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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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 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.
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
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
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.
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.
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.
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, 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.
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.
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.
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.
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.
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
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 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.
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.
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.
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)
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
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.
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
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.
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.
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.
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.
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 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 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 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.
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.
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.
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.
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.
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 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.
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.
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.
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
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.
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.
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
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.
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.
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 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.
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.
Holographic analyzer and image scanner
NASA Technical Reports Server (NTRS)
1978-01-01
The characteristics, components, and operating procedures are described for a holographic camera real images projection displayer and scanner unit having the capability to upgrade to multiple types of automated raster scan patterns. Schematics of the optical components are included with a diagram of the electric circuit connections.
Music holographic physiotherapy by laser
NASA Astrophysics Data System (ADS)
Liao, Changhuan
1996-09-01
Based on the relationship between music and nature, the paper compares laser and light with music sound on the principles of synergetics, describes music physically and objectively, and proposes a music holographic therapy by laser. Maybe it will have certain effects on mechanism study and clinical practice of the music therapy.
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.
Holographic diagnostics of biological microparticles
NASA Astrophysics Data System (ADS)
Dyomin, Victor V.; Sokolov, Vladimir V.
1996-05-01
Problem of studies of biological microojects is actual one for ecology, medicine, biology. Holographic techniques are useful to solve the problem. The above microojects are transparent or semitransparent ones in a visible light rather often. The case of an optically soft particle, (that is of a particle whose substance has the refractive index close to that of the surrounding medium) is quite probable in biological water suspensions. Some peculiarities of holographing optically soft microparticles are analyzed in this paper. We propose a technique to calculate a light intensity distribution in the plane of a hologram and in the plane of a holographic image of a particle of an arbitrary shape at an arbitrary distance from the latter plane. The efficiency of the approach proposed is demonstrated by calculational results obtained analytically for some simple cases. In a more complicated cases the technique can make a basis for numerical computations. The method of determining of refractive index of transparent and semitransparent microparticles is proposed. We also present in this paper some experimental results on holographic detection of the water drops and such optically soft particles as ovums of helmints in human jaundice.
Tuning Ion Conducting Pathways Using Holographic Polymerization
NASA Astrophysics Data System (ADS)
Smith, Derrick; Li, Christopher; Dong, Bin; Bunning, Timothy
2012-02-01
While much research has demonstrated repeatable characteristics of electrolyte membranes, the fundamentals behind the interactions during ionic diffusion in solid polymer electrolyte membranes for battery applications are not well understood, specifically the role of nanostructures, which hold the key to improving performance of energy storage devices such as fuel cells and Lithium ion batteries. The challenges in fabricating highly controlled model systems are largely responsible for the interdependent ambiguities between nanostructures and the corresponding ion conducting behavior. In this work, Holographic Polymer Electrolyte Membranes (hPEM) volume gratings comprised of alternating layers of crosslinked polymer resin and lithium ion salt were fabricated using holographic polymerization with an average d-spacing of approximately 200 nm. These one-dimensional confinement structures were used to quantitatively study the anisotropic ionic conductivity between the directions of in-plane and normal to the layers, and the unique ion conducting behavior was correlated with nanoscale phase separation. These volume gratings also offer an exciting route to fabricate multifunctional gratings for optic and sensing applications.
Holoviewer system for preproduction of holographic stereograms
NASA Astrophysics Data System (ADS)
Gustafsson, Jonny
1999-03-01
A system for transmission and previsualization of digital data for production of holographic stereograms has been developed. The aim of this system is to help the communication between producers of holographic stereograms and their clients. The client accesses the system through a Java applet, a small program, which is automatically downloaded and run on the clients local computer. The client loads a file in VRML format into the applet and the 3D model is displayed using the VRML browser plug-in usually delivered with WWW browsers. The Java applet overrides the controls of the VRML browser and provides only the manipulations possible and necessary for preparing the hologram production and visualizing the result. The applet permits the client to somewhat modify the scene e.g. by adding lights and manipulating them. After finishing the settings and visualizations of the hologram, the client may save the file with the new settings on her own computer in order to resume work later on. When satisfied she may upload the file with all settings to the hologram producer. The computer of the hologram producer is running a small, specially designed http server which will receive the file from the client for further handling.
Single-pulsed digital holographic topometry
NASA Astrophysics Data System (ADS)
Hirsch, Sven; Heintz, Stephanie; Thelen, Andrea; Gisbert, Nicola; Hering, Peter
2007-07-01
For the planning and documentation of maxillofacial surgery highly resolved tissue information is needed. In our approach, the surface of an object is displayed and measured with pulsed holography. With a single laser pulse (Nd:YAG) of 20 ns the object surface is recorded on a CCD sensor, movement artifacts are systematically avoided. With the knowledge of the recording parameters, the original wave field is synthesized numerically from the holographic interference pattern. The calculated slices are combined into an image stack, representing the digitized real image. This wave field represents the object geometrically correct, but focussed and unfocussed regions overlay. The focussed regions are identified numerically and combined into a height map, the texture information is extracted from the real image simultaneously. Both, height and texture are combined, yielding pixel-precise textured surface models. With this novel method it is possible to capture the surface of moving objects, even 3d motion series are possible. Skin can be detected in the real image, giving the potential application for facial measurements. Compared to our analog holographic topometry, there are still limitations regarding the extent of the imageable field and the axial resolution. The quick display of the reconstructed real image allows a direct appraisal of the object topology. This method is a valuable tool for the surface visualization of living subjects, offering potential for completely new fields of application.
Karami, K.
2010-01-01
Author of ref. 1, M.R. Setare (JCAP 01 (2007) 023), by redefining the event horizon measured from the sphere of the horizon as the system's IR cut-off for an interacting holographic dark energy model in a non-flat universe, showed that the generalized second law of thermodynamics is satisfied for the special range of the deceleration parameter. His paper includes an erroneous calculation of the entropy of the cold dark matter. Also there are some missing terms and some misprints in the equations of his paper. Here we present that his conclusion is not true and the generalized second law is violated for the present time independently of the deceleration parameter.
Holographic Ricci dark energy as running vacuum
NASA Astrophysics Data System (ADS)
George, Paxy; Mathew, Titus K.
2016-04-01
Holographic Ricci dark energy (DE) that has been proposed ago has faced problems of future singularity. In the present work, we consider the Ricci DE with an additive constant in its density as running vacuum energy. We have analytically solved the Friedmann equations and also the role played by the general conservation law followed by the cosmic components together. We have shown that the running vacuum energy status of the Ricci DE helps to remove the possible future singularity in the model. The additive constant in the density of the running vacuum played an important role, such that, without that, the model predicts either eternal deceleration or eternal acceleration. But along with the additive constant, equivalent to a cosmological constant, the model predicts a late time acceleration in the expansion of the universe, and in the far future of the evolution it tends to de Sitter universe.
Holographic complexity in gauge/string superconductors
NASA Astrophysics Data System (ADS)
Momeni, Davood; Mansoori, Seyed Ali Hosseini; Myrzakulov, Ratbay
2016-05-01
Following a methodology similar to [1], we derive a holographic complexity for two dimensional holographic superconductors (gauge/string superconductors) with backreactions. Applying a perturbation method proposed by Kanno in Ref. [2], we study behaviors of the complexity for a dual quantum system near critical points. We show that when a system moves from the normal phase (T >Tc) to the superconductor phase (T
Compact holographic printer using RGB waveguide holographic optical elements
NASA Astrophysics Data System (ADS)
Pyun, Kyungsuk P.; Choi, Chilsung; Morozov, Alexander V.; Kim, Sunil; An, Jungkwuen
2013-03-01
We propose compact holographic printer using RGB waveguide hologram while reducing overall device size and quantity of elements with integrated functionality of each optical element. For glasses-free 3D experience anywhere anytime, it is critical to make holography device that can be as compact and integrated as possible. Compared to the conventional optics-based structure, our RGB WGH-based one reduces the overall size by 20 times, the number of components by 10 times, and improves the optical efficiency by 3 times, with comparable holographic quality to the conventional optics-based approaches. Proposed research can be useful for both general consumers and professionals like 3D photography and medical 3D image printing applications.
Antisymmetric tensor field and spontaneous magnetization in holographic duality
NASA Astrophysics Data System (ADS)
Cai, Rong-Gen; Yang, Run-Qiu
2015-08-01
A real antisymmetric tensor field was introduced to realize a holographic magnetic ordered phase in our previous papers. However, a more careful analysis shows there is a vector ghost in the model. In this paper we present a modified Lagrangian density for the antisymmetric tensor, which is ghost free and causality is well defined, and keeps all the significant results in the original model qualitatively. We show this modified Lagrangian density could come from the dimensional compactification of p -form field in string/M theory. For static curved space-time, we also prove that this modified model is ghost free and does not violate causality. This new model offers a solid foundation for the application of antisymmetric tensor field in holographic duality, especially for the spontaneous magnetization.
Holographic projection with higher image quality.
Qu, Weidong; Gu, Huarong; Tan, Qiaofeng
2016-08-22
The spatial resolution limited by the size of the spatial light modulator (SLM) in the holographic projection can hardly be increased, and speckle noise always appears to induce the degradation of image quality. In this paper, the holographic projection with higher image quality is presented. The spatial resolution of the reconstructed image is 2 times of that of the existing holographic projection, and speckles are suppressed well at the same time. Finally, the effectiveness of the holographic projection is verified in experiments. PMID:27557197
Volume holographic gratings: fabrication and characterization
NASA Astrophysics Data System (ADS)
Bianco, G.; Ferrara, M. A.; Borbone, F.; Roviello, A.; Pagliarulo, V.; Grilli, S.; Ferraro, P.; Striano, V.; Coppola, G.
2015-05-01
Volume Holographic Gratings is designed and fabricated to obtain a simple, lightweight and cheap light deflector. The entire process, starting from the chemical preparation of the photosensitive material, to the recording of Volume Holographic Gratings and their appropriate characterization, is reported. The recording material was a new photopolymer sensitive to light at 532nm. Results showed that the recorded Volume Holographic Grating presents a very high value of the diffraction efficiency, up to 94%. In addition, a flexible material is used to write Volume Holographic Gratings.
Investigation of uses of holographic optical elements
NASA Technical Reports Server (NTRS)
Zech, R. G.; Latta, J. N.
1973-01-01
The data represent a thorough study of the aberrations and imaging properties of holographic optical elements. Principle studies include (1) the indepth experimental investigation of single holographic optical elements, (2) the verification of the accuracy of the theoretical computer-based description of hologram behavior, (3) the computer-generation of interferograms that are characteristic of a prescribed aberrated imaging condition, (4) the experimental verification of wavelength optimization, (5) the experimental determination of the space bandwidth product of single holographic optical elements as a function of bending and field angle, and (6) the first experimental study of the aberration properties of holographic optical elements constructed in very thick (750 microns) recording media.
Tomita, Yasuo; Hata, Eiji; Momose, Keisuke; Takayama, Shingo; Liu, Xiangming; Chikama, Katsumi; Klepp, Jürgen; Pruner, Christian; Fally, Martin
2016-01-01
We present an overview of recent investigations of photopolymerizable nanocomposite photonic materials in which, thanks to their high degree of material selectivity, recorded volume gratings possess high refractive index modulation amplitude and high mechanical/thermal stability at the same time, providing versatile applications in light and neutron optics. We discuss the mechanism of grating formation in holographically exposed nanocomposite materials, based on a model of the photopolymerization-driven mutual diffusion of monomer and nanoparticles. Experimental inspection of the recorded grating’s morphology by various physicochemical and optical methods is described. We then outline the holographic recording properties of volume gratings recorded in photopolymerizable nanocomposite materials consisting of inorganic/organic nanoparticles and monomers having various photopolymerization mechanisms. Finally, we show two examples of our holographic applications, holographic digital data storage and slow-neutron beam control. PMID:27594769
Light-front holographic QCD and emerging confinement
NASA Astrophysics Data System (ADS)
Brodsky, Stanley J.; de Téramond, Guy F.; Dosch, Hans Günter; Erlich, Joshua
2015-07-01
In this report we explore the remarkable connections between light-front dynamics, its holographic mapping to gravity in a higher-dimensional anti-de Sitter (AdS) space, and conformal quantum mechanics. This approach provides new insights into the origin of a fundamental mass scale and the physics underlying confinement dynamics in QCD in the limit of massless quarks. The result is a relativistic light-front wave equation for arbitrary spin with an effective confinement potential derived from a conformal action and its embedding in AdS space. This equation allows for the computation of essential features of hadron spectra in terms of a single scale. The light-front holographic methods described here give a precise interpretation of holographic variables and quantities in AdS space in terms of light-front variables and quantum numbers. This leads to a relation between the AdS wave functions and the boost-invariant light-front wave functions describing the internal structure of hadronic bound-states in physical space-time. The pion is massless in the chiral limit and the excitation spectra of relativistic light-quark meson and baryon bound states lie on linear Regge trajectories with identical slopes in the radial and orbital quantum numbers. In the light-front holographic approach described here currents are expressed as an infinite sum of poles, and form factors as a product of poles. At large q2 the form factor incorporates the correct power-law fall-off for hard scattering independent of the specific dynamics and is dictated by the twist. At low q2 the form factor leads to vector dominance. The approach is also extended to include small quark masses. We briefly review in this report other holographic approaches to QCD, in particular top-down and bottom-up models based on chiral symmetry breaking. We also include a discussion of open problems and future applications.
Light-front holographic QCD and emerging confinement
Brodsky, Stanley J.; de Téramond, Guy F.; Dosch, Hans Günter; Erlich, Joshua
2015-05-21
In this study we explore the remarkable connections between light-front dynamics, its holographic mapping to gravity in a higher-dimensional anti-de Sitter (AdS) space, and conformal quantum mechanics. This approach provides new insights into the origin of a fundamental mass scale and the physics underlying confinement dynamics in QCD in the limit of massless quarks. The result is a relativistic light-front wave equation for arbitrary spin with an effective confinement potential derived from a conformal action and its embedding in AdS space. This equation allows for the computation of essential features of hadron spectra in terms of a single scale. The light-front holographic methods described here give a precise interpretation of holographic variables and quantities in AdS space in terms of light-front variables and quantum numbers. This leads to a relation between the AdS wave functions and the boost-invariant light-front wave functions describing the internal structure of hadronic bound-states in physical spacetime. The pion is massless in the chiral limit and the excitation spectra of relativistic light-quark meson and baryon bound states lie on linear Regge trajectories with identical slopes in the radial and orbital quantum numbers. In the light-front holographic approach described here currents are expressed as an infinite sum of poles, and form factors as a product of poles. At large q^{2} the form factor incorporates the correct power-law fall-off for hard scattering independent of the specific dynamics and is dictated by the twist. At low q^{2} the form factor leads to vector dominance. The approach is also extended to include small quark masses. We briefly review in this report other holographic approaches to QCD, in particular top-down and bottom-up models based on chiral symmetry breaking. We also include a discussion of open problems and future applications.
Persistent superconductor currents in holographic lattices.
Iizuka, Norihiro; Ishibashi, Akihiro; Maeda, Kengo
2014-07-01
We consider a persistent superconductor current along the direction with no translational symmetry in a holographic gravity model. Incorporating a lattice structure into the model, we numerically construct novel solutions of hairy charged stationary black branes with momentum or rotation along the latticed direction. The lattice structure prevents the horizon from rotating, and the total momentum is only carried by matter fields outside the black brane horizon. This is consistent with the black hole rigidity theorem, and it suggests that in dual field theory with lattices, superconductor currents are made up of "composite" fields, rather than "fractionalized" degrees of freedom. We also show that our solutions are consistent with the superfluid hydrodynamics. PMID:25032917
Collinear holographic data storage system
NASA Astrophysics Data System (ADS)
Tan, Xiaodi; Lin, Xiao; Wu, Anan
2013-08-01
Holographic data storage system is a promising candidate of the next-generation of storage equipment. However, conventional technologies (called 2-axis holography) still have essential issues for commercialization of products. In this paper, we introduce the collinear holography that can produce a small, practical data storage system more easily than conventional 2-axis holography. In this technology the information and reference beams are displayed co-axially by the same SLM. With this unique configuration the optical pickup can be placed on one side of the recording media. The special media structure uses a pre-formatted reflective layer for the focus/tracking servo and for reading address information. It also uses a dichroic mirror interlayer for detecting holographic recording information without interfering with the preformatted information. A 2-dimensional digital page data format is used and the shift-multiplexing method is employed to increase recording density.
