Toru
2007-04-15
We study baryons in holographic QCD with D4/D8/D8 multi-D-brane system. In holographic QCD, the baryon appears as a topologically nontrivial chiral soliton in a four-dimensional effective theory of mesons. We call this topological soliton brane-induced Skyrmion. Some review of D4/D8/D8 holographic QCD is presented from the viewpoints of recent hadron physics and QCD phenomenologies. A four-dimensional effective theory with pions and {rho} mesons is uniquely derived from the non-Abelian Dirac-Born-Infeld (DBI) action of D8 brane with D4 supergravity background at the leading order of large N{sub c}, without small amplitude expansion of meson fields to discuss chiral solitons. For the hedgehog configuration of pion and {rho}-meson fields, we derive the energy functional and the Euler-Lagrange equation of brane-induced Skyrmion from the meson effective action induced by holographic QCD. Performing the numerical calculation, we obtain the soliton solution and figure out the pion profile F(r) and the {rho}-meson profile G-tilde(r) of the brane-induced Skyrmion with its total energy, energy density distribution, and root-mean-square radius. These results are compared with the experimental quantities of baryons and also with the profiles of standard Skyrmion without {rho} mesons. We analyze interaction terms of pions and {rho} mesons in brane-induced Skyrmion, and find a significant {rho}-meson component appearing in the core region of a baryon.
Walking technipions in a holographic model
NASA Astrophysics Data System (ADS)
Kurachi, Masafumi; Matsuzaki, Shinya; Yamawaki, Koichi
2014-11-01
We calculate masses of the technipions in the walking technicolor model with the anomalous dimension γm=1 , based on a holographic model which has a naturally light technidilaton ϕ as a composite Higgs with mass mϕ≃125 GeV . The one-family model (with four weak doublets) is taken as a concrete example in such a framework, with the inputs being Fπ=v /2 ≃123 GeV and mϕ≃125 GeV as well as γm=1 . It is shown that technipion masses are enhanced by the large anomalous dimension to typically O (1 ) TeV . We find a correlation between the technipion masses and S(TC ) , the S parameter arising only from the technicolor sector. The current LHC data on the technipion mass limit thus constrains S(TC ) to be not as large as O (1 ), giving a direct constraint on the technicolor model building. This is a new constraint on the technicolor sector alone, quite independent of other sectors connected by the extended-technicolor-type interactions—in sharp contrast to the conventional S parameter constraint from the precision electroweak measurements.
A holographic model for quantum critical responses
NASA Astrophysics Data System (ADS)
Myers, Robert C.; Sierens, Todd; Witczak-Krempa, William
2016-05-01
We analyze the dynamical response functions of strongly interacting quantum critical states described by conformal field theories (CFTs). We construct a self-consistent holographic model that incorporates the relevant scalar operator driving the quantum critical phase transition. Focusing on the finite temperature dynamical conductivity σ( ω, T ), we study its dependence on our model parameters, notably the scaling dimension of the relevant operator. It is found that the conductivity is well-approximated by a simple ansatz proposed in [1] for a wide range of parameters. We further dissect the conductivity at large frequencies ω ≫ T using the operator product expansion, and show how it reveals the spectrum of our model CFT. Our results provide a physically-constrained framework to study the analytic continuation of quantum Monte Carlo data, as we illustrate using the O(2) Wilson-Fisher CFT. Finally, we comment on the variation of the conductivity as we tune away from the quantum critical point, setting the stage for a comprehensive analysis of the phase diagram near the transition.
Interacting holographic dark energy models: a general approach
NASA Astrophysics Data System (ADS)
Som, S.; Sil, A.
2014-08-01
Dark energy models inspired by the cosmological holographic principle are studied in homogeneous isotropic spacetime with a general choice for the dark energy density . Special choices of the parameters enable us to obtain three different holographic models, including the holographic Ricci dark energy (RDE) model. Effect of interaction between dark matter and dark energy on the dynamics of those models are investigated for different popular forms of interaction. It is found that crossing of phantom divide can be avoided in RDE models for β>0.5 irrespective of the presence of interaction. A choice of α=1 and β=2/3 leads to a varying Λ-like model introducing an IR cutoff length Λ -1/2. It is concluded that among the popular choices an interaction of the form Q∝ Hρ m suits the best in avoiding the coincidence problem in this model.
Implementation of linguistic models by holographic technique
NASA Astrophysics Data System (ADS)
Pavlov, Alexander V.; Shevchenko, Yanina Y.
2004-01-01
In this paper we consider linguistic model as an algebraic model and restrict our consideration to the semantics only. The concept allows "natural-like" language to be used by human-teacher to describe for machine the way of the problem solving, which is based on human"s knowledge and experience. Such imprecision words as "big", "very big", "not very big", etc can be used for human"s knowledge representation. Technically, the problem is to match metric scale, used by the technical device, with the linguistic scale, intuitively formed by the person. We develop an algebraic description of 4-f Fourier-holography setup by using triangular norms based approach. In the model we use the Fourier-duality of the t-norms and t-conorms, which is implemented by 4-f Fourier-holography setup. We demonstrate the setup is described adequately by De-Morgan"s law for involution. Fourier-duality of the t-norms and t-conorms leads to fuzzy-valued logic. We consider General Modus Ponens rule implementation to define the semantical operators, which are adequate to the setup. We consider scales, formed in both +1 and -1 orders of diffraction. We use representation of linguistic labels by fuzzy numbers to form the scale and discuss the dependence of the scale grading on the holographic recording medium operator. To implement reasoning with multi-parametric input variable we use Lorentz function to approximate linguistic labels. We use an example of medical diagnostics for experimental illustration of reasoning on the linguistic scale.
Charmonium sum rules applied to a holographic model
Hohler, Paul M.
2011-01-15
The heavy-quark QCD sum rules are applied to a model of charmonium based upon the gauge/gravity duality. We find that there is strong agreement between the moments of the polarization function calculated from the holographic model and the experimental data suggesting that the model is consistent with the heavy-quark QCD sum rules at zero temperature.
Power-Law entropy corrected holographic dark energy model
NASA Astrophysics Data System (ADS)
Sheykhi, Ahmad; Jamil, Mubasher
2011-10-01
Among various scenarios to explain the acceleration of the universe expansion, the holographic dark energy (HDE) model has got a lot of enthusiasm recently. In the derivation of holographic energy density, the area relation of the black hole entropy plays a crucial role. Indeed, the power-law corrections to entropy appear in dealing with the entanglement of quantum fields in and out the horizon. Inspired by the power-law corrected entropy, we propose the so-called "power-law entropy-corrected holographic dark energy" (PLECHDE) in this Letter. We investigate the cosmological implications of this model and calculate some relevant cosmological parameters and their evolution. We also briefly study the so-called "power-law entropy-corrected agegraphic dark energy" (PLECADE).
Holographic shell model: Stack data structure inside black holes?
NASA Astrophysics Data System (ADS)
Davidson, Aharon
2014-03-01
Rather than tiling the black hole horizon by Planck area patches, we suggest that bits of information inhabit, universally and holographically, the entire black core interior, a bit per a light sheet unit interval of order Planck area difference. The number of distinguishable (tagged by a binary code) configurations, counted within the context of a discrete holographic shell model, is given by the Catalan series. The area entropy formula is recovered, including Cardy's universal logarithmic correction, and the equipartition of mass per degree of freedom is proven. The black hole information storage resembles, in the count procedure, the so-called stack data structure.
Holographic p-wave superconductor models with Weyl corrections
NASA Astrophysics Data System (ADS)
Zhang, Lu; Pan, Qiyuan; Jing, Jiliang
2015-04-01
We study the effect of the Weyl corrections on the holographic p-wave dual models in the backgrounds of AdS soliton and AdS black hole via a Maxwell complex vector field model by using the numerical and analytical methods. We find that, in the soliton background, the Weyl corrections do not influence the properties of the holographic p-wave insulator/superconductor phase transition, which is different from that of the Yang-Mills theory. However, in the black hole background, we observe that similarly to the Weyl correction effects in the Yang-Mills theory, the higher Weyl corrections make it easier for the p-wave metal/superconductor phase transition to be triggered, which shows that these two p-wave models with Weyl corrections share some similar features for the condensation of the vector operator.
Cosmology of a holographic induced gravity model with curvature effects
Bouhmadi-Lopez, Mariam; Errahmani, Ahmed; Ouali, Taoufiq
2011-10-15
We present a holographic model of the Dvali-Gabadadze-Porrati scenario with a Gauss-Bonnet term in the bulk. We concentrate on the solution that generalizes the normal Dvali-Gabadadze-Porrati branch. It is well known that this branch cannot describe the late-time acceleration of the universe even with the inclusion of a Gauss-Bonnet term. Here, we show that this branch in the presence of a Gauss-Bonnet curvature effect and a holographic dark energy with the Hubble scale as the infrared cutoff can describe the late-time acceleration of the universe. It is worthwhile to stress that such an energy density component cannot do the same job on the normal Dvali-Gabadadze-Porrati branch (without Gauss-Bonnet modifications) nor in a standard four-dimensional relativistic model. The acceleration on the brane is also presented as being induced through an effective dark energy which corresponds to a balance between the holographic one and geometrical effects encoded through the Hubble parameter.
Holographic ρ mesons in an external magnetic field
NASA Astrophysics Data System (ADS)
Callebaut, N.; Dudal, D.; Verschelde, H.
2013-03-01
We study the ρ meson in a uniform magnetic field eB using a holographic QCD-model, more specifically a D4/D8/overline{D8} brane setup in the confinement phase at zero temperature with two quenched flavours. The parameters of the model are fixed by matching to corresponding dual field theory parameters at zero magnetic field. We show that the up- and down-flavour branes respond differently to the presence of the magnetic field in the dual QCD-like theory, as expected because of the different electromagnetic charge carried by up- and down-quark. We discuss how to recover the Landau levels, indicating an instability of the QCD vacuum at eB=m_{ρ}^2 towards a phase where charged ρ mesons are condensed, as predicted by Chernodub using effective QCD-models. We improve on these existing effective QCD-model analyses by also taking into account the chiral magnetic catalysis effect, which tells us that the constituent quark masses rise with eB. This turns out to increase the value of the critical magnetic field for the onset of ρ meson condensation to eB≈ 1.1m_{ρ}^2≈ 0.67Ge{{V}^2} . We briefly discuss the influence of pions, which turn out to be irrelevant for the condensation in the approximation made.
Quantisation of the holographic Ricci dark energy model
NASA Astrophysics Data System (ADS)
Albarran, Imanol; Bouhmadi-López, Mariam
2015-08-01
While general relativity is an extremely robust theory to describe the gravitational interaction in our Universe, it is expected to fail close to singularities like the cosmological ones. On the other hand, it is well known that some dark energy models might induce future singularities; this can be the case for example within the setup of the Holographic Ricci Dark Energy model (HRDE). On this work, we perform a cosmological quantisation of the HRDE model and obtain under which conditions a cosmic doomsday can be avoided within the quantum realm. We show as well that this quantum model not only avoid future singularities but also the past Big Bang.
On a holographic model for confinement/deconfinement
Bayona, C. A. Ballon; Boschi-Filho, Henrique; Braga, Nelson R. F.; Zayas, Leopoldo A. Pando
2008-02-15
We study the thermodynamics of the hard wall model, which consists of the introduction of an infrared cutoff in asymptotically AdS spaces. This is a toy model for confining backgrounds in the context of the gauge/gravity correspondence. We use holographic renormalization and reproduce the existence of a Hawking-Page phase transition recently discussed by Herzog. We also show that the entropy jumps from N{sup 0} to N{sup 2}, which reinforces the interpretation of this transition as the gravity dual of confinement/deconfinement. We also show that similar results hold for the phenomenologically motivated soft wall model, underlining the potential universality of our analysis.
Reactive radical facilitated reaction-diffusion modeling for holographic photopolymerization
Liu Jianhua; Pu Haihui; Gao Bin; Gao Hongyue; Yin Dejin; Dai Haitao
2010-02-08
A phenomenological concentration of reactive radical is proposed to take the role of curing light intensity in explicit proportion to the reaction rate for the conventional reaction-diffusion model. This revision rationally eliminates the theoretical defect of null reaction rate in modeling of the postcuring process, and facilitates the applicability of the model in the whole process of holographic photopolymerizations in photocurable monomer and nematic liquid crystal blend system. Excellent consistencies are obtained in both curing and postcuring processes between simulated and experimentally measured evolutions of the first order diffraction efficiency of the formed composite Bragg gratings.
Modeling swelling and absorption dynamics for holographic sensing in analytes sensitive photopolymer
NASA Astrophysics Data System (ADS)
Liu, Hongpeng; Yu, Dan; Mao, Dongyao; Geng, Yaohui; Wang, Weibo
2016-06-01
A theoretical model is developed to describe holographic sensing and swelling of grating fringe in photopolymer. In experiments, diffraction spectrum responses of grating are characterized to exhibit holographic sensing processes. Analytic expressions between swelling of grating fringe and environmental factors, such as relative humidity and organic vapor concentrations, are extracted based on experimental results. The primary factors are introduced into the model to simulate the sensing process, including swelling ratio, nanozeolites dispersion, and organic vapor absorption. Finally, numerical results are presented for improving the sensitivity of holographic sensor. This work can accelerate the development of holographic sensor and provide a theoretical base for exploring sensing mechanism of polymer.
Brane-induced Skyrmion on S{sup 3}: Baryonic matter in holographic QCD
Nawa, Kanabu; Suganuma, Hideo; Kojo, Toru
2009-01-15
We study baryonic matter in holographic QCD with D4/D8/D8 multi-D brane system in type IIA superstring theory. The baryon is described as the 'brane-induced Skyrmion', which is a topologically nontrivial chiral soliton in the four-dimensional meson effective action induced by holographic QCD. We employ the ''truncated-resonance model'' approach for the baryon analysis, including pion and {rho} meson fields below the ultraviolet cutoff scale M{sub KK}{approx}1 GeV, to keep the holographic duality with QCD. We describe the baryonic matter in large N{sub c} as single brane-induced Skyrmion on the three-dimensional closed manifold S{sup 3} with finite radius R. The interactions between baryons are simulated by the curvature of the closed manifold S{sup 3}, and the decrease of the size of S{sup 3} represents the increase of the total baryon-number density in the medium in this modeling. We investigate the energy density, the field configuration, the mass and the root-mean-square radius of single baryon on S{sup 3} as the function of its radius R. We find a new picture of 'pion dominance' near the critical density in the baryonic matter, where all the (axial) vector meson fields disappear and only the pion fields survive. We also find the swelling phenomena of the baryons as the precursor of the deconfinement, and propose the mechanism of the swelling in the general context of QCD. The properties of the deconfinement and the chiral symmetry restoration in the baryonic matter are examined by taking the proper order parameters. We also compare our truncated-resonance model with another instanton description of the baryon in holographic QCD, considering the role of cutoff scale M{sub KK}.
A Composite Holographic Associative Recall Model.
ERIC Educational Resources Information Center
Metcalfe Eich, Janet
1982-01-01
A model of association formation, storage, and retrieval is described. Experiments which test new predictions derived from the model against human recall are reported. The model is applied to previous findings: prototype abstraction, the A-B A-D paradigm and the Osgood transfer surface. Previous models of memory are discussed. (Author/RD)
Betin, A Yu; Bobrinev, V I; Evtikhiev, N N; Zherdev, A Yu; Zlokazov, E Yu; Lushnikov, D S; Markin, V V; Odinokov, S B; Starikov, S N; Starikov, R S
2013-01-31
A method of computer generation and projection recording of microholograms for holographic memory systems is presented; the results of mathematical modelling and experimental implementation of the method are demonstrated. (holographic memory)
A model of the holographic principle: Randomness and additional dimension
NASA Astrophysics Data System (ADS)
Boyarsky, Abraham; Góra, Paweł; Proppe, Harald
2010-01-01
In recent years an idea has emerged that a system in a 3-dimensional space can be described from an information point of view by a system on its 2-dimensional boundary. This mysterious correspondence is called the Holographic Principle and has had profound effects in string theory and our perception of space-time. In this note we describe a purely mathematical model of the Holographic Principle using ideas from nonlinear dynamical systems theory. We show that a random map on the surface S of a 3-dimensional open ball B has a natural counterpart in B, and the two maps acting in different dimensional spaces have the same entropy. We can reverse this construction if we start with a special 3-dimensional map in B called a skew product. The key idea is to use the randomness, as imbedded in the parameter of the 2-dimensional random map, to define a third dimension. The main result shows that if we start with an arbitrary dynamical system in B with entropy E we can construct a random map on S whose entropy is arbitrarily close to E.
Thermodynamical Aspects of Modified Holographic Dark Energy Model
NASA Astrophysics Data System (ADS)
Li, Hui; Zhang, Yi
2014-07-01
We investigate the unified first law and the generalized second law in a modified holographic dark energy model. The thermodynamical analysis on the apparent horizon can work and the corresponding entropy formula is extracted from the systematic algorithm. The entropy correction term depends on the extra-dimension number of the brane as expected, but the interplay between the correction term and the extra dimensions is more complicated. With the unified first law of thermodynamics well-founded, the generalized second law of thermodynamics is discussed and it is found that the second law can be violated in certain circumstances. Particularly, if the number of the extra dimensions is larger than one, the generalized law of thermodynamics is always satisfied; otherwise, the validity of the second law can only be guaranteed with the Hubble radius greatly smaller than the crossover scale rc of the 5-dimensional DGP model.
Entropy Corrected Holographic Dark Energy f(T) Gravity Model
NASA Astrophysics Data System (ADS)
Sharif, M.; Rani, Shamaila
2014-01-01
This paper is devoted to study the power-law entropy corrected holographic dark energy (ECHDE) model in the framework of f(T) gravity. We assume infrared (IR) cutoff in terms of Granda-Oliveros (GO) length and discuss the constructed f(T) model in interacting as well as in non-interacting scenarios. We explore some cosmological parameters like equation of state (EoS), deceleration, statefinder parameters as well as ωT-ωT‧ analysis. The EoS and deceleration parameters indicate phantom behavior of the accelerated expansion of the universe. It is mentioned here that statefinder trajectories represent consistent results with ΛCDM limit, while evolution trajectory of ωT-ωT‧ phase plane does not approach to ΛCDM limit for both interacting and non-interacting cases.
Analysis of holographic interferograms of aerodynamic models in a wind tunnel
NASA Technical Reports Server (NTRS)
Perry, R. L.
1985-01-01
Holographic interferometry provides a non-invasive technique for estimating variations in the air density distribution around aerodynamic models in wind tunnels. The testing of this technique has been underway for some time and has been reported previously for a two dimensional aerodynamic model. Results obtained from tests using three dimensional aerodynamic models are summarized. Holograms were made of aerodynamic models in a wind tunnel. Interferograms were made from these holograms. The interference fringes in these holographic interferograms were digitized and this information was entered into the HOLOFT program. The HOLOFT program successfully calculated the known stagnation air density at the nose of a model and the known air density distribution across the cross section passing through the stagnation point for the axisymmetrical case of this model at a Mach number of 0.8. Thus the technique of holographic interferometry does work.The HOLOFT program stands for HOLOgraphic Inversion by 2-D Fourier Transform.
Nonequilibrium Dynamics and Phase Transitions in Holographic Models.
Janik, Romuald A; Jankowski, Jakub; Soltanpanahi, Hesam
2016-08-26
We study the poles of the retarded Green's functions of strongly coupled field theories exhibiting a variety of phase structures from a crossover up to a first order phase transition. These theories are modeled by a dual gravitational description. The poles of the holographic Green's functions appear at the frequencies of the quasinormal modes of the dual black hole background. We establish that near the transition, in all cases considered, the applicability of a hydrodynamic description breaks down already at lower momenta than in the conformal case. We establish the appearance of the spinodal region in the case of the first order phase transition at temperatures for which the speed of sound squared is negative. An estimate of the preferential scale attained by the unstable modes is also given. We additionally observe a novel diffusive regime for sound modes for a range of wavelengths. PMID:27610844
Confinement-deconfinement phase transition for heavy quarks in a soft wall holographic QCD model
NASA Astrophysics Data System (ADS)
Yang, Yi; Yuan, Pei-Hung
2015-12-01
We study confinement-deconfinement phase transition for heavy quarks in a soft wall holographic QCD model. We consider a black hole background in an Einstein-Maxwell-scalar system and add probe open strings to the background. Combining the various configurations of the open strings and the phase structure of the black hole background itself, we obtain the confinement-deconfinement phase diagram for heavy quarks in the holographic QCD model.
Cosmology of some holographic dark energy models in chameleonic Brans-Dicke gravity
NASA Astrophysics Data System (ADS)
Sharif, M.; Waheed, Saira
2013-11-01
We study some holographic dark energy models in chameleonic Brans-Dicke field gravity by taking interaction between the dark energy components in FRW universe. Firstly, we take the holographic dark energy model with Granda-Oliveros cut-off and discuss interacting as well as non-interacting cases. Secondly, we consider the holographic dark energy with both power-law as well as logarithmic corrections using Hubble scale as infrared cut-off in interacting case only. We describe the evolution of some cosmological parameters for these holographic dark energy models. It is concluded that the phantom crossing can be achieved more easily in the presence of chameleonic Brans-Dicke field as compared to simple Brans-Dicke as well as Einstein's gravity. Also, the deceleration parameter strongly confirms the accelerated expanding behavior of the universe.
New model for holographic storage by simultaneous angular multiplexing
NASA Astrophysics Data System (ADS)
Ibarra, J. C.; Urzua, D.; Olivares-Peréz, A.; Ortiz-Gutierrez, M.
2006-05-01
We describe a technique for holographic storage by simultaneous angular multiplexing to obtain a large-scale holographic memory. We recorded 72 objects at the same time in one point on holographic plate PFG-03M from Slavich Co., using a He-Ne laser (λ = 633 nm). Each object is placed on a circular photographic transparency, separate 0.94 degree each one. The technique allows us simultaneous reconstruction of the 72 images without cross-talk. The diffraction efficiency obtained at order one is 6%. Experimental results are shown.
Avoiding Boltzmann Brain domination in holographic dark energy models
NASA Astrophysics Data System (ADS)
Horvat, R.
2015-11-01
In a spatially infinite and eternal universe approaching ultimately a de Sitter (or quasi-de Sitter) regime, structure can form by thermal fluctuations as such a space is thermal. The models of Dark Energy invoking holographic principle fit naturally into such a category, and spontaneous formation of isolated brains in otherwise empty space seems the most perplexing, creating the paradox of Boltzmann Brains (BB). It is thus appropriate to ask if such models can be made free from domination by Boltzmann Brains. Here we consider only the simplest model, but adopt both the local and the global viewpoint in the description of the Universe. In the former case, we find that if a dimensionless model parameter c, which modulates the Dark Energy density, lies outside the exponentially narrow strip around the most natural c = 1 line, the theory is rendered BB-safe. In the latter case, the bound on c is exponentially stronger, and seemingly at odds with those bounds on c obtained from various observational tests.
On the internal consistency of holographic dark energy models
Horvat, R
2008-10-15
Holographic dark energy (HDE) models, underpinned by an effective quantum field theory (QFT) with a manifest UV/IR connection, have become convincing candidates for providing an explanation of the dark energy in the universe. On the other hand, the maximum number of quantum states that a conventional QFT for a box of size L is capable of describing relates to those boxes which are on the brink of experiencing a sudden collapse to a black hole. Another restriction on the underlying QFT is that the UV cut-off, which cannot be chosen independently of the IR cut-off and therefore becomes a function of time in a cosmological setting, should stay the largest energy scale even in the standard cosmological epochs preceding a dark energy dominated one. We show that, irrespective of whether one deals with the saturated form of HDE or takes a certain degree of non-saturation in the past, the above restrictions cannot be met in a radiation dominated universe, an epoch in the history of the universe which is expected to be perfectly describable within conventional QFT.