Multi-wavelength holographic profilometry
NASA Astrophysics Data System (ADS)
Barbosa, E. A.; Gesualdi, M. R.; Muramatsu, M.
2006-01-01
A novel method for surface profilometry by holography is presented. We used a diode laser emitting at many wavelengths simultaneously as the light source and a Bi 12TiO 20 (BTO) crystal as the holographic medium in single exposure processes. The employ of multi-wavelength, large free spectral range (FSR) lasers leads to holographic images covered of interference fringes corresponding to the contour lines of the studied surface. In order to obtain the relief of the studied surface, the fringe analysis was performed by the phase stepping technique (PST) and the phase unwrapping was carried out by the Cellular-automata method. We analysed the relief of a tilted flat metallic bar and a tooth prosthesis.
Advances in holographic particle velocimetry
NASA Astrophysics Data System (ADS)
Simmons, Scott; Meng, Hui; Hussain, Fazle; Liu, David
1993-12-01
Holographic particle velocimetry (HPV) is a promising technique for 3D flow velocity and hence vorticity measurements to study turbulence, coherent structures and vortex interactions. We discuss various aspects in the development of this technique ranging from hologram recording configurations such as in-line, off-axis and multibeam to data processing. Difficulties in implementation are analyzed and solutions are discussed. We also present preliminary measurement results in a 3D vortex flow using one of our prototype HPV systems.
Holographic recording materials - A review
NASA Technical Reports Server (NTRS)
Kurtz, R. L.; Owen, R. B.
1975-01-01
Holographic recording materials in current use are examined along with a few of their applications. Some experimental media are also studied. No effort is made to rank the commercial materials, since satisfactory results can be obtained with any of them. The discussion covers silver halide plates and films, photoresists, thermoplastics, photopolymers, dichromated gelatin, photochromic materials, electrooptical crystals, styryl free radical film, and TEP film. A convenient summation of some material properties is presented in tabular form.
Sound modes in holographic superfluids
Herzog, Christopher P.; Yarom, Amos
2009-11-15
Superfluids support many different types of sound waves. We investigate the relation between the sound waves in a relativistic and a nonrelativistic superfluid by using hydrodynamics to calculate the various sound speeds. Then, using a particular holographic scalar gravity realization of a strongly interacting superfluid, we compute first, second, and fourth sound speeds as a function of the temperature. The relativistic low temperature results for second sound differ from Landau's well known prediction for the nonrelativistic, incompressible case.
Beam shaping for holographic techniques
NASA Astrophysics Data System (ADS)
Laskin, Alexander; Laskin, Vadim; Ostrun, Aleksei
2014-09-01
Uniform intensity of laser radiation is very important in holographic and interferometry technologies, therefore transformation of typical Gaussian distribution of a TEM00 laser to flat-top (top hat) is an actual technical task, it is solved by applying beam shaping optics. Holography and interferometry have specific requirements to a uniform laser beam, most important of them are flatness of phase front and extended depth of field. There are different refractive and diffractive beam shaping approaches used in laser industrial and scientific applications, but only few of them are capable to fulfil the optimum conditions for beam quality demanding holography and interferometry. We suggest applying refractive field mapping beam shapers piShaper, which operational principle presumes almost lossless transformation of Gaussian to flat-top beam with flatness of output wavefront, conserving of beam consistency, providing collimated low divergent output beam, high transmittance, extended depth of field, negligible wave aberration, and achromatic design provides capability to work with several lasers with different wavelengths simultaneously. This approach is used in SLM-based technologies of Computer Generated Holography, Dot-Matrix mastering of security holograms, holographic data storage, holographic projection, lithography, interferometric recording of Volume Bragg Gratings. High optical quality of resulting flat-top beam allows applying additional optical components to vary beam size and shape, thus adapting an optical system to requirements of a particular application. This paper will describe design basics of refractive beam shapers and optical layouts of their applying in holographic systems. Examples of real implementations and experimental results will be presented as well.
Holographic system for nondestructive testing
NASA Technical Reports Server (NTRS)
Kurtz, R. L. (Inventor)
1975-01-01
A description is given of a holographic system for nondestructive testing. The system is comprised of a mirror which illuminates the test object surface; the mirror is positionable to direct illumination on an object at varying angles with respect to a line normal to the surface of the object. In this manner holograms may be produced with varying degrees of sensitivity enabling optimum observation of dimensions of deformation of an object occurring between test exposures.
Electromagnetic holographic imaging of bioimpedance
NASA Astrophysics Data System (ADS)
Smith, Dexter G.; Ko, Harvey W.; Lee, Benjamin R.; Partin, Alan W.
1998-05-01
The electromagnetic bioimpedance method has successfully measured the very subtle conductivity changes associated with brain edema and prostate tumor. This method provides noninvasive measurements using non-ionizing magnetic fields applied with a small coil that avoids the use of contact electrodes. This paper introduces results from combining a holographic signal processing algorithm and a low power coil system that helps provide the 3D image of impedance contrast that should make the noninvasive electromagnetic bioimpedance method useful in health care.
RGB digital lensless holographic microscopy
NASA Astrophysics Data System (ADS)
Garcia-Sucerquia, Jorge
2013-11-01
The recent introduction of color digital lensless holographic microscopy (CDLHM) has shown the possibility of imaging microscopic specimens at full color without the need of lenses. Owing to the simplicity, robustness, and compactness of the digital lensless holographic microscopes (DLHM), they have been presented as the ideal candidates to being developed into portable holographic microscopes. However, in the case of CDLHM the utilization of three independent lasers hinders the portability option for this microscope. In this contribution an alternative to reduce the complexity of CDLHM aimed to recover the portability of this microscopy technology is presented. A super-bright white-light light-emitting diode (LED) is spectrally and spatially filtered to produce the needed illumination by CDLHM to work. CDLHM with LED illumination is used to image at full color a section of the head of a drosophila melanogaster fly (fruit fly). The LED-CDLHM method shows the capability of imaging objects of 2μm size in comparison with the micrometer resolution reported for LASER-CDLHM.
Holographic gunsights for small arms
NASA Astrophysics Data System (ADS)
Tai, Anthony M.; Sieczka, Eric J.; Radler, Richard; Upatnieks, Juris
1996-05-01
Holographic gunsights were first demonstrated in the mid 1970s by researchers at the Environmental Research Institute of Michigan (ERIM) under contracts with the Air Force and the Army. The sights utilized He-Ne gas lasers and were designed for use with large weapons systems. With the advent of low cost visible laser diode, ERIM formed a new company, EOTech, to develop, manufacture and market a holographic gun sight for small arms. A hologram is used to reconstruct the image of a reticle pattern that appears at the target plane. Unlike red-dot sights, virtually any reticle pattern, 2D or 3D, can be formed. The design challenges include an opto-mechanical package that is compact, light weight and low cost which can withstand recoils up to 4,000 Gs and provide fine elevation/windage pointing adjustments, and optics that are aberration-free and stable over a wide temperature range. Manufacturing challenges include the mass production of high quality holographic optics at low cost and the precision alignment of the very low f/number optics.
Holographic lens for optical correlator
NASA Astrophysics Data System (ADS)
Semenov, G. B.; Koreshev, S. N.; Pavlov, A. V.; Shubnikov, Y. I.
1984-08-01
Aberrations in holographic optics place limitations on the information capacity of the data that can be processed by holographic optical correlators. Nonetheless, the aberrations can be reduced sufficiently for an extensive class of devices such as those for real time data input using space-time light modulators and a TV channel. This paper analyzes the aberrations of holographic lenses, demonstrating the feasibility of an off-axis lens for correlation image analysis with aberrations similar to an axial lens. A requirement that the wave aberrations not exceed a quarter-wavelength was placed on the lens. Equations are solved for coma and astigmatism, and used to plot the maximum wave aberrations as a function of the spatial frequency of the proposed signal for three cases: (1) normal propagation of a diverging beam and oblique propagation of a plane beam; (2) oblique propagation of diverging and parallel beams, symmetrical with respect to the normal to the photographic plate; (3) oblique propagation of the diverging beam and normal propagation of the parallel beam. The angle between the beam axes was 45 deg in all cases, with a lens focal length of 350 mm and an operture of 32 mm.
Medical applications of holographic stereograms
NASA Astrophysics Data System (ADS)
Tsujiuchi, Jumpei
1991-02-01
A method for displaying 3D images of medical objects by using holographic stereogram is described together with basic properties of reconstructed images of cylindrical holographic stereograms. INTRODUCTI ON A holographic stereogram (HS) is a synthesized hologram from an original film which consists of a series of ordinary photographs taken from different directions of an object and is possible to apply to an object whose hologram is very difficult or impossible to take with conventional techniques [U. Such a feature of HS can be used for 3D display of medical images such as X-ray images computer assisted tomogrphy (CT) images nuclear magnetic reasonance images (MRI) or ultrasonic images of a patient. CYLINDRICAL HOLOGRAPHI C STEREOGRAMS The original film of the medical HS is taken by rotating around the body axis of a patient a U-shaped arm equipment one end of which has a pulse X-ray source and the other end a movie camera with an image intensifier [2]. Synthesis of HS is carried out by using a special optical system the hologram is shaped into a cylinder and is reconstructed by illuminating the hologram with a small white light source located on the axis of the cylinder. Such a HS is called multiplex hologram (MH) the most popular HS and the reconstructed image can be observed in the cylinder. The formation of reconstructed image is made in unusual way and fundamental properties
Monitoring by holographic radar systems
NASA Astrophysics Data System (ADS)
Catapano, Ilaria; Crocco, Lorenzo; Affinito, Antonio; Gennarelli, Gianluca; Soldovieri, Francesco
2013-04-01
Nowadays, radar technology represents a significant opportunity to collect useful information for the monitoring and conservation of critical infrastructures. Radar systems exploit the non-invasive interaction between the matter and the electromagnetic waves at microwave frequencies. Such an interaction allows obtaining images of the region under test from which one can infer the presence of potential anomalies such as deformations, cracks, water infiltrations, etc. This information turns out to be of primary importance in practical scenarios where the probed structure is in a poor state of preservation and renovation works must be planned. In this framework, the aim of this contribution is to describe the potentialities of the holographic radar Rascan 4/4000, a holographic radar developed by Remote Sensing Laboratory of Bauman Moscow State Technical University, as a non-destructive diagnostic tool capable to provide, in real-time, high resolution subsurface images of the sounded structure [1]. This radar provides holograms of hidden anomalies from the amplitude of the interference signal arising between the backscattered signal and a reference signal. The performance of the holographic radar is appraised by means of several experiments. Preliminary tests concerning the imaging below the floor and inside wood structures are carried out in controlled conditions at the Electromagnetic Diagnostic Laboratory of IREA-CNR. After, with reference to bridge monitoring for security aim, the results of a measurement campaign performed on the Musmeci bridge are presented [2]. Acknowledgments This research has been performed in the framework of the "Active and Passive Microwaves for Security and Subsurface imaging (AMISS)" EU 7th Framework Marie Curie Actions IRSES project (PIRSES-GA-2010-269157). REFERENCES [1] S. Ivashov, V. Razevig, I. Vasilyev, A. Zhuravlev, T. Bechtel, L. Capineri, The holographic principle in subsurface radar technology, International Symposium to
Holographic recording in acrylamide photopolymers: thickness limitations.
Mahmud, Mohammad Sultan; Naydenova, Izabela; Pandey, Nitesh; Babeva, Tzwetanka; Jallapuram, Raghavendra; Martin, Suzanne; Toal, Vincent
2009-05-10
Holographic recording in thick photopolymer layers is important for application in holographic data storage, volume holographic filters, and correlators. Here, we studied the characteristics of acrylamide-based photopolymer layers ranging in thickness from 250 microm to 1 mm. For each thickness, samples with three different values of absorbance were studied. By measuring the diffraction efficiency growth of holographically recorded gratings and studying the diffraction patterns obtained, the influence of scattering on the diffraction efficiency of thick volume holographic gratings was analyzed. It was found that, above a particular thickness and absorbance, the diffraction efficiency significantly decreased because of increased holographic scattering. From the diffraction efficiency dependence on absorbance and thickness it is possible to choose photopolymer layer properties that are suitable for a particular holographic application. This study was carried out to determine the highest layer thickness that could be used for phase code multiplexed holographic data storage utilizing thick photopolymer layers as a recording medium. Based on our studies to date we believe that the layer to be used for phase coded reference beam recording with 0.1 absorbance at 532 nm can have a thickness up to 450 microm. The potential use of thicker layers characterized by low scattering losses is part of our continuing research. PMID:19424384
Image compensation using wavelet transform for tilt servo control in holographic data storage system
NASA Astrophysics Data System (ADS)
Kim, Jang Hyun; Yang, Hyunseok
2015-09-01
A holographic data storage system is very important in the division of a mass storage device. In this regard, tilt servo control is the main problem in the study of holographic data storage system. Tracking servo and tilt servo control are very important research area in holographic data storage system. In this paper, we propose two algorithms. The first algorithm is image compensation using the wavelet transform method and the second algorithm is intelligent servo control using fuzzy rules for the exact tilt control in the holographic data storage system. We need to obtain a good pattern in binary data using a CMOS camera. We have developed two step-by-step operations. Firstly, to obtain exact image data, image data compensation carried out by the wavelet transform method. Finally, we have realized an intelligence control model using fuzzy rules, which was generated by a subtractive clustering algorithm. Therefore, we control radial and tangential tilt servo control using fuzzy rules in a holographic data storage system and perform image data compensation by the wavelet transform method. Our system does not require responses in the tilt servo control system. Therefore, this system has the advantage terms of time. Consequently, the practical pattern of tilt servo control was found by an intelligence algorithm through image processing in the holographic data storage system.
Second-harmonic diffraction from holographic volume grating.
Nee, Tsu-Wei
2006-10-01
The full polarization property of holographic volume-grating enhanced second-harmonic diffraction (SHD) is investigated theoretically. The nonlinear coefficient is derived from a simple atomic model of the material. By using a simple volume-grating model, the SHD fields and Mueller matrices are first derived. The SHD phase-mismatching effect for a thick sample is analytically investigated. This theory is justified by fitting with published experimental SHD data of thin-film samples. The SHD of an existing polymethyl methacrylate (PMMA) holographic 2-mm-thick volume-grating sample is investigated. This sample has two strong coupling linear diffraction peaks and five SHD peaks. The splitting of SHD peaks is due to the phase-mismatching effect. The detector sensitivity and laser power needed to measure these peak signals are quantitatively estimated. PMID:16985536
Dense hadronic matter in holographic QCD
NASA Astrophysics Data System (ADS)
Kim, Keun-Young; Sin, Sang-Jin; Zahed, Ismail
2013-10-01
We provide a method to study hadronic matter at finite density in the context of the Sakai-Sugimoto model. We introduce the baryon chemical potential through the external U(1) v gauge field in the induced (DBI plus CS) action on the D8-probe-brane, where baryons are skyrmions. Vector dominance is manifest at finite density. We derive the effect of the baryon density on the energy density, and on the dispersion relations of pions and vector mesons at large N c . The energy density asymptotes are constant at large density, suggesting that dense matter at large N c freezes, with the pion velocity dropping to zero. Holographic dense matter enforces exactly the tenets of vector dominance and efficiently screens vector mesons. At the freezing point, the ρ — ππ coupling vanishes with a finite rho mass of about 20% its vacuum value.
3D holographic portraits: presence and absence
NASA Astrophysics Data System (ADS)
Oliveria, Rosa M.; Bernardo, Luís Miguel
2011-02-01
Authors writing about the portrait insist on the status of extending the model image portrayed beyond the absence and even death. The portrait also has this ability and suggests immortality. The picture suspends the time, making the absent present. The portrait has been, over time, one of the themes mostly used in art. No wonder that in holography it is an important subject as well. The face is a body area of privileged communication and expression. It expresses emotions through looks, smiles, movements and expressions. Being Holography, so far, the recording technology that represents the object most similar to the original, with the same parallax, we may fall into a mimetic representation of reality. On Art Holography even by following paths already traversed, the resulting holograms are always different because of the unique concept that each artist-holographer puts into his work. As with any other artistic technology, each artist uses the medium differently and with different results.
Vortex flow for a holographic superconductor
Maeda, Kengo; Okamura, Takashi
2011-03-15
We investigate energy dissipation associated with the motion of the scalar condensate in a holographic superconductor model constructed from the charged scalar field coupled to the Maxwell field. Upon application of constant magnetic and electric fields, we analytically construct the vortex-flow solution and find the vortex-flow resistance near the second-order phase transition where the scalar condensate begins. The characteristic feature of the nonequilibrium state agrees with the one predicted by the time-dependent Ginzburg-Landau (TDGL) theory. We evaluate the kinetic coefficient in the TDGL equation along the line of the second-order phase transition. At zero magnetic field, the other coefficients in the TDGL equation are also evaluated just below the critical temperature.
Towards a Holographic Marginal Fermi Liquid
Jensen, Kristan; Kachru, Shamit; Karch, Andreas; Polchinski, Joseph; Silverstein, Eva
2011-08-15
We present an infinite class of 2+1 dimensional field theories which, after coupling to semi-holographic fermions, exhibit strange metallic behavior in a suitable large N limit. These theories describe lattices of hypermultiplet defects interacting with parity-preserving supersymmetric Chern-Simons theories with U(N) x U(N) gauge groups at levels {+-}k. They have dual gravitational descriptions in terms of lattices of probe M2 branes in AdS{sub 4} x S{sup 7}/Z{sub k} (for N >> 1,N >> k{sup 5}) or probe D2 branes in AdS{sub 4} x CP{sup 3} (for N >> k >> 1,N << k{sup 5}). We discuss several challenges one faces in maintaining the success of these models at finite N, including backreaction of the probes in the gravity solutions and radiative corrections in the weakly coupled field theory limit.
Holographic brain: a good analogy gone bad
NASA Astrophysics Data System (ADS)
Caulfield, H. John
2002-07-01
One way of honoring the world's two greatest holographers is to remove from their field the association with the offbeat world of the holographic mind. Basing itself on analogical musings of two very creative scientists who were themselves not holographers, this 'field' of the holographic brain has strayed far from science and into the absurd. So much absurdity has been written by so many people that the one legitimate study of holographic principle in dolphins has been grouped too often with the nonsense. Here is taken most of the 'target statements' form one book. We could not bear to read them all this closely. We will attempt to determine what tidbit of fact led to the statements and to suggest alternative explanations when there is something to explain.
Vector Meson Form Factors and Wave Functions from Holographic QCD
Hovhannes Grigoryan; Anatoly Radyushkin
2007-10-10
Based on the holographic dual model of QCD, we study 2- and 3-point functions of vector currents and derive form factors as well as wave functions for the vector mesons. As a result, generalized vector-meson dominance representation for form factors is obtained with a very specific VMD pattern. The calculated electric radius of the rho-meson is shown to be in a good agreement with predictions from lattice QCD.
Holographic nondestructive testing for ortopedical stomatology and dental implantology
NASA Astrophysics Data System (ADS)
Vorobyev, Victor A.; Soboleva, Nataly N.; Vitrik, Oleg B.; Vitrik, Yana I.; Guserv, Michel E.; Bukayev, Murat F.; Alexeenko, Igor V.; Kuzmina, Elena V.; Malov, Alexander N.; Antonyuk, Serge V.; Vigovsky, Yury N.; Levit, Vasily V.; Qutyakova, Nataly V.; Malov, Sergey N.
2003-09-01
The results of the mathematical calculations for the tooth bridge prostheses are discussed. Holographic interferometry with double exposition is used for verification of the model calculation results. This method may be used to define the safety degree and the quality of the implant and besides, the dentures influence on the bone tissue. There were given the results of the experimental work on different kinds of implants and the way they can be inserted into the jaw.
Full 3D microwave quasi-holographic imaging
NASA Astrophysics Data System (ADS)
Castelli, Juan-Carlos; Tardivel, Francois
A full 3D quasi-holographic image processing technique developed by ONERA is described. A complex backscattering coefficient of a drone scale model was measured for discrete values of the 3D backscattered wave vector in a frequency range between 4.5-8 GHz. The 3D image processing is implemented on a HP 1000 mini-computer and will be part of LASER 2 software to be used in three RCS measurement indoor facilities.
Holographic description of QGP production in heavy ion collisions
NASA Astrophysics Data System (ADS)
Aref'eva, Irina
2016-01-01
Dual holographic approach provides a powerful tool to study the static properties of the QGP as well as its thermalization. There are holographic models that reproduce perfectly the static properties of the QGP, meanwhile others holographic models are used to get non-static characteristics such as the thermalization time in heavy ions collisions and the charged multiplicity. Holographic thermalization means a black hole formation in the dual space-time and particles multiplicities is defined by the entropy of the produced black hole. In this talk, we report results (arXiv:1409.7558) of study the holographic thermalization in a bottom-up AdS/QCD dual confinement background that provides the Cornell potential and QCD β -function. We perturb this background by colliding domain shock waves that are assumed to be dual to colliding heavy ions. It is known, that only for a special background the entropy of the black hole produced in the domain shock waves collision reproduces energy dependence of particles multiplicities obtained at RHIC and LHC. This background is different from the confinement background. We note that this special background approximates the confinement background in an intermediate domain. We assume that the main part of entropy is produced in this intermediate domain. This permits us to estimate the thermalization time. We show that the dependence of the multiplicity on the energy for the intermediate background has an asymptotic expansion whose first term depends on energy as E1/3, which is rather close to the experimental dependence of particles multiplicities on colliding ions energy obtained at RHIC and LHC. Motivated by recent experimental indications in favor of anisotropic thermalization, we also discuss a holographic thermalization scenario in the anisotropic 5-dimensional Lifshitz-like background. Collision of domain walls in this background has been recently considered in (arXiv:1410.4595). Our estimates show that for the critical exponent
Holographic Optical Elements with Electro-optic Control
NASA Astrophysics Data System (ADS)
Ermold, Michael Leigh
Although polymeric and liquid crystalline materials have been separately studied for many years, optical devices based the interaction between these two materials in a composite device have come to the forefront of technology in recent years. Liquid crystals typically have strong interactions with the surfaces with which they make contact, with the dominant effects arising from geometrical and chemical contributions. It is this surface interaction that allows the construction of thin, flat liquid crystal displays that now can be found in almost every type of portable electronic device requiring information display. Instead of the liquid crystals lying on a polymer surface, they can be embedded within a thin film. In this format, the liquid crystal will assume the shape of ellipsoidal cavities, forming the so-called polymer dispersed liquid crystals. The index mismatch between the liquid crystal and the surrounding polymer matrix creates a highly efficient scattering device. This index mismatch can be modulated by applied electric fields, facilitating electronic grayscale control of the scattering efficiency. With a sufficiently high applied field, the device can be made transparent. Utilizing the holographic techniques developed by Gabor, Leith, and Upatnieks, polymer dispersed liquid crystals can be formed under holographic conditions to produce holographic polymer dispersed liquid crystals (H-PDLC). The resulting stratified structure is composed of layers of hardened polymer separated by layers of liquid crystal droplet-rich planes. Optical structures in this form also possess the same electro-optic properties as their unstructured predecessors. A whole host of diffractive optical devices can be created via holographic means, which includes, but is not limited to transmission gratings, reflection gratings, 2D and 3D photonic crystals and holographic optical elements. In this work, I have examined the role of H-PLDC gratings that function as holographic focusing
Synfograms: a new generation of holographic applications
NASA Astrophysics Data System (ADS)
Meulien Öhlmann, Odile; Öhlmann, Dietmar; Zacharovas, Stanislovas J.
2008-04-01
The new synthetic Four-dimensional printing technique (Syn4D) Synfogram is introducing time (animation) into spatial configuration of the imprinted three-dimensional shapes. While lenticular solutions offer 2 to 9 stereoscopic images Syn4D offers large format, full colors true 3D visualization printing of 300 to 2500 frames imprinted as holographic dots. This past 2 years Syn4D high-resolution displays proved to be extremely efficient for museums presentation, engineering design, automobile prototyping, and advertising virtual presentation as well as, for portrait and fashion applications. The main advantages of syn4D is that it offers a very easy way of using a variety of digital media, like most of 3D Modelling programs, 3D scan system, video sequences, digital photography, tomography as well as the Syn4D camera track system for life recording of spatial scenes changing in time. The use of digital holographic printer in conjunction with Syn4D image acquiring and processing devices separates printing and imaging creation in such a way that makes four-dimensional printing similar to a conventional digital photography processes where imaging and printing are usually separated in space and time. Besides making content easy to prepare, Syn4D has also developed new display and lighting solutions for trade show, museum, POP, merchandising, etc. The introduction of Synfograms is opening new applications for real life and virtual 4D displays. In this paper we will analyse the 3D market, the properties of the Synfograms and specific applications, the problems we encounter, solutions we find, discuss about customers demand and need for new product development.
Phenol adsorption using holographic interferometry in photorefractive crystals
NASA Astrophysics Data System (ADS)
Kurzeluk, Mona; Guzun, Anicuta; Petris, Adrian; Vlad, Valentin I.
2001-06-01
Phenol is a major pollutant under strict effluent restriction. Its toxicity is well known, both in aquatic environment and human health. Among the purification technologies, adsorption is widely used in ecological procedures for chemical industry, for water and air purification. In order to check up the adsorbent properties of different adsorbent materials, it is necessary to determine some modeling parameters as the diffusion constants and concentration profiles in the vicinity of the adsorbent. The visualization and measuring method used in this work is double-exposure holographic interferometry using a Bi12TiO20 (BTO) photorefractive crystal (PRC) as reusable recording material and a low cost laser diode, as coherent light source. By holographic methods, we are studying phenol adsorption on granulated active coal and active coal powder. The visualization of the diffusion layer and measurements of its dynamics have been performed.
Crosstalk analysis of multilayer collinear volume holographic data storage
NASA Astrophysics Data System (ADS)
Liu, Jinqiu; Cao, Liangcai; Li, Chengmingyue; Li, Jianhua; He, Qingsheng; Jin, Guofan
2013-09-01
An optical model to describe the reconstructed image of the collinear holographic data storage system is presented. The 2-D shape of the recording spot in the medium is simulated. The system structure parameters that influence the signal-to-noise ratio (SNR) of the reconstructed image are investigated in order to choose proper optical components to improve data storage density of the system. The role of the random binary phase mask (RBPM) utilized in the multilayer collinear holographic system is investigated. It is proved that the inter-layer crosstalk can be effectively suppressed by using different RBPMs. Different layers of data pages can be recorded with the SNR increased by a factor of six at least and the shift selectivity along z-axis can also be improved significantly.
Read-only high accuracy volume holographic optical correlator
NASA Astrophysics Data System (ADS)
Zhao, Tian; Li, Jingming; Cao, Liangcai; He, Qingsheng; Jin, Guofan
2011-10-01
A read-only volume holographic correlator (VHC) is proposed. After the recording of all of the correlation database pages by angular multiplexing, a stand-alone read-only high accuracy VHC will be separated from the VHC recording facilities which include the high-power laser and the angular multiplexing system. The stand-alone VHC has its own low power readout laser and very compact and simple structure. Since there are two lasers that are employed for recording and readout, respectively, the optical alignment tolerance of the laser illumination on the SLM is very sensitive. The twodimensional angular tolerance is analyzed based on the theoretical model of the volume holographic correlator. The experimental demonstration of the proposed read-only VHC is introduced and discussed.
Dynamics of holographic entanglement entropy following a local quench
NASA Astrophysics Data System (ADS)
Rangamani, Mukund; Rozali, Moshe; Vincart-Emard, Alexandre
2016-04-01
We discuss the behaviour of holographic entanglement entropy following a local quench in 2+1 dimensional strongly coupled CFTs. The entanglement generated by the quench propagates along an emergent light-cone, reminiscent of the Lieb-Robinson light-cone propagation of correlations in non-relativistic systems. We find the speed of propagation is bounded from below by the entanglement tsunami velocity obtained earlier for global quenches in holographic systems, and from above by the speed of light. The former is realized for sufficiently broad quenches, while the latter pertains for well localized quenches. The non-universal behavior in the intermediate regime appears to stem from finite-size effects. We also note that the entanglement entropy of subsystems reverts to the equilibrium value exponentially fast, in contrast to a much slower equilibration seen in certain spin models.
Holographic flow visualization at the Langley Expansion Tube
NASA Technical Reports Server (NTRS)
Goad, W. K.; Burner, A. W.
1981-01-01
A holographic system used for flow visualization at the Langley Expansion Tube is described. A ruby laser which can be singly or doubly pulsed during the short run time of less than 300 microns is used as the light source. With holography, sensitivity adjustments can be optimized after a run instead of before a run as with conventional flow visualization techniques. This results in an increased reliability of the flow visualization available for the study of real-gas effects on flow about models. Holographic techniques such as single-plate schlieren and shadowgraph, two plate interferometry, double pulse interferometry for perfect infinite-fringe interferograms, and double-pulse interferometry used to examine changes in the flow over a short time period are described and examples presented.
Multilayer Volume Holographic Optical Memory
NASA Technical Reports Server (NTRS)
Markov, Vladimir; Millerd, James; Trolinger, James; Norrie, Mark; Downie, John; Timucin, Dogan; Lau, Sonie (Technical Monitor)
1998-01-01
We demonstrate a scheme for volume holographic storage based on the features of shift selectivity of a speckle reference wave hologram. The proposed recording method allows more efficient use of the recording medium and increases the storage density in comparison with spherical or plane-wave reference beams. Experimental results of multiple hologram storage and replay in a photorefractive crystal of iron-doped lithium niobate are presented. The mechanism of lateral and longitudinal shift selectivity are described theoretically and shown to agree with experimental measurements.
Holographic thermalization with Weyl corrections
NASA Astrophysics Data System (ADS)
Dey, Anshuman; Mahapatra, Subhash; Sarkar, Tapobrata
2016-01-01
We consider holographic thermalization in the presence of a Weyl correction in five dimensional AdS space. We first obtain the Weyl corrected black brane solution perturbatively, up to first order in the coupling. The corresponding AdS-Vaidya like solution is then constructed. This is then used to numerically analyze the time dependence of the two point correlation functions and the expectation values of rectangular Wilson loops in the boundary field theory, and we discuss how the Weyl correction can modify the thermalization time scales in the dual field theory. In this context, the subtle interplay between the Weyl coupling constant and the chemical potential is studied in detail.
Holographic Complexity Equals Bulk Action?
NASA Astrophysics Data System (ADS)
Brown, Adam R.; Roberts, Daniel A.; Susskind, Leonard; Swingle, Brian; Zhao, Ying
2016-05-01
We conjecture that the quantum complexity of a holographic state is dual to the action of a certain spacetime region that we call a Wheeler-DeWitt patch. We illustrate and test the conjecture in the context of neutral, charged, and rotating black holes in anti-de Sitter spacetime, as well as black holes perturbed with static shells and with shock waves. This conjecture evolved from a previous conjecture that complexity is dual to spatial volume, but appears to be a major improvement over the original. In light of our results, we discuss the hypothesis that black holes are the fastest computers in nature.
50 years of holographic interferometry
NASA Astrophysics Data System (ADS)
Stetson, Karl A.
2015-01-01
Fifty years ago, Robert L. Powell and I discovered holographic interferometry while working at the Radar Laboratory of the University of Michigan's Institute of Science and Technology. I have worked in this field for this entire time span, watched it grow from an unexplored technology to become a widespread industrial testing method, and I have contributed to these developments. In this paper, I will trace my history in this field from our discovery to my involvement in its theory and applications. I will conclude with a discussion of digital holography, which is currently replacing photographic holography for most research and industrial applications.