Dynamical condensation in a holographic superconductor model with anisotropy
NASA Astrophysics Data System (ADS)
Bai, Xiaojian; Lee, Bum-Hoon; Park, Miok; Sunly, Khimphun
2014-09-01
We study dynamical condensation process in a holographic superconductor model with anisotropy. The time-dependent numerical solution is constructed for the Einstein-Maxwell-dilaton theory with complex scalar in asymptotic AdS spacetime. The introduction of dilaton field generates the anisotropy in boundary spatial directions. In analogy of isotropic case, we have two black hole solutions below certain critical temperature T c , the anisotropic charged black hole with and without scalar hair, corresponding respectively to the supercooled normal phase and superconducting phase in the boundary theory. We observe a nonlinear evolution from a supercooled anisotropic black hole without scalar hair to a anisotropic hairy black hole. Via AdS/CFT correspondence, we extract time evolution of the condensate operator, which shows an exponential growth and subsequent saturation, similar to the isotropic case. Furthermore, we obtain a nontrivial time evolution of the boundary pressure, while in isotropic case it remains a constant. We also generalize quasinormal modes calculation to anisotropic black holes and shows scalar quasinormal modes match with relaxation time scale of the condensate operator. In addition, we present the final temperature and anisotropic pressure as functions of initial temperature and background anisotropy.
Interacting Entropy-Corrected Holographic Chaplygin Gas Model
NASA Astrophysics Data System (ADS)
Farooq, M. Umar; Jamil, Mubasher; Rashid, Muneer A.
2010-10-01
Holographic dark energy (HDE), presents a dynamical view of dark energy which is consistent with the observational data and has a solid theoretical background. Its definition follows from the entropy-area relation S( A), where S and A are entropy and area respectively. In the framework of loop quantum gravity, a modified definition of HDE called “entropy-corrected holographic dark energy” (ECHDE) has been proposed recently to explain dark energy with the help of quantum corrections to the entropy-area relation. Using this new definition, we establish a correspondence between modified variable Chaplygin gas, new modified Chaplygin gas and the viscous generalized Chaplygin gas with the entropy corrected holographic dark energy and reconstruct the corresponding scalar potentials which describe the dynamics of the scalar field.
Holographic f(T)-gravity model with power-law entropy correction
NASA Astrophysics Data System (ADS)
Karami, K.; Asadzadeh, S.; Abdolmaleki, A.; Safari, Z.
2013-10-01
Using the correspondence between the f(T)-gravity model and the holographic dark energy model with the power-law entropy correction, we reconstruct the holographic f(T)-gravity model with the power-law entropy correction. We fit the model parameters by using the latest observational data including type Ia supernovae, baryon acoustic oscillations, cosmic microwave background, and Hubble parameter data. We also check the viability of our model using a cosmographic analysis approach. Using the best-fit values of the model, we obtain the evolutionary behavior of the effective torsion equation-of-state parameter of the power-law entropy-corrected holographic f(T)-gravity model, as well as the deceleration parameter of the Universe. We also investigate different energy conditions in our model. Furthermore, we examine the validity of the generalized second law of gravitational thermodynamics. Finally, we point out the growth rate of the matter density perturbation in our model. We conclude that in the power-law entropy-corrected holographic f(T)-gravity model, the Universe begins a matter-dominated phase and approaches a de Sitter regime at late times, as expected. It also can justify the transition from the quintessence state to the phantom regime in the near past, as indicated by recent observations. Moreover, this model is consistent with current data, it passes the cosmographic test, and it fits the data of the growth factor as well as the ΛCDM model.
NASA Astrophysics Data System (ADS)
Reddy, D. R. K.; Raju, P.; Sobhanbabu, K.
2016-04-01
Five dimensional spherically symmetric space-time filled with two minimally interacting fields; matter and holographic dark energy components is investigated in a scalar tensor theory of gravitation proposed by Brans and Dicke (Phys. Rev. 124:925, 1961). To obtain a determinate solution of the highly non-linear field equations we have used (i) a relation between metric potentials and (ii) an equation of state which represents disordered radiation in five dimensional universe. The solution obtained represents a minimally interacting and radiating holographic dark energy model in five dimensional universe. Some physical and Kinematical properties of the model are, also, studied.
A dynamical system analysis of holographic dark energy models with different IR cutoff
NASA Astrophysics Data System (ADS)
Mahata, Nilanjana; Chakraborty, Subenoy
2015-07-01
The paper deals with a dynamical system analysis of the cosmological evolution of an holographic dark energy (HDE) model interacting with dark matter (DM) which is chosen in the form of dust. The infrared cutoff of the holographic model is considered as future event horizon or Ricci length scale. The interaction term between dark energy (DE) and DM is chosen of following three types: (i) proportional to the sum of the energy densities of the two dark components, (ii) proportional to the product of the matter energy densities and (iii) proportional to DE density. The dynamical equations are reduced to an autonomous system for the three cases and corresponding phase space is analyzed.
Holographic dark energy models: a comparison from the latest observational data
Li, Miao; Li, Xiao-Dong; Wang, Shuang; Zhang, Xin E-mail: renzhe@mail.ustc.edu.cn E-mail: zhangxin@mail.neu.edu.cn
2009-06-01
The holographic principle of quantum gravity theory has been applied to the dark energy (DE) problem, and so far three holographic DE models have been proposed: the original holographic dark energy (HDE) model, the agegraphic dark energy (ADE) model, and the holographic Ricci dark energy (RDE) model. In this work, we perform the best-fit analysis on these three models, by using the latest observational data including the Union+CFA3 sample of 397 Type Ia supernovae (SNIa), the shift parameter of the cosmic microwave background (CMB) given by the five-year Wilkinson Microwave Anisotropy Probe (WMAP5) observations, and the baryon acoustic oscillation (BAO) measurement from the Sloan Digital Sky Survey (SDSS). The analysis shows that for HDE, χ{sub min}{sup 2} = 465.912; for RDE, χ{sub min}{sup 2} = 483.130; for ADE, χ{sub min}{sup 2} = 481.694. Among these models, HDE model can give the smallest χ{sup 2}{sub min}. Besides, we also use the Bayesian evidence (BE) as a model selection criterion to make a comparison. It is found that for HDE, ADE, and RDE, Δln BE = −0.86, −5.17, and −8.14, respectively. So, it seems that the HDE model is more favored by the observational data.
Holographic Dark Energy Model with Time Varying G as Well as c 2 Parameter
NASA Astrophysics Data System (ADS)
Borah, Bharat; Ansari, M.
2014-04-01
In this paper, we study a holographic dark energy model with time varying gravitational constant G as well as holographic parameter c 2 in flat FRW space-time geometry. We obtain the evolution of equation of state parameter and the exact differential equation, which determine the evolution of the dark energy density based on varying G and c 2 parameter. Also, we determine the deceleration parameter to explain the expansion of the universe. Further, we study the validity of the generalized second law of thermodynamics in this scenario. Finally, we find out a cosmological implication of our work by evaluating the holographic dark energy equation of state for low red-shifts containing both varying G and c 2 parameter corrections.
Anisotropic modified holographic Ricci dark energy cosmological model with hybrid expansion law
NASA Astrophysics Data System (ADS)
Das, Kanika; Sultana, Tazmin
2015-11-01
Here in this paper we present a locally rotationally symmetric Bianchi type-II metric filled with dark matter and anisotropic modified holographic Ricci dark energy. To solve the Einstein's field equations we have taken the hybrid expansion law (HEL) which exhibits a cosmic transition of the universe from decelerating to accelerating phase. We have investigated the physical and geometrical properties of the model. It is observed that the anisotropy of the universe and that of the modified holographic Ricci dark energy tends to zero at later times and the universe becomes homogeneous, isotropic and flat. We have also studied the cosmic jerk parameter.
On the Baryonic Density and Susceptibilities in a Holographic Model of QCD
Kim, Keun-young; Liao, Jinfeng
2009-06-16
In this paper, we calculate analytically the baryonic density and susceptibilities, which are sensitive probes to the fermionic degrees of freedom, in a holographic model of QCD both in its hot QGP phase and in its cold dense phase. Interesting patterns due to strong coupling dynamics will be shown and valuable lessons for QCD will be discussed.
Nucleon statistics in holographic QCD: Aharonov-Bohm effect in a matrix model
Hashimoto, Koji; Iizuka, Norihiro
2010-11-15
We show that the Aharonov-Bohm effect in the nuclear matrix model [K. Hashimoto, N. Iizuka, and P. Yi, J. High Energy Phys. 10 (2010), 3.] derives the statistical nature of nucleons in holographic QCD. For N{sub c}=odd (even), the nucleon is shown to be a fermion (boson).
Nucleon statistics in holographic QCD: Aharonov-Bohm effect in a matrix model
NASA Astrophysics Data System (ADS)
Hashimoto, Koji; Iizuka, Norihiro
2010-11-01
We show that the Aharonov-Bohm effect in the nuclear matrix model [K. Hashimoto, N. Iizuka, and P. Yi, J. High Energy Phys.JHEPFG1029-8479 10 (2010), 3.10.1007/JHEP10(2010)003] derives the statistical nature of nucleons in holographic QCD. For Nc=odd (even), the nucleon is shown to be a fermion (boson).
Stochastic resonance in pattern recognition by a holographic neuron model
NASA Astrophysics Data System (ADS)
Stoop, R.; Buchli, J.; Keller, G.; Steeb, W.-H.
2003-06-01
The recognition rate of holographic neural synapses, performing a pattern recognition task, is significantly higher when applied to natural, rather than artificial, images. This shortcoming of artificial images can be largely compensated for, if noise is added to the input pattern. The effect is the result of a trade-off between optimal representation of the stimulus (for which noise is favorable) and keeping as much as possible of the stimulus-specific information (for which noise is detrimental). The observed mechanism may play a prominent role for simple biological sensors.
NASA Astrophysics Data System (ADS)
Karami, K.; Khaledian, M. S.; Jamil, Mubasher
2011-02-01
Here we consider the entropy-corrected version of the holographic dark energy (DE) model in the non-flat universe. We obtain the equation of state parameter in the presence of interaction between DE and dark matter. Moreover, we reconstruct the potential and the dynamics of the quintessence, tachyon, K-essence and dilaton scalar field models according to the evolutionary behavior of the interacting entropy-corrected holographic DE model.
NASA Astrophysics Data System (ADS)
Gallego, Sergi; Ortuño, Manuel; Neipp, Cristian; Márquez, Andrés; Beléndez, Augusto; Pascual, Inmaculada
2005-10-01
Several theoretical models have been proposed to predict the behavior of photopolymers as holographic recording materials. Basically these models have been applied to study thin layers (around 100 µm thick). The increasing importance of holographic memories recorded in photopolymers (thickness of >500 µm) makes it necessary to extend the ideas proposed by these models to study thick photopolymer layers. We calculate the temporal evolution of the diffraction efficiencies for thick layers using a first-harmonic diffusion model, and the results obtained are compared with the corresponding values for thin layers. Furthermore, the values of the average diffusivity of the polymer chains after the grating is formed are also obtained. In general, we find that the monomer and polymer diffusivity increases when higher values of thickness are used.
Revisit of the interacting holographic dark energy model after Planck 2015
NASA Astrophysics Data System (ADS)
Feng, Lu; Zhang, Xin
2016-08-01
We investigate the observational constraints on the interacting holographic dark energy model. We consider five typical interacting models with the interaction terms Q = 3βHρde, Q = 3βHρc, Q = 3βH(ρde+ρc), Q = 3βH√ρdeρc, and Q = 3βHρdeρc/ρde+ρc, respectively, where β is a dimensionless coupling constant. The observational data we use in this paper include the JLA compilation of type Ia supernovae data, the Planck 2015 distance priors data of cosmic microwave background observation, the baryon acoustic oscillations measurements, and the Hubble constant direct measurement. We make a comparison for these five interacting holographic dark energy models by employing the information criteria, and we find that, within the framework of holographic dark energy, the Q = 3βHρdeρc/ρde+ρc model is most favored by current data, and the Q = 3βHρc model is relatively not favored by current data. For the Q = 3βHρde and Q = 3βHρdeρc/ρde+ρc models, a positive coupling β can be detected at more than 2σ significance.
Pion in the Holographic Model with 5D Yang-Mills Fields
Grigoryan, Hovhannes; Radyushkin, Anatoly
2008-12-01
We study pion in the holographic model of Hirn and Sanz which contains two Yang-Mills fields defined in the background of the sliced AdS space. The infrared boundary conditions imposed on these fields generate the spontaneous breaking of the chiral symmetry down to its vector subgroup. Within the framework of this model, we get an analytic expression for the pion form factor and a compact result for its radius. We also extend the holographic model to include Chern-Simons term which is required to reproduce the appropriate axial anomaly of QCD. As a result, we calculate the anomalous form factor of the pion and predict its Q^2-slope for the kinematics when one of the photons is almost on-shell. We also observe that the anomalous form factor with one real and one virtual photon is given by the same analytic expression as the electromagnetic form factor of a charged pion.
Biomechanical model produced from light-activated dental composite resins: a holographic analysis
NASA Astrophysics Data System (ADS)
Pantelić, Dejan; Vasiljević, Darko; Blažić, Larisa; Savić-Šević, Svetlana; Murić, Branka; Nikolić, Marko
2013-11-01
Light-activated dental composites, commonly applied in dentistry, can be used as excellent material for producing biomechanical models. They can be cast in almost any shape in an appropriate silicone mold and quickly solidified by irradiation with light in the blue part of the spectrum. In that way, it is possible to obtain any number of nearly identical casts. The models can be used to study the behavior of arbitrary structure under mechanical loads. To test the technique, a simple mechanical model of the tooth with a mesio-occluso-distal cavity was manufactured. Composite resin restoration was placed inside the cavity and light cured. Real-time holographic interferometry was used to analyze the contraction of the composite resin and its effect on the surrounding material. The results obtained in the holographic experiment were in good agreement with those obtained using the finite element method.
P-T phase diagram of a holographic s+p model from Gauss-Bonnet gravity
NASA Astrophysics Data System (ADS)
Nie, Zhang-Yu; Zeng, Hui
2015-10-01
In this paper, we study the holographic s+p model in 5-dimensional bulk gravity with the Gauss-Bonnet term. We work in the probe limit and give the Δ-T phase diagrams at three different values of the Gauss-Bonnet coefficient to show the effect of the Gauss-Bonnet term. We also construct the P-T phase diagrams for the holographic system using two different definitions of the pressure and compare the results.
Holographic testing of composite propfans for a cruise missile wind tunnel model
NASA Technical Reports Server (NTRS)
Miller, Christopher J.
1994-01-01
Each of the approximately 90 composite propfan blades constructed for a 55 percent scale cruise missile wind tunnel model were holographically tested to obtain natural frequencies and mode shapes. These data were used not only for quality assurance, but also to select sets of similar blades for each blade row. Presented along with the natural frequency data is a description of a computer-based image processing system developed to supplement the photographic based system for holographic image analysis and storage. The new system is quicker and cheaper, the holograms are indexed better, and several engineers can access the data simultaneously. The only negative effect is a slight reduction in image resolution, which does not influence the end use.
NASA Astrophysics Data System (ADS)
Banks, Tom
2012-10-01
The theory of holographic spacetime (HST) generalizes both string theory and quantum field theory (QFT). It provides a geometric rationale for supersymmetry (SUSY) and a formalism in which super-Poincare invariance follows from Poincare invariance. HST unifies particles and black holes, realizing both as excitations of noncommutative geometrical variables on a holographic screen. Compact extra dimensions are interpreted as finite-dimensional unitary representations of super-algebras, and have no moduli. Full field theoretic Fock spaces, and continuous moduli are both emergent phenomena of super-Poincare invariant limits in which the number of holographic degrees of freedom goes to infinity. Finite radius de Sitter (dS) spaces have no moduli, and break SUSY with a gravitino mass scaling like Λ1/4. In regimes where the Covariant Entropy Bound is saturated, QFT is not a good description in HST, and inflation is such a regime. Following ideas of Jacobson, the gravitational and inflaton fields are emergent classical variables, describing the geometry of an underlying HST model, rather than "fields associated with a microscopic string theory". The phrase in quotes is meaningless in the HST formalism, except in asymptotically flat and AdS spacetimes, and some relatives of these.
NASA Astrophysics Data System (ADS)
Karami, Kayoomars; Abdolmaleki, Asrin
2013-07-01
In the present work, we reconstruct different f(T)-gravity models corresponding to the original and entropy-corrected versions of the holographic and new agegraphic dark energy models. We also obtain the equation of state parameters of the corresponding f(T)-gravity models. We conclude that the original holographic and new agegraphic f(T)-gravity models behave like the phantom or quintessence model, whereas in the entropy-corrected models, the equation of state parameter can justify the transition from the quintessence state to the phantom regime as indicated by the recent observations.
Modified Holographic Ricci Dark Energy Model and Statefinder Diagnosis in Flat Universe
NASA Astrophysics Data System (ADS)
Mathew, Titus K.; Suresh, Jishnu; Divakaran, Divya
2013-07-01
Evolution of the universe with modified holographic Ricci dark energy model is considered. Dependency of the equation of state parameter and deceleration parameter on the redshift and model parameters are obtained. It is shown that the density evolution of both the nonrelativistic matter and dark energy are same until recent times. The evolutionary trajectories of the model for different model parameters are obtained in the statefinder planes, r - s and r - q planes. The present statefinder parameters are obtained for different model parameter values, using that the model is differentiated from other standard models like the ΛCDM model. We have also shown that the evolutionary trajectories are depending on the model parameters, and at past times the dark energy is behaving like cold dark matter, with equation of state equal to zero.
Statefinder diagnosis for holographic dark energy models in modified f(R,T) gravity
NASA Astrophysics Data System (ADS)
Singh, C. P.; Kumar, Pankaj
2016-05-01
In this paper we consider the non-viscous and viscous holographic dark energy models in modified f(R,T) gravity in which the infra-red cutoff is set by the Hubble horizon. We find power-law and exponential form of scale factor for non-viscous and viscous models, respectively. It is shown that the Hubble horizon as an infra-red cut-off is suitable for both the models to explain the recent accelerated expansion. In non-viscous model, we find that there is no phase transition. However, viscous model explains the phase transition from decelerated phase to accelerated phase. The cosmological parameters like deceleration parameter and statefinder parameters are discussed to analyze the dynamics of evolution of the Universe for both the models. The trajectories for viscous model are plotted in r-s and r-q planes to discriminate our model with the existing dark energy models which show the quintessence like behavior.
Correspondence between entropy-corrected holographic and Gauss-Bonnet dark-energy models
NASA Astrophysics Data System (ADS)
Setare, M. R.; Jamil, Mubasher
2010-11-01
In the present work we investigate the cosmological implications of the entropy-corrected holographic dark-energy (ECHDE) density in the Gauss-Bonnet framework. This is motivated from the loop quantum gravity corrections to the entropy-area law. Assuming the two cosmological scenarios are valid simultaneously, we show that there is a correspondence between the ECHDE scenario in flat universe and the phantom dark-energy model in the framework of the Gauss-Bonnet theory with a potential. This correspondence leads consistently to an accelerating universe.
Entropy-corrected holographic scalar field models of dark energy in Kaluza-Klein universe
NASA Astrophysics Data System (ADS)
Sharif, M.; Jawad, Abdul
2013-12-01
We investigate the evolution of interacting holographic dark energy with logarithmic corrections in the flat Kaluza-Klein universe. We evaluate the equation of state parameter and also reconstruct the scalar field models in this scenario. For this purpose, the well-known choice of scale factor in the power law form is taken. It is interesting to mention here that the corresponding equation of state parameter crosses the phantom divide line for a particular choice of interacting parameters. Finally, we conclude that the behavior of the dynamical scalar field as well as the scalar potential is consistent with the present observations.
f(T) Gravity from Holographic Ricci Dark Energy Model with New Boundary Conditions
NASA Astrophysics Data System (ADS)
Huang, Peng; Huang, Yong-Chang; Yuan, Fang-Fang
2013-11-01
Commonly used boundary conditions in reconstructing f(T) gravity from holographic Ricci dark energy (RDE) model are found to cause some problem, we therefore propose new boundary conditions in this paper. By reconstructing f(T) gravity from the RDE with these new boundary conditions, we show that the new ones are better than the present commonly used ones since they can give the physically expected information, which is lost when the commonly used ones are taken in the reconstruction, of the resulting f(T) theory. Thus, the new boundary conditions proposed here are more suitable for the reconstruction of f(T) gravity.
An exemplar model of performance in the artificial grammar task: holographic representation.
Jamieson, Randall K; Hauri, Brian R
2012-06-01
We apply a multitrace model of memory to explain performance in the artificial grammar task. The model blends the convolution method for representation from Jones and Mewhort's BEAGLE model (Jones, M. N., & Mewhort, D. J. K. (2007). Representing word meaning and order information in a composite holographic lexicon. Psychological Review, 114, 1-37) of semantic memory with the multitrace storage and retrieval model from Hintzman's MINERVA 2 model (Hintzman, D. L. (1986). "Schema abstraction" in a multiple-trace memory model. Psychological Review, 93, 411-428) of episodic memory. We report an artificial grammar experiment, and we fit the model to those data at the level of individual items. We argue that performance in the artificial grammar task is best understood as a process of retrospective inference from memory. PMID:22686158
Three-dimensional numerical model of holographic grating formation in photopolymer materials
NASA Astrophysics Data System (ADS)
Li, Haoyu; Qi, Yue; Malallah, Ra'ed; Sheridan, John T.
2015-05-01
When the large thickness is used as the holographic storage materials, a non-ignorable problem is the light intensity attenuation in depth due to high absorptive of the dye. For this reason more completely modeling the evolutions inside the material is necessary to consider into the developed standard kinetic model. In this paper the photo-polymerization processes during the large thickness holographic grating formation are analyzed. A 3-dimensional algorithm is present by deriving the system partial differential rate equations governing each associated chemical species, and using the finite difference approximation, these equations can be solved numerically. This extended model describes the time varying behaviors of the non-uniform photo-physical and the photochemical evolutions in photopolymer materials. In this model both dye molecules consumption and light energy absorption are calculated time varyingly, and then the polymer and monomer concentrations distributions are obtained. Applying the Lorenz-Lorenz relationship, the non-uniform grating formatted in material depth, and its refractive index, which is distorted from ideal sinusoidal spatial distribution, can be more accurately predicted.
Instability in interacting dark sector: an appropriate holographic Ricci dark energy model
NASA Astrophysics Data System (ADS)
Herrera, Ramón; Hipólito-Ricaldi, W. S.; Videla, Nelson
2016-08-01
In this paper we investigate the consequences of phantom crossing considering the perturbative dynamics in models with interaction in their dark sector. By mean of a general study of gauge-invariant variables in comoving gauge, we relate the sources of instabilities in the structure formation process with the phantom crossing. In order to illustrate these relations and its consequences in more detail, we consider a specific case of an holographic dark energy interacting with dark matter. We find that in spite of the model is in excellent agreement with observational data at background level, however it is plagued of instabilities in its perturbative dynamics. We reconstruct the model in order to avoid these undesirable instabilities, and we show that this implies a modification of the concordance model at background. Also we find drastic changes on the parameters space in our model when instabilities are avoided.
A holographic model for QCD in the Veneziano limit at finite temperature and density
NASA Astrophysics Data System (ADS)
Alho, T.; Järvinen, M.; Kajantie, K.; Kiritsis, E.; Rosen, C.; Tuominen, K.