Holographic storage of multicolor information.
NASA Technical Reports Server (NTRS)
Burton, G. T.; Clay, B. R.
1972-01-01
Discussion of the merits of the use of holography for storing multicolor information. Holography is shown capable to provide in a compact, easily duplicated, inexpensive, and readily retrievable manner the storage capacity required for the ever growing amounts of alphanumeric, graphic, continuous tone, color, and black-and-white data generated. Following a definition of the holographic concept, the advantages of holography for multicolor information recording, indexing, registration, and reconstruction are reviewed. Special attention is given to display applications including a multicolor moving-map display, a NASA multifunction display, and an automatic-test-equipment information storage system.
Three Dimensional Holographic Archival Memory
Gibbard, Bruce
2006-11-09
To address the DOE need for the storage and handling of terabyte of nuclear physics data, Physical Optics Corporation (POC) developed a new multi-terabit, 90° recording geometry 3D holographic archival optical memory storage and search system. In contrast to state-of-the-art memory approaches, 3DHAM handles the data through highly parallel optical processing in conjunction with highly redundant hologram multiplexing. The 3DHAM system advantages also stem from its unique 3D volume-recording medium, which theoretically has a significantly greater data density than diskbased systems.
Holographic Complexity Equals Bulk Action?
Brown, Adam R; Roberts, Daniel A; Susskind, Leonard; Swingle, Brian; Zhao, Ying
2016-05-13
We conjecture that the quantum complexity of a holographic state is dual to the action of a certain spacetime region that we call a Wheeler-DeWitt patch. We illustrate and test the conjecture in the context of neutral, charged, and rotating black holes in anti-de Sitter spacetime, as well as black holes perturbed with static shells and with shock waves. This conjecture evolved from a previous conjecture that complexity is dual to spatial volume, but appears to be a major improvement over the original. In light of our results, we discuss the hypothesis that black holes are the fastest computers in nature. PMID:27232013
Benini, Francesco; Dymarsky, Anatoly; Franco, Sebastian; Kachru, Shamit; Simic, Dusan; Verlinde, Herman; /Princeton, Inst. Advanced Study
2009-06-19
We discuss gravitational backgrounds where supersymmetry is broken at the end of a warped throat, and the SUSY-breaking is transmitted to the Standard Model via gauginos which live in (part of) the bulk of the throat geometry. We find that the leading effect arises from splittings of certain 'messenger mesons,' which are adjoint KK-modes of the D-branes supporting the Standard Model gauge group. This picture is a gravity dual of a strongly coupled field theory where SUSY is broken in a hidden sector and transmitted to the Standard Model via a relative of semi-direct gauge mediation.
Yeom, Han-Ju; Kim, Hee-Jae; Kim, Seong-Bok; Zhang, HuiJun; Li, BoNi; Ji, Yeong-Min; Kim, Sang-Hoo; Park, Jae-Hyeung
2015-12-14
We propose a bar-type three-dimensional holographic head mounted display using two holographic optical elements. Conventional stereoscopic head mounted displays may suffer from eye fatigue because the images presented to each eye are two-dimensional ones, which causes mismatch between the accommodation and vergence responses of the eye. The proposed holographic head mounted display delivers three-dimensional holographic images to each eye, removing the eye fatigue problem. In this paper, we discuss the configuration of the bar-type waveguide head mounted displays and analyze the aberration caused by the non-symmetric diffraction angle of the holographic optical elements which are used as input and output couplers. Pre-distortion of the hologram is also proposed in the paper to compensate the aberration. The experimental results show that proposed head mounted display can present three-dimensional see-through holographic images to each eye with correct focus cues. PMID:26698993
Magnonic holographic devices for special type data processing
NASA Astrophysics Data System (ADS)
Khitun, Alexander
2013-04-01
In this work, we consider the possibility of building magnetic analog logic devices utilizing spin wave interference for special task data processing. As an example, we consider a multi-terminal magnonic matrix switch comprising multiferroic elements and a two-dimensional grid of magnetic waveguides connected via four-terminal cross-junctions. The multiferroic elements are placed on the periphery of the switch and used as input/output ports for signal conversion among the electric and magnetic domains. Data processing is accomplished via the use of spin wave interference within the magnonic matrix. We present the results of numerical modeling illustrating device operation for pattern matching, finding the period of the data string, and image processing. We also present the results of numerical modeling showing the device capabilities as a magnetic holographic memory. Magnonic holographic devices are of great potential to complement the conventional general-type processors in special task data processing and may provide a new direction for functional throughput enhancement. According to estimates, magnonic holographic devices can provide up to 1 Tb/cm2 data storage density and data processing rate exceeding 1018 bits/s/cm2. The physical limitations and practical challenges of the proposed approach are discussed.
NASA Astrophysics Data System (ADS)
Afshordi, N.; Mann, R. B.; Pourhasan, R.
2015-11-01
We present a cosmological model in which the Universe emerges out of the collapse of a five-dimensional (5D) star as a spherical three-brane. The initial singularity of the big bang becomes hidden behind a causal horizon. Near scale-invariant primordial curvature perturbations can be induced on the brane via a thermal atmosphere that is in equilibrium with the brane, circumventing the need for a separate inflationary process and providing an important test of the model.
Moving through a multiplex holographic scene
NASA Astrophysics Data System (ADS)
Mrongovius, Martina
2013-02-01
This paper explores how movement can be used as a compositional element in installations of multiplex holograms. My holographic images are created from montages of hand-held video and photo-sequences. These spatially dynamic compositions are visually complex but anchored to landmarks and hints of the capturing process - such as the appearance of the photographer's shadow - to establish a sense of connection to the holographic scene. Moving around in front of the hologram, the viewer animates the holographic scene. A perception of motion then results from the viewer's bodily awareness of physical motion and the visual reading of dynamics within the scene or movement of perspective through a virtual suggestion of space. By linking and transforming the physical motion of the viewer with the visual animation, the viewer's bodily awareness - including proprioception, balance and orientation - play into the holographic composition. How multiplex holography can be a tool for exploring coupled, cross-referenced and transformed perceptions of movement is demonstrated with a number of holographic image installations. Through this process I expanded my creative composition practice to consider how dynamic and spatial scenes can be conveyed through the fragmented view of a multiplex hologram. This body of work was developed through an installation art practice and was the basis of my recently completed doctoral thesis: 'The Emergent Holographic Scene — compositions of movement and affect using multiplex holographic images'.
Intellectual property analysis of holographic materials business
NASA Astrophysics Data System (ADS)
Reingand, Nadya; Hunt, David
2006-02-01
The paper presents an overview of intellectual property in the field of holographic photosensitive materials and highlights the possibilities offered by patent searching and analysis. Thousands of patent documents relevant to holographic materials have been uncovered by the study. The search was performed in the following databases: U.S. Patent Office, European Patent Office, and Japanese Patent Office for the time frame of 1971 through November 2005. The patent analysis has unveiled trends in patent temporal distribution, leading IP portfolios, companies competition within the holographic materials market and other interesting insights.
Holographic holes and differential entropy
NASA Astrophysics Data System (ADS)
Headrick, Matthew; Myers, Robert C.; Wien, Jason
2014-10-01
Recently it has been shown that the Bekenstein-Hawking entropy formula evaluated on certain closed surfaces in the bulk of a holographic spacetime has an interpretation as the differential entropy of a particular family of intervals (or strips) in the boundary theory [1, 2]. We first extend this construction to bulk surfaces which vary in time. We then give a general proof of the equality between the gravitational entropy and the differential entropy. This proof applies to a broad class of holographic backgrounds possessing a generalized planar symmetry and to certain classes of higher-curvature theories of gravity. To apply this theorem, one can begin with a bulk surface and determine the appropriate family of boundary intervals by considering extremal surfaces tangent to the given surface in the bulk. Alternatively, one can begin with a family of boundary intervals; as we show, the differential entropy then equals the gravitational entropy of a bulk surface that emerges from the intersection of the neighboring entanglement wedges, in a continuum limit.
Holographic opto-fluidic microscopy
Bishara, Waheb; Zhu, Hongying; Ozcan, Aydogan
2010-01-01
Over the last decade microfluidics has created a versatile platform that has significantly advanced the ways in which micro-scale organisms and objects are controlled, processed and investigated, by improving the cost, compactness and throughput aspects of analysis. Microfluidics has also expanded into optics to create reconfigurable and flexible optical devices such as reconfigurable lenses, lasers, waveguides, switches, and on-chip microscopes. Here we present a new opto-fluidic microscopy modality, i.e., Holographic Opto-fluidic Microscopy (HOM), based on lensless holographic imaging. This imaging modality complements the miniaturization provided by microfluidics and would allow the integration of microscopy into existing on-chip microfluidic devices with various functionalities. Our imaging modality utilizes partially coherent in-line holography and pixel super-resolution to create high-resolution amplitude and phase images of the objects flowing within micro-fluidic channels, which we demonstrate by imaging C. elegans, Giardia lamblia, and Mulberry pollen. HOM does not involve complicated fabrication processes or precise alignment, nor does it require a highly uniform flow of objects within microfluidic channels. PMID:21197025
Holographic opto-fluidic microscopy.
Bishara, Waheb; Zhu, Hongying; Ozcan, Aydogan
2010-12-20
Over the last decade microfluidics has created a versatile platform that has significantly advanced the ways in which micro-scale organisms and objects are controlled, processed and investigated, by improving the cost, compactness and throughput aspects of analysis. Microfluidics has also expanded into optics to create reconfigurable and flexible optical devices such as reconfigurable lenses, lasers, waveguides, switches, and on-chip microscopes. Here we present a new opto-fluidic microscopy modality, i.e., Holographic Opto-fluidic Microscopy (HOM), based on lensless holographic imaging. This imaging modality complements the miniaturization provided by microfluidics and would allow the integration of microscopy into existing on-chip microfluidic devices with various functionalities. Our imaging modality utilizes partially coherent in-line holography and pixel super-resolution to create high-resolution amplitude and phase images of the objects flowing within micro-fluidic channels, which we demonstrate by imaging C. elegans, Giardia lamblia, and Mulberry pollen. HOM does not involve complicated fabrication processes or precise alignment, nor does it require a highly uniform flow of objects within microfluidic channels. PMID:21197025
Holographic Applications for Black Holes and Condensed Matter
NASA Astrophysics Data System (ADS)
Way, Benson
This dissertation investigates extensions of AdS/CFT and its applications to black holes and condensed matter. We begin by introducing the AdS/CFT correspondence and the various numerical methods we employ. We then apply these methods to construct a 'black funnel'. These solutions are dual to a Hartle-Hawking state of a strongly coupled field theory on a black hole background. We then study the Lifshitz spacetime which is dual to a non-relativistic field theory with an anisotropic scaling symmetry. This spacetime has a curvature singularity due to diverging tidal forces. We examine the properties of a test string as it propagates in this background and find that the singularity causes the string to experience infinite mode production. We explore the effects of a confinement/deconfinement transition. In the Lifshitz spacetime, this additional ingredient makes the zero temperature limit singularity-free. We also add a confinement/deconfinement transition to the holographic superconductor and produce its phase diagram. This system has a rich phase structure with a conducting phase, an insulating phase, a confining superconductor, and a deconfined superconductor. Surprisingly, it also allows for a situation where a superconductor can transition to an insulator by lowering the temperature. We attempt to reproduce some known results in condensed matter from a holographic standpoint. We construct a holographic model of a Josephson junction and reproduce the familiar properties associated with it. We then study the effects of finite size on holographic superconductors and find a behaviour consistent with the known results of strongly coupled superconductors.
Holographic Superconductor Vortices
Montull, Marc; Pomarol, Alex; Silva, Pedro J.
2009-08-28
A gravity dual of a superconductor at finite temperature has been recently proposed. We present the vortex configuration of this model and study its properties. In particular, we calculate the free energy as a function of an external magnetic field, the magnetization, and the superconducting density. We also find the two critical magnetic fields that define the region in which the vortex configurations are energetically favorable.
All-optical nonlinear holographic correlation using bacteriorhodopsin films
NASA Astrophysics Data System (ADS)
Thoma, Ralph; Dratz, Michael; Hampp, Norbert
1995-05-01
Films made of the halobacterial photochrome bacteriorhodopsin (BR) can be used in a number of holographic real-time applications. Their application as active material in a dual-axis joint- Fourier-transform (DAJFT) real-time correlator was shown recently. The BR films have a strong nonlinear intensity dependence on the light-induced absorption and refractive-index changes. Therefore the holographic diffraction efficiency also shows a nonlinear dependence on the writing intensity. We investigate the effect of this nonlinearity on the result of the correlation process in a bacteriorhodopsin-based DAJFT correlator. Numerical models supporting the experimental observations are presented. It was found that the BR film combines the holographic function for most objects with that of a spatial bandpass filter, whose center frequency is tuned by the writing intensity. This results in smaller peak widths and a suppression of the sidelobes. BR films allow the application of this nonlinear behavior in real time to the all-optical correlation process.
Holographic conductivity for logarithmic charged dilaton-Lifshitz solutions
NASA Astrophysics Data System (ADS)
Dehyadegari, A.; Sheykhi, A.; Kord Zangeneh, M.
2016-07-01
We disclose the effects of the logarithmic nonlinear electrodynamics on the holographic conductivity of Lifshitz dilaton black holes/branes. We analyze thermodynamics of these solutions as a necessary requirement for applying gauge/gravity duality, by calculating conserved and thermodynamic quantities such as the temperature, entropy, electric potential and mass of the black holes/branes. We calculate the holographic conductivity for a (2 + 1)-dimensional brane boundary and study its behavior in terms of the frequency per temperature. Interestingly enough, we find out that, in contrast to the Lifshitz-Maxwell-dilaton black branes which have conductivity for all z, here in the presence of nonlinear gauge field, the holographic conductivity does exist provided z ≤ 3 and vanishes for z > 3. It is shown that independent of the nonlinear parameter β, the real part of the conductivity is the same for a specific value of frequency per temperature in both AdS and Lifshitz cases. Besides, the behavior of real part of conductivity for large frequencies has a positive slope with respect to large frequencies for a system with Lifshitz symmetry whereas it tends to a constant for a system with AdS symmetry. This behavior may be interpreted as existence of an additional charge carrier rather than the AdS case, and is due to the presence of the scalar dilaton field in model. Similar behavior for optical conductivity of single-layer graphene induced by mild oxygen plasma exposure has been reported.
DeWolfe, Oliver; Rosen, Christopher; Gubser, Steven S.
2011-04-15
We numerically construct a family of five-dimensional black holes exhibiting a line of first-order phase transitions terminating at a critical point at finite chemical potential and temperature. These black holes are constructed so that the equation of state and baryon susceptibilities approximately match QCD lattice data at vanishing chemical potential. The critical end point in the particular model we consider has temperature 143 MeV and chemical potential 783 MeV. Critical exponents are calculated, with results that are consistent with mean-field scaling relations.
Modular digital holographic fringe data processing system
NASA Technical Reports Server (NTRS)
Downward, J. G.; Vavra, P. C.; Schebor, F. S.; Vest, C. M.
1985-01-01
A software architecture suitable for reducing holographic fringe data into useful engineering data is developed and tested. The results, along with a detailed description of the proposed architecture for a Modular Digital Fringe Analysis System, are presented.
Some applications of holographic interferometry in biomechanics
NASA Astrophysics Data System (ADS)
Ebbeni, Jean P. L.
1992-03-01
Holographic interferometry is well adapted for the determination of 2D strain fields in osseous structures. The knowledge of those strain fields is important for the understanding of structure behavior such as arthrosis.
Holographic Interferometry--A Laboratory Experiment.
ERIC Educational Resources Information Center
de Frutos, A. M.; de la Rosa, M. I.
1988-01-01
Explains the problem of analyzing a phase object, separating the contribution due to thickness variations and that due to refractive index variations. Discusses the design of an interferometer and some applications. Provides diagrams and pictures of holographic images. (YP)
Emergence in holographic scenarios for gravity
NASA Astrophysics Data System (ADS)
Dieks, Dennis; van Dongen, Jeroen; de Haro, Sebastian
2015-11-01
'Holographic' relations between theories have become an important theme in quantum gravity research. These relations entail that a theory without gravity is equivalent to a gravitational theory with an extra spatial dimension. The idea of holography was first proposed in 1993 by Gerard 't Hooft on the basis of his studies of evaporating black holes. Soon afterwards the holographic 'AdS/CFT' duality was introduced, which since has been intensively studied in the string theory community and beyond. Recently, Erik Verlinde has proposed that even Newton's law of gravitation can be related holographically to the 'thermodynamics of information' on screens. We discuss these scenarios, with special attention to the status of the holographic relation in them and to the question of whether they make gravity and spacetime emergent. We conclude that only Verlinde's scheme straightforwardly instantiates emergence. However, assuming a non-standard interpretation of AdS/CFT may create room for the emergence of spacetime and gravity there as well.
Hybrid holographic non-destructive test system
NASA Technical Reports Server (NTRS)
Kurtz, R. L. (Inventor)
1978-01-01
An automatic hybrid holographic non-destructive testing (HNDT) method and system capable of detecting flaws or debonds contained within certain materials are described. This system incorporates the techniques of optical holography, acoustical/optical holography and holographic correlation in determining the structural integrity of a test object. An automatic processing system including a detector and automatic data processor is used in conjunction with the three holographic techniques for correlating and interpreting the information supplied by the non-destructive systems. The automatic system also includes a sensor which directly translates an optical data format produced by the holographic techniques into electrical signals and then transmits this information to a digital computer for indicating the structural properties of the test object. The computer interprets the data gathered and determines whether further testing is necessary as well as the format of this new testing procedure.
Noncontact dimensional measurement system using holographic scanning
NASA Astrophysics Data System (ADS)
Sagan, Stephen F.; Rosso, Robert S.; Rowe, David M.
1997-07-01
Holographic scanning systems have been used for years in point-of-sale bar code scanners and other low resolution applications. These simple scanning systems could not successfully provide the accuracy and precision required to measure, inspect and control the production of today's high tech optical fibers, medical extrusions and electrical cables. A new class of instruments for the precision measurement of industrial processes has been created by the development of systems with a unique combination of holographic optical elements that can compensate for the wavelength drift in laser diodes, the application of proprietary post-processing algorithms, and the advancements in replication methods to fabricate low cost holographic scanning discs. These systems have improved upon the performance of traditional polygon mirror scanners. This paper presents the optical configuration and design features that have been incorporated into a holographic scanning inspection system that provides higher productivity, increased product quality and lower production costs for many manufacturers.
Meson wave function from holographic approaches
Vega, Alfredo; Schmidt, Ivan; Branz, Tanja; Gutsche, Thomas; Lyubovitskij, Valery E.
2010-08-04
We discuss the light-front wave function for the valence quark state of mesons using the AdS/CFT correspondence. We consider two kinds of wave functions obtained in different holographic Soft-Wall approaches.
Holographic dark energy with varying gravitational constant
NASA Astrophysics Data System (ADS)
Jamil, Mubasher; Saridakis, Emmanuel N.; Setare, M. R.
2009-08-01
We investigate the holographic dark energy scenario with a varying gravitational constant, in flat and non-flat background geometry. We extract the exact differential equations determining the evolution of the dark energy density-parameter, which include G-variation correction terms. Performing a low-redshift expansion of the dark energy equation of state, we provide the involved parameters as functions of the current density parameters, of the holographic dark energy constant and of the G-variation.
Holographic data processing methods for medical prognosis
NASA Astrophysics Data System (ADS)
Antonov, V. A.; Grosmann, M. H.; Kartavenko, V. I.; Larkin, A. I.; Trukhanov, K. A.
2015-10-01
The various methods of laser coherent photonic implementations of multiparametric classification are discussed in this paper. The holographic and optical data processing methods for medical application are considered. Inverse two-phase coding and analysis of light distribution in the correlation plane enables us to realize a number of algorithms: search for a precedent, Hamming distance measurement, Bayes probability algorithm, deterministic and ‘correspondence’ algorithms. The experimental holographic results for medicine prognosis are shown.
Iron (III)/multiacrylate-based holographic mixtures
NASA Astrophysics Data System (ADS)
Lucchetta, D. E.; Nucara, L.; Criante, L.; Simoni, F.; Boni, A.; Xu, Ji-Hua; Bizzarri, R.; Castagna, R.
2013-11-01
We propose an holographic mixture, based on a nonconventional photoinitiator mixed with an acrylate monomer, in which high resolution thick holographic gratings are written. The used mixture that preferably works at UV and Blue-visible wavelengths shows many interesting features, such as high post-polymerization transparency, high writing resolution, and high angular selectivity. The information is permanently storable. Standard experimental techniques have been used to characterize the physical properties of the written gratings.
Holographic Optical Elements as Scanning Lidar Telescopes
NASA Technical Reports Server (NTRS)
Schwemmer, Geary K.; Rallison, Richard D.; Wilkerson, Thomas D.; Guerra, David V.
2003-01-01
We have investigated and developed the use of holographic optical elements (HOE) and holographic transmission gratings for scanning lidar telescopes. By rotating a flat HOE in its own plane with the focal spot on the rotation axis, a very simple and compact conical scanning telescope is possible. We developed and tested transmission and reflection HOES for use with the first three harmonics of Nd:YAG lasers, and designed, built, and tested two lidar systems based on this technology.
Level of holographic noise in interferometry
NASA Astrophysics Data System (ADS)
Smolyaninov, Igor I.
2009-04-01
The level of holographic noise expected to be observed in interferometric gravitational wave detectors such as GEO600 is reexamined. It is demonstrated that earlier estimates are based on assumed linear diffractive behavior of Planck radiation. Since nonlinear effects, such as self-focusing, are expected to appear at much lower energies, the expected level of holographic noise must be reduced by many orders of magnitude.
Operating manual holographic interferometry system for 2 x 2 foot transonic wind tunnel
NASA Technical Reports Server (NTRS)
Craig, J. E.
1981-01-01
A holographic interferometer system was installed in a 2X2 foot transonic wind tunnel. The system incorporates a modern, 10 pps, Nd:YAG pulsed laser which provides reliable operation and is easy to align. The spatial filtering requirements of the unstable resonator beam are described as well as the integration of the system into the existing Schieren system. A two plate holographic interferometer is used to reconstruct flow field data. For static wind tunnel models the single exposure holograms are recorded in the usual manner; however, for dynamic models such as oscillating airfoils, synchronous laser hologram recording is used.
Analytical study on holographic superfluid in AdS soliton background
NASA Astrophysics Data System (ADS)
Lai, Chuyu; Pan, Qiyuan; Jing, Jiliang; Wang, Yongjiu
2016-06-01
We analytically study the holographic superfluid phase transition in the AdS soliton background by using the variational method for the Sturm-Liouville eigenvalue problem. By investigating the holographic s-wave and p-wave superfluid models in the probe limit, we observe that the spatial component of the gauge field will hinder the phase transition. Moreover, we note that, different from the AdS black hole spacetime, in the AdS soliton background the holographic superfluid phase transition always belongs to the second order and the critical exponent of the system takes the mean-field value in both s-wave and p-wave models. Our analytical results are found to be in good agreement with the numerical findings.
A simple holographic superconductor with momentum relaxation
NASA Astrophysics Data System (ADS)
Kim, Keun-Young; Kim, Kyung Kiu; Park, Miok
2015-04-01
We study a holographic superconductor model with momentum relaxation due to massless scalar fields linear to spatial coordinates( ψ I = βδ Ii x i ), where β is the strength of momentum relaxation. In addition to the original superconductor induced by the chemical potential( μ) at β = 0, there exists a new type of superconductor induced by β even at μ = 0. It may imply a new `pairing' mechanism of particles and antiparticles interacting with β, which may be interpreted as `impurity'. Two parameters μ and β compete in forming superconducting phase. As a result, the critical temperature behaves differently depending on β/μ. It decreases when β/μ is small and increases when β/μ is large, which is a novel feature compared to other models. After analysing ground states and phase diagrams for various β/μ, we study optical electric( σ), thermoelectric( α), and thermal() conductivities. When the system undergoes a phase transition from normal to a superconducting phase, 1 /ω pole appears in the imaginary part of the electric conductivity, implying infinite DC conductivity. If β/μ < 1, at small ω, a two-fluid model with an imaginary 1 /ω pole and the Drude peak works for σ, α, and , but If β/μ > 1 a non-Drude peak replaces the Drude peak. It is consistent with the coherent/incoherent metal transition in its metal phase. The Ferrell-Glover-Tinkham (FGT) sum rule is satisfied for all cases even when μ = 0.
Moothanchery, Mohesh; Bavigadda, Viswanath; Toal, Vincent; Naydenova, Izabela
2013-12-10
Shrinkage of photopolymer materials is an important factor for their use in holographic data storage and for fabrication of holographic optical elements. Dimensional change in the holographic element leads to a requirement for compensation in the reading angle and/or wavelength. Normally, shrinkage is studied at the end of the polymerization process and no information about the dynamics is obtained. The aim of this study was to use holographic interferometry to measure the shrinkage that occurs during holographic recording of transmission diffraction gratings in acrylamide photopolymer layers. Shrinkage in photopolymer layers can be measured over the whole recorded area by real-time capture of holographic interferograms at regular intervals during holographic recording using a complimentary metal-oxide-semiconductor camera. The optical path length change, and hence the shrinkage, are determined from the captured fringe patterns. Through analysis of the real-time shrinkage curves, it is possible to distinguish two processes that determine the value of shrinkage in the photopolymer layer. These processes are ascribed to monomer polymerization and crosslinking of polymer chains. The dependence of shrinkage of the layers on the conditions of recording such as recording intensity, single or double beam exposure, and the physical properties of the layers, such as thickness, were studied. Higher shrinkage was observed with recordings at lower intensities and in thinner layers. Increased shrinkage was also observed in the case of single beam polymerization in comparison to the case of double beam holographic exposure. PMID:24513896
NASA Astrophysics Data System (ADS)
Smith, Steven L.; Harvey, Karen; Richardson, Martin; Blyth, Jeff
2011-02-01
HARMAN technology's new holographic emulsions; red sensitive and green sensitive assisted by smaller grain sizes, novel sensitization and coating technology have been shown to achieve high diffraction efficiencies and narrow band reconstruction capabilities. Authors demonstrate processing optimizations and material behavior characteristics for Transmission image Masters as well as Holographic Optical Elements (HOE's).
Holographic Equilibration of Nonrelativistic Plasmas
NASA Astrophysics Data System (ADS)
Gürsoy, Umut; Jansen, Aron; Sybesma, Watse; Vandoren, Stefan
2016-07-01
We study far-from-equilibrium physics of strongly interacting plasmas at criticality and zero charge density for a wide range of dynamical scaling exponents z in d dimensions using holographic methods. In particular, we consider homogeneous isotropization of asymptotically Lifshitz black branes with full backreaction. We find stable evolution and equilibration times that exhibit small dependence of z and are of the order of the inverse temperature. Performing a quasinormal mode analysis, we find a corresponding narrow range of relaxation times, fully characterized by the fraction z /(d -1 ). For z ≥d -1 , equilibration is overdamped, whereas for z
Coherent Digital Holographic Adaptive Optics
NASA Astrophysics Data System (ADS)
Liu, Changgeng
A new type of adaptive optics (AO) based on the principles of digital holography (DH) is proposed and developed for the use in wide-field and confocal retinal imaging. Digital holographic adaptive optics (DHAO) dispenses with the wavefront sensor and wavefront corrector of the conventional AO system. DH is an emergent imaging technology that gives direct numerical access to the phase of the optical field, thus allowing precise control and manipulation of the optical field. Incorporation of DH in an ophthalmic imaging system can lead to versatile imaging capabilities at substantially reduced complexity and cost of the instrument. A typical conventional AO system includes several critical hardware pieces: spatial light modulator, lenslet array, and a second CCD camera in addition to the camera for imaging. The proposed DHAO system replaces these hardware components with numerical processing for wavefront measurement and compensation of aberration through the principles of DH. (Abstract shortened by UMI.).
Excited Baryons in Holographic QCD
de Teramond, Guy F.; Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins
2011-11-08
The light-front holographic QCD approach is used to describe baryon spectroscopy and the systematics of nucleon transition form factors. Baryon spectroscopy and the excitation dynamics of nucleon resonances encoded in the nucleon transition form factors can provide fundamental insight into the strong-coupling dynamics of QCD. The transition from the hard-scattering perturbative domain to the non-perturbative region is sensitive to the detailed dynamics of confined quarks and gluons. Computations of such phenomena from first principles in QCD are clearly very challenging. The most successful theoretical approach thus far has been to quantize QCD on discrete lattices in Euclidean space-time; however, dynamical observables in Minkowski space-time, such as the time-like hadronic form factors are not amenable to Euclidean numerical lattice computations.
Survey of holographic security systems
NASA Astrophysics Data System (ADS)
Kontnik, Lewis T.; Lancaster, Ian M.
1990-04-01
The counterfeiting of products and financial instruments is a major problem throughout the world today. The dimensions of the problem are growing, accelerated by the expanding availability of production technologies to sophisticated counterfeiters and the increasing capabilities of these technologies. Various optical techniques, including holography, are beingused in efforts to mark authentic products and to distinguish them from copies. Industry is recognizing that the effectiveness of these techniques depends on such factors as the economics of the counterfeiting process and the distribution channels for the products involved, in addition to the performance of the particular optical security technologies used. This paper surveys the nature of the growing counterfeit market place and reviews the utility of holographic optical security systems. In particular, we review the use of holograms on credit cards and other products; and outline certain steps the holography industry should take to promote these application.
Defect CFTs and holographic multiverse
Fiol, Bartomeu
2010-07-01
We investigate some aspects of a recent proposal for a holographic description of the multiverse. Specifically, we focus on the implications on the suggested duality of the fluctuations of a bubble separating two universes with different cosmological constants. We do so by considering a similar problem in a 2+1 CFT with a codimension one defect, obtained by an M5-brane probe embedding in AdS{sub 4} × S{sup 7}, and studying its spectrum of fluctuations. Our results suggest that the kind of behavior required by the spectrum of bubble fluctuations is not likely to take place in defect CFTs with an AdS dual, although it might be possible if the defect supports a non-unitary theory.
Holographic viscosity of fundamental matter.
Mateos, David; Myers, Robert C; Thomson, Rowan M
2007-03-01
A holographic dual of a finite-temperature SU(Nc) gauge theory with a small number of flavors Nf
String junctions and holographic interfaces
Chiodaroli, Marco; Gutperle, Michael; Hung, Ling-Yan; Krym, Darya
2011-01-15
In this paper we study half-BPS type IIB supergravity solutions with multiple AdS{sub 3}xS{sup 3}xM{sub 4} asymptotic regions, where M{sub 4} is either T{sup 4} or K{sub 3}. These solutions were first constructed in [M. Chiodaroli, M. Gutperle, and D. Krym, J. High Energy Phys. 02 (2010) 066.] and have geometries given by the warped product of AdS{sub 2}xS{sup 2}xM{sub 4} over {Sigma}, where {Sigma} is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. n half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [M. Chiodaroli, M. Gutperle, and D. Krym, J. High Energy Phys. 02 (2010) 066.] are constructed introducing two meromorphic and two harmonic functions defined on {Sigma}. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution charged only under Ramond-Ramond three-form fields reduce to relations involving the positions of the poles and the residues of the relevant harmonic and meromorphic functions. The degeneration limit in which some of the poles collide is analyzed in detail. Finally, we calculate the holographic boundary entropy for a junction of three CFTs and obtain a simple expression in terms of poles and residues.
Holographic memory system based on projection recording of computer-generated 1D Fourier holograms.