2014-04-01
A holographic model of QCD in the limit of large number of colors, N c , and massless fermion flavors, N f , but constant ratio x f = N f /N c is analyzed at finite temperature and chemical potential. The five dimensional gravity model contains three bulk fields: a scalar dilaton sourcing Tr F 2, a scalar tachyon dual to and a 4-vector dual to the baryon current γ μ q. The main result is the μ, T phase diagram of the holographic theory. A first order deconfining transition along T h ( μ) and a chiral transition at T χ ( μ) > T h ( μ) are found. The chiral transition is of second order for small μ and becomes of first order at larger μ. The two regimes are separated by a tricritical point. The dependence of thermodynamical quantities including the speed of sound and susceptibilities on the chemical potential and temperature is computed. A new quantum critical regime is found at zero temperature and finite chemical potential. It is controlled by an AdS2 × R 3 geometry and displays semi-local criticality.
Pomeron and odderon Regge trajectories from a dynamical holographic model
NASA Astrophysics Data System (ADS)
Capossoli, Eduardo Folco; Li, Danning; Boschi-Filho, Henrique
2016-09-01
In this work we use gauge/string dualities and a dynamical model that takes into account dynamical corrections to the metric of the anti de Sitter space due to a quadratic dilaton field and calculate the masses of even and odd spin glueball states with P = C = + 1, and P = C = - 1, respectively. Then we construct the corresponding Regge trajectories which are associated with the pomeron for even states with P = C = + 1, and with the odderon for odd states with P = C = - 1. We compare our results with those coming from experimental data as well as other models.
The S-parameter in holographic technicolor models
NASA Astrophysics Data System (ADS)
Agashe, Kaustubh; Csáki, Csaba; Reece, Matthew; Grojean, Christophe
2007-12-01
We study the S parameter, considering especially its sign, in models of electroweak symmetry breaking (EWSB) in extra dimensions, with fermions localized near the UV brane. Such models are conjectured to be dual to 4D strong dynamics triggering EWSB. The motivation for such a study is that a negative value of S can significantly ameliorate the constraints from electroweak precision data on these models, allowing lower mass scales (TeV or below) for the new particles and leading to easier discovery at the LHC. We first extend an earlier proof of S>0 for EWSB by boundary conditions in arbitrary metric to the case of general kinetic functions for the gauge fields or arbitrary kinetic mixing. We then consider EWSB in the bulk by a Higgs VEV showing that S is positive for arbitrary metric and Higgs profile, assuming that the effects from higher-dimensional operators in the 5D theory are sub-leading and can therefore be neglected. For the specific case of AdS5 with a power law Higgs profile, we also show that S ~ +O(1), including effects of possible kinetic mixing from higher-dimensional operator (of NDA size) in the 5D theory. Therefore, our work strongly suggests that S is positive in calculable models in extra dimensions.
A holographic model of d-wave superconductor vortices with Lifshitz scaling
NASA Astrophysics Data System (ADS)
Guo, Hong; Shu, Fu-Wen; Chen, Jing-He; Li, Hui; Yu, Ze
2016-02-01
We study analytically the d-wave holographic superconductors with Lifshitz scaling in the presence of external magnetic field. The vortex lattice solutions of the model have also been obtained with different Lifshitz scaling. Our results imply that holographic d-wave superconductor is indeed a type II one even for different Lifshitz scaling. This is the same as the conventional d-wave superconductors in the Ginzburg-Landau (GL) theory. Our results also indicates that the dynamical exponent z cannot affect the droplet solutions, and the vortex lattice solutions receive its effects only in the radial part. This naively implies that it does not have direct influence on the shape of vortex lattice even after the higher-order corrections are taken into consideration (away from the phase transition point Bc). However, it has effects on the upper critical magnetic field Bc2 through the fact that a larger z results in a smaller Bc2 and therefore influences the size (characterized by r0 ≡ 1/Bc2) of the vortex lattices. Furthermore, close comparisons between our results and those of the GL theory reveal the fact that the upper critical magnetic field Bc2 is inversely proportional to the square of the superconducting coherence length ξ, regardless of the anisotropy between space and time.
NASA Astrophysics Data System (ADS)
Shimada, Ken-ichi; Ishii, Toshiki; Hoshizawa, Taku; Takashima, Yuzuru
2015-08-01
Holographic Data Storage System (HDSS) is one of promising candidates for future high density Optical Data Storage (ODS) system. Modern HDSS using angularly multiplexed recording employs a complicated opt-mechanical system for controlling angle of the reference beam or disk positioning precisely and quickly to achieve high density and fast recording. However, mechanical instabilities during recording and involved degradation of signal quality in HDSS is one of the obstacles to prevent the technology from being a robust system. We analytically formulated effects of mechanical instabilities of a Galvano mirror and spindle motor on the HDSS by incorporating the concept of time averaged holography. Mechanical parameters such as amplitude and frequency of mechanical oscillation are related to optical parameters such as amplitude and phase of reference and signal beams. Through comparison of simulation results with experimental results, we confirmed that the developed optical model was able to predict signal level of a degraded holographic image due to mechanical instabilities. Then, the analytical formulation led to a new method of optical and post recovery for mechanical instability during recording hologram. The optical post recovery method enables a robust implementation of HDSS against mechanical instabilities.
The properties of the lightest scalar mesons in a holographic QCD model
NASA Astrophysics Data System (ADS)
He, Bing-Ran; Harada, Masayasu; Kim, Youngman; Ma, Yong-Liang
2014-09-01
We study a mixing structure of light scalar mesons corresponding to the two-quark state, four-quark state and the glueball state using a bottom-up holographic QCD model. In our model, the geometry of the five dimensional space-time and the vacuum expectation value of the glueball field are determined through the Einstein equation by requiring that the dilaton potential can reproduce the asymptotic freedom of QCD and the glueball field arises as the fluctuation with respect to the gravity background. By using the geometry as a background, we add the scalar field corresponding to the two-quark state and four-quark state. Using this model, we study the spectra of the light iso-scalar scalar mesons and the mixing among the glueball, the two-quark states and four-quark states.
NASA Astrophysics Data System (ADS)
Lin, Chun-Hua; Cho, Sheng-Lung; Lin, Shiuan-Huei; Chi, Sien; Hsu, Ken-Yuh
2014-11-01
We investigate a two-wavelength method for recording a persistent hologram in a doped photopolymer. The recording method is based on two separated optical excitations of the four-energy-level system of the doped element, one at λ=325 nm as the sensitizing wavelength and the other at λ=647 nm as the writing wavelength, allowing for an experimental demonstration of nondestructive readout in phenanthrenequinone-doped poly(methyl methacrylate). Further, a four-energy-level rate equations model is proposed for describing the dynamics of hologram recording. The model successfully explains our experimental finding and further provides a general method to investigate such a two-wavelength holographic recording in photopolymer.
NASA Astrophysics Data System (ADS)
Prabir, Rudra
2016-07-01
In this assignment we will present a reconstruction scheme between f(R) gravity with ordinary and entropy corrected (m,n)-type holographic dark energy. The correspondence is established and expressions for the reconstructed f(R) models are determined. To study the evolution of the reconstructed models plots are generated. The stability of the calculated models are also investigated using the squared speed of sound in the background of the reconstructed gravities.
A new model of holographic QCD and chiral condensate in dense matter
NASA Astrophysics Data System (ADS)
Seki, Shigenori; Sin, Sang-Jin
2013-10-01
We consider the model of holographic QCD with asymptotic freedom and gluon condensation in its vacuum. It consists of the color D4-branes and D0-branes as a background and the flavor D8-branes as a probe. By taking a specific field theory limit, the effective coupling decreases. We then introduce the uniformly distributed baryons in terms of the baryon vertices and study the density dependence of chiral condensate, which is evaluated using the worldsheet instanton method. In the confined phase, the chiral condensate as a function of density monotonically decreases in high baryon density. Such behavior is in agreement with the expectation, while in extremely low density it increases. We attribute this anomaly to the incorrect approximation of uniformity in very low density. In the deconfined phase the chiral condensate monotonically decreases in the whole region of density.
Phase transitions, {theta} behavior, and instantons in QCD and its holographic model
Parnachev, Andrei; Zhitnitsky, Ariel R.
2008-12-15
In the holographic model of QCD, {theta} dependence sharply changes at the point of confinement-deconfinement phase transition. In large N QCD such a change in {theta} behavior can be related to the breakdown of the instanton expansion at some critical temperature T{sub c}. Associating this temperature with confinement-deconfinement phase transition leads to the description of the latter in terms of dissociation of instantons into the fractionally charged instanton quarks. To elucidate this picture, we introduce the nonvanishing chiral condensate in the deconfining phase and assume a specific Lagrangian for the {eta}{sup '} field in the confining phase. In the resulting picture the high-temperature phase of the theory consists of the dilute gas of instantons, while the low-temperature phase is described in terms of freely moving fractional instanton quarks.
Light liquid: a holographic 'lake' installed on the roof of an architect's model townscape
NASA Astrophysics Data System (ADS)
Pepper, A.
2013-02-01
There has been considerable speculation about the use of holography in architecture and interior design over the past 20 years, with some spectacular examples having been realised. A number of installed works are referenced which use interior and exterior structures and spaces. Scale is considered as well as the possibility of architectural works existing within an artificial (model) environment. The visual, conceptual and critical values such an installation provokes are interrogated, with particular reference to 'Light Liquid, a holographic 'lake' installed within the 2011 Miniment[s] exhibition at Nottingham Trent University, UK. Aspects of miniature public art interventions, and whether they can have a critical validity within a contrived and artificial environment, are examined.
NASA Astrophysics Data System (ADS)
Ghosh, Rahul; Debnath, Ujjal
2014-05-01
We have discussed the correspondence of the well-accepted f( G) gravity theory with two dark energy models: ( m, n)-type holographic dark energy (( m, n)-type HDE) and entropy-corrected ( m, n)-type holographic dark energy. For this purpose, we have considered the power law form of the scale factor a( t) = a 0 t p , p > 1. The reconstructed f( G) in these models has been found and the models in both cases are found to be realistic. We have also discussed the classical stability issues in both models. The ( m, n)-type HDE and its entropy-corrected version are more stable than the ordinary HDE model.
A modified holographic dark energy model with infrared infinite extra dimension(s)
NASA Astrophysics Data System (ADS)
Gong, Yungui; Li, Tianjun
2010-01-01
We propose a modified holographic dark energy (MHDE) model with the Hubble scale as the infrared (IR) cutoff. Introducing the infinite extra dimension(s) at very large distance scale, we consider the black hole mass in higher dimensions as the ultraviolet cutoff. Thus, we can probe the effects of the IR infinite extra dimension(s). As a concrete example, we consider the Dvali-Gabadadze-Porrati (DGP) model and its generalization. We find that the DGP model is dual to the MHDE model in five dimensions, and the ΛCDM model is dual to the MHDE model in six dimensions. Fitting the MHDE model to the observational data, we obtain that Ωm0=0.269-0.027+0.030, Ωk0=0.003-0.012+0.011, and the number of the spatial dimensions is N=4.78-0.44+0.68. The best fit value of N implies that there might exist two IR infinite extra dimensions.
NASA Astrophysics Data System (ADS)
Wadle, Stephen; Wuest, Daniel; Cantalupo, John; Lakes, Roderic S.
1994-01-01
Holographic diffusers are prepared using silver halide (Agfa 8E75 and Kodak 649F) and photopolymer (Polaroid DMP 128 and DuPont 600, 705, and 150 series) media. It is possible to control the diffusion angle in three ways: by selection of the properties of the source diffuser, by control of its subtended angle, and by selection of the holographic medium. Several conventional diffusers based on refraction or scattering of light are examined for comparison.
Cosmological constraints on the new holographic dark energy model with action principle
NASA Astrophysics Data System (ADS)
Li, Miao; Li, Xiao-Dong; Meng, Jun; Zhang, Zhenhui
2013-07-01
Recently, a new holographic dark energy (HDE) model with action principle was proposed [M. Li and R. X. Miao, arXiv:1210.0966]. It is the first time that the HDE model is derived from the action principle. This model completely solves the causality and circular problems in the original HDE model and automatically gives rise to a dark radiation component. Thus, it is worth investigating such an interesting model by confronting it with the current cosmological observations, so that we can check whether the model is consistent with the data and determine the regions of parameter space allowed. These issues are explored in this work. First, we investigate the dynamical behaviors and the cosmic expansion history of the model and discuss how they are related with the model parameter c. Then, we fit the model to a combination of the present Union2.1+BAO+CMB+H0 data. We find the model yields χmin2=548.798 (in a nonflat universe), comparable to the results of the original HDE model (549.461) and the concordant ΛCDM model (550.354). At 95.4% C.L., we get 1.41
Mackey, Dana; O'Reilly, Paul; Naydenova, Izabela
2016-05-01
This paper introduces an improved mathematical model for holographic grating formation in an acrylamide-based photopolymer, which consists of partial differential equations derived from physical laws. The model is based on the two-way diffusion theory of [Appl. Opt.43, 2900 (2004)10.1364/AO.43.002900APOPAI1559-128X], which assumes short polymer chains are free to diffuse, and generalizes a similar model presented in [J. Opt. Soc. Am. B27, 197 (2010)10.1364/JOSAB.27.000197JOBPDE0740-3224] by introducing an immobilization rate governed by chain growth and cross-linking. Numerical simulations were carried out in order to investigate the behavior of the photopolymer system for short and long exposures, with particular emphasis on the effect of recording parameters (such as illumination frequency and intensity), as well as material permeability, on refractive index modulation, refractive index profile, and grating distortion. The model reproduces many well-known experimental observations, such as the decrease of refractive index modulation at high spatial frequencies and appearance of higher harmonics in the refractive index profile when the diffusion rate is much slower than the polymerization rate. These properties are supported by a theoretical investigation which uses perturbation techniques to approximate the solution over various time scales. PMID:27140889
Cheng, Jeffrey Tao; Hamade, Mohamad; Merchant, Saumil N.; Rosowski, John J.; Harrington, Ellery; Furlong, Cosme
2013-01-01
Sound-induced motions of the surface of the tympanic membrane (TM) were measured using stroboscopic holography in cadaveric human temporal bones at frequencies between 0.2 and 18 kHz. The results are consistent with the combination of standing-wave-like modal motions and traveling-wave-like motions on the TM surface. The holographic techniques also quantified sound-induced displacements of the umbo of the malleus, as well as volume velocity of the TM. These measurements were combined with sound-pressure measurements near the TM to compute middle-ear input impedance and power reflectance at the TM. The results are generally consistent with other published data. A phenomenological model that behaved qualitatively like the data was used to quantify the relative magnitude and spatial frequencies of the modal and traveling-wave-like displacement components on the TM surface. This model suggests the modal magnitudes are generally larger than those of the putative traveling waves, and the computed wave speeds are much slower than wave speeds predicted by estimates of middle-ear delay. While the data are inconsistent with simple modal displacements of the TM, an alternate model based on the combination of modal motions in a lossy membrane can also explain these measurements without invoking traveling waves. PMID:23363110
Cheng, Jeffrey Tao; Hamade, Mohamad; Merchant, Saumil N; Rosowski, John J; Harrington, Ellery; Furlong, Cosme
2013-02-01
Sound-induced motions of the surface of the tympanic membrane (TM) were measured using stroboscopic holography in cadaveric human temporal bones at frequencies between 0.2 and 18 kHz. The results are consistent with the combination of standing-wave-like modal motions and traveling-wave-like motions on the TM surface. The holographic techniques also quantified sound-induced displacements of the umbo of the malleus, as well as volume velocity of the TM. These measurements were combined with sound-pressure measurements near the TM to compute middle-ear input impedance and power reflectance at the TM. The results are generally consistent with other published data. A phenomenological model that behaved qualitatively like the data was used to quantify the relative magnitude and spatial frequencies of the modal and traveling-wave-like displacement components on the TM surface. This model suggests the modal magnitudes are generally larger than those of the putative traveling waves, and the computed wave speeds are much slower than wave speeds predicted by estimates of middle-ear delay. While the data are inconsistent with simple modal displacements of the TM, an alternate model based on the combination of modal motions in a lossy membrane can also explain these measurements without invoking traveling waves. PMID:23363110
Batell, Brian; Gherghetta, Tony
2007-08-15
We compute the precise elementary/composite field content of mass eigenstates in holographic duals of warped models in a slice of AdS{sub 5}. This is accomplished by decomposing the bulk fields not in the usual Kaluza-Klein basis, but rather into a holographic basis of 4D fields, corresponding to purely elementary source or conformal field theory (CFT) composite fields. Generically, this decomposition yields kinetic and mass mixing between the elementary and composite sectors of the holographic theory. Depending on where the bulk zero mode is localized, the elementary/composite content may differ radically, which we show explicitly for several examples including the bulk Randall-Sundrum graviton, bulk gauge boson, and Higgs boson.
Digital holographic microscopy for imaging growth and treatment response in 3D tumor models
NASA Astrophysics Data System (ADS)
Li, Yuyu; Petrovic, Ljubica; Celli, Jonathan P.; Yelleswarapu, Chandra S.
2014-03-01
While three-dimensional tumor models have emerged as valuable tools in cancer research, the ability to longitudinally visualize the 3D tumor architecture restored by these systems is limited with microscopy techniques that provide only qualitative insight into sample depth, or which require terminal fixation for depth-resolved 3D imaging. Here we report the use of digital holographic microscopy (DHM) as a viable microscopy approach for quantitative, non-destructive longitudinal imaging of in vitro 3D tumor models. Following established methods we prepared 3D cultures of pancreatic cancer cells in overlay geometry on extracellular matrix beds and obtained digital holograms at multiple timepoints throughout the duration of growth. The holograms were digitally processed and the unwrapped phase images were obtained to quantify nodule thickness over time under normal growth, and in cultures subject to chemotherapy treatment. In this manner total nodule volumes are rapidly estimated and demonstrated here to show contrasting time dependent changes during growth and in response to treatment. This work suggests the utility of DHM to quantify changes in 3D structure over time and suggests the further development of this approach for time-lapse monitoring of 3D morphological changes during growth and in response to treatment that would otherwise be impractical to visualize.
SU-E-T-196: Heat Diffusion Modeling for Digital Holographic Interferometry Dosimetry
Cavan, A; Meyer, J
2014-06-01
Purpose: We have previously demonstrated that with Digital Holographic Interferometry (DHI) 2D spatial calorimetric measurements of high dose rate radiation sources can be obtained. The impact of heat transfer must be considered when undertaking any form of calorimetric measurement, as the radiation induced temperature distributions are subject to degradation due to heat diffusion. Unaccounted for, this limits the accuracy of the approach especially for long delivery times. Methods: 3D modelling of the heat diffusion in water was undertaken, and two different approaches developed to account for this effect. The mathematical framework to describe heat diffusion in 3D was applied, with the differential equations solved numerically using an implicit method. The first approach involved the comparison of the DHI measurements to an independent dose model of the source. The model was forward modeled to account for the heat diffusion during irradiation, allowing a direct comparison to validate the measured results. The second approach involved the correction of the measured data directly, by comparing the temperature distribution of two instances and subtracting the effects of heat diffusion of the first distribution from the second instance. This required the use of the Abel transform to approximate the 3D dose distribution from the 2D DHI results, thus limiting the approach to radiation applications possessing cylindrical symmetry. Results: The first approach resulted in higher accuracy and was more straightforward, but has a major limitation in that the measured results are only able to be utilized in comparison with an independent dose model. The applicability of the second approach is affected by noise in the measurement data and introduces higher uncertainties, but results in higher usability of the final data. Conclusion: Both approaches were implemented, and if used in conjunction would provide the most utility for the interpretation and use of DHI measurements.
Phase transitions in a holographic s + p model with back-reaction
NASA Astrophysics Data System (ADS)
Nie, Zhang-Yu; Cai, Rong-Gen; Gao, Xin; Li, Li; Zeng, Hui
2015-11-01
In a previous paper (Nie et al. in JHEP 1311:087,
Inflation with holographic dark energy
NASA Astrophysics Data System (ADS)
Chen, Bin; Li, Miao; Wang, Yi
2007-07-01
We investigate the corrections of the holographic dark energy to inflation paradigm. We study the evolution of the holographic dark energy in the inflationary universe in detail, and carry out a model-independent analysis on the holographic dark energy corrections to the primordial scalar power spectrum. It turns out that the corrections generically make the spectrum redder. To be consistent with the experimental data, there must be a upper bound on the reheating temperature. We also discuss the corrections due to different choices of the infrared cutoff.
Analysis on a general class of holographic type dark energy models
Huang, Zhuo-Peng; Wu, Yue-Liang E-mail: ylwu@itp.ac.cn
2012-07-01
We present a detail analysis on a general class of holographic type dark energy models characterized by the length scale L = 1/a{sup n}(t)∫{sub 0}{sup t}dt' a{sup m}(t'). We show that n ≥ 0 is required by the recent cosmic accelerated expansion of universe. In the early universe dominated by the constituent with constant equation of state w{sub m}, we have w{sub de} ≅ −1−2n/3 for n ≥ 0 and m < 0, and w{sub de} ≅ −(2/3)(n−m)+w{sub m} for n > m ≥ 0. The models with n > m ≥ 0 become single-parameter models like the ΛCDM model due to the analytic feature Ω{sub de} ≅ d{sup 2}/4(2m+3w{sub m}+3){sup 2}a{sup 2(n−m)} at radiation- and matter-dominated epoch. Whereas the cases n = m ≥ 0 should be abandoned as the dark energy cannot dominate the universe forever and there might be too large fraction of dark energy in early universe, and the cases m > n ≥ 0 are forbidden by the self-consistent requirement Ω{sub de} << 1 in the early universe. Thus a detailed study on the single-parameter models corresponding to cases n > m ≥ 0 is carried out by using recent observations. The best-fit analysis indicates that the conformal-age-like models with n = m+1, i.e. L∝1/Ha in early universe, are more favored and also the models with smaller n for the given n−m are found to fit the observations better. The equation of state of the dark energy in models with n = m+1 > 0 transits from w{sub de} < −1 during inflation to w{sub de} > −1 in radiation- and matter-dominated epoch, and then back to w{sub de} < −1 eventually. The best-fit result of the case (n = 0, m = −1) which is so-called ηHDE model proposed in (Huang 2012) is the most favorable model and compatible with the ΛCDM model.
Zhai, Zhong-Xu; Liu, Wen-Biao; Zhang, Tong-Jie E-mail: tjzhang@bnu.edu.cn
2011-08-01
The newly released observational H(z) data (OHD) is used to constrain Λ(t)CDM models as holographic and agegraphic dark energy. By the use of the length scale and time scale as the IR cut-off including Hubble horizon (HH), future event horizon (FEH), age of the universe (AU), and conformal time (CT), we achieve four different Λ(t)CDM models which can describe the present cosmological acceleration respectively. In order to get a comparison between such Λ(t)CDM models and standard ΛCDM model, we use the information criteria (IC), Om(z) diagnostic, and statefinder diagnostic to measure the deviations. Furthermore, by simulating a larger Hubble parameter data sample in the redshift range of 0.1 < z < 2.0, we get the improved constraints and more sufficient comparison. We show that OHD is not only able to play almost the same role in constraining cosmological parameters as SNe Ia does but also provides the effective measurement of the deviation of the DE models from standard ΛCDM model. In the holographic and agegraphic scenarios, the results indicate that the FEH is more preferable than HH scenario. However, both two time scenarios show better approximations to ΛCDM model than the length scenarios.
Holographic RG flows in six dimensional F(4) gauged supergravity
NASA Astrophysics Data System (ADS)
Karndumri, Parinya
2013-01-01
We study critical points of F (4) gauged supergravity in six dimensions coupled to three vector multiplets. Scalar fields are described by {{mathbb{R}}+}× {SOleft( {4,3} right)}/{SO(4)× SO(3)} coset space, and the gauge group is given by SO(3)R × SO(3) with SO(3)R being the R-symmetry. We identify new non-supersymmetric critical points of the scalar potential. One of these new critical points is shown to be stable with all scalar masses above the BF bound and should correspond to a new non-supersymmetric CFT in five dimensions. On the other hand, the maximally supersymmetric critical point with all scalars vanishing is dual to an SCFT5 arising from a near horizon geometry of the D4-D8 brane system in type I' theory with an enhanced global symmetry E 1 SU(2). We give a numerical RG flow solution interpolating between this SCFT and the new stable critical point. The flow describes a non-supersymmetric deformation driven by relevant operators of dimension 3. We identify the dual operators with the mass terms for hypermultiplet scalars in the dual field theory. The solution provides another example of holographic RG flows in AdS6/CFT5 correspondence.