Betin, A Yu; Bobrinev, V I; Donchenko, S S; Odinokov, S B; Evtikhiev, N N; Starikov, R S; Starikov, S N; Zlokazov, E Yu
2014-10-01
Utilization of computer generation of holographic structures significantly simplifies the optical scheme that is used to record the microholograms in a holographic memory record system. Also digital holographic synthesis allows to account the nonlinear errors of the record system to improve the microholograms quality. The multiplexed record of holograms is a widespread technique to increase the data record density. In this article we represent the holographic memory system based on digital synthesis of amplitude one-dimensional (1D) Fourier transform holograms and the multiplexed record of these holograms onto the holographic carrier using optical projection scheme. 1D Fourier transform holograms are very sensitive to orientation of the anamorphic optical element (cylindrical lens) that is required for encoded data object reconstruction. The multiplex record of several holograms with different orientation in an optical projection scheme allowed reconstruction of the data object from each hologram by rotating the cylindrical lens on the corresponding angle. Also, we discuss two optical schemes for the recorded holograms readout: a full-page readout system and line-by-line readout system. We consider the benefits of both systems and present the results of experimental modeling of 1D Fourier holograms nonmultiplex and multiplex record and reconstruction. PMID:25322249
Light-front holographic QCD and emerging confinement
Brodsky, Stanley J.; de Téramond, Guy F.; Dosch, Hans Günter; Erlich, Joshua
2015-05-21
In this study we explore the remarkable connections between light-front dynamics, its holographic mapping to gravity in a higher-dimensional anti-de Sitter (AdS) space, and conformal quantum mechanics. This approach provides new insights into the origin of a fundamental mass scale and the physics underlying confinement dynamics in QCD in the limit of massless quarks. The result is a relativistic light-front wave equation for arbitrary spin with an effective confinement potential derived from a conformal action and its embedding in AdS space. This equation allows for the computation of essential features of hadron spectra in terms of a single scale. Themore » light-front holographic methods described here give a precise interpretation of holographic variables and quantities in AdS space in terms of light-front variables and quantum numbers. This leads to a relation between the AdS wave functions and the boost-invariant light-front wave functions describing the internal structure of hadronic bound-states in physical spacetime. The pion is massless in the chiral limit and the excitation spectra of relativistic light-quark meson and baryon bound states lie on linear Regge trajectories with identical slopes in the radial and orbital quantum numbers. In the light-front holographic approach described here currents are expressed as an infinite sum of poles, and form factors as a product of poles. At large q2 the form factor incorporates the correct power-law fall-off for hard scattering independent of the specific dynamics and is dictated by the twist. At low q2 the form factor leads to vector dominance. The approach is also extended to include small quark masses. We briefly review in this report other holographic approaches to QCD, in particular top-down and bottom-up models based on chiral symmetry breaking. We also include a discussion of open problems and future applications.« less
A low-resolution 3D holographic volumetric display
NASA Astrophysics Data System (ADS)
Khan, Javid; Underwood, Ian; Greenaway, Alan; Halonen, Mikko
2010-05-01
A simple low resolution volumetric display is presented, based on holographic volume-segments. The display system comprises a proprietary holographic screen, laser projector, associated optics plus a control unit. The holographic screen resembles a sheet of frosted glass about A4 in size (20x30cm). The holographic screen is rear-illuminated by the laser projector, which is in turn driven by the controller, to produce simple 3D images that appear outside the plane of the screen. A series of spatially multiplexed and interleaved interference patterns are pre-encoded across the surface of the holographic screen. Each illumination pattern is capable of reconstructing a single holographic volume-segment. Up to nine holograms are multiplexed on the holographic screen in a variety of configurations including a series of numeric and segmented digits. The demonstrator has good results under laboratory conditions with moving colour 3D images in front of or behind the holographic screen.
Matrix theory for baryons: an overview of holographic QCD for nuclear physics
NASA Astrophysics Data System (ADS)
Aoki, Sinya; Hashimoto, Koji; Iizuka, Norihiro
2013-10-01
We provide, for non-experts, a brief overview of holographic QCD (quantum chromodynamics) and a review of the recent proposal (Hashimoto et al 2010 (arXiv:1003.4988[hep-th])) of a matrix-like description of multi-baryon systems in holographic QCD. Based on the matrix model, we derive the baryon interaction at short distances in multi-flavor holographic QCD. We show that there is a very universal repulsive core of inter-baryon forces for a generic number of flavors. This is consistent with a recent lattice QCD analysis for Nf = 2, 3 where the repulsive core looks universal. We also provide a comparison of our results with the lattice QCD and the operator product expansion analysis.
Matrix theory for baryons: an overview of holographic QCD for nuclear physics.
Aoki, Sinya; Hashimoto, Koji; Iizuka, Norihiro
2013-10-01
We provide, for non-experts, a brief overview of holographic QCD (quantum chromodynamics) and a review of the recent proposal (Hashimoto et al 2010 (arXiv:1003.4988[hep-th])) of a matrix-like description of multi-baryon systems in holographic QCD. Based on the matrix model, we derive the baryon interaction at short distances in multi-flavor holographic QCD. We show that there is a very universal repulsive core of inter-baryon forces for a generic number of flavors. This is consistent with a recent lattice QCD analysis for Nf = 2, 3 where the repulsive core looks universal. We also provide a comparison of our results with the lattice QCD and the operator product expansion analysis. PMID:24088334
Yu, Dan; Liu, Hongpeng; Mao, Dongyao; Geng, Yaohui; Wang, Weibo; Sun, Liping; Lv, Jiang
2015-11-01
Holographic sensing of organic vapor is characterized at transmission and reflection geometries in ZSM-5 nanozeolites dispersed acrylamide photopolymer. Nano-zeolites as absorption medium are dispersed into the polymer to enhance the absorptivity to organic vapor. Obvious enhancements of spectrum strength are observed during the sensing process. Two primary factors causing the enhancement, absorption of nanozeolites and photopolymerization induced by broadband white light, are analyzed experimentally. Significant increment provides a quick and intuitive identification strategy for holographic sensing. Accompanying with the wavelength blue-shift, the shrinkage of sample is measured quantitatively under homogeneous white light. It is further demonstrated that the significance of nanozeolites absorption. Finally a theoretical model with mutual diffusion is used to simulate the swelling process. This study provides significant foundation for the application of holographic sensor. PMID:26561180
Holographic data storage: rebirthing a commercialization effort
NASA Astrophysics Data System (ADS)
Anderson, Ken; Ayres, Mark; Sissom, Brad; Askham, Fred
2014-02-01
The realization of a commercial holographic data storage device has remained elusive for many decades. The most recent efforts were by InPhase Technologies between 2001 and 2009 resulting in 52 functioning prototypes capable of 300GB/disk and 20MB/s transfer rates. Despite being the world's first fully functional holographic drives, the primary competitor to holographic archive storage at that time, LTO, had already achieved 800GB and 120MB/in 2008; and by 2010, LTO had achieved 1.5TB and 140MB/s. This left InPhase at a competitive disadvantage to LTO archive solutions despite other strengths such as robustness, random access, and longer-term archive lifetime. Looking into the future, holographic data storage must be highly competitive with tape in three critical areas: cost/TB, capacity/footprint, and transfer rate. If this can be achieved, holographic data storage would become a superior solution given the low latencies and overall robustness to propel it into being the archive storage front-runner. New technology advancements by Akonia Holographics have enabled the potential for ultra-high capacity holographic storage devices that are capable of world record bit densities of over 2Tbit/in2, 200-300MB/s transfer rates, and a media cost less than $10/TB in the next 5 years. A demonstration platform based on these new advances has been designed and is currently being built by Akonia to progressively demonstrate bit densities of 2Tb/in2, 4Tb/in2, and 8Tb/in2 over the next year.
The Compact and Inexpensive "Arrowhead" Setup for Holographic Interferometry
ERIC Educational Resources Information Center
Ladera, Celso L.; Donoso, Guillermo
2011-01-01
Hologram recording and holographic interferometry are intrinsically sensitive to phase changes, and therefore both are easily perturbed by minuscule optical path perturbations. It is therefore very convenient to bank on holographic setups with a reduced number of optical components. Here we present a compact off-axis holographic setup that…
Printable Nanophotonic Devices via Holographic Laser Ablation.
Zhao, Qiancheng; Yetisen, Ali K; Sabouri, Aydin; Yun, Seok Hyun; Butt, Haider
2015-09-22
Holography plays a significant role in applications such as data storage, light trapping, security, and biosensors. However, conventional fabrication methods remain time-consuming, costly, and complex, limiting the fabrication of holograms and their extensive use. Here, we demonstrate a single-pulse laser ablation technique to write parallel surface gratings and Fresnel zone plates. We utilized a 6 ns high-energy green laser pulse to form interference patterns to record a surface grating with 820 nm periodicity and asymmetric zone plate holograms on 4.5 nm gold-coated substrates. The holographic recording process was completed within seconds. The optical characteristics of the interference patterns have been computationally modeled, and well-ordered polychromatic diffraction was observed from the fabricated holograms. The zone plate showed a significant diffraction angle of 32° from the normal incident for the focal point. The nanosecond laser interference ablation for rapid hologram fabrication holds great potential in a vast range of optical devices. PMID:26301907
Holographic Wave Functions, Meromorphization and Counting Rules
Anatoly Radyushkin
2006-05-10
We study the large-Q{sup 2} behavior of the meson form factor F{sub M} (Q{sup 2}) constructed using the holographic light-front wave functions proposed recently by Brodsky and de Teramond. We show that this model can be also obtained within the Migdal's regularization approach (''meromorphization''), if one applies it to 3-point function for scalar currents made of scalar quarks. We found that the asymptotic 1/Q{sup 2} behavior of F{sub M} (Q{sup 2}) is generated by soft Feynman mechanism rather than by short distance dynamics, which causes very late onset of the 1/Q{sup 2} asymptotic behavior. It becomes visible only for unaccessible momenta Q{sup 2} {approx}> 10, GeV{sup 2}. Using meromorphization for spin-1/2 quarks, we demonstrated that resulting form factor F{sup spinor}{sub M} (Q{sup 2}) has 1/Q{sup 4} asymptotic behavior. Now, owing to the late onset of this asymptotic pattern, F{sup spinor}{sub M} (Q{sup 2}) imitates the 1/Q{sup 2} behavior in the few GeV{sup 2} region.
Holographic interpretation of acoustic black holes
NASA Astrophysics Data System (ADS)
Ge, Xian-Hui; Sun, Jia-Rui; Tian, Yu; Wu, Xiao-Ning; Zhang, Yun-Long
2015-10-01
With the attempt to find the holographic description of the usual acoustic black holes in fluid, we construct an acoustic black hole formed in the d -dimensional fluid located at the timelike cutoff surface of a neutral black brane in asymptotically AdSd +1 spacetime; the bulk gravitational dual of the acoustic black hole is presented at the first order of the hydrodynamic fluctuation. Moreover, the Hawking-like temperature of the acoustic black hole horizon is showed to be connected to the Hawking temperature of the real anti-de Sitter (AdS) black brane in the bulk, and the duality between the phonon scattering in the acoustic black hole and the sound channel quasinormal mode propagating in the bulk perturbed AdS black brane is extracted. We thus point out that the acoustic black hole appearing in fluid, which was originally proposed as an analogous model to simulate Hawking radiation of the real black hole, is not merely an analogy, it can indeed be used to describe specific properties of the real AdS black holes, in the spirit of the fluid/gravity duality.
Holographic fluorescence microscopy with incoherent digital holographic adaptive optics.
Jang, Changwon; Kim, Jonghyun; Clark, David C; Lee, Seungjae; Lee, Byoungho; Kim, Myung K
2015-01-01
Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: a wavefront sensor, wavefront corrector, and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, for example, lenslet arrays for sensing or multiactuator deformable mirrors for correcting. We have previously introduced an alternate approach based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile are possible not only with conventional coherent digital holography, but also with a new type of digital holography using incoherent light: selfinterference incoherent digital holography (SIDH). The SIDH generates a complex—i.e., amplitude plus phase—hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. Adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media. PMID:26146767
Didactical Holographic Exhibit Including Holo TV (holographic Television)
NASA Astrophysics Data System (ADS)
Lunazzi, José J.; Magalhães, Daniel S. F.; Rivera, Noemí I. R.
2008-04-01
Our Institute of Physics exposes since 1980 didactical exhibitions of holography in Brazil where nice holograms are shown altogether with basic experiments of geometric and wave optics. This experiments lead to the understanding of the phenomenon of images of an ample way. Thousands of people have been present at them, in their majority of the Universidade Estadual de Campinas, where since 2002 they have taken the format of a course without formal evaluation. This way the exhibition has been divided in four modules, in each one of them are shown different holograms, experiments of optics and applications of diffractive images with white light developed in the Institute of Physics. The sequence of the learning through the modules begins with the geometric optics, later we explain the wave optics and finally holography. The phenomenon of the diffraction in daily elements is shown experimentally from the beginning. As well as the application of the holographic screens in white light: the television images that appear in front of the screen and the spectator can try to experience the reality illusion. Put something so exclusive (that only exists in the laboratory) to the public is a way to approximate the persons to an investigation in course. The vision of images that seem to be of holograms, but in movement, and size of until a square meter completes this exhibition of an exclusive way in the world.
Holographic fluorescence microscopy with incoherent digital holographic adaptive optics
NASA Astrophysics Data System (ADS)
Jang, Changwon; Kim, Jonghyun; Clark, David C.; Lee, Seungjae; Lee, Byoungho; Kim, Myung K.
2015-11-01
Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: a wavefront sensor, wavefront corrector, and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, for example, lenslet arrays for sensing or multiactuator deformable mirrors for correcting. We have previously introduced an alternate approach based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile are possible not only with conventional coherent digital holography, but also with a new type of digital holography using incoherent light: selfinterference incoherent digital holography (SIDH). The SIDH generates a complex-i.e., amplitude plus phase-hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. Adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media.
Phase structures of holographic screen thermodynamics
NASA Astrophysics Data System (ADS)
Jiang, Wei-Jian; Chen, Yi-Xin; Li, Jian-Long
2014-07-01
Holographic screens are the generalization of the event horizon of a black hole in entropic force scheme, which are defined by setting Newton potential ϕ constant, i.e. e2ϕ = c = const. We demonstrate that the integrated first law of thermodynamics is equivalent to the (r-r) component of Einstein equations, so that we strengthen the correspondence between thermodynamics and gravity. We show that there are not only the first law of thermodynamics, but also kinds of phase transitions of holographic screens. These phase transitions are characterized by the discontinuity of their heat capacities. In (n+1)-dimensional Reissner-Nordström-anti-de Sitter (RN-AdS) spacetime, we analyze three kinds of phase transitions, which are of the holographic screens with Q = 0 (charge), constant Φ (electrostatic potential) and nonzero constant Q. In the Q = 0 case, only the holographic screens with 0≤c<1 can undergo phase transition. In the constant Φ case, the constraints become as 0<= c+16˜ {Γ }2Φ 2<1, where ˜ {Γ } is a dimensional-dependent parameter. By verifying the Ehrenfest equations, we show that the phase transitions in this case are all second order phase transitions. In the constant Q case, there might be two, or one, or no phase transitions of holographic screens, depending on the values of Q and c.
Phase structure of a holographic double monolayer Dirac semimetal
NASA Astrophysics Data System (ADS)
Grignani, Gianluca; Marini, Andrea; Pigna, Adriano-Costantino; Semenoff, Gordon W.
2016-06-01
We study a holographic D3/probe-D5-brane model of a double monolayer Dirac semimetal in a magnetic field and in the presence of a nonzero temperature. Intra-and inter-layer exciton condensates can form by varying the balanced charge density on the layers, the spatial separation and the temperature. Constant temperature phase diagrams for a wide range of layer separations and charge densities are found. The presence of a finite temperature makes the phase diagrams extremely rich and in particular leads to the appearance of a symmetric phase which was missing at zero temperature.
Holographic superconductors with the general RF2-type couplings
NASA Astrophysics Data System (ADS)
Sert, Özcan
2016-05-01
We explore the effects of the general non-minimally coupled RF2-type couplings on the holographic s-wave superconductors numerically in the Schwarzschild-anti-de Sitter (AdS) background. We calculate the condensation and conductivity of the model for the coupling parameters a1 and β. We obtain that the bigger deviations of the parameter a1 from the minimal case lead to the larger deviations of the gap frequency from the universal value ωg/Tc ≈ 8. Moreover, the smaller β and a1 cause to gradually stronger and narrower coherence peak.