Bao, Ning; Nezami, Sepehr; Ooguri, Hirosi; Stoica, Bogdan; Sully, James; Walter, Michael
2015-09-21
We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phasemore » space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.« less
Bao, Ning; Nezami, Sepehr; Ooguri, Hirosi; Stoica, Bogdan; Sully, James; Walter, Michael
2015-09-21
We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phase space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.
NASA Astrophysics Data System (ADS)
Bao, Ning; Nezami, Sepehr; Ooguri, Hirosi; Stoica, Bogdan; Sully, James; Walter, Michael
2015-09-01
We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phase space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.
Complex 2D matrix model and geometrical map on the complex-Nc plane
NASA Astrophysics Data System (ADS)
Nawa, Kanabu; Ozaki, Sho; Nagahiro, Hideko; Jido, Daisuke; Hosaka, Atsushi
2013-08-01
We study the parameter dependence of the internal structure of resonance states by formulating a complex two-dimensional (2D) matrix model, where the two dimensions represent two levels of resonances. We calculate a critical value of the parameter at which a "nature transition" with character exchange occurs between two resonance states, from the viewpoint of geometry on complex-parameter space. Such a critical value is useful for identifying the internal structure of resonance states with variation of the parameter in the system. We apply the model to analyze the internal structure of hadrons with variation of the color number N_c from infty to a realistic value 3. By regarding 1/N_c as the variable parameter in our model, we calculate a critical color number of the nature transition between hadronic states in terms of a quark-antiquark pair and a mesonic molecule as exotics from the geometry on the complex-N_c plane. For large-N_c effective theory, we employ the chiral Lagrangian induced by holographic QCD with a D4/D8/overline {D8} multi-D brane system in type IIA superstring theory.
NASA Astrophysics Data System (ADS)
Anninos, Dionysios; Anous, Tarek; Denef, Frederik; Peeters, Lucas
2015-04-01
We establish the existence of stable and metastable stationary black hole bound states at finite temperature and chemical potentials in global and planar four-dimensional asymptotically anti-de Sitter space. We determine a number of features of their holographic duals and argue they represent structural glasses. We map out their thermodynamic landscape in the probe approximation, and show their relaxation dynamics exhibits logarithmic aging, with aging rates determined by the distribution of barriers.
Influence of TFT-LCD pixel structure on holographic representation
NASA Astrophysics Data System (ADS)
Wang, Hongjun; Wang, Zhao; Tian, Ailing; Liu, Bingcai
2008-09-01
As a new holographic display device, TFT-LCD (Thin Film Transistor Liquid Crystal Displays) is key technical component of holographic representation for easy controlled by computer. With the development of exquisite processing technology, that it instead of the traditional holographic plate become historical necessity and would be the development direction of holographic optics. Based on principles of holography and display character of LCD, the property which the LCD was used as a holographic plate was analyzed. The emphasis on discuss influence of LCD black matrix on holographic representation. First, analyzed on LCD pixel structure, the LCD pixel structure mathematical model was established. LCD was character representation by pixel structure parameters. Then, the influence of LCD pixels structure on holographic representation was analyzed by computer simulation. Meanwhile, the SONY LCX023 was chosen for holographic plate, the He-Ne laser which the wavelength is 0.6328um was holographic representation light source. The holographic representation system was established for test influence of LCD on holographic representation. Final, compared between computer simulations and optical experimental results, the mathematical model of LCD was proved to be true. When aperture ratio is 0.625, the holographic representation wouldn't be distinguished between representation images. At the same time, some useful results was acquired for improve application effects of LCD in holographic representation.
Gaps, Pseudogaps, and the Nature of Charge in Holographic Fermion Models
NASA Astrophysics Data System (ADS)
Vanacore, Garrett; Phillips, Philip
Building on prior holographic constructions of Fermi arcs and Mott physics, we investigate the landscape of gapped and gapless strongly-correlated phases resulting from bulk fermion interactions in gauge/gravity duality. We test a proposed connection between bulk chiral symmetry and gapless boundary states, and discuss implications for discrete symmetry breaking in pseudogapped systems like the cuprate superconductors. Numerical methods are used to treat gravitational backreaction of bulk fermions, allowing more rigorous investigation of the existence of holographic Fermi surfaces and their adherence to Luttinger's rule. We use these techniques to study deviations from Luttinger's rule in holography, testing a recent claim that momentum-deconfined charges are at the heart of the Mott state.
NASA Astrophysics Data System (ADS)
Sarkar, Sanjay
2016-01-01
The present work deals with the accretion of two interacting fluids: dark matter and a hypothetical fluid as the holographic dark energy components onto wormhole in a non-flat FRW universe. First of all, following Cruz et al. (Phys. Lett. B 669, 271 2008), we obtained an exact solution of the Einstein's field equations. Solution describes effectively the actual acceleration and indicates a big rip type future singularity of the universe. After that we have studied the evolution of the mass of wormhole embedded in this FRW universe in order to reproduce a stable universe protected against future-time singularity. We found that the accretion of these dark components leads to a gradual increase of wormhole mass. It is also observed that contrary to the case as shown by Cruz et al. (Phys. Lett. B 669, 271 2008), the big rip singularity of the universe with a divergent Hubble parameter of this dark energy model may be avoided by a big trip. We have established a correspondence between the holographic dark energy with the polytropic gas dark energy model and obtained the potential as well as dynamics of the scalar field which describes the polytropic cosmology.
Intelligent holographic databases
NASA Astrophysics Data System (ADS)
Barbastathis, George
Memory is a key component of intelligence. In the human brain, physical structure and functionality jointly provide diverse memory modalities at multiple time scales. How could we engineer artificial memories with similar faculties? In this thesis, we attack both hardware and algorithmic aspects of this problem. A good part is devoted to holographic memory architectures, because they meet high capacity and parallelism requirements. We develop and fully characterize shift multiplexing, a novel storage method that simplifies disk head design for holographic disks. We develop and optimize the design of compact refreshable holographic random access memories, showing several ways that 1 Tbit can be stored holographically in volume less than 1 m3, with surface density more than 20 times higher than conventional silicon DRAM integrated circuits. To address the issue of photorefractive volatility, we further develop the two-lambda (dual wavelength) method for shift multiplexing, and combine electrical fixing with angle multiplexing to demonstrate 1,000 multiplexed fixed holograms. Finally, we propose a noise model and an information theoretic metric to optimize the imaging system of a holographic memory, in terms of storage density and error rate. Motivated by the problem of interfacing sensors and memories to a complex system with limited computational resources, we construct a computer game of Desert Survival, built as a high-dimensional non-stationary virtual environment in a competitive setting. The efficacy of episodic learning, implemented as a reinforced Nearest Neighbor scheme, and the probability of winning against a control opponent improve significantly by concentrating the algorithmic effort to the virtual desert neighborhood that emerges as most significant at any time. The generalized computational model combines the autonomous neural network and von Neumann paradigms through a compact, dynamic central representation, which contains the most salient features
NASA Astrophysics Data System (ADS)
Nojiri, Shin'ichi; Odintsov, Sergei D.
2006-08-01
The unifying approach to early-time and late-time universe based on phantom cosmology is proposed. We consider gravity-scalar system which contains usual potential and scalar coupling function in front of kinetic term. As a result, the possibility of phantom-non-phantom transition appears in such a way that universe could have effectively phantom equation of state at early time as well as at late time. In fact, the oscillating universe may have several phantom and non-phantom phases. Role in each of two phase and can be absorbed into the redefinition of the scalar field. Right on the transition point, however, the factor cannot be absorbed into the redefinition and play the role to connect two phases smoothly. Holographic dark energy where infrared cutoff is identified with combination of FRW parameters: Hubble constant, particle and future horizons, cosmological constant and universe life-time (if finite). Depending on the specific choice of the model the number of interesting effects occur: the possibility to solve the coincidence problem, crossing of phantom divide and unification of early-time inflationary and late-time accelerating phantom universe. The bound for holographic entropy which decreases in phantom era is also discussed.
NASA Astrophysics Data System (ADS)
Raju, P.; Sobhanbabu, K.; Reddy, D. R. K.
2016-02-01
Five-dimensional spherically symmetric space-time filled with two minimally interacting fields, matter and holographic dark energy components, is investigated in a scalar tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett. A 113:467, 1986). An explicit solution of the field equations is obtained. Some physical and kinematic properties of the model are also studied.
NASA Astrophysics Data System (ADS)
Khodam-Mohammadi, A.
In this work, the PLECHDE model with Granda-Oliveros (G-O) IR-cutoff is studied. The evolution of dark energy density, deceleration and EoS parameters are calculated. I demonstrate that under a condition, our universe can accelerate near the phantom barrier at present time. We calculate these parameters also in PLECHDE at Ricci scale, when α = 2 and β = 1, and a comparison between Ricci scale, G-O cutoff and non-corrected HDE without matter field with G-O cutoff is done. The correspondence between this model and some scalar field of dark energy models is established. By this method, the evolutionary treatment of kinetic energy and potential for quintessence, tachyon, K-essence and dilaton fields, are obtained. I show that the results has a good compatibility with previous work in the limiting case of flat, dark dominated and non-corrected holographic dark energy.
Adams, Allan; Chesler, Paul M; Liu, Hong
2014-04-18
We construct turbulent black holes in asymptotically AdS4 spacetime by numerically solving Einstein's equations. Using the AdS/CFT correspondence we find that both the dual holographic fluid and bulk geometry display signatures of an inverse cascade with the bulk geometry being well approximated by the fluid-gravity gradient expansion. We argue that statistically steady-state black holes dual to d dimensional turbulent flows have horizons whose area growth has a fractal-like structure with fractal dimension D=d+4/3. PMID:24785028
NASA Astrophysics Data System (ADS)
Ian, Richard; King, Elisabeth
1988-01-01
Proposed is an exploratory study to verify the feasibility of an inexpensive micro-climate control system for both marine and freshwater pond and tank aquaculture, offering good control over water temperature, incident light flux, and bandwidth, combined with good energy efficiency. The proposed control system utilizes some familiar components of passive solar design, together with a new holographic glazing system which is currently being developed by, and proprietary to Advanced Environmental Research Group (AERG). The use of solar algae ponds and tanks to warm and purify water for fish and attached macroscopic marine algae culture is an ancient and effective technique, but limited seasonally and geographically by the availability of sunlight. Holographic Diffracting Structures (HDSs) can be made which passively track, accept and/or reject sunlight from a wide range of altitude and azimuth angles, and redirect and distribute light energy as desired (either directly or indirectly over water surface in an enclosed, insulated structure), effectively increasing insolation values by accepting sunlight which would not otherwise enter the structure.
Constraining holographic inflation with WMAP
Easther, Richard; Flauger, Raphael; McFadden, Paul; Skenderis, Kostas E-mail: Raphael.Flauger@yale.edu E-mail: K.Skenderis@uva.nl
2011-09-01
In a class of recently proposed models, the early universe is strongly coupled and described holographically by a three-dimensional, weakly coupled, super-renormalizable quantum field theory. This scenario leads to a power spectrum of scalar perturbations that differs from the usual empirical ΛCDM form and the predictions of generic models of single field, slow roll inflation. This spectrum is characterized by two parameters: an amplitude, and a parameter g related to the coupling constant of the dual theory. We estimate these parameters, using WMAP and other astrophysical data. We compute Bayesian evidence for both the holographic model and standard ΛCDM and find that their difference is not significant, although ΛCDM provides a somewhat better fit to the data. However, it appears that Planck will permit a definitive test of this holographic scenario.
NASA Astrophysics Data System (ADS)
Karami, K.; Khaledian, M. S.
2011-03-01
Here, we peruse cosmological usage of the most promising candidates of dark energy in the framework of f( R) theory. We reconstruct the different f( R) modified gravity models in the spatially flat FRW universe according to the ordinary and entropy-corrected versions of the holographic and new agegraphic dark energy models, which describe accelerated expansion of the universe. We also obtain the equation of state parameter of the corresponding f( R)-gravity models. We conclude that the holographic and new agegraphic f( R)-gravity models can behave like phantom or quintessence models. Whereas the equation of state parameter of the entropy-corrected models can transit from quintessence state to phantom regime as indicated by recent observations.
Indeterminacy of holographic quantum geometry
NASA Astrophysics Data System (ADS)
Hogan, Craig J.
2008-10-01
An effective theory based on wave optics is used to describe indeterminacy of position in holographic spacetime with a UV cutoff at the Planck scale. Wave functions describing spacetime positions are modeled as complex disturbances of quasimonochromatic radiation. It is shown that the product of standard deviations of two position wave functions in the plane of a holographic light sheet is equal to the product of their normal separation and the Planck length. For macroscopically separated positions the transverse uncertainty is much larger than the Planck length, and is predicted to be observable as a “holographic noise” in relative position with a distinctive shear spatial character, and an absolutely normalized frequency spectrum with no parameters once the fundamental wavelength is fixed from the theory of gravitational thermodynamics. The spectrum of holographic noise is estimated for the GEO600 interferometric gravitational-wave detector and is shown to approximately account for currently unexplained noise between about 300 and 1400 Hz. In a holographic world, this result directly and precisely measures the fundamental minimum interval of time.
NASA Astrophysics Data System (ADS)
Zhang, Jing-Fei; Zhao, Ming-Ming; Li, Yun-He; Zhang, Xin
2015-04-01
The model of holographic dark energy (HDE) with massive neutrinos and/or dark radiation is investigated in detail. The background and perturbation evolutions in the HDE model are calculated. We employ the PPF approach to overcome the gravity instability difficulty (perturbation divergence of dark energy) led by the equation-of-state parameter w evolving across the phantom divide w=-1 in the HDE model with c<1. We thus derive the evolutions of density perturbations of various components and metric fluctuations in the HDE model. The impacts of massive neutrino and dark radiation on the CMB anisotropy power spectrum and the matter power spectrum in the HDE scenario are discussed. Furthermore, we constrain the models of HDE with massive neutrinos and/or dark radiation by using the latest measurements of expansion history and growth of structure, including the Planck CMB temperature data, the baryon acoustic oscillation data, the JLA supernova data, the Hubble constant direct measurement, the cosmic shear data of weak lensing, the Planck CMB lensing data, and the redshift space distortions data. We find that ∑ mν<0.186 eV (95% CL) and Neff=3.75+0.28-0.32 in the HDE model from the constraints of these data.
Holographic magnetic phase transition
Lifschytz, Gilad; Lippert, Matthew
2009-09-15
We study four-dimensional interacting fermions in a strong magnetic field, using the holographic Sakai-Sugimoto model of intersecting D4- and D8-branes in the deconfined, chiral-symmetric parallel phase. We find that as the magnetic field is varied, while staying in the parallel phase, the fermions exhibit a first-order phase transition in which their magnetization jumps discontinuously. Properties of this transition are consistent with a picture in which some of the fermions jump to the lowest Landau level. Similarities to known magnetic phase transitions are discussed.
Holographic effective field theories
NASA Astrophysics Data System (ADS)
Martucci, Luca; Zaffaroni, Alberto
2016-06-01
We derive the four-dimensional low-energy effective field theory governing the moduli space of strongly coupled superconformal quiver gauge theories associated with D3-branes at Calabi-Yau conical singularities in the holographic regime of validity. We use the dual supergravity description provided by warped resolved conical geometries with mobile D3-branes. Information on the baryonic directions of the moduli space is also obtained by using wrapped Euclidean D3-branes. We illustrate our general results by discussing in detail their application to the Klebanov-Witten model.
Holographic p -wave superfluid
NASA Astrophysics Data System (ADS)
Wu, Ya-Bo; Lu, Jun-Wang; Zhang, Wen-Xin; Zhang, Cheng-Yuan; Lu, Jian-Bo; Yu, Fang
2014-12-01
In the probe limit, we numerically construct a holographic p -wave superfluid model in the four-dimensional (4D) and five-dimensional (5D) anti-de Sitter black holes coupled to a Maxwell-complex vector field. We find that, for the condensate with the fixed superfluid velocity, the results are similar to the s -wave cases in both 4D and 5D spacetimes. In particular, the Cave of Winds and the phase transition, always being of second order, take place in the 5D case. Moreover, we find that the translating superfluid velocity from second order to first order S/yμ increases with the mass squared. Furthermore, for the supercurrent with fixed temperature, the results agree with the Ginzburg-Landau prediction near the critical temperature. In addition, this complex vector superfluid model is still a generalization of the SU(2) superfluid model, and it also provides a holographic realization of the H e3 superfluid system.
On a holographic dark energy model with a Nojiri-Odintsov cut-off in general relativity
NASA Astrophysics Data System (ADS)
Khurshudyan, Martiros
2016-07-01
In this paper we consider the models of the accelerated expanding large scale universe (according to general relativity) containing a generalized holographic dark energy with a Nojiri-Odintsov cut-off. The second component of the darkness is assumed to be the pressureless cold dark matter according to observed symmetries of the large scale universe. Moreover, we assume specific forms of the interaction between these two components and besides the cosmographic analysis, we discuss appropriate results from Om and Om3 analysis and organize a closer look to the models via the statefinder hierarchy analysis, too. In this way we study mainly impact of the interaction on the dynamics of the background of our universe (within specific forms of interaction). To complete the cosmographic analysis, the present day values of the statefinder parameters (r,s) and (ω^'_{de}, ω_{de}) has been estimated for all cases and the validity of the generalized second law of thermodynamics is demonstrated. Our study showed that theoretical results from considered phenomenological models are consistent with the available observational data and symmetries.
Holographic Methods in X-ray Crystallography
Energy Science and Technology Software Center (ESTSC)
1995-07-28
The holographic method makes use of partially modeled electron density and experimentally-measured structure factor amplitudes to recover electron density corresponding to the unmodeled part of a crystal structure. This paper describes a fast algorithm that makes it possible to apply the holographic method to sizable crystallographic problems. The algorithm uses positivity constraints on the electron density, and can incorporate a target electron density, making it similar to solvent flattening. Using both synthetic and experimental data,more » we assess the potential for applying the holographic method to macromolecular x-ray crystallography.« less
NASA Astrophysics Data System (ADS)
Adabi, Farzin; Karami, Kayoomars; Felegary, Fereshte; Azarmi, Zohre
2012-01-01
We study the entropy-corrected version of the holographic dark energy (HDE) model in the framework of modified Friedmann-Robertson-Walker cosmology. We consider a non-flat universe filled with an interacting viscous entropy-corrected HDE (ECHDE) with dark matter. Also included in our model is the case of the variable gravitational constant G. We obtain the equation of state and the deceleration parameters of the interacting viscous ECHDE. Moreover, we reconstruct the potential and the dynamics of the quintessence, tachyon, K-essence and dilaton scalar field models according to the evolutionary behavior of the interacting viscous ECHDE model with time-varying G.
Engineering holographic graphene
Semenoff, Gordon W.
2012-09-24
We present a top-down string theory holographic model of strongly interacting relativistic 2 + 1-dimensional fermions, paying careful attention to the discrete symmetries of parity and time reversal invariance. Our construction is based on probe D7-branes in AdS{sub 5} Multiplication-Sign S{sup 5}, stabilized by internal fluxes. We find three solutions, a parity and time reversal invariant conformal field theory which can be viewed as a particular deformation of Coulomb interacting graphene, a parity and time reversal violating but gapless field theory and a system with a parity and time reversal violating charge gap. We show that the Chern-Simons-like electric response function, which is generated perturbatively at one-loop order by parity violating fermions and which is protected by a no-renormalization theorem at orders beyond one loop, indeed appears with the correctly quantized coefficient in the charge gapped theory. In the gapless parity violating solution, the Chern-Simons response function obtains quantum corrections which we compute in the holographic theory.
NASA Astrophysics Data System (ADS)
Li, Yuyu; Petrovic, Ljubica; La, Jeffrey; Celli, Jonathan P.; Yelleswarapu, Chandra S.
2014-11-01
We report the use of digital holographic microscopy (DHM) as a viable microscopy approach for quantitative, nondestructive longitudinal imaging of in vitro three-dimensional (3-D) tumor models. Following established methods, we prepared 3-D cultures of pancreatic cancer cells in overlay geometry on extracellular matrix beds and obtained digital holograms at multiple time points throughout the duration of growth. The holograms were digitally processed and the unwrapped phase images were obtained to quantify the nodule thickness over time under normal growth and in cultures subject to chemotherapy treatment. In this manner, total nodule volumes are rapidly estimated and demonstrated here to show contrasting time-dependent changes during growth and in response to treatment. This work suggests the utility of DHM to quantify changes in 3-D structure over time and suggests the further development of this approach for time-lapse monitoring of 3-D morphological changes during growth and in response to treatment that would otherwise be impractical to visualize.
Holographic entropy production
NASA Astrophysics Data System (ADS)
Tian, Yu; Wu, Xiao-Ning; Zhang, Hongbao
2014-10-01
The suspicion that gravity is holographic has been supported mainly by a variety of specific examples from string theory. In this paper, we propose that such a holography can actually be observed in the context of Einstein's gravity and at least a class of generalized gravitational theories, based on a definite holographic principle where neither is the bulk space-time required to be asymptotically AdS nor the boundary to be located at conformal infinity, echoing Wilson's formulation of quantum field theory. After showing the general equilibrium thermodynamics from the corresponding holographic dictionary, in particular, we provide a rather general proof of the equality between the entropy production on the boundary and the increase of black hole entropy in the bulk, which can be regarded as strong support to this holographic principle. The entropy production in the familiar holographic superconductors/superfluids is investigated as an important example, where the role played by the holographic renormalization is explained.
Some recent advances in the bottom-up holographic approach to QCD
Afonin, S. S.
2014-07-23
We give a brief report on our recent results in the bottom-up holographic approach to QCD. The holographic description of the heavy vector quarkonia and generalization of the Soft Wall model are discussed.
Interactive holographic display
NASA Astrophysics Data System (ADS)
Son, Jung-Young; Lee, Beam-Ryeol; Kim, Jin-Woong; Chernyshov, Oleksii O.; Park, Min-Chul
2014-06-01
A holographic display which is capable of displaying floating holographic images is introduced. The display is for user interaction with the image on the display. It consists of two parts; multiplexed holographic image generation and a spherical mirror. The time multiplexed image from 2 X 10 DMD frames appeared on PDLC screen is imaged by the spherical mirror and becomes a floating image. This image is combined spatially with two layered TV images appearing behind. Since the floating holographic image has a real spatial position and depth, it allows a user to interact with the image.
Holographic Gratings for Optical Processing
NASA Technical Reports Server (NTRS)
Kukhtarev, Nickolai
2002-01-01
Investigation of astronomical objects and tracking of man-made space objects lead to generation of huge amount of information for optical processing. Traditional big-size optical elements (such as optical telescopes) have a tendency for increasing aperture size in order to improve sensitivity. This tendency leads to increasing of weight and costs of optical systems and stimulate search for the new, more adequate technologies. One approach to meet these demands is based on developing of holographic optical elements using new polymeric materials. We have investigated possibility to use new material PQ-PMMA (phenantrenequinone-doped PMMA (Polymethyl Methacrylate)) for fabrication of highly selective optical filters and fast spatial-temporal light modulators. This material was originally developed in Russia and later was tested in CalTech as a candidate material for optical storage. Our theoretical investigation predicts the possibility of realization of fast spatial and temporal light modulation, using volume reflection-type spectral filter. We have developed also model of holographic-grating recording in PQ-PMMA material, based on diffusional amplification. This mechanism of recording allow to receive high diffraction efficiency during recording of reflection-type volume holographic grating (holographic mirror). We also investigated recording of dynamic gratings in the photorefractive crystals LiNbO3 (LN) for space-based spectroscopy and for adaptive correction of aberrations in the telescope's mirrors. We have shown, that specific 'photogalvanic' mechanism of holographic grating recording in LN allow to realize recording of blazed gratings for volume and surface gratings. Possible applications of dynamic gratings in LN for amplification of images, transmitted through an imaging fiber guide was also demonstrated.