Vortex in holographic two-band superfluid/superconductor
NASA Astrophysics Data System (ADS)
Wu, Mu-Sheng; Wu, Shang-Yu; Zhang, Hai-Qing
2016-05-01
We construct numerically static vortex solutions in a holographic model of two-band superconductor with an interband Josephson coupling in both the superfluid and superconductor regime. We investigate the effects of the interband coupling on the order parameter of each superconducting band in the vortex solution, and we find that it is different for each of the two bands. We compute also the free energy, critical magnetic field, magnetic penetration length and coherence lengths for the two bands, and we study their dependence on the interband coupling and temperature. Interestingly, we find that the coherence lengths of the two bands are close to identical.
Quantum gravity and the holographic dark energy cosmology
NASA Astrophysics Data System (ADS)
Nastase, Horatiu
2016-04-01
The holographic dark energy model is obtained from a cosmological constant generated by generic quantum gravity effects giving a minimum length. By contrast, the usual bound for the energy density to be limited by the formation of a black hole simply gives the Friedmann equation. The scale of the current cosmological constant relative to the inflationary scale is an arbitrary parameter characterizing initial conditions, which however can be fixed by introducing a physical principle during inflation, as a function of the number of e-folds and the inflationary scale.
Quark masses and the meson spectrum: A holographic approach
NASA Astrophysics Data System (ADS)
Afonin, S. S.; Pusenkov, I. V.
2015-09-01
Based on experimental data, we can assume that the radial spectrum of vector mesons with a hidden quark flavor has a Regge form and propose its concrete form. The parameters of the Regge spectrum turn out to depend strongly on the mass of the quarks forming the mesons. We consider the problem of finding the form of these dependences in the framework of the holographic approach to strong interactions. The obtained results agree well with the phenomenology and with models of Veneziano-like dual amplitudes.
Marker-free cell discrimination by holographic optical tweezers
NASA Astrophysics Data System (ADS)
Schaal, F.; Warber, M.; Zwick, S.; van der Kuip, H.; Haist, T.; Osten, W.
2009-06-01
We introduce a method for marker-free cell discrimination based on optical tweezers. Cancerous, non-cancerous, and drug-treated cells could be distinguished by measuring the trapping forces using holographic optical tweezers. We present trapping force measurements on different cell lines: normal pre-B lymphocyte cells (BaF3; "normal cells"), their Bcr-Abl transformed counterparts (BaF3-p185; "cancer cells") as a model for chronic myeloid leukaemia (CML) and Imatinib treated BaF3-p185 cells. The results are compared with reference measurements obtained by a commercial flow cytometry system.
Bacteriorhodopsin Material and Film Fabrication Issues for Holographic Applications
NASA Technical Reports Server (NTRS)
Downie, John D.; Timucin, Dogan A.; Smithey, Daniel T.; Crew, Marshall; Rayfield, George W.; Lan, Sonie (Technical Monitor)
1998-01-01
We discuss issues associated with bacteriorhodopsin (BR) materials and films that affect optical performance in holographic applications. For the D85N variant, some critical parameters include degree of hydration and recording wavelength. The quantum efficiency of the molecular state transition is observed to be apparently dependent on the illumination wavelength. We explain this effect by modeling the photo-activity of the D85N variant as two competing photocycles between the 9-cis and 13-cis retinal configurations. We are able to determine the pure excited P-state absorbance spectrum from the ground state spectrum and mixed population spectra obtained by bleaching to steady-state conditions.
Holography and the virtual patient: the holographic medical image
NASA Astrophysics Data System (ADS)
Ko, Kathryn; Erickson, Ronald R.; Webster, John M.
1996-12-01
Practical holographic systems utilizing the pulsed laser are finding potential applications in medicine. Exploiting both the hologram's true 3D image and holographic interferometry these techniques enhance the physician's vision beyond the 2D radiological imaging of even the best CT and MRI. The authors describe the use of pulsed laser holography as applied to the morphological specialties: anatomy, pathology, and surgery. The authors report on the Holographic Brain Anatomy Atlas for medical education; pathologic documentation with holography, and the use of holographic interferometry in surgical planning. The techniques are outlined and a discussion on the interpretation of holographic interferometry with living subjects is provided.
Cosmic accelerated expansion and the entropy-corrected holographic dark energy
NASA Astrophysics Data System (ADS)
Sadjadi, H. Mohseni; Jamil, Mubasher
2011-06-01
By considering the logarithmic correction to the energy density, we study the behavior of Hubble parameter in the holographic dark energy model. We assume that the universe is dominated by interacting dark energy and matter and the accelerated expansion of the universe, which may be occurred in the early universe or late time, is studied.
Brodsky, Stanley J.; de Teramond, Guy F.; /Costa Rica U.
2012-02-16
The relation between the hadronic short-distance constituent quark and gluon particle limit and the long-range confining domain is yet one of the most challenging aspects of particle physics due to the strong coupling nature of Quantum Chromodynamics, the fundamental theory of the strong interactions. The central question is how one can compute hadronic properties from first principles; i.e., directly from the QCD Lagrangian. The most successful theoretical approach thus far has been to quantize QCD on discrete lattices in Euclidean space-time. Lattice numerical results follow from computation of frame-dependent moments of distributions in Euclidean space and dynamical observables in Minkowski spacetime, such as the time-like hadronic form factors, are not amenable to Euclidean lattice computations. The Dyson-Schwinger methods have led to many important insights, such as the infrared fixed point behavior of the strong coupling constant, but in practice, the analyses are limited to ladder approximation in Landau gauge. Baryon spectroscopy and the excitation dynamics of nucleon resonances encoded in the nucleon transition form factors can provide fundamental insight into the strong-coupling dynamics of QCD. New theoretical tools are thus of primary interest for the interpretation of the results expected at the new mass scale and kinematic regions accessible to the JLab 12 GeV Upgrade Project. The AdS/CFT correspondence between gravity or string theory on a higher-dimensional anti-de Sitter (AdS) space and conformal field theories in physical space-time has led to a semiclassical approximation for strongly-coupled QCD, which provides physical insights into its nonperturbative dynamics. The correspondence is holographic in the sense that it determines a duality between theories in different number of space-time dimensions. This geometric approach leads in fact to a simple analytical and phenomenologically compelling nonperturbative approximation to the full light
A holographic quantum Hall ferromagnet
NASA Astrophysics Data System (ADS)
Kristjansen, C.; Pourhasan, R.; Semenoff, G. W.
2014-02-01
A detailed numerical study of a recent proposal for exotic states of the D3-probe D5 brane system with charge density and an external magnetic field is presented. The state has a large number of coincident D5 branes blowing up to a D7 brane in the presence of the worldvolume electric and magnetic fields which are necessary to construct the holographic state. Numerical solutions have shown that these states can compete with the the previously known chiral symmetry breaking and maximally symmetric phases of the D3-D5 system. Moreover, at integer filling fractions, they are incompressible with integer quantized Hall conductivities. In the dual superconformal defect field theory, these solutions correspond to states which break the chiral and global flavor symmetries spontaneously. The region of the temperature-density plane where the D7 brane has lower energy than the other known D5 brane solutions is identified. A hypothesis for the structure of states with filling fraction and Hall conductivity greater than one is made and tested by numerical computation. A parallel with the quantum Hall ferromagnetism or magnetic catalysis phenomenon which is observed in graphene is drawn. As well as demonstrating that the phenomenon can exist in a strongly coupled system, this work makes a number of predictions of symmetry breaking patterns and phase transitions for such systems.
Holographic confinement in inhomogeneous backgrounds
NASA Astrophysics Data System (ADS)
Marolf, Donald; Wien, Jason
2016-08-01
As noted by Witten, compactifying a d-dimensional holographic CFT on an S 1 gives a class of ( d - 1)-dimensional confining theories with gravity duals. The proto-typical bulk solution dual to the ground state is a double Wick rotation of the AdS d+1 Schwarzschild black hole known as the AdS soliton. We generalize such examples by allowing slow variations in the size of the S 1, and thus in the confinement scale. Coefficients governing the second order response of the system are computed for 3 ≤ d ≤ 8 using a derivative expansion closely related to the fluid-gravity correspondence. The primary physical results are that i) gauge-theory flux tubes tend to align orthogonal to gradients and along the eigenvector of the Hessian with the lowest eigenvalue, ii) flux tubes aligned orthogonal to gradients are attracted to gradients for d ≤ 6 but repelled by gradients for d ≥ 7, iii) flux tubes are repelled by regions where the second derivative along the tube is large and positive but are attracted to regions where the eigenvalues of the Hessian are large and positive in directions orthogonal to the tube, and iv) for d > 3, inhomogeneities act to raise the total energy of the confining vacuum above its zeroth order value.
Holographic entanglement beyond classical gravity
NASA Astrophysics Data System (ADS)
Barrella, Taylor; Dong, Xi; Hartnoll, Sean A.; Martin, Victoria L.
2013-09-01
The Rényi entropies and entanglement entropy of 1+1 CFTs with gravity duals can be computed by explicit construction of the bulk spacetimes dual to branched covers of the boundary geometry. At the classical level in the bulk this has recently been shown to reproduce the conjectured Ryu-Takayanagi formula for the holographic entanglement entropy. We study the one-loop bulk corrections to this formula. The functional determinants in the bulk geometries are given by a sum over certain words of generators of the Schottky group of the branched cover. For the case of two disjoint intervals on a line we obtain analytic answers for the one-loop entanglement entropy in an expansion in small cross-ratio. These reproduce and go beyond anticipated universal terms that are not visible classically in the bulk. We also consider the case of a single interval on a circle at finite temperature. At high temperatures we show that the one-loop contributions introduce expected finite size corrections to the entanglement entropy that are not present classically. At low temperatures, the one-loop corrections capture the mixed nature of the density matrix, also not visible classically below the Hawking-Page temperature.
Exact holographic mapping in free fermion systems
NASA Astrophysics Data System (ADS)
Lee, Ching Hua; Qi, Xiao-Liang
2016-01-01
In this paper, we perform a detailed analysis of the exact holographic mapping first introduced in arXiv:1309.6282, which was proposed as an explicit example of holographic duality between quantum many-body systems and gravitational theories. We obtain analytic results for free fermion systems that not only confirm previous numerical results, but also elucidate the exact relationships between the various physical properties of the bulk and boundary systems. These analytic results allow us to study the asymptotic properties that are difficult to probe numerically, such as the near-horizon regime of the black-hole geometry. We shall also explore a few interesting but hitherto unexplored bulk geometries, such as that corresponding to a boundary critical fermion with a nontrivial dynamical critical exponent. Our analytic framework also allows us to study the holographic mapping of some of these boundary theories in dimensions 2+1 or higher.
Photopolymeric multifunctional dendrimer toward holographic applications.
Jeong, Yong-Cheol; Jung, Bokyung; Park, Jung-Ki
2012-09-26
We present a photopolymeric multifunctional dendrimer for holographic applications. In this study, we described a synthesis of multiphotoreactive dendrimer and phase compatible polymer matrix as well as a numerical simulation of the dendrimer. This holographic photopolymer containing a nanosized photoreactive organic dendrimer could address the aggregation issue of conventional inorganic nanoparticle additives and allowed writing-induced shrinkage to be successfully reduced to the extent of acceptable values for 130 μm thick film. In this report, holographic performance including diffraction efficiency (DE), transmission, photosensitivity, modulation of refractive index, polarization sensitivity, and volume shrinkage has been discussed. The page-wise recording by using an amplitude spatial light modulator (SLM) was also demonstrated. PMID:22950741
Holographic trace anomaly and local renormalization group
NASA Astrophysics Data System (ADS)
Rajagopal, Srivatsan; Stergiou, Andreas; Zhu, Yechao
2015-11-01
The Hamilton-Jacobi method in holography has produced important results both at a renormalization group (RG) fixed point and away from it. In this paper we use the Hamilton-Jacobi method to compute the holographic trace anomaly for four- and six-dimensional boundary conformal field theories (CFTs), assuming higher-derivative gravity and interactions of scalar fields in the bulk. The scalar field contributions to the anomaly appear in CFTs with exactly marginal operators. Moving away from the fixed point, we show that the Hamilton-Jacobi formalism provides a deep connection between the holographic and the local RG. We derive the local RG equation holographically, and verify explicitly that it satisfies Weyl consistency conditions stemming from the commutativity of Weyl scalings. We also consider massive scalar fields in the bulk corresponding to boundary relevant operators, and comment on their effects to the local RG equation.
Planck constraints on holographic dark energy
Li, Miao; Zhang, Zhenhui; Li, Xiao-Dong; Ma, Yin-Zhe; Zhang, Xin E-mail: xiaodongli@kias.re.kr E-mail: zhangxin@mail.neu.edu.cn
2013-09-01
We perform a detailed investigation on the cosmological constraints on the holographic dark energy (HDE) model by using the Plank data. We find that HDE can provide a good fit to the Plank high-l (l ∼> 40) temperature power spectrum, while the discrepancy at l ≅ 20-40 found in the ΛCDM model remains unsolved in the HDE model. The Plank data alone can lead to strong and reliable constraint on the HDE parameter c. At the 68% confidence level (CL), we obtain c = 0.508 ± 0.207 with Plank+WP+lensing, favoring the present phantom behavior of HDE at the more than 2σ CL. By combining Plank+WP with the external astrophysical data sets, i.e. the BAO measurements from 6dFGS+SDSS DR7(R)+BOSS DR9, the direct Hubble constant measurement result (H{sub 0} = 73.8 ± 2.4 kms{sup −1}Mpc{sup −1}) from the HST, the SNLS3 supernovae data set, and Union2.1 supernovae data set, we get the 68% CL constraint results c = 0.484 ± 0.070, 0.474 ± 0.049, 0.594 ± 0.051, and 0.642 ± 0.066, respectively. The constraints can be improved by 2%-15% if we further add the Plank lensing data into the analysis. Compared with the WMAP-9 results, the Plank results reduce the error by 30%-60%, and prefer a phantom-like HDE at higher significant level. We also investigate the tension between different data sets. We find no evident tension when we combine Plank data with BAO and HST. Especially, we find that the strong correlation between Ω{sub m}h{sup 3} and dark energy parameters is helpful in relieving the tension between the Plank and HST measurements. The residual value of χ{sup 2}{sub Plank+WP+HST}−χ{sup 2}{sub Plank+WP} is 7.8 in the ΛCDM model, and is reduced to 1.0 or 0.3 if we switch the dark energy to w model or the holographic model. When we introduce supernovae data sets into the analysis, some tension appears. We find that the SNLS3 data set is in tension with all other data sets; for example, for the Plank+WP, WMAP-9 and BAO+HST, the corresponding Δχ{sup 2} is equal to 6
Simulating the energy performance of holographic glazings
NASA Astrophysics Data System (ADS)
Papamichael, K.; Beltran, L.; Furler, Reto; Lee, E. S.; Selkowitz, Steven E.; Rubin, Michael
1994-09-01
The light diffraction properties of holographic diffractive structures present an opportunity to improve the daylight performance in side-lit office spaces by redirecting and reflecting sunlight off the ceiling, providing adequate daylight illumination up to 30 ft (9.14 m) from the window wall. Prior studies of prototypical holographic glazings, installed above conventional `view' windows, have shown increased daylight levels over a deeper perimeter area than clear glass, for selected sun positions. In this study, we report on the simulation of the energy performance of prototypical holographic glazings assuming a commercial office building in the inland Los Angeles climate. The simulation of the energy performance involved determination of both luminous and thermal performance. Since the optical complexity of holographic glazings prevented the use of conventional algorithms for the simulation of their luminous performance, we used a newly developed method that combines experimentally determined directional workplane illuminance coefficients with computer-based analytical routines to determine a comprehensive set of daylight factors for many sun positions. These daylight factors were then used within the DOE-2.1D energy simulation program to determine hourly daylight and energy performance over the course of an entire year for four window orientations. Since the prototypical holographic diffractive structures considered in this study were applied on single pane clear glass, we also simulated the performance of hypothetical glazings, assuming the daylight performance of the prototype holographic glazings and the thermal performance of double-pane and low-e glazings. Finally, we addressed various design and implementation issues towards potential performance improvement.