Pion condensation in holographic QCD
Albrecht, Dylan; Erlich, Joshua
2010-11-01
We study pion condensation at zero temperature in a hard-wall holographic model of hadrons with isospin chemical potential. We find that the transition from the hadronic phase to the pion condensate phase is first order except in a certain limit of model parameters. Our analysis suggests that immediately across the phase boundary the condensate acts as a stiff medium approaching the Zel'dovich limit of equal energy density and pressure.
Holographic multiverse and conformal invariance
Garriga, Jaume; Vilenkin, Alexander E-mail: vilenkin@cosmos.phy.tufts.edu
2009-11-01
We consider a holographic description of the inflationary multiverse, according to which the wave function of the universe is interpreted as the generating functional for a lower dimensional Euclidean theory. We analyze a simple model where transitions between inflationary vacua occur through bubble nucleation, and the inflating part of spacetime consists of de Sitter regions separated by thin bubble walls. In this model, we present some evidence that the dual theory is conformally invariant in the UV.
Applications of holographic spacetime
NASA Astrophysics Data System (ADS)
Torres, Terrence J.
Here we present an overview of the theory of holographic spacetime (HST), originally devised and primarily developed by Tom Banks and Willy Fischler, as well as its various applications and predictions for cosmology and particle phenomenology. First we cover the basic theory and motivation for holographic spacetime and move on to present the latest developments therein as of the time of this writing. Then we indicate the origin of the quantum degrees of freedom in the theory and then present a correspondence with low energy effective field theory. Further, we proceed to show the general origins of inflation and the cosmic microwave background (CMB) within the theory of HST as well as predict the functional forms of two and three point correlation functions for scalar and tensor curvature fluctuations in the early universe. Next, we constrain the theory parameters by insisting on agreement with observational bounds on the scalar spectral index of CMB fluctuations from the Planck experiment as well as theoretical bounds on the number of e-folds of inflation. Finally, we argue that HST predicts specific gauge structures for the low-energy effective field theory at the present era and proceed to construct a viable supersymmetric model extension. Constraints on model parameters and couplings are then calculated by numerically minimizing the theory's scalar potential and comparing the resultant model mass spectra to current observational limits from the LHC SUSY searches. In the end we find that the low-energy theory, while presenting a little hierarchy problem, is fully compatible with current observational limits. Additionally, the high-energy underlying theory is generically compatible with observational constraints stemming from inflation, and predictions on favored model parameters are given.
Holographic quenches with a gap
NASA Astrophysics Data System (ADS)
da Silva, Emilia; Lopez, Esperanza; Mas, Javier; Serantes, Alexandre
2016-06-01
In order to holographically model quenches with a gapped final hamiltonian, we consider a gravity-scalar theory in anti-de Sitter space with an infrared hard wall. We allow a time dependent profile for the scalar field at the wall. This induces an energy exchange between bulk and wall and generates an oscillating scalar pulse. We argue that such backgrounds are the counterpart of quantum revivals in the dual field theory. We perform a qualitative comparison with the quench dynamics of the massive Schwinger model, which has been recently analyzed using tensor network techniques. Agreement is found provided the width of the oscillating scalar pulse is inversely linked to the energy density communicated by the quench. We propose this to be a general feature of holographic quenches.
Striped holographic superconductor
Flauger, Raphael; Pajer, Enrico; Papanikolaou, Stefanos
2011-03-15
We study inhomogeneous solutions of a 3+1-dimensional Einstein-Maxwell-scalar theory. Our results provide a holographic model of superconductivity in the presence of a charge density wave sourced by a modulated chemical potential. We find that below a critical temperature T{sub c} superconducting stripes develop. We show that they are thermodynamically favored over the normal state by computing the grand canonical potential. We investigate the dependence of T{sub c} on the modulation's wave vector, which characterizes the inhomogeneity. We find that it is qualitatively similar to that expected for a weakly coupled Bardeen-Cooper-Schrieer theory, but we point out a quantitative difference. Finally, we use our solutions to compute the conductivity along the direction of the stripes.
Holographic Chern-Simons defects
NASA Astrophysics Data System (ADS)
Fujita, Mitsutoshi; Melby-Thompson, Charles M.; Meyer, René; Sugimoto, Shigeki
2016-06-01
We study SU( N ) Yang-Mills-Chern-Simons theory in the presence of defects that shift the Chern-Simons level from a holographic point of view by embedding the system in string theory. The model is a D3-D7 system in Type IIB string theory, whose gravity dual is given by the AdS soliton background with probe D7 branes attaching to the AdS boundary along the defects. We holographically renormalize the free energy of the defect system with sources, from which we obtain the correlation functions for certain operators naturally associated to these defects. We find interesting phase transitions when the separation of the defects as well as the temperature are varied. We also discuss some implications for the Fractional Quantum Hall Effect and for 2-dimensional QCD.
Holographic renormalization of 3D minimal massive gravity
NASA Astrophysics Data System (ADS)
Alishahiha, Mohsen; Qaemmaqami, Mohammad M.; Naseh, Ali; Shirzad, Ahmad
2016-01-01
We study holographic renormalization of 3D minimal massive gravity using the Chern-Simons-like formulation of the model. We explicitly present Gibbons- Hawking term as well as all counterterms needed to make the action finite in terms of dreibein and spin-connection. This can be used to find correlation functions of stress tensor of holographic dual field theory.
Holographic Roberge Weiss transitions II: Defect theories and the Sakai Sugimoto model
NASA Astrophysics Data System (ADS)
Rafferty, James
2011-09-01
We extend the work of [1], including an imaginary chemical potential for quark number into the Sakai Sugimoto model and codimension k defect theories. The phase diagram of these models are a function of three parameters, the temperature, chemical potential and the asymptotic separation of the flavour branes, related to a mass for the quarks in the boundary theories. We compute the phase diagrams and the pressure due to the flavours of the theories as a function of these parameters and show that there are Roberge Weiss transitions in the high temperature phases, chiral symmetry restored for the Sakai Sugimoto model and deconfined for the defect models, while at low temperatures there are no Roberge Weiss transitions. In all the models we consider the transitions between low and high temperature phases are first order, hence the points where they meet the Roberge Weiss lines are triple points. The pressure for the defect theories scales in the way we expect from dimensional analysis while the Sakai Sugimoto model exhibits unusual scaling. We show that the models we consider are all analytic in μ 2 when μ 2 is small.
Holographic cold nuclear matter and neutron star
NASA Astrophysics Data System (ADS)
Ghoroku, Kazuo; Kubo, Kouki; Tachibana, Motoi; Toyoda, Fumihiko
2014-04-01
We have previously found a new phase of cold nuclear matter based on a holographic gauge theory, where baryons are introduced as instanton gas in the probe D8//lineD8 branes. In our model, we could obtain the equation of state (EOS) of our nuclear matter by introducing Fermi momentum. Then, here we apply this model to the neutron star and study its mass and radius by solving the Tolman-Oppenheimer-Volkoff (TOV) equations in terms of the EOS given here. We give some comments for our holographic model from a viewpoint of the other field theoretical approaches.
Shape of mesons in holographic QCD
Torabian, Mahdi; Yee, Ho-Ung
2009-10-15
Based on the expectation that the constituent quark model may capture the right physics in the large N limit, we point out that the orbital angular momentum of the quark-antiquark pair inside light mesons of low spins in the constituent quark model may provide a clue for the holographic dual string model of large N QCD. Our discussion, relying on a few suggestive assumptions, leads to a necessity of world-sheet fermions in the bulk of dual strings that can incorporate intrinsic spins of fundamental QCD degrees of freedom. We also comment on the interesting issue of the size of mesons in holographic QCD.
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.
NASA Astrophysics Data System (ADS)
Vieira, Tárcio A.; Zamboni-Rached, Michel; Gesualdi, Marcos R. R.
2014-03-01
In this paper we experimentally implement the spatial shape modeling of nondiffracting optical beams via computer generated holograms reconstructed optically by spatial light modulators. The results reported here are an experimental confirmation of the so-called Frozen Wave method, developed a few years ago. Optical beams of this type have potential applications in optical tweezers, medicine, atom guiding, remote sensing, etc.
The energy performance of prototype holographic glazings
NASA Astrophysics Data System (ADS)
Papamichael, K.; Beltran, L.; Furler, R.; Lee, E. S.; Selkowitz, S.; Rubin, M.
1993-02-01
We report on the simulation of the energy performance of prototype holographic glazings in commercial office buildings in a California climate. These prototype glazings, installed above conventional side windows, are designed to diffract the transmitted solar radiation and reflect it off the ceiling, providing adequate daylight illumination for typical office tasks up to 10m from the window. In this study, we experimentally determined a comprehensive set of solar-optical properties and characterized the contribution of the prototype holographic glazings to workplane illuminance in a scale model of a typical office space. We then used the scale model measurements to simulate the energy performance of the holographic glazings over the course of an entire year for four window orientations (North, East, South and West) for the inland Los Angeles climate, using the DOE-2.lD building energy analysis computer program. The results of our experimental analyses indicate that these prototype holographic glazings diffract only a small fraction of the incident light. The results of this study indicate that these prototype holographic glazings will not save energy in commercial office buildings. Their performance is very similar to that of clear glass, which, through side windows, cannot efficiently illuminate more than a 4-6 m depth of a building's perimeter, because the cooling penalties due to solar heat gain are greater than the electric lighting savings due to daylighting.
Permanent holographic storage medium
NASA Technical Reports Server (NTRS)
Gange, R. A.
1976-01-01
Storage unit is electrostatically-charged multilayered laminate. Ability of system to store information in holographic forms is due to specific electrical, optical, and chemical characteristics of its materials.
ERIC Educational Resources Information Center
Kirkpatrick, Larry D.; Rugheimer, Mac
1979-01-01
Describes the viewing sessions and the holograms of a holographic road show. The traveling exhibits, believed to stimulate interest in physics, include a wide variety of holograms and demonstrate several physical principles. (GA)
NASA Technical Reports Server (NTRS)
Preston, K., Jr.
1972-01-01
The characteristics of the holographic logic computer are discussed. The holographic operation is reviewed from the Fourier transform viewpoint, and the formation of holograms for use in performing digital logic are described. The operation of the computer with an experiment in which the binary identity function is calculated is discussed along with devices for achieving real-time performance. An application in pattern recognition using neighborhood logic is presented.
Holographic content addressable storage
NASA Astrophysics Data System (ADS)
Chao, Tien-Hsin; Lu, Thomas; Reyes, George
2015-03-01
We have developed a Holographic Content Addressable Storage (HCAS) architecture. The HCAS systems consists of a DMD (Digital Micromirror Array) as the input Spatial Light Modulator (SLM), a CMOS (Complementary Metal-oxide Semiconductor) sensor as the output photodetector and a photorefractive crystal as the recording media. The HCAS system is capable of performing optical correlation of an input image/feature against massive reference data set stored in the holographic memory. Detailed system analysis will be reported in this paper.
A computer test of holographic flavour dynamics
NASA Astrophysics Data System (ADS)
Filev, Veselin G.; O'Connor, Denjoe
2016-05-01
We perform computer simulations of the Berkooz-Douglas (BD) matrix model, holographically dual to the D0/D4-brane intersection. We generate the fundamental condensate versus bare mass curve of the theory both holographically and from simulations of the BD model. Our studies show excellent agreement of the two approaches in the deconfined phase of the theory and significant deviations in the confined phase. We argue the discrepancy in the confined phase is explained by the embedding of the D4-brane which yields stronger α' corrections to the condensate in this phase.
NASA Astrophysics Data System (ADS)
Lee, Cheok Peng; Chia, Yong Poo; Singh, Vijay Raj; Asundi, A.; Khoo, Xuan Jie; Tay, Kiat Long; Zhou, Junxiang
2009-12-01
This paper describes how a Digital Holographic Projector is designed and implemented to project two-dimension virtual images onto the volumetric display media. In this research, we focus on the method to create 3D models, diffractive algorithm and the display media. A 3D model is generated based on the 360° view with views at every 10° interval from a 3D perspective view software. The hologram interference fringes are re-producing from the Fraunhofer algorithm. In order to make more flexible and portable, a Compact Vision System is introduced to storage multiply interference fringes. At the same time, the fringes are sent out at 30 Hz frame by frame continually to the digital micro-mirror1. With the presence of Nd: YVO4 green laser and various optical components, the 3D 360° hologram images are dynamically reconstructed and projected onto the high speed rotating diffuser forming a 3D model at any viewing angle on the volumetric display media. Both volumetric display media, wet and dry methods are demonstrated to show their feasibility and convenience. Finally, the dry volumetric technique with vertical projection mounting is adopted and as the result shown that the speckle noise is significance reduced.
NASA Astrophysics Data System (ADS)
Lee, Cheok Peng; Chia, Yong Poo; Singh, Vijay Raj; Asundi, A.; Khoo, Xuan Jie; Tay, Kiat Long; Zhou, Junxiang
2010-03-01
This paper describes how a Digital Holographic Projector is designed and implemented to project two-dimension virtual images onto the volumetric display media. In this research, we focus on the method to create 3D models, diffractive algorithm and the display media. A 3D model is generated based on the 360° view with views at every 10° interval from a 3D perspective view software. The hologram interference fringes are re-producing from the Fraunhofer algorithm. In order to make more flexible and portable, a Compact Vision System is introduced to storage multiply interference fringes. At the same time, the fringes are sent out at 30 Hz frame by frame continually to the digital micro-mirror1. With the presence of Nd: YVO4 green laser and various optical components, the 3D 360° hologram images are dynamically reconstructed and projected onto the high speed rotating diffuser forming a 3D model at any viewing angle on the volumetric display media. Both volumetric display media, wet and dry methods are demonstrated to show their feasibility and convenience. Finally, the dry volumetric technique with vertical projection mounting is adopted and as the result shown that the speckle noise is significance reduced.
Recchia, Gabriel; Sahlgren, Magnus; Kanerva, Pentti; Jones, Michael N.
2015-01-01
Circular convolution and random permutation have each been proposed as neurally plausible binding operators capable of encoding sequential information in semantic memory. We perform several controlled comparisons of circular convolution and random permutation as means of encoding paired associates as well as encoding sequential information. Random permutations outperformed convolution with respect to the number of paired associates that can be reliably stored in a single memory trace. Performance was equal on semantic tasks when using a small corpus, but random permutations were ultimately capable of achieving superior performance due to their higher scalability to large corpora. Finally, “noisy” permutations in which units are mapped to other units arbitrarily (no one-to-one mapping) perform nearly as well as true permutations. These findings increase the neurological plausibility of random permutations and highlight their utility in vector space models of semantics. PMID:25954306
Interacting Entropy-Corrected Holographic Dark Energy and IR Cut-Off Length
NASA Astrophysics Data System (ADS)
Sadeghi, J.; Pourhassan, B.; Abbaspour Moghaddam, Z.
2014-01-01
In this paper we consider holographic dark energy model with corrected holographic energy density and show that this model may be equivalent to the modified Chaplygin gas model. Then we obtain relation between entropy corrected holographic dark energy model and scalar field models. We do these works by using choices of IR cut-off length proportional to the Hubble radius, the event horizon radius, the Ricci length, and the Granda-Oliveros length.
Collapse and revival in holographic quenches
NASA Astrophysics Data System (ADS)
da Silva, Emilia; Lopez, Esperanza; Mas, Javier; Serantes, Alexandre
2015-04-01
We study holographic models related to global quantum quenches in finite size systems. The holographic set up describes naturally a CFT, which we consider on a circle and a sphere. The enhanced symmetry of the conformal group on the circle motivates us to compare the evolution in both cases. Depending on the initial conditions, the dual geometry exhibits oscillations that we holographically interpret as revivals of the initial field theory state. On the sphere, this only happens when the energy density created by the quench is small compared to the system size. However on the circle considerably larger energy densities are compatible with revivals. Two different timescales emerge in this latter case. A collapse time, when the system appears to have dephased, and the revival time, when after rephasing the initial state is partially recovered. The ratio of these two times depends upon the initial conditions in a similar way to what is observed in some experimental setups exhibiting collapse and revivals.
Conically Scanned Holographic LIDAR Telescope
NASA Technical Reports Server (NTRS)
Schwemmer, Geary
1993-01-01
Holographic LIDAR telescope includes holographic disk, rotation of which sweeps collimated, monochromatic beam of light from laser through conical scan. Holographic disk diffracts light scattered back from target volume or area to focal point located at stationary photomultiplier detector. Two conical baffles prevent stray light from reaching detector.
Interacting holographic dark energy with logarithmic correction
Jamil, Mubasher; Farooq, M. Umar E-mail: mufarooq@yahoo.com
2010-03-01
The holographic dark energy (HDE) is considered to be the most promising candidate of dark energy. Its definition is motivated from the entropy-area relation which depends on the theory of gravity under consideration. Recently a new definition of HDE is proposed with the help of quantum corrections to the entropy-area relation in the setup of loop quantum cosmology. Employing this new definition, we investigate the model of interacting dark energy and derive its effective equation of state. Finally we establish a correspondence between generalized Chaplygin gas and entropy-corrected holographic dark energy.
Dynamical behavior of the extended holographic dark energy with the Hubble horizon
Liu Jie; Gong Yungui; Chen Ximing
2010-04-15
The extended holographic dark energy model with the Hubble horizon as the infrared cutoff avoids the problem of the circular reasoning of the holographic dark energy model. Unfortunately, it is hit with the no-go theorem. In this paper, we consider the extended holographic dark energy model with a potential, V({phi}), for the Brans-Dicke scalar field. With the addition of a potential for the Brans-Dicke scalar field, the extended holographic dark energy model using the Hubble horizon as the infrared cutoff is a viable dark energy model, and the model has the dark energy dominated attractor solution.
Design and evaluation of daylighting applications of holographic glazings
Papamichael, K.; Ehrlich, C.; Ward, G.
1996-12-01
According to the contractual agreement, BTP would develop a computer model of the POC holographic structures and then simulate the performance of alternative designs using the RADIANCE lighting and rendering computer program [Ward 1990]. The RADIANCE model would then be used to evaluate the daylight performance of alternative designs of holographic glazings in a prototypical office space. The simulation process would be validated against actual photometric measurements of holographic glazing samples developed by POC. The results would be used to evaluate the potential for increased electric lighting savings through increased daylight illuminance levels at distances more than 15 ft--20 ft (4.6 m--6.1 m ) from the window wall.
NASA Astrophysics Data System (ADS)
Khitun, Alexander; Kozhevnikov, Alexander; Gertz, Frederick; Filimonov, Yuri
2015-03-01
Collective oscillation of spins in magnetic lattice known as spin waves (magnons) possess relatively long coherence length at room temperature, which makes it possible to build sub-micrometer scale holographic devices similar to the devices developed in optics. In this work, we present a prototype 2-bit magnonic holographic memory. The memory consists of the double-cross waveguide structure made of Y3Fe2(FeO4)3 with magnets placed on the top of waveguide junctions. Information is encoded in the orientation of the magnets, while the read-out is accomplished by the spin waves generated by the micro-antennas placed on the edges of the waveguides. The interference pattern produced by multiple spin waves makes it possible to build a unique holographic image of the magnetic structure and recognize the state of the each magnet. The development of magnonic holographic devices opens a new horizon for building scalable holographic devices compatible with conventional electronic devices. This work was supported in part by the FAME Center, one of six centers of STARnet, a Semiconductor Research Corporation program sponsored by MARCO and DARPA and by the National Science Foundation under the NEB2020 Grant ECCS-1124714.
Computer generated holographic microtags
Sweatt, W.C.
1998-03-17
A microlithographic tag comprising an array of individual computer generated holographic patches having feature sizes between 250 and 75 nanometers is disclosed. The tag is a composite hologram made up of the individual holographic patches and contains identifying information when read out with a laser of the proper wavelength and at the proper angles of probing and reading. The patches are fabricated in a steep angle Littrow readout geometry to maximize returns in the -1 diffracted order. The tags are useful as anti-counterfeiting markers because of the extreme difficulty in reproducing them. 5 figs.
Computer generated holographic microtags
Sweatt, William C.
1998-01-01
A microlithographic tag comprising an array of individual computer generated holographic patches having feature sizes between 250 and 75 nanometers. The tag is a composite hologram made up of the individual holographic patches and contains identifying information when read out with a laser of the proper wavelength and at the proper angles of probing and reading. The patches are fabricated in a steep angle Littrow readout geometry to maximize returns in the -1 diffracted order. The tags are useful as anti-counterfeiting markers because of the extreme difficulty in reproducing them.
Holographic baryons from oblate instantons
NASA Astrophysics Data System (ADS)
Rozali, Moshe; Stang, Jared B.; Van Raamsdonk, Mark
2014-02-01
We investigate properties of baryons in a family of holographic field theories related to the Sakai-Sugimoto model of holographic QCD. Starting with the N f = 2 Sakai-Sugimoto model, we truncate to a 5D Yang-Mills action for the gauge fields associated with the noncompact directions of the flavor D8-branes. We define a free parameter γ that controls the strength of this Yang-Mills term relative to the Chern-Simons term that couples the Abelian gauge field to the SU(2) instanton density. Moving away from γ = 0 should incorporate some of the effects of taking the Sakai-Sugimoto model away from large 't Hooft coupling λ. In this case, the baryon ground state corresponds to an oblate SU(2) instanton on the bulk flavor branes: the usual SO(4) symmetric instanton is deformed to spread more along the field theory directions than the radial direction. We numerically construct these anisotropic instanton solutions for various values of γ and calculate the mass and baryon charge profile of the corresponding baryons. Using the value γ = 2.55 that has been found to best fit the mesonic spectrum of QCD, we find a value for the baryon mass of 1.19 GeV, significantly more realistic than the value 1.60 GeV computed previously using an SO(4) symmetric ansatz for the instanton.
Lifshitz holographic superconductor in Hořava-Lifshitz gravity
NASA Astrophysics Data System (ADS)
Luo, Cheng-Jian; Kuang, Xiao-Mei; Shu, Fu-Wen
2016-08-01
We study the holographic phase transition of superconductor dual to a Lifshitz black brane probed by an anisotropic scalar field in the probe limit in Hořava-Lifshitz gravity. With the use of numerical and analytical method, we investigate how the critical temperature of the condensation is affected by the Lifshitz exponent z, α-correction term in the action as well as the dimensions of the gravity. We also numerically explore the condensation of the dual operator and optical conductivity of the holographic system. Various interesting properties of the holographic condensation affected by the parameters of model are discussed.
NASA Astrophysics Data System (ADS)
Shimada, Ken-ichi; Ishii, Toshiki; Hoshizawa, Taku; Takashima, Yuzuru
2015-09-01
Mechanical instabilities during recording and involved degradation of signal quality in high density and high data transfer rate holographic data storage system (HDSS) is one of the obstacles to prevent the technology from being a stable system. We analytically formulated effects of mechanical instabilities of a Galvano mirror and spindle motor on the HDSS by incorporating the concept of a time-averaged holography. Mechanical parameters such as amplitude and frequency of mechanical oscillation are related to optical parameters such as amplitude and phase of reference and signal beams. Especially, the analytical formulation led to a new method of optical and post compensation for mechanical instability during recording hologram. The optical post compensation method enables a robust implementation of HDSS against mechanical instabilities.
NASA Astrophysics Data System (ADS)
Fernández de Córdoba, P.; Isidro, J. M.; Vazquez Molina, J.
2016-07-01
We present a map of standard quantum mechanics onto a dual theory, that of the classical thermodynamics of irreversible processes. While no gravity is present in our construction, our map exhibits features that are reminiscent of the holographic principle of quantum gravity.
NASA Technical Reports Server (NTRS)
Gange, Robert Allen (Inventor)
1977-01-01
A holographic recording medium comprising a conductive substrate, a photoconductive layer and an electrically alterable layer of a linear, low molecular weight hydrocarbon polymer has improved fatigue resistance. An acrylic barrier layer can be interposed between the photoconductive and electrically alterable layers.
Chidi holographic video system
NASA Astrophysics Data System (ADS)
Nwodoh, Thomas A.; Benton, Stephen A.
2000-03-01
Holo-Chidi is a holographic video processing system designed at the MIT Media Laboratory for real-time computation of Computer Generated Holograms and the subsequent display of the holograms at video frame rates. It's processing engine is adapted from Chidi which is reconfigurable multimedia processing system used for real-time synthesis and analysis of digital video frames. Holo-Chidi is made of two main components: the sets of Chidi processor cards and the display video concentrator card. The processor cards are used for hologram computation while the display video concentrator card acts as frame buffer for the system. The display video concentrator also formats the computed holographic data and converts them to analog form for feeding the acousto-optic modulators of the Media Lab's Mark-II holographic display system. The display video concentrator card can display the computed holograms from the Chidi cards loaded from its high-speed I/O interface port or precomputed holograms loaded from a PC through the United Serial Bus port of its communications processor at above video refresh rates. This paper discusses the design of the display video concentrator used to display holographic video in the Mark-II system.
Holographic renormalization group and cosmology in theories with quasilocalized gravity
NASA Astrophysics Data System (ADS)
Csáki, Csaba; Erlich, Joshua; Hollowood, Timothy J.; Terning, John
2001-03-01
We study the long distance behavior of brane theories with quasilocalized gravity. The five-dimensional (5D) effective theory at large scales follows from a holographic renormalization group flow. As intuitively expected, the graviton is effectively four dimensional at intermediate scales and becomes five dimensional at large scales. However, in the holographic effective theory the essentially 4D radion dominates at long distances and gives rise to scalar antigravity. The holographic description shows that at large distances the Gregory-Rubakov-Sibiryakov (GRS) model is equivalent to the model recently proposed by Dvali, Gabadadze, and Porrati (DGP), where a tensionless brane is embedded into 5D Minkowski space, with an additional induced 4D Einstein-Hilbert term on the brane. In the holographic description the radion of the GRS model is automatically localized on the tensionless brane, and provides the ghostlike field necessary to cancel the extra graviton polarization of the DGP model. Thus, there is a holographic duality between these theories. This analysis provides physical insight into how the GRS model works at intermediate scales; in particular it sheds light on the size of the width of the graviton resonance, and also demonstrates how the holographic renormalization group can be used as a practical tool for calculations.
Holographic renormalization group and cosmology in theories with quasilocalized gravity
Csaki, Csaba; Erlich, Joshua; Hollowood, Timothy J.; Terning, John
2001-03-15
We study the long distance behavior of brane theories with quasilocalized gravity. The five-dimensional (5D) effective theory at large scales follows from a holographic renormalization group flow. As intuitively expected, the graviton is effectively four dimensional at intermediate scales and becomes five dimensional at large scales. However, in the holographic effective theory the essentially 4D radion dominates at long distances and gives rise to scalar antigravity. The holographic description shows that at large distances the Gregory-Rubakov-Sibiryakov (GRS) model is equivalent to the model recently proposed by Dvali, Gabadadze, and Porrati (DGP), where a tensionless brane is embedded into 5D Minkowski space, with an additional induced 4D Einstein-Hilbert term on the brane. In the holographic description the radion of the GRS model is automatically localized on the tensionless brane, and provides the ghostlike field necessary to cancel the extra graviton polarization of the DGP model. Thus, there is a holographic duality between these theories. This analysis provides physical insight into how the GRS model works at intermediate scales; in particular it sheds light on the size of the width of the graviton resonance, and also demonstrates how the holographic renormalization group can be used as a practical tool for calculations.
Friedmann Propulsion in an Flat Holographic Universe
NASA Astrophysics Data System (ADS)
Binder, Bernd
2008-01-01
Because of inversion symmetries in holographic systems, the spatial compression of lower-dimensional holographic memory leads to an expansion of the holographic image and vice versa (scaling duality), where the geometric mean between the small quantum memory and cosmic image scale defines the inversion scale, the unit scale to normalize the global holographic currents of momentum exchange. Assigning to the cosmic image (bulk) a 4d, to the quantum memory (baryon) a 2d, and to the inversion scale a 3d spherical topology, the cosmic critical density in the flat FRW cosmic test model corresponds to 1 memory unit (baryon). Otherwise, if we expect expansion driven by 3d Einstein gravity on all scales, we get the well known cosmic ``dark matter'' deficit of 96% or 0.04 baryons per unit volume. The cosmic deficit or quantum excess is assigned by Gauss law to the topological ratio 4d bulk surface S3 to 2d quantum surface S1, which dilutes gravity or the mass density by the dimensionless factor 0.04~S3/2/S13 = 1/(8π) leading to a theoretical Hubble parameter of 73.2 kms-1 Mpc-1. Regarding propulsion based on fractional linear transforms mapping the quantum compression by inversion to a cosmic expansion, the anisotropic transform resembles the Alcubierre mechanism if expansion is behind and the compression ahead of the spaceship.
Holographic spectrograph for space telescope
NASA Astrophysics Data System (ADS)
Ditto, Thomas D.; Lysenko, Sergiy; Crenshaw, Melissa
2013-09-01
A spectrograph is described which is made with dual Holographic Optical Elements (HOEs) which are identical and parallel to each other. Both optics are collimating transmission HOEs with focal points that are at equal and opposite distances from each other. The identical HOEs are formed by the interference of a plane wave parallel to the grating plane with an off-axis spherical wave originating in the near-field. In playback, a spectrum can be formed from a point source radiator placed at the position of the recording spherical wave. If played back at an arbitrary wavelength other than the recording wavelength, the image exhibits coma. This spectrograph is intended for an unusual configuration where many nearly monochromatic sources of known wavelengths are separately positioned relative to the first HOE. The special application is in a space telescope capable of resolving spectra from habitable planets within 10 pc. HOEs of this type could be fabricated on membrane substrates with a low areal mass and stowable on rolls for insertion into the second Lagrange point. The intended application is for a 50 x 10 meter class primary objective holographic space telescope with 50 x 10 m HOEs in the spectrograph. We present a computer model of the spectrograph.. Experimental results are compared with predictions from theory. A single HOE is shown to perform over a wider bandwidth and is demonstrated.
Characterization of quantum phase transition using holographic entanglement entropy
NASA Astrophysics Data System (ADS)
Ling, Yi; Liu, Peng; Wu, Jian-Pin
2016-06-01
The entanglement exhibits extremal or singular behavior near quantum critical points (QCPs) in many condensed matter models. These intriguing phenomena, however, still call for a widely accepted understanding. In this paper we study this issue in holographic framework. We investigate the connection between the holographic entanglement entropy (HEE) and the quantum phase transition (QPT) in a lattice-deformed Einstein-Maxwell-Dilaton theory. Novel backgrounds exhibiting metal-insulator transitions (MIT) have been constructed in which both metallic phase and insulating phase have vanishing entropy density in zero temperature limit. We find that the first order derivative of HEE with respect to lattice parameters exhibits extremal behavior near QCPs. We propose that it would be a universal feature that HEE or its derivatives with respect to system parameters can characterize QPT in a generic holographic system. Our work opens a window for understanding the relation between entanglement and the QPT from a holographic perspective.
Thermodynamics of interacting holographic dark energy
NASA Astrophysics Data System (ADS)
Arevalo, Fabiola; Cifuentes, Paulo; Peña, Francisco
2016-01-01
The thermodynamics of a scheme of dark matter-dark energy interaction is studied considering a holographic model for the dark energy in a flat Friedmann-Lemaitre-Robertson-Walker background. We obtain a total entropy rate for a general horizon and we study the Generalized Second Law of Thermodynamics for a cosmological interaction as a free function. Additionally, we discuss two horizons related to the Ricci and Ricci-like model and its effect on an interacting system.
Holographic Optical Data Storage
NASA Technical Reports Server (NTRS)
Timucin, Dogan A.; Downie, John D.; Norvig, Peter (Technical Monitor)
2000-01-01
Although the basic idea may be traced back to the earlier X-ray diffraction studies of Sir W. L. Bragg, the holographic method as we know it was invented by D. Gabor in 1948 as a two-step lensless imaging technique to enhance the resolution of electron microscopy, for which he received the 1971 Nobel Prize in physics. The distinctive feature of holography is the recording of the object phase variations that carry the depth information, which is lost in conventional photography where only the intensity (= squared amplitude) distribution of an object is captured. Since all photosensitive media necessarily respond to the intensity incident upon them, an ingenious way had to be found to convert object phase into intensity variations, and Gabor achieved this by introducing a coherent reference wave along with the object wave during exposure. Gabor's in-line recording scheme, however, required the object in question to be largely transmissive, and could provide only marginal image quality due to unwanted terms simultaneously reconstructed along with the desired wavefront. Further handicapped by the lack of a strong coherent light source, optical holography thus seemed fated to remain just another scientific curiosity, until the field was revolutionized in the early 1960s by some major breakthroughs: the proposition and demonstration of the laser principle, the introduction of off-axis holography, and the invention of volume holography. Consequently, the remainder of that decade saw an exponential growth in research on theory, practice, and applications of holography. Today, holography not only boasts a wide variety of scientific and technical applications (e.g., holographic interferometry for strain, vibration, and flow analysis, microscopy and high-resolution imagery, imaging through distorting media, optical interconnects, holographic optical elements, optical neural networks, three-dimensional displays, data storage, etc.), but has become a prominent am advertising
Analytic holographic superconductor
NASA Astrophysics Data System (ADS)
Herzog, Christopher P.
2010-06-01
We investigate a holographic superconductor that admits an analytic treatment near the phase transition. In the dual 3+1-dimensional field theory, the phase transition occurs when a scalar operator of scaling dimension two gets a vacuum expectation value. We calculate current-current correlation functions along with the speed of second sound near the critical temperature. We also make some remarks about critical exponents. An analytic treatment is possible because an underlying Heun equation describing the zero mode of the phase transition has a polynomial solution. Amusingly, the treatment here may generalize for an order parameter with any integer spin, and we propose a Lagrangian for a spin-two holographic superconductor.
Holographic subsonic flow visualization.
Reinheimer, C J; Wiswall, C E; Schmiege, R A; Harris, R J; Dueker, J E
1970-09-01
A pulsed ruby laser holographic interferometer was used to detect density gradients in the airflow around an airfoil at subsonic speeds in a low speed wind tunnel. These experiments proved that vibration of the optical components or object between exposures of the interferometric hologram does not destroy the detection of density gradients but actually can aid in the flow visualization. The density gradients determined from the fringe pattern analysis are consistent with the anticipated flow pattern. PMID:20094197
Holographic Plossl Retroreflectors
NASA Technical Reports Server (NTRS)
Waluschka, Eugene
2006-01-01
Holographic retroreflectors that function equivalently to Plossl eyepieces have been developed and used in free-space optical communication systems that utilize laser beams. Plossl eyepieces are well known among telescope designers. They have been adopted for use a retroreflectors and as focusing elements (for reception) and collimating elements (for transmission) in optical communication systems. A retro-reflector that incorporates a Plossl eyepiece is termed a cat's-eye retroreflector.
Investigation of Holographic Scanners
NASA Astrophysics Data System (ADS)
Xiang, Lian Qin
Holographic scanners are capable of challenging both the speed and resolution of polygon scanners. This work investigates, in detail, the design and operation of a holographic scanner with an aspherical reflector. The characteristics of this holographic scanner are presented through theoretical analyses and computer simulation. The calculated data and the experimental results show that this system has excellent scan line straightness and scan linearity. The influence of the eccentricity and wobble of the hologram on the quality of the scan lines can be minimized by proper choice of system parameters. This unique system can readily perform 1-D, 2 -D, 3-D and selective scans. These features make suitable applications for robot vision, part inspection, high speed printing, and input/output devices for computers. If the hologram is operating in the reflective mode, there are no transmissive components in this scanner. It can be used with acoustic waves and electromagnetic waves with longer wavelengths, such as infrared, microwaves, millimeter waves. Since it is difficult to find a suitable recording material for these waves, a technique for making computer -generated holograms has also been developed here. The practical considerations for making quality holograms are summarized. An improved coating process for photoresist and a novel anti-reflection setup for the hologram plate are developed. The detailed experimental processes are included. The planar grating scanner for one dimensional, two-dimensional and cross-scanning patterns is analyzed and demonstrated. A comparison is made with two other two-dimensional scanners.
Imaging diffractometer with holographic encoding enhancements for laser sensing and characterization
NASA Astrophysics Data System (ADS)
Binford, Joseph L., III; Duncan, Bradley D.; Parker, Jack H., Jr.; Beecher, Elizabeth A.; Delong, Mark L.
2007-06-01
What is believed to be a novel holographic optical encoding scheme has been developed to enhance the performance of laser sensors designed for the measurement of wavelength and angular trajectory. A prototype holographic imaging diffractometer has been created to reconstruct holographic cueing patterns superimposed in the focal plane of wide-angle scene imagery. Based on experimental pattern metric measurements at the focal plane, a theoretical model is used to compute the laser source wavelength and its apparent propagation direction within the sensor's field of view. The benefits of incorporating holographic enhancements within an imager-based sensor architecture are discussed.
Representing Word Meaning and Order Information in a Composite Holographic Lexicon
ERIC Educational Resources Information Center
Jones, Michael N.; Mewhort, Douglas J. K.
2007-01-01
The authors present a computational model that builds a holographic lexicon representing both word meaning and word order from unsupervised experience with natural language. The model uses simple convolution and superposition mechanisms to learn distributed holographic representations for words. The structure of the resulting lexicon can account…
Method and apparatus for holographic wavefront diagnostics
Toeppen, John S.
1995-01-01
A wavefront diagnostic apparatus has an optic and a measuring system. The optic forms a holographic image in response to a beam of light striking a hologram formed on a surface of the optic. The measuring system detects the position of the array of holographic images and compares the positions of the array of holographic images to a reference holographic image.
Method and apparatus for holographic wavefront diagnostics
Toeppen, J.S.
1995-04-25
A wavefront diagnostic apparatus has an optic and a measuring system. The optic forms a holographic image in response to a beam of light striking a hologram formed on a surface of the optic. The measuring system detects the position of the array of holographic images and compares the positions of the array of holographic images to a reference holographic image. 3 figs.
Laser addressed holographic memory system
NASA Technical Reports Server (NTRS)
Gange, R. A.; Wagle, E. M.; Steinmetz, C. C.
1973-01-01
Holographic recall and storage system uses red-lipid microcrystalline wax as storage medium. When laser beam strikes wax, its energy heats point of incidence enough to pass wax through transition temperature. Holograph image can then be written or erased in softened wax.
HOMES Holographic Optical Method for Exoplanet Spectroscopy
NASA Astrophysics Data System (ADS)
Ditto, Thomas D.; McGrew, Stephen P.
2013-09-01
A novel telescope architecture is proposed specifically for the purpose of taking spectra of exoplanets orbiting stars within 10 pc ("the neighborhood"). The primary objective and the secondary spectrograph are holographic optical elements (HOEs) formed on flat membrane substrates of low areal mass that can be transported on cylinder rolls that are compatible with the payload geometry of delivery vehicles. Ribbon-shaped HOEs of up to 100 x 10 meters are contemplated. Computer models are presented with these dimensions. The models predict resolving power better than 10 mas. Because the primary separates wavelengths, we consider coronagraphs that use the divide and conquer strategy of one wavelength at a time. After delivery at the second Lagrange point, the stowed membranes are unfurled into flat holographic optics positioned in a four part formation spanning 1 km of open space.
Vector fields in holographic cosmology
NASA Astrophysics Data System (ADS)
B. Hartle, James; Hawking, S. W.; Hertog, Thomas
2013-11-01
We extend the holographic formulation of the semiclassical no-boundary wave function (NBWF) to models with Maxwell vector fields. It is shown that the familiar saddle points of the NBWF have a representation in which a regular, Euclidean asymptotic AdS geometry smoothly joins onto a Lorentzian asymptotically de Sitter universe through a complex transition region. The tree level probabilities of Lorentzian histories are fully specified by the action of the AdS region of the saddle points. The scalar and vector matter profiles in this region are complex from an AdS viewpoint, with universal asymptotic phases. The dual description of the semiclassical NBWF thus involves complex deformations of Euclidean CFTs.
Robust holographic storage system design.
Watanabe, Takahiro; Watanabe, Minoru
2011-11-21
Demand is increasing daily for large data storage systems that are useful for applications in spacecraft, space satellites, and space robots, which are all exposed to radiation-rich space environment. As candidates for use in space embedded systems, holographic storage systems are promising because they can easily provided the demanded large-storage capability. Particularly, holographic storage systems, which have no rotation mechanism, are demanded because they are virtually maintenance-free. Although a holographic memory itself is an extremely robust device even in a space radiation environment, its associated lasers and drive circuit devices are vulnerable. Such vulnerabilities sometimes engendered severe problems that prevent reading of all contents of the holographic memory, which is a turn-off failure mode of a laser array. This paper therefore presents a proposal for a recovery method for the turn-off failure mode of a laser array on a holographic storage system, and describes results of an experimental demonstration. PMID:22109441
Holographic dark energy and late cosmic acceleration
NASA Astrophysics Data System (ADS)
Pavón, Diego
2007-06-01
It has been persuasively argued that the number of effective degrees of freedom of a macroscopic system is proportional to its area rather than to its volume. This entails interesting consequences for cosmology. Here we present a model based on this 'holographic principle' that accounts for the present stage of accelerated expansion of the Universe and significantly alleviates the coincidence problem also for non-spatially flat cosmologies. Likewise, we comment on a recently proposed late transition to a fresh decelerated phase.
Holographic dark energy from minimal supergravity
NASA Astrophysics Data System (ADS)
Landim, Ricardo C. G.
2016-02-01
We embed models of holographic dark energy (HDE) coupled to dark matter (DM) in minimal supergravity plus matter, with one chiral superfield. We analyze two cases. The first one has the Hubble radius as the infrared (IR) cutoff and the interaction between the two fluids is proportional to the energy density of the DE. The second case has the future event horizon as IR cutoff while the interaction is proportional to the energy density of both components of the dark sector.
NASA Astrophysics Data System (ADS)
Ficnar, Andrej
In this dissertation we study the phenomenon of jet quenching in quark-gluon plasma using the AdS/CFT correspondence. We start with a weakly coupled, perturbative QCD approach to energy loss, and present a Monte Carlo code for computation of the DGLV radiative energy loss of quarks and gluons at an arbitrary order in opacity. We use the code to compute the radiated gluon distribution up to n=9 order in opacity, and compare it to the thin plasma (n=1) and the multiple soft scattering (n=infinity) approximations. We furthermore show that the gluon distribution at finite opacity depends in detail on the screening mass mu and the mean free path lambda. In the next part, we turn to the studies of how heavy quarks, represented as "trailing strings" in AdS/CFT, lose energy in a strongly coupled plasma. We study how the heavy quark energy loss gets modified in a "bottom-up" non-conformal holographic model, constructed to reproduce some properties of QCD at finite temperature and constrained by fitting the lattice gauge theory results. The energy loss of heavy quarks is found to be strongly sensitive to the medium properties. We use this model to compute the nuclear modification factor RAA of charm and bottom quarks in an expanding plasma with Glauber initial conditions, and comment on the range of validity of the model. The central part of this thesis is the energy loss of light quarks in a strongly coupled plasma. Using the standard model of "falling strings", we present an analytic derivation of the stopping distance of light quarks, previously available only through numerical simulations, and also apply it to the case of Gauss-Bonnet higher derivative gravity. We then present a general formula for computing the instantaneous energy loss in non-stationary string configurations. Application of this formula to the case of falling strings reveals interesting phenomenology, including a modified Bragg-like peak at late times and an approximately linear path dependence. Based
Holographic movie: the first step to holographic video
NASA Astrophysics Data System (ADS)
Higuchi, Kazuhito; Ishikawa, Jun; Hiyama, Shigeo
1992-05-01
Holographic movies can be seen as a tool to estimate the picture quality of moving holographic images as a step towards holographic television. With this in mind, we have developed an experimental holographic movie system and produced a short duration 3D movie. A number of dolls and moving objects were positioned within a background and illuminated with a He-Ne laser (632.8 nm). Conventional film-making techniques were used during holographic recording to create a more attractive sequence. The techniques included stop-motion, tracking, enhanced depth perception, up-shots, and overlaps. A series of 300 Fresnel type holograms was recorded on standard holographic films. An interesting technical point is that the film was 10 mm high by 200 mm wide. After developing, the films were sandwiched between two rigid acrylic drums (about 1 m in diameter). The drum is rotated and the films illuminated with the He-Ne laser. The display speed can be varied from 6 to 24 frames per second. The films are viewed through a window. Even though this prototype is relatively primitive the resulting holographic movie is quite effective. Several interesting effects were noted. For example, it was found that objects in the movie must not rapidly shift their depth because the human eye cannot track them is they do.
NASA Astrophysics Data System (ADS)
Thacker, H. B.; Xiong, Chi; Kamat, Ajinkya S.
2011-11-01
The Witten-Sakai-Sugimoto construction of holographic QCD in terms of D4 color branes and D8 flavor branes in type IIA string theory is used to investigate the role of topological charge in the chiral dynamics of quarks in QCD. The QCD theta term arises from a compactified five-dimensional Chern-Simons term on the D4 branes. This term couples the QCD topological charge to the Ramond-Ramond (RR) U(1) gauge field of type IIA string theory. For large Nc the contribution of instantons (D0 branes) is suppressed, and the nonzero topological susceptibility of pure-glue QCD is attributed to the presence of D6 branes, which constitute magnetic sources of the RR gauge field. The topological charge of QCD is required, by an anomaly inflow argument, to coincide in space-time with the intersection of the D6 branes and the D4 color branes. This clarifies the relation between D6 branes and the coherent, codimension-one topological charge membranes observed in QCD Monte Carlo calculations. Using open-string/closed-string duality, we interpret a quark loop (represented by a D4-D8 open-string loop) in terms of closed-string exchange between color and flavor branes. The role of the RR gauge field in quark-antiquark annihilation processes is discussed. RR exchange in the s-channel generates a 4-quark contact term which produces an η' mass insertion and provides an explanation for the observed spin-parity structure of the Okubo-Zweig-Iizuka rule. The (logDetU)2 form of the U(1) anomaly emerges naturally. RR exchange in the t-channel of the qq¯ scattering amplitude produces a Nambu-Jona-Lasinio interaction which may provide a mechanism for spontaneous breaking of SU(Nf)×SU(Nf).
Holographic dark energy with time varying parameter c 2
NASA Astrophysics Data System (ADS)
Malekjani, M.; Zarei, R.; Honari-Jafarpour, M.
2013-02-01
We consider the holographic dark energy model in which the model parameter c 2 evolves slowly with time. First we calculate the evolution of EoS parameter as well as the deceleration parameter in this generalized version of holographic dark energy (GHDE). Depending on the parameter c 2, the phantom regime can be achieved earlier or later compare with original version of holographic dark energy. The evolution of energy density of GHDE model is investigated in terms of parameter c 2. We also show that the time-dependency of c 2 can effect on the transition epoch from decelerated phase to accelerated expansion. Finally, we perform the statefinder diagnostic for GHDE model and show that the evolutionary trajectories of the model in s- r plane are strongly depend on the parameter c 2.
Constraints on holographic cosmologies from strong lensing systems
Cárdenas, Víctor H.; Bonilla, Alexander; Motta, Verónica; Campo, Sergio del E-mail: alex.bonilla@uv.cl E-mail: sdelcamp@ucv.cl
2013-11-01
We use strongly gravitationally lensed (SGL) systems to put additional constraints on a set of holographic dark energy models. Data available in the literature (redshift and velocity dispersion) is used to obtain the Einstein radius and compare it with model predictions. We found that the ΛCDM is the best fit to the data. Although a preliminary statistical analysis seems to indicate that two of the holographic models studied show interesting agreement with observations, a stringent test lead us to the result that neither of the holographic models are competitive with the ΛCDM. These results highlight the importance of Strong Lensing measurements to provide additional observational constraints to alternative cosmological models, which are necessary to shed some light into the dark universe.
Properties of multilayer nonuniform holographic structures
Pen, E F; Rodionov, Mikhail Yu
2010-12-09
Experimental results and analysis of properties of multilayer nonuniform holographic structures formed in photopolymer materials are presented. The theoretical hypotheses is proved that the characteristics of angular selectivity for the considered structures have a set of local maxima, whose number and width are determined by the thicknesses of intermediate layers and deep holograms and that the envelope of the maxima coincides with the selectivity contour of a single holographic array. It is also experimentally shown that hologram nonuniformities substantially distort shapes of selectivity characteristics: they become asymmetric, the local maxima differ in size and the depths of local minima reduce. The modelling results are made similar to experimental data by appropriately choosing the nonuniformity parameters. (imaging and image processing. holography)
Holographic Josephson junction from massive gravity
NASA Astrophysics Data System (ADS)
Hu, Ya-Peng; Li, Huai-Fan; Zeng, Hua-Bi; Zhang, Hai-Qing
2016-05-01
We study the holographic superconductor-normal metal-superconductor (SNS) Josephson junction in de Rham-Gabadadze-Tolley massive gravity. If the boundary theory is independent of spatial directions, i.e., if the chemical potential is homogeneous in spatial directions, we find that the graviton mass parameter will make it more difficult for the normal metal-superconductor phase transition to take place. In the holographic model of the Josephson junction, it is found that the maximal tunneling current will decrease according to the graviton mass parameter. Besides, the coherence length of the junction decreases as well with respect to the graviton mass parameter. If one interprets the graviton mass parameter as the effect of momentum dissipation in the boundary field theory, this indicates that the stronger the momentum dissipation is, the smaller the coherence length is.
Reheating of the Universe as holographic thermalization
NASA Astrophysics Data System (ADS)
Kawai, Shinsuke; Nakayama, Yu
2016-08-01
Assuming gauge/gravity correspondence we study reheating of the Universe using its holographic dual. Inflaton decay and thermalisation of the decay products correspond to collapse of a spherical shell and formation of a blackhole in the dual anti-de Sitter (AdS) spacetime. The reheating temperature is computed as the Hawking temperature of the developed blackhole probed by a dynamical boundary, and is determined by the inflaton energy density and the AdS radius, with corrections from the dynamics of the shell collapse. For given initial energy density of the inflaton field the holographic model typically gives lower reheating temperature than the instant reheating scenario, while it is shown to be safely within phenomenological bounds.
Interferometric holographic cinematography
NASA Astrophysics Data System (ADS)
Fagot, H.
1985-07-01
Double exposition holographic interferometry was employed to obtain a 35 mm scientific film. The deformations and deplacements of a loudspeaker were visualized at 20 to 70 Hz vibration frequencies. A 30 mJ YAG laser was used. The two successive pulses of each hologram are produced at 4 ms interval by the same laser beam. The 35 mm camera operates at 10 Hz. The device is limited to low frequency phenomena. The development of higher frequency systems is discussed with a view to nondestructive control of vibration in aircraft structures.
Simplification of holographic procedures.
Carcel, J T; Rodemann, A H; Florman, E; Domeshek, S
1966-07-01
The present state of the holographic art has set many stringent parameters on the production of holograms, such as extreme mechanical, temperature, and air stability for long periods of time, and slow film emulsions with extremely high resolution. The Physical Sciences Laboratory of the U.S. Naval Training Device Center has investigated, experimented, and produced many clear high resolution holograms in a ground-level Butler Building without close temperature controls and using other than expensive, massive, and extremely rigid optical mounts and equipment. PMID:20049046
Fast fluorescence holographic microscopy
Qin, Wan; Yang, Xiaoqi; Li, Yingying; Peng, Xiang; Qu, Xinghua; Yao, Hai; Gao, Bruce Z.
2015-01-01
FINCHSCOPE is a new technology of fluorescence holographic microscopy. It has been successfully applied to recording high-resolution three-dimensional fluorescence images of biological specimens without the need for scanning. In this study, we revealed and analyzed an intrinsic phenomenon, called ghost lens effect, on spatial light modulator which is the core element enabling the incoherent correlation in the FINCHSCOPE. The ghost lens effect can degrade the imaging quality by introducing multiple spherical waves with different focal lengths into the correlation and thus increasing the noise in the recorded holograms. PMID:25767693
Conically scanned holographic lidar telescope
NASA Technical Reports Server (NTRS)
Schwemmer, Geary (Inventor)
1993-01-01
An optical scanning device utilizing a source of optical energy such as laser light backscattered from the earth's atmosphere or transmitted outward as in a lidar, a rotating holographic optical element having an axis of rotation perpendicular to the plane of its substrate, and having a stationary focus which may or may not be located on its axis of rotation, with the holographic optical element diffracting the source of optical energy at an angle to its rotation axis enabling a conical scanning area and a motor for supporting and rotating the rotating holographic optical element, is described.
Intellectual property in holographic interferometry
NASA Astrophysics Data System (ADS)
Reingand, Nadya; Hunt, David
2006-08-01
This paper presents an overview of patents and patent applications on holographic interferometry, and highlights the possibilities offered by patent searching and analysis. Thousands of patent documents relevant to holographic interferometry were uncovered by the study. The search was performed in the following databases: U.S. Patent Office, European Patent Office, Japanese Patent Office and Korean Patent Office for the time frame from 1971 through May 2006. The patent analysis unveils trends in patent temporal distribution, patent families formation, significant technological coverage within the market of system that employ holographic interferometry and other interesting insights.
Holographic Solar Photon Thrusters
NASA Technical Reports Server (NTRS)
Johnson, Les; Matloff, Greg
2006-01-01
A document discusses a proposal to incorporate holographic optical elements into solar photon thrusters (SPTs). First suggested in 1990, SPTs would be systems of multiple reflective, emissive, and absorptive surfaces (solar sails) that would be attached to spacecraft orbiting the Earth to derive small propulsive forces from radiation pressures. An SPT according to the proposal would include, among other things, a main sail. One side of the sail would be highly emissive and would normally face away from the Earth. The other side would be reflective and would be covered by white-light holographic images that would alternately become reflective, transmissive, and absorptive with small changes in the viewing angle. When the spacecraft was at a favorable orbital position, the main sail would be oriented to reflect sunlight in a direction to maximize the solar thrust; when not in a favorable position, the main sail would be oriented to present a substantially absorptive/emissive aspect to minimize the solar drag. By turning the main sail slightly to alternate between the reflective and absorptive/ emissive extremes, one could achieve nearly a doubling or halving of the radiational momentum transfer and, hence, of the solar thrust.
NASA Astrophysics Data System (ADS)
Hopwood, Anthony I.
1991-10-01
This paper discusses a new type of holographic overlay, FLASHPRINT, which may be used in both security and packaging applications. Unlike the more common embossed holograms currently used, FLASHPRINT leads to reduced set-up costs and offers a simpler process. This reduces the long lead times characteristic of the existing technology and requires the customer to provide only two-dimensional artwork. The overlay material contains a covert 2-D image. The image may be switched on or off by simply tilting the overlay in a light source. The overlay is replayed in the 'on' position to reveal the encoded security message as a highly saturated gold colored image. This effect is operable for a wide range of lighting conditions and viewing geometries. In the 'off' position the overlay is substantially transparent. These features make the visual effect of the overlay attractive to incorporate into product design. They may be laminated over complex printed artwork such as labels and security passes without masking the printed message. When switched 'on' the image appears both sharp and more than seven times brighter than white paper. The image remains sharp and clear even in less favorable lighting conditions. Although the technique offers a low set-up cost for the customer, through its simplicity, it remains as technically demanding and difficult to counterfeit as any holographic process.
The traveltime holographic principle
NASA Astrophysics Data System (ADS)
Huang, Yunsong; Schuster, Gerard T.
2015-01-01
Fermat's interferometric principle is used to compute interior transmission traveltimes τpq from exterior transmission traveltimes τsp and τsq. Here, the exterior traveltimes are computed for sources s on a boundary B that encloses a volume V of interior points p and q. Once the exterior traveltimes are computed, no further ray tracing is needed to calculate the interior times τpq. Therefore this interferometric approach can be more efficient than explicitly computing interior traveltimes τpq by ray tracing. Moreover, the memory requirement of the traveltimes is reduced by one dimension, because the boundary B is of one fewer dimension than the volume V. An application of this approach is demonstrated with interbed multiple (IM) elimination. Here, the IMs in the observed data are predicted from the migration image and are subsequently removed by adaptive subtraction. This prediction is enabled by the knowledge of interior transmission traveltimes τpq computed according to Fermat's interferometric principle. We denote this principle as the `traveltime holographic principle', by analogy with the holographic principle in cosmology where information in a volume is encoded on the region's boundary.
Holographic sensors for diagnostics of solution components
Kraiskii, A V; Suitanov, T T; Postnikov, V A; Khamidulin, A V
2010-02-28
The properties of holographic sensors of two types are studied. The sensors are based on a three-dimensional polymer-network matrix of copolymers of acrylamide, acrylic acid (which are sensitive to the medium acidity and bivalent metal ions) and aminophenylboronic acid (sensitive to glucose). It is found that a change in the ionic composition of a solution results in changes in the distance between layers and in the diffraction efficiency of holograms. Variations in the shape of spectral lines, which are attributed to the inhomogeneity of a sensitive layer, and nonmonotonic changes in the emulsion thickness and diffraction efficiency were observed during transient processes. The composition of the components of a hydrogel medium is selected for systems which can be used as a base for glucose sensors with the mean holographic response in the region of physiological glucose concentration in model solutions achieving 40 nm/(mmol L{sup -1}). It is shown that the developed holographic sensors can be used for the visual and instrumental determination of the medium acidity, alcohol content, ionic strength, bivalent metal salts and the quality of water, in particular, for drinking. (laser applications and other topics in quantum electronics)
Holographic thermalization in a quark confining background
Ageev, D. S. Aref’eva, I. Ya.
2015-03-15
We study holographic thermalization of a strongly coupled theory inspired by two colliding shock waves in a vacuum confining background. Holographic thermalization means a black hole formation, in fact, a trapped surface formation. As the vacuum confining background, we considered the well-know bottom-up AdS/QCD model that provides the Cornell potential and reproduces the QCD β-function. We perturb the vacuum background by colliding domain shock waves that are assumed to be holographically dual to heavy ions collisions. Our main physical assumption is that we can make a restriction on the time of trapped surface formation, which results in a natural limitation on the size of the domain where the trapped surface is produced. This limits the intermediate domain where the main part of the entropy is produced. In this domain, we can use an intermediate vacuum background as an approximation to the full confining background. We find that the dependence of the multiplicity on energy for the intermediate background has an asymptotic expansion whose first term depends on energy as E{sup 1/3}, which is very similar to the experimental dependence of particle multiplicities on the colliding ion energy obtained from the RHIC and LHC. However, this first term, at the energies where the approximation of the confining metric by the intermediate background works, does not saturate the exact answer, and we have to take the nonleading terms into account.
Holographic microscopy studies of emulsions
NASA Technical Reports Server (NTRS)
Witherow, W. K.
1981-01-01
A holographic microscopy system that records and observes the dynamic properties of separation of dispersed immiscible fluids is described. The holographic construction system and reconstruction system that were used to obtain particle size and distribution information from the holograms are discussed. The holographic microscopy system is used to observed the phase separating processes in immiscible fluids that were isothermally cooled into the two phase region. Nucleation, growth rates, coalescence, and particle motion are successfully demonstrated with this system. Thus a holographic particle sizing system with a resolution of 2 micrometers and a field of view of 100 cu cm was developed that provides the capability of testing the theories of separating immiscible fluids for particle number densities in the range of 10 to 10 to the 7th power particles.
Holographic dark energy with cosmological constant
NASA Astrophysics Data System (ADS)
Hu, Yazhou; Li, Miao; Li, Nan; Zhang, Zhenhui
2015-08-01
Inspired by the multiverse scenario, we study a heterotic dark energy model in which there are two parts, the first being the cosmological constant and the second being the holographic dark energy, thus this model is named the ΛHDE model. By studying the ΛHDE model theoretically, we find that the parameters d and Ωhde are divided into a few domains in which the fate of the universe is quite different. We investigate dynamical behaviors of this model, and especially the future evolution of the universe. We perform fitting analysis on the cosmological parameters in the ΛHDE model by using the recent observational data. We find the model yields χ2min=426.27 when constrained by Planck+SNLS3+BAO+HST, comparable to the results of the HDE model (428.20) and the concordant ΛCDM model (431.35). At 68.3% CL, we obtain -0.07<ΩΛ0<0.68 and correspondingly 0.04<Ωhde0<0.79, implying at present there is considerable degeneracy between the holographic dark energy and cosmological constant components in the ΛHDE model.
Dynamical instability of holographic QCD at finite density
NASA Astrophysics Data System (ADS)
Chuang, Wu-Yen; Dai, Shou-Huang; Kawamoto, Shoichi; Lin, Feng-Li; Yeh, Chen-Pin
2011-05-01
In this paper we study the dynamical instability of Sakai-Sugimoto’s holographic QCD model at finite baryon density. In this model, the baryon density, represented by the smeared instanton on the world volume of the probe D8-D8¯ mesonic brane, sources the world-volume electric field, and through the Chern-Simons term it will induce the instability to form a chiral helical wave at sufficient high density. Our results show that this kind of instability occurs for sufficiently high baryon number densities. The phase diagram of holographic QCD will thus be changed from the one which is based only on thermodynamics.
Dynamical instability of holographic QCD at finite density
Chuang, Wu-Yen; Dai, Shou-Huang; Kawamoto, Shoichi; Lin, Feng-Li; Yeh, Chen-Pin
2011-05-15
In this paper we study the dynamical instability of Sakai-Sugimoto's holographic QCD model at finite baryon density. In this model, the baryon density, represented by the smeared instanton on the world volume of the probe D8-D8 mesonic brane, sources the world-volume electric field, and through the Chern-Simons term it will induce the instability to form a chiral helical wave at sufficient high density. Our results show that this kind of instability occurs for sufficiently high baryon number densities. The phase diagram of holographic QCD will thus be changed from the one which is based only on thermodynamics.
Magnetic response of holographic Lifshitz superconductors: Vortex and Droplet solutions
NASA Astrophysics Data System (ADS)
Lala, Arindam
2014-07-01
In this paper a holographic model of s-wave superconductor with anisotropic Lifshitz scaling has been considered. In the presence of an external magnetic field our holographic model exhibits both vortex and droplet solutions. Based on analytic methods we have shown that the anisotropy has no effect on the vortex and droplet solutions whereas it may affect the condensation. Our vortex solution closely resembles the Ginzburg-Landau theory and a relation between the upper critical magnetic field and superconducting coherence length has been speculated from this comparison. Using Sturm-Liouville method, the effect of anisotropy on the critical parameters in insulator/superconductor phase transitions has been analyzed.
Holographic entanglement entropy close to quantum phase transitions
NASA Astrophysics Data System (ADS)
Ling, Yi; Liu, Peng; Niu, Chao; Wu, Jian-Pin; Xian, Zhuo-Yu
2016-04-01
We investigate the holographic entanglement entropy (HEE) of a strip geometry in four dimensional Q-lattice backgrounds, which exhibit metal-insulator transitions in the dual field theory. Remarkably, we find that the HEE always displays a peak in the vicinity of the quantum critical points. Our model provides the first direct evidence that the HEE can be used to characterize the quantum phase transition (QPT). We also conjecture that the maximization behavior of HEE at quantum critical points would be universal in general holographic models.
Causality & holographic entanglement entropy
NASA Astrophysics Data System (ADS)
Headrick, Matthew; Hubeny, Veronika E.; Lawrence, Albion; Rangamani, Mukund
2014-12-01
We identify conditions for the entanglement entropy as a function of spatial region to be compatible with causality in an arbitrary relativistic quantum field theory. We then prove that the covariant holographic entanglement entropy prescription (which relates entanglement entropy of a given spatial region on the boundary to the area of a certain extremal surface in the bulk) obeys these conditions, as long as the bulk obeys the null energy condition. While necessary for the validity of the prescription, this consistency requirement is quite nontrivial from the bulk standpoint, and therefore provides important additional evidence for the prescription. In the process, we introduce a codimension-zero bulk region, named the entanglement wedge, naturally associated with the given boundary spatial region. We propose that the entanglement wedge is the most natural bulk region corresponding to the boundary reduced density matrix.
Holographic Recording Materials Development
NASA Technical Reports Server (NTRS)
Verber, C. M.; Schwerzel, R. E.; Perry, P. J.; Craig, R. A.
1976-01-01
Organic photorefractive materials were evaluated for application in a reversible holographic memory system. Representative indigo and thioindigo derivatives and several stilbene derivatives were studied as well as 15, 16-dialkyldihydropyrene derivatives the following goals were achieved: (1) the successful writing of phase holograms in a thioindigo/polymer gel system, (2) the successful writing and erasing of phase holograms in a variety of indigo/polymer gel and indigo/solid polymer systems, and (3) the identification of indigoid dyes and 15, 16-dialkyldihydropyrene derivatives as materials potentially suitable for utilization in an operational system. Photochemical studies of the stilbene, indigo, thioindigo, and dialkyldihydropyrene derivatives in solution and in a variety of polymer matrix materials were conducted with the goal of optimizing the photorefractive behavior of the chemical system as a whole. The spectroscopic properties required of optimal photorefractive materials were identified, and it was shown that both the indigoid dyes and the dialkyldihydropyrenes closely match the required properties.
NASA Astrophysics Data System (ADS)
Johnson, Clifford V.
2014-10-01
It is shown that in theories of gravity where the cosmological constant is considered a thermodynamic variable, it is natural to use black holes as heat engines. Two examples are presented in detail using AdS charged black holes as the working substance. We notice that for static black holes, the maximally efficient traditional Carnot engine is also a Stirling engine. The case of negative cosmological constant supplies a natural realization of these engines in terms of the field theory description of the fluids to which they are holographically dual. We first propose a precise picture of how the traditional thermodynamic dictionary of holography is extended when the cosmological constant is dynamical and then conjecture that the engine cycles can be performed by using renormalization group flow. We speculate about the existence of a natural dual field theory counterpart to the gravitational thermodynamic volume.
Holographic Vortex Coronagraph
NASA Technical Reports Server (NTRS)
Palacios, David
2010-01-01
A holographic vortex coronagraph (HVC) has been proposed as an improvement over conventional coronagraphs for use in high-contrast astronomical imaging for detecting planets, dust disks, and other broadband light scatterers in the vicinities of stars other than the Sun. Because such light scatterers are so faint relative to their parent stars, in order to be able to detect them, it is necessary to effect ultra-high-contrast (typically by a factor of the order of 1010) suppression of broadband light from the stars. Unfortunately, the performances of conventional coronagraphs are limited by low throughput, dispersion, and difficulty of satisfying challenging manufacturing requirements. The HVC concept offers the potential to overcome these limitations.
Holographic humidity response of slanted gratings in moisture-absorbing acrylamide photopolymer.
Yu, Dan; Liu, Hongpeng; Mao, Dongyao; Geng, Yaohui; Wang, Weibo; Sun, Liping; Lv, Jiang
2015-08-01
Holographic humidity response is characterized in detail using transmission and reflection geometry in moisture-absorbing acrylamide photopolymer. The diffraction spectrum and its temporal evolution at various relative humidity are measured and analyzed. The quantitative relations between relative humidity and holographic properties of slanted gratings are determined. The responsibility of holographic gratings for various relative humidity is observed by the spectrum response of gratings. The extracted humidity constants reflect the applicability of reflection and transmission gratings at different humidity regions. The humidity reversibility experiment is achieved for confirming repeatability of the sensor. These experiments provide a probability for improving the applicability of a holographic humidity sensor. Finally, the extended diffusion model is derived by introducing the expansion coefficient to describe the dynamic swelling process. This work can accelerate development of the holographic sensor and provide a novel strategy for exploring the swelling mechanism of photopolymer. PMID:26368095
Compact Holographic Data Storage
NASA Technical Reports Server (NTRS)
Chao, T. H.; Reyes, G. F.; Zhou, H.
2001-01-01
NASA's future missions would require massive high-speed onboard data storage capability to Space Science missions. For Space Science, such as the Europa Lander mission, the onboard data storage requirements would be focused on maximizing the spacecraft's ability to survive fault conditions (i.e., no loss in stored science data when spacecraft enters the 'safe mode') and autonomously recover from them during NASA's long-life and deep space missions. This would require the development of non-volatile memory. In order to survive in the stringent environment during space exploration missions, onboard memory requirements would also include: (1) survive a high radiation environment (1 Mrad), (2) operate effectively and efficiently for a very long time (10 years), and (3) sustain at least a billion write cycles. Therefore, memory technologies requirements of NASA's Earth Science and Space Science missions are large capacity, non-volatility, high-transfer rate, high radiation resistance, high storage density, and high power efficiency. JPL, under current sponsorship from NASA Space Science and Earth Science Programs, is developing a high-density, nonvolatile and rad-hard Compact Holographic Data Storage (CHDS) system to enable large-capacity, high-speed, low power consumption, and read/write of data in a space environment. The entire read/write operation will be controlled with electrooptic mechanism without any moving parts. This CHDS will consist of laser diodes, photorefractive crystal, spatial light modulator, photodetector array, and I/O electronic interface. In operation, pages of information would be recorded and retrieved with random access and high-speed. The nonvolatile, rad-hard characteristics of the holographic memory will provide a revolutionary memory technology meeting the high radiation challenge facing the Europa Lander mission. Additional information is contained in the original extended abstract.
Characterization of the holographic imaging grating of GOMOS UVIS spectrometer
NASA Astrophysics Data System (ADS)
Graeffe, Jussi; Saari, Heikki K.; Astola, Heikki; Rainio, Kari; Mazuray, Lorand; Pierot, Dominique; Craen, Pierre; Gruslin, Michel; Lecat, Jean-Herve; Bonnemason, Francis; Flamand, Jean; Thevenon, Alain
1996-11-01
A Finnish-French group has proposed an imaging spectrometer- based instrument for the ENVISAT Earth observation satellite of ESA, which yields a global mapping of the vertical profile of ozone and other related atmospheric gases. The GOMOS instrument works by measuring the UV-visible spectrum of a star that is occulting behind the Earth's atmosphere. The prime contractor of GOMOS is Matra Marconi Space France. The focal plane optics are designed and manufactured by Spacebel Instrumentation S.A. and the holographic grating by Jobin-Yvon. VTT Automation, Measurement Technology has participated in the GOMOS studies since 1989 and is presently responsible for the verification tests of the imaging quality and opto-mechanical interfaces of the holographic imaging grating of GOMOS. The UVIS spectrometer of GOMOS consists of a holographic, aberration corrected grating and of a CCD detector. The alignment of the holographic grating needs as an input very accurate knowledge of the mechanical interfaces. VTT Automation has designed, built and tested a characterization system for the holographic grating. This system combines the accurate optical imaging measurements with the absolute knowledge of the geometrical parameters at the accuracy of plus or minus 10 micrometers which makes the system unique. The developed system has been used for two breadboard gratings and the qualification model grating. The imaging quality results and their analysis together with alignment procedure utilizing of the knowledge of mechanical interfaces is described.
Logarithmic entropy corrected holographic dark energy with nonminimal kinetic coupling
NASA Astrophysics Data System (ADS)
Amani, Ali R.; Sadeghi, J.; Farajollahi, H.; Pourali, M.
2012-01-01
In this paper, we have considered a cosmological model with the non--minimal kinetic coupling terms and investigated its cosmological implications with respect to the logarithmic entropy-- corrected holographic dark energy (LECHDE). The correspondence between LECHDE in flat FRW cosmology and the phantom dark energy model with the aim to interpret the current universe acceleration is also examined.
Holographic bounds and Higgs inflation
NASA Astrophysics Data System (ADS)
Horvat, R.
2011-05-01
In a recently proposed scenario for primordial inflation, where the Standard Model (SM) Higgs boson plays a role of the inflation field, an effective field theory (EFT) approach is the most convenient for working out the consequences of breaking of perturbative unitarity, caused by the strong coupling of the Higgs field to the Ricci scalar. The domain of validity of the EFT approach is given by the ultraviolet (UV) cutoff, which, roughly speaking, should always exceed the Hubble parameter in the course of inflation. On the other hand, applying the trusted principles of quantum gravity to a local EFT demands that it should only be used to describe states in a region larger than their corresponding Schwarschild radius, manifesting thus a sort of UV/IR correspondence. We consider both constraints on EFT, to ascertain which models of the SM Higgs inflation are able to simultaneously comply with them. We also show that if the gravitational coupling evolves with the scale factor, the holographic constraint can be alleviated significantly with minimal set of canonical assumptions, by forcing the said coupling to be asymptotically free.
Internet-based preproduction system for holographic stereograms
NASA Astrophysics Data System (ADS)
Gustafsson, Jonny
2001-01-01
A system has been designed with the aim of helping the communication between a produce of holographic stereograms and users of 3D computer graphics. The user of the system communicates with the producer through a small program, an applet, which is transferred over the Internet. In the applet the user makes all settings necessary for producing the hologram, and then sends the 3D file together with its settings to a holographic printer for production of the hologram. The system uses virtual reality modeling language as an interchangeable graphics format and Java as programming language. It is believed that the system will significantly improve the dissemination of holographic hard copies to ordinary users of computer graphics.
Three-dimensional holographic reconstruction from computational tomography images
NASA Astrophysics Data System (ADS)
Zhao, Yan; Cao, Liangcai; Zhang, Hao; He, Qingsheng; Jin, Guofan
2014-11-01
An angular spectrum holographic algorithm is proposed for generating three-dimensional (3D) reconstruction from multiple computational tomography (CT) slices. Objects consist of multiple slices can be easily modeled by the angular spectrum. So the 3D structure can be built through the superposition of computer generated phase holograms originally from parallel discrete planes at different depths. Then the superposed phase hologram is uploaded to the phase-only spatial light modulator (SLM). With the SLM illuminated by the coherent light, the 3D reconstruction is observed by a camera. The proposed method is more computationally efficient compared with the point source algorithm, and the angular spectrum holographic algorithm can process more large-capacity CT data for the 3D visualization. Experiment demonstrates the feasibility of reconstructing CT biological structure with holographic display.
Gleeson, Michael R; Guo, Jinxin; Sheridan, John T
2011-11-01
An understanding of the photochemical and photo-physical processes, which occur during photopolymerization is of extreme importance when attempting to improve a photopolymer material's performance for a given application. Recent work carried out on the modelling of the mechanisms which occur in photopolymers during- and post-exposure, has led to the development of a tool, which can be used to predict the behaviour of these materials under a wide range of conditions. In this paper, we explore this Non-local Photo-polymerisation Driven Diffusion model, illustrating some of the useful trends, which the model predicts and we analyse their implications on the improvement of photopolymer material performance. PMID:22109119
Holographic optical elements: Fabrication and testing
NASA Technical Reports Server (NTRS)
Zech, R. G.; Shareck, M.; Ralston, L. M.
1974-01-01
The basic properties and use of holographic optical elements were investigated to design and construct wide-angle, Fourier-transform holographic optical systems for use in a Bragg-effect optical memory. The performance characteristics are described along with the construction of the holographic system.
Holographic Information Storage and Retrieval. Final Report.
ERIC Educational Resources Information Center
Spencer, J. R.
A four-month investigation was made of holographic information storage and retrieval. After an extensive review of the state of the art of various holographic systems, it was concluded that digital holographic storage techniques hold the greatest promise for commercial development, especially since they are particularly well suited to computer…
Fourier holographic display for augmented reality using holographic optical element
NASA Astrophysics Data System (ADS)
Li, Gang; Lee, Dukho; Jeong, Youngmo; Lee, Byoungho
2016-03-01
A method for realizing a three-dimensional see-through augmented reality in Fourier holographic display is proposed. A holographic optical element (HOE) with the function of Fourier lens is adopted in the system. The Fourier hologram configuration causes the real scene located behind the lens to be distorted. In the proposed method, since the HOE is transparent and it functions as the lens just for Bragg matched condition, there is not any distortion when people observe the real scene through the lens HOE (LHOE). Furthermore, two optical characteristics of the recording material are measured for confirming the feasibility of using LHOE in the proposed see-through augmented reality holographic display. The results are verified experimentally.
In-line digital holographic imaging in volume holographic microscopy.
Zhai, Xiaomin; Lin, Wei-Tang; Chen, Hsi-Hsun; Wang, Po-Hao; Yeh, Li-Hao; Tsai, Jui-Chang; Singh, Vijay Raj; Luo, Yuan
2015-12-01
A dual-plane in-line digital holographic imaging method incorporating volume holographic microscopy (VHM) is presented to reconstruct objects in a single shot while eliminating zero-order and twin-image diffracted waves. The proposed imaging method is configured such that information from different axial planes is acquired simultaneously using multiplexed volume holographic imaging gratings, as used in VHM, and recorded as in-line holograms where the corresponding reference beams are generated in the fashion of Gabor's in-line holography. Unlike conventional VHM, which can take axial intensity information only at focal depths, the proposed method digitally reconstructs objects at any axial position. Further, we demonstrate the proposed imaging technique's ability to effectively eliminate zero-order and twin images for single-shot three-dimensional object reconstruction. PMID:26625046
Holographic lithography for biomedical applications
NASA Astrophysics Data System (ADS)
Stankevicius, E.; Balciunas, E.; Malinauskas, M.; Raciukaitis, G.; Baltriukiene, D.; Bukelskiene, V.
2012-06-01
Fabrication of scaffolds for cell growth with appropriate mechanical characteristics is top-most important for successful creation of tissue. Due to ability of fast fabrication of periodic structures with a different period, the holographic lithography technique is a suitable tool for scaffolds fabrication. The scaffolds fabricated by holographic lithography can be used in various biomedical investigations such as the cellular adhesion, proliferation and viability. These investigations allow selection of the suitable material and geometry of scaffolds which can be used in creation of tissue. Scaffolds fabricated from di-acrylated poly(ethylene glycol) (PEG-DA-258) over a large area by holographic lithography technique are presented in this paper. The PEG-DA scaffolds fabricated by holographic lithography showed good cytocompatibility for rabbit myogenic stem cells. It was observed that adult rabbit muscle-derived myogenic stem cells grew onto PEG-DA scaffolds. They were attached to the pillars and formed cell-cell interactions. It demonstrates that the fabricated structures have potential to be an interconnection channel network for cell-to-cell interactions, flow transport of nutrients and metabolic waste as well as vascular capillary ingrowth. These results are encouraging for further development of holographic lithography by improving its efficiency for microstructuring three-dimensional scaffolds out of biodegradable hydrogels
High dynamic range holographic data storage media
NASA Astrophysics Data System (ADS)
Askham, Fred; Ayres, Mark R.; Urness, Adam C.
2015-08-01
Holographic data storage (HDS) employs the physics of holography to record digital data in three dimensions in a highly stable photopolymer medium. The photopolymer medium must provide the essential characteristics of low scatter and high dynamic range while maintaining low recording induced physical shrinkage and long archival lifetimes. In this article, we report on media advancements employing Akonia's DREDTM technology which provide a 5x increase in media dynamic range with unchanged media shrinkage. We also discuss the implications of these results for photopolymer media mechanistic models.
Holographic Quark Matter and Neutron Stars
NASA Astrophysics Data System (ADS)
Hoyos, Carlos; Jokela, Niko; Rodríguez Fernández, David; Vuorinen, Aleksi
2016-07-01
We use a top-down holographic model for strongly interacting quark matter to study the properties of neutron stars. When the corresponding equation of state (EOS) is matched with state-of-the-art results for dense nuclear matter, we consistently observe a first-order phase transition at densities between 2 and 7 times the nuclear saturation density. Solving the Tolman-Oppenheimer-Volkov equations with the resulting hybrid EOSs, we find maximal stellar masses in excess of two solar masses, albeit somewhat smaller than those obtained with simple extrapolations of the nuclear matter EOSs. Our calculation predicts that no quark matter exists inside neutron stars.
Holographic Quark Matter and Neutron Stars.
Hoyos, Carlos; Jokela, Niko; Rodríguez Fernández, David; Vuorinen, Aleksi
2016-07-15
We use a top-down holographic model for strongly interacting quark matter to study the properties of neutron stars. When the corresponding equation of state (EOS) is matched with state-of-the-art results for dense nuclear matter, we consistently observe a first-order phase transition at densities between 2 and 7 times the nuclear saturation density. Solving the Tolman-Oppenheimer-Volkov equations with the resulting hybrid EOSs, we find maximal stellar masses in excess of two solar masses, albeit somewhat smaller than those obtained with simple extrapolations of the nuclear matter EOSs. Our calculation predicts that no quark matter exists inside neutron stars. PMID:27472110
Nonvolatile Rad-Hard Holographic Memory
NASA Technical Reports Server (NTRS)
Chao, Tien-Hsin; Zhou, Han-Ying; Reyes, George; Dragoi, Danut; Hanna, Jay
2001-01-01
We are investigating a nonvolatile radiation-hardened (rad-hard) holographic memory technology. Recently, a compact holographic data storage (CHDS) breadboard utilizing an innovative electro-optic scanner has been built and demonstrated for high-speed holographic data storage and retrieval. The successful integration of this holographic memory breadboard has paved the way for follow-on radiation resistance test of the photorefractive (PR) crystal, Fe:LiNbO3. We have also started the investigation of using two-photon PR crystals that are doubly doped with atoms of iron group (Ti, Cr, Mn, Cu) and of rare-earth group (Nd, Tb) for nonvolatile holographic recordings.
Improvements of holographic data storage technology
NASA Astrophysics Data System (ADS)
Huang, Zhen; Liu, Guodong; Wang, Zhengzi; Cao, Guoqiang; Hou, Yibing
2005-09-01
Holographic data storage has many advantages, which makes it become one of the most hopeful next-generation data storage techniques. In the past, the struggles of holographic data storage have been frustrated for the absence of suitable system components and recording materials. Recently, the development of practical components for holographic systems, such as SLMs, CCDs and some newly recording materials, has rekindled interest in this technology. In this paper, we analyze the present situation of holographic data storage techniques and some latest improvements of key components and recording materials in relative companies or laboratories are summarized. At last, market outlook of holographic data storage products is discussed.
Formation of nonlinear holographic images in powerful laser systems.
Bel'kov, Sergey A; Garanin, Sergey G; Epatko, Igor V; Serov, Rene V; Voronich, Ivan N
2012-08-20
The formation of nonlinear holographic images behind a multislab amplifier is studied. The analytical expressions describing magnitudes and locations of intensity maxima depending on the corresponding image number are derived. Comparison with numerical calculations results is given. On the basis of numerical modeling, analysis of gain saturation, slab thickness, and slab aberrations influence is carried out. PMID:22907023
Full Color Holographic Endoscopy
NASA Astrophysics Data System (ADS)
Osanlou, A.; Bjelkhagen, H.; Mirlis, E.; Crosby, P.; Shore, A.; Henderson, P.; Napier, P.
2013-02-01
The ability to produce color holograms from the human tissue represents a major medical advance, specifically in the areas of diagnosis and teaching. This has been achieved at Glyndwr University. In corporation with partners at Gooch & Housego, Moor Instruments, Vivid Components and peninsula medical school, Exeter, UK, for the first time, we have produced full color holograms of human cell samples in which the cell boundary and the nuclei inside the cells could be clearly focused at different depths - something impossible with a two-dimensional photographic image. This was the main objective set by the peninsula medical school at Exeter, UK. Achieving this objective means that clinically useful images essentially indistinguishable from the object human cells could be routinely recorded. This could potentially be done at the tip of a holo-endoscopic probe inside the body. Optimised recording exposure and development processes for the holograms were defined for bulk exposures. This included the optimisation of in-house recording emulsions for coating evaluation onto polymer substrates (rather than glass plates), a key step for large volume commercial exploitation. At Glyndwr University, we also developed a new version of our in-house holographic (world-leading resolution) emulsion.
Scanning holographic lidar telescope
NASA Technical Reports Server (NTRS)
Schwemmer, Geary K.; Wilkerson, Thomas D.
1993-01-01
We have developed a unique telescope for lidar using a holographic optical element (HOE) as the primary optic. The HOE diffracts 532 nm laser backscatter making a 43 deg angle with a normal to its surface to a focus located 130 cm along the normal. The field of view scans a circle as the HOE rotates about the normal. The detector assembly and baffling remain stationary, compared to conventional scanning lidars in which the entire telescope and detector assembly require steering, or which use a large flat steerable mirror in front of the telescope to do the pointing. The spectral bandpass of our HOE is 50 nm (FWHM). Light within that bandpass is spectrally dispersed at 0.6 nm/mm in the focal plane. An aperture stop reduces the bandpass of light reaching the detector from one direction to 1 nm while simultaneously reducing the field of view to 1 mrad. Wavelengths outside the 50 nm spectral bandpass pass undiffracted through HOE to be absorbed by a black backing. Thus, the HOE combines three functions into one optic: the scanning mirror, the focusing mirror, and a narrowband filter.
Holographic characterization of protein aggregates
NASA Astrophysics Data System (ADS)
Wang, Chen; Zhong, Xiao; Ruffner, David; Stutt, Alexandra; Philips, Laura; Ward, Michael; Grier, David
Holographic characterization directly measures the size distribution of subvisible protein aggregates in suspension and offers insights into their morphology. Based on holographic video microscopy, this analytical technique records and interprets holograms of individual aggregates in protein solutions as they flow down a microfluidic channel, without requiring labeling or other exceptional sample preparation. The hologram of an individual protein aggregate is analyzed in real time with the Lorenz-Mie theory of light scattering to measure that aggregate's size and optical properties. Detecting, counting and characterizing subvisible aggregates proceeds fast enough for time-resolved studies, and lends itself to tracking trends in protein aggregation arising from changing environmental factors. No other analytical technique provides such a wealth of particle-resolved characterization data in situ. Holographic characterization promises accelerated development of therapeutic protein formulations, improved process control during manufacturing, and streamlined quality assurance during storage and at the point of use. Mrsec and MRI program of the NSF, Spheryx Inc.
Holographic films from carotenoid pigments
NASA Astrophysics Data System (ADS)
Toxqui-López, S.; Lecona-Sánchez, J. F.; Santacruz-Vázquez, C.; Olivares-Pérez, A.; Fuentes-Tapia, I.
2014-02-01
Carotenoids pigments presents in pineapple can be more than just natural dyes, which is one of the applications that now at day gives the chemical industry. In this research shown that can be used in implementing of holographic recording Films. Therefore we describe the technique how to obtain this kind of pigments trough spay drying of natural pineapple juice, which are then dissolved with water in a proportion of 0.1g to 1mL. The obtained sample is poured into glass substrates using the gravity method, after a drying of 24 hours in laboratory normal conditions the films are ready. The films are characterized by recording transmission holographic gratings (LSR 445 NL 445 nm) and measuring the diffraction efficiency holographic parameter. This recording material has good diffraction efficiency and environmental stability.
Holographic photolysis of caged neurotransmitters
Lutz, Christoph; Otis, Thomas S.; DeSars, Vincent; Charpak, Serge; DiGregorio, David A.; Emiliani, Valentina
2009-01-01
Stimulation of light-sensitive chemical probes has become a powerful tool for the study of dynamic signaling processes in living tissue. Classically, this approach has been constrained by limitations of lens–based and point-scanning illumination systems. Here we describe a novel microscope configuration that incorporates a nematic liquid crystal spatial light modulator (LC-SLM) to generate holographic patterns of illumination. This microscope can produce illumination spots of variable size and number and patterns shaped to precisely match user-defined elements in a specimen. Using holographic illumination to photolyse caged glutamate in brain slices, we demonstrate that shaped excitation on segments of neuronal dendrites and simultaneous, multi-spot excitation of different dendrites enables precise spatial and rapid temporal control of glutamate receptor activation. By allowing the excitation volume shape to be tailored precisely, the holographic microscope provides an extremely flexible method for activation of various photosensitive proteins and small molecules. PMID:19160517
Glueball decay in holographic QCD
Hashimoto, Koji; Tan, C.-I; Terashima, Seiji
2008-04-15
Using holographic QCD based on D4-branes and D8-anti-D8-branes, we have computed couplings of glueballs to light mesons. We describe glueball decay by explicitly calculating its decay widths and branching ratios. Interestingly, while glueballs remain less well understood both theoretically and experimentally, our results are found to be consistent with the experimental data for the scalar glueball candidate f{sub 0}(1500). More generally, holographic QCD predicts that decay of any glueball to 4{pi}{sup 0} is suppressed, and that mixing of the lightest glueball with qq mesons is small.
Invisible engineering of holographic illusion
NASA Astrophysics Data System (ADS)
Richardson, Martin J.
1993-03-01
Recent developments in production techniques of pulsed holograms and holographic stereograms have ameliorated to provide high quality three dimensional illusions that echo the apparently innate need of society to replicate itself through artificial means. A commercial platform has been found for these archetypical illusions through the mass production and distribution of embossed stereograms that depict popular celebrities from the music industry. As pulse recordings of the rich and famous become better known, and as former presidents queue to join the holographic hall of fame, the author asks `is it documentation or entertainment that is shaping the future of holography?'
Hadron physics in holographic QCD
NASA Astrophysics Data System (ADS)
Santra, A. B.; Lombardo, U.; Bonanno, A.
2012-07-01
Hadron physics deals with the study of strongly interacting subatomic particles such as neutrons, protons, pions and others, collectively known as baryons and mesons. Physics of strong interaction is difficult. There are several approaches to understand it. However, in the recent years, an approach called, holographic QCD, based on string theory (or gauge-gravity duality) is becoming popular providing an alternative description of strong interaction physics. In this article, we aim to discuss development of strong interaction physics through QCD and string theory, leading to holographic QCD.
Lindley, R.A.
1993-10-01
This thesis discusses the following on resonant holographic measurements of laser ablation plume expansion: Introduction to laser ablation; applications of laser ablation; The study of plume expansion; holographic interferometry; resonant holographic interferometry; accounting for finite laser bandwidth; The solution for doppler broadening and finite bandwidth; the main optical table; the lumonics laser spot shape; developing and reconstructing the holograms; plume expansion in RF/Plasma Environments; Determining {lambda}{sub o}; resonant refraction effects; fringe shift interpretation; shot-to-shot consistency; laser ablation in vacuum and low pressure, inert, background gas; theoretically modeling plume expansion in vacuum and low pressure, inert, background gas; and laser ablation in higher pressure, inert, background gas.
NASA Astrophysics Data System (ADS)
Thizy, C.; Eliot, F.; Ballhause, D.; Olympio, K. R.; Kluge, R.; Shannon, A.; Laduree, G.; Logut, D.; Georges, M. P.
2013-04-01
Thermo-elastic distortions of composite structures have been measured by a holographic camera using a BSO photorefractive crystal as the recording medium. The first test campaign (Phase 1) was performed on CFRP struts with titanium end-fittings glued to the tips of the strut. The samples were placed in a vacuum chamber. The holographic camera was located outside the chamber and configured with two illuminations to measure the relative out-of-plane and in-plane (in one direction) displacements. The second test campaign (Phase 2) was performed on a structure composed of a large Silicon Carbide base plate supported by 3 GFRP struts with glued Titanium end-fittings. Thermo-elastic distortions have been measured with the same holographic camera used in phase 1, but four illuminations, instead of two, have been used to provide the three components of displacement. This technique was specially developed and validated during the phase 2 in CSL laboratory. The system has been designed to measure an object size of typically 250x250 mm2; the measurement range is such that the sum of the largest relative displacements in the three measurement directions is maximum 20 μm. The validation of the four-illuminations technique led to measurement uncertainties of 120 nm for the relative in-plane and out-of-plane displacements, 230 nm for the absolute in-plane displacement and 400 nm for the absolute out-of-plane displacement. For both campaigns, the test results have been compared to the predictions obtained by finite element analyses and the correlation of these results was good.
NASA Technical Reports Server (NTRS)
Knopp, Jerome
1996-01-01
Astronauts are required to interface with complex systems that require sophisticated displays to communicate effectively. Lightweight, head-mounted real-time displays that present holographic images for comfortable viewing may be the ideal solution. We describe an implementation of a liquid crystal television (LCTV) as a spatial light modulator (SLM) for the display of holograms. The implementation required the solution of a complex set of problems. These include field calculations, determination of the LCTV-SLM complex transmittance characteristics and a precise knowledge of the signal mapping between the LCTV and frame grabbing board that controls it. Realizing the hologram is further complicated by the coupling that occurs between the phase and amplitude in the LCTV transmittance. A single drive signal (a gray level signal from a framegrabber) determines both amplitude and phase. Since they are not independently controllable (as is true in the ideal SLM) one must deal with the problem of optimizing (in some sense) the hologram based on this constraint. Solutions for the above problems have been found. An algorithm has been for field calculations that uses an efficient outer product formulation. Juday's MEDOF 7 (Minimum Euclidean Distance Optimal Filter) algorithm used for originally for filter calculations has been successfully adapted to handle metrics appropriate for holography. This has solved the problem of optimizing the hologram to the constraints imposed by coupling. Two laboratory methods have been developed for determining an accurate mapping of framegrabber pixels to LCTV pixels. A friendly software system has been developed that integrates the hologram calculation and realization process using a simple set of instructions. The computer code and all the laboratory measurement techniques determining SLM parameters have been proven with the production of a high quality test image.
Holographic enhanced remote sensing system
NASA Technical Reports Server (NTRS)
Iavecchia, Helene P.; Gaynor, Edwin S.; Huff, Lloyd; Rhodes, William T.; Rothenheber, Edward H.
1990-01-01
The Holographic Enhanced Remote Sensing System (HERSS) consists of three primary subsystems: (1) an Image Acquisition System (IAS); (2) a Digital Image Processing System (DIPS); and (3) a Holographic Generation System (HGS) which multiply exposes a thermoplastic recording medium with sequential 2-D depth slices that are displayed on a Spatial Light Modulator (SLM). Full-parallax holograms were successfully generated by superimposing SLM images onto the thermoplastic and photopolymer. An improved HGS configuration utilizes the phase conjugate recording configuration, the 3-SLM-stacking technique, and the photopolymer. The holographic volume size is currently limited to the physical size of the SLM. A larger-format SLM is necessary to meet the desired 6 inch holographic volume. A photopolymer with an increased photospeed is required to ultimately meet a display update rate of less than 30 seconds. It is projected that the latter two technology developments will occur in the near future. While the IAS and DIPS subsystems were unable to meet NASA goals, an alternative technology is now available to perform the IAS/DIPS functions. Specifically, a laser range scanner can be utilized to build the HGS numerical database of the objects at the remote work site.
Holographic nondestructive testing of laminates
NASA Technical Reports Server (NTRS)
Stuckenberg, F. H.
1973-01-01
Very small differences in laminate thickness result in interference fringes in holograph image. These indicate presence of unbonded area. Theoretical knowledge of membrane deflection may be used in conjunction with reduced number of pretest experiments to determine number of optical fringes that should appear for given laminate.