Holographic fluorescence microscopy with incoherent digital holographic adaptive optics
NASA Astrophysics Data System (ADS)
Jang, Changwon; Kim, Jonghyun; Clark, David C.; Lee, Byoungho; Kim, Myung K.
2015-03-01
Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: wavefront sensor, wavefront corrector and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, e.g., lenslet arrays for sensing or multi-acuator deformable mirrors for correcting. We have previously introduced an alternate approach to adaptive optics based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile is possible not only with the conventional coherent type of digital holography, but also with a new type of digital holography using incoherent light: self-interference incoherent digital holography (SIDH). The SIDH generates complex - i.e. amplitude plus phase - hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using a guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. The adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media.
Entropy-Corrected Holographic Dark Energy
NASA Astrophysics Data System (ADS)
Wei, Hao
2009-10-01
The holographic dark energy (HDE) is now an interesting candidate of dark energy, which has been studied extensively in the literature. In the derivation of HDE, the black hole entropy plays an important role. In fact, the entropy-area relation can be modified due to loop quantum gravity or other reasons. With the modified entropy-area relation, we propose the so-called “entropy-corrected holographic dark energy" (ECHDE) in the present work. We consider many aspects of ECHDE and find some interesting results. In addition, we briefly consider the so-called “entropy-corrected agegraphic dark energy" (ECADE).
Holographic superconductors from the massive gravity
NASA Astrophysics Data System (ADS)
Zeng, Hua Bi; Wu, Jian-Pin
2014-08-01
A holographic superconductor is constructed in the background of a massive gravity theory. In the normal state without condensation, the conductivity exhibits a Drude peak that approaches a delta function in the massless gravity limit as studied by David Vegh. In the superconducting state, besides the infinite dc conductivity, the ac conductivity has Drude behavior at low frequency followed by a power-law fall. These results are in agreement with that found earlier by Horowitz and Santos, who studied a holographic superconductor with an implicit periodic potential beyond the probe limit. The results also agree with measurements on some cuprates.
Experimental approach toward holographic interferometric fringe interpretation
NASA Technical Reports Server (NTRS)
Liu, H. K.
1974-01-01
Current literature concerning the measurement of small displacements by the laser holographic technique was reviewed. It was found that existing theories are extremely difficult, if not impossible, to apply to any realistic nondestructive testing conditions in which the geometries of the objects are complex and the three-dimensional displacements are irregular. An experimental approach was adopted for interpreting correlation between real time holographic fringe patterns and small displacements. Preliminary results show that the present method is feasible for the quantitative interpretation of the fringes as well as the calibration of the mobile HNDT system.
Digital holographic Michelson interferometer for nanometrology
NASA Astrophysics Data System (ADS)
Sevrygin, Alexander A.; Korotkov, V. I.; Pulkin, S. A.; Tursunov, I. M.; Venediktov, D. V.; Venediktov, V. Yu.; Volkov, O. V.
2014-11-01
The paper considers the dynamic holographic interferometry schemes with amplification (multiplication) of holographic fringes and with correction for distortions, imposed by the interferometer scheme elements. The use of digital microscope and of the matrix light modulator with direct addressing provides the completely digital closed-loop performance of the overall system for real-time evaluation of nano-scale objects size. Considered schemes were verified in the laboratory experiment, using the Michelson micro-interferometer, equipped by the USB-microscope and digital holography stage, equipped by the Holoeye spatial light modulator.
Improved performance in coaxial holographic data recording.
Tanaka, Kenji; Hara, Masaaki; Tokuyama, Kazutatsu; Hirooka, Kazuyuki; Ishioka, Koji; Fukumoto, Atsushi; Watanabe, Kenjiro
2007-11-26
We describe a coaxial holographic recording system for achieving high recording density. We implement several techniques, such as an objective lens with high numerical aperture (NA), high capacity page data format, a random binary phase mask, and an optical noise reduction element. Our system successfully realizes a hologram recording/retrieving at a low diffraction efficiency less than 2.0 x 10(-3) and achieves a raw data density of 180 Gbit/in.(2), thus demonstrating the potential of a coaxial holographic system for high-density optical storage systems. PMID:19550907
Low holographic concentration effects on CIGS
NASA Astrophysics Data System (ADS)
Castillo, Jose E.; Russo, Juan M.; Zhang, Deming; Kostuk, Raymond K.; Rosenberg, Glenn A.
2010-08-01
We present the results of combining copper indium gallium (di)selenide (CIGS) photovoltaic cells with holographic planar concentrating film over a broad range of illumination levels. The film, originally designed for silicon bifacial solar applications worked well with the CIGS cells. The Voc, cell efficiency and fill factor reached full operating values at lower light levels; with a significant boost in performance being recorded. The holographic regions of the concentrator act as extended heat transfer surfaces, allowing the CIGS cells to operate at lower operational temperatures than they normally would in a traditional PV application.
Holographic interferometry: A user`s guide
Griggs, D.
1993-10-01
This manual describes the procedures and components necessary to produce a holographic interferogram of a flow field in the Sandia National Laboratories hypersonic wind tunnel. In contrast to classical interferometry, holographic interferometry records the amplitude and phase distribution of a lightwave passing through the flow field at some instant of time. This information can then be reconstructed outside the wind tunnel for visual analysis and digital processing, yielding precise characterizations of aerodynamic phenomena. The reconstruction and subsequent hologram image storage process is discussed, with particular attention paid to the digital image processor and the data reduction technique.
Holographic entropy increases in quadratic curvature gravity
NASA Astrophysics Data System (ADS)
Bhattacharjee, Srijit; Sarkar, Sudipta; Wall, Aron C.
2015-09-01
Standard methods for calculating the black hole entropy beyond general relativity are ambiguous when the horizon is nonstationary. We fix these ambiguities in all quadratic curvature gravity theories, by demanding that the entropy be increasing at every time, for linear perturbations to a stationary black hole. Our result matches with the entropy formula found previously in holographic entanglement entropy calculations. We explicitly calculate the entropy increase for Vaidya-like solutions in Ricci-tensor gravity to show that (unlike the Wald entropy) the holographic entropy obeys a second law.
General properties of holographic entanglement entropy
NASA Astrophysics Data System (ADS)
Headrick, Matthew
2014-03-01
The Ryu-Takayanagi formula implies many general properties of entanglement entropies in holographic theories. We review the known properties, such as continuity, strong subadditivity, and monogamy of mutual information, and fill in gaps in some of the previously-published proofs. We also add a few new properties, including: properties of the map from boundary regions to bulk regions implied by the RT formula, such as monotonicity; conditions under which subadditivity-type inequalities are saturated; and an inequality concerning reflection-symmetric states. We attempt to draw lessons from these properties about the structure of the reduced density matrix in holographic theories.
Real-time holographic surveillance system
Collins, H.D.; McMakin, D.L.; Hall, T.E.; Gribble, R.P.
1995-10-03
A holographic surveillance system is disclosed including means for generating electromagnetic waves; means for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; means for receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; means for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and means for displaying the processed information to determine nature of the target. The means for processing the electrical signals includes means for converting analog signals to digital signals followed by a computer means to apply a backward wave algorithm. 21 figs.
Real-time holographic surveillance system
Collins, H. Dale; McMakin, Douglas L.; Hall, Thomas E.; Gribble, R. Parks
1995-01-01
A holographic surveillance system including means for generating electromagnetic waves; means for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; means for receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; means for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and means for displaying the processed information to determine nature of the target. The means for processing the electrical signals includes means for converting analog signals to digital signals followed by a computer means to apply a backward wave algorithm.
Real-time wideband holographic surveillance system
Sheen, D.M.; Collins, H.D.; Hall, T.E.; McMakin, D.L.; Gribble, R.P.; Severtsen, R.H.; Prince, J.M.; Reid, L.D.
1996-09-17
A wideband holographic surveillance system including a transceiver for generating a plurality of electromagnetic waves; antenna for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; the transceiver also receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; a computer for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and a display for displaying the processed information to determine nature of the target. The computer has instructions to apply a three dimensional backward wave algorithm. 28 figs.
Real-time wideband holographic surveillance system
Sheen, David M.; Collins, H. Dale; Hall, Thomas E.; McMakin, Douglas L.; Gribble, R. Parks; Severtsen, Ronald H.; Prince, James M.; Reid, Larry D.
1996-01-01
A wideband holographic surveillance system including a transceiver for generating a plurality of electromagnetic waves; antenna for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; the transceiver also receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; a computer for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and a display for displaying the processed information to determine nature of the target. The computer has instructions to apply a three dimensional backward wave algorithm.
NASA Astrophysics Data System (ADS)
Guntaka, Sridhar Reddy; Toal, Vincent; Martin, Suzanne
2002-12-01
A diffractive optical element is described that can be used to implement a very simple self-aligning electronic speckle-pattern interferometer and holographic interferometer that requires only a laser source and a camera in the optical setup.
Sakai, Tadakatsu; Sugimoto, Shigeki
2005-12-02
We propose a holographic dual of QCD with massless flavors on the basis of a D4/D8-brane configuration within a probe approximation. We are led to a five-dimensional Yang-Mills theory on a curved space-time along with a Chern-Simons five-form on it, both of which provide us with a unifying framework to study the massless pion and an infinite number of massive vector mesons. We make sample computations of the physical quantities that involve the mesons and compare them with the experimental data. It is found that most of the results of this model are compatible with the experiments.
NASA Astrophysics Data System (ADS)
Sakai, Tadakatsu; Sugimoto, Shigeki
2005-12-01
We propose a holographic dual of QCD with massless flavors on the basis of a D4/D8-brane configuration within a probe approximation. We are led to a five-dimensional Yang-Mills theory on a curved space-time along with a Chern-Simons five-form on it, both of which provide us with a unifying framework to study the massless pion and an infinite number of massive vector mesons. We make sample computations of the physical quantities that involve the mesons and compare them with the experimental data. It is found that most of the results of this model are compatible with the experiments.
Holographic display for see-through augmented reality using mirror-lens holographic optical element.
Li, Gang; Lee, Dukho; Jeong, Youngmo; Cho, Jaebum; Lee, Byoungho
2016-06-01
A holographic display system for realizing a three-dimensional optical see-through augmented reality (AR) is proposed. A multi-functional holographic optical element (HOE), which simultaneously performs the optical functions of a mirror and a lens, is adopted in the system. In the proposed method, a mirror that is used to guide the light source into a reflection type spatial light modulator (SLM) and a lens that functions as Fourier transforming optics are recorded on a single holographic recording material by utilizing an angular multiplexing technique of volume hologram. The HOE is transparent and performs the optical functions just for Bragg matched condition. Therefore, the real-world scenes that are usually distorted by a Fourier lens or an SLM in the conventional holographic display can be observed without visual disturbance by using the proposed mirror-lens HOE (MLHOE). Furthermore, to achieve an optimized optical recording condition of the MLHOE, the optical characteristics of the holographic material are measured. The proposed holographic AR display system is verified experimentally. PMID:27244395
A practical approach to the Hamilton-Jacobi formulation of holographic renormalization
NASA Astrophysics Data System (ADS)
Elvang, Henriette; Hadjiantonis, Marios
2016-06-01
We revisit the subject of holographic renormalization for asymptotically AdS spacetimes. For many applications of holography, one has to handle the divergences associated with the on-shell gravitational action. The brute force approach uses the Fefferman- Graham (FG) expansion near the AdS boundary to identify the divergences, but subsequent reversal of the expansion is needed to construct the infinite counterterms. While in principle straightforward, the method is cumbersome and application/reversal of FG is formally unsatisfactory. Various authors have proposed an alternative method based on the Hamilton-Jacobi equation. However, this approach may appear to be abstract, difficult to implement, and in some cases limited in applicability. In this paper, we clarify the Hamilton-Jacobi formulation of holographic renormalization and present a simple algorithm for its implementation to extract cleanly the infinite counterterms. While the derivation of the method relies on the Hamiltonian formulation of general relativity, the actual application of our algorithm does not. The work applies to any D-dimensional holographic dual with asymptotic AdS boundary, Euclidean or Lorentzian, and arbitrary slicing. We illustrate the method in several examples, including the FGPW model, a holographic model of 3d ABJM theory, and cases with marginal scalars such as a dilaton-axion system.
Massive 2-form field and holographic ferromagnetic phase transition
NASA Astrophysics Data System (ADS)
Cai, Rong-Gen; Yang, Run-Qiu; Wu, Ya-Bo; Zhang, Cheng-Yuan
2015-11-01
In this paper we investigate in some detail the holographic ferromagnetic phase transition in an AdS4 black brane background by introducing a massive 2-form field coupled to the Maxwell field strength in the bulk. In two probe limits, one is to neglect the back reaction of the 2-form field to the background geometry and to the Maxwell field, and the other to neglect the back reaction of both the Maxwell field and the 2-form field, we find that the spontaneous magnetization and the ferromagnetic phase transition always happen when the temperature gets low enough with similar critical behavior. We calculate the DC resistivity in a semi-analytical method in the second probe limit and find it behaves as the colossal magnetic resistance effect in some materials. In the case with the first probe limit, we obtain the off-shell free energy of the holographic model near the critical temperature and compare with the Ising-like model. We also study the back reaction effect and find that the phase transition is always second order. In addition, we find an analytical Reissner-Norström-like black brane solution in the Einstein-Maxwell-2-form field theory with a negative cosmological constant.
Layers of deformed instantons in holographic baryonic matter
NASA Astrophysics Data System (ADS)
Preis, Florian; Schmitt, Andreas
2016-07-01
We discuss homogeneous baryonic matter in the decompactified limit of the Sakai-Sugimoto model, improving existing approximations based on flat-space instantons. We allow for an anisotropic deformation of the instantons in the holographic and spatial directions and for a density-dependent distribution of arbitrarily many instanton layers in the bulk. Within our approximation, the baryon onset turns out to be a second-order phase transition, at odds with nature, and there is no transition to quark matter at high densities, at odds with expectations from QCD. This changes when we impose certain constraints on the shape of single instantons, motivated by known features of holographic baryons in the vacuum. Then, a first-order baryon onset and chiral restoration at high density are possible, and at sufficiently large densities two instanton layers are formed dynamically. Our results are a further step towards describing realistic, strongly interacting matter over a large density regime within a single model, desirable for studies of compact stars.
A framework for holographic scene representation and image synthesis.
Ziegler, Remo; Kaufmann, Peter; Gross, Markus
2007-01-01
We present a framework for the holographic representation and display of graphics objects. As opposed to traditional graphics representations, our approach reconstructs the light wave reflected or emitted by the original object directly from the underlying digital hologram. Our novel holographic graphics pipeline consists of several stages including the digital recording of a full-parallax hologram, the reconstruction and propagation of its wavefront, and rendering of the final image onto conventional, framebuffer-based displays. The required view-dependent depth image is computed from the phase information inherently represented in the complex-valued wavefront. Our model also comprises a correct physical modeling of the camera taking into account optical elements, such as lens and aperture. It thus allows for a variety of effects including depth of field, diffraction, interference, and features built-in anti-aliasing. A central feature of our framework is its seamless integration into conventional rendering and display technology which enables us to elegantly combine traditional 3D object or scene representations with holograms. The presented work includes the theoretical foundations and allows for high quality rendering of objects consisting of large numbers of elementary waves while keeping the hologram at a reasonable size. PMID:17218755
Feature based recognition of submerged objects in holographic imagery
NASA Astrophysics Data System (ADS)
Ratto, Christopher R.; Beagley, Nathaniel; Baldwin, Kevin C.; Shipley, Kara R.; Sternberger, Wayne I.
2014-05-01
The ability to autonomously sense and characterize underwater objects in situ is desirable in applications of unmanned underwater vehicles (UUVs). In this work, underwater object recognition was explored using a digital holographic system. Two experiments were performed in which several objects of varying size, shape, and material were submerged in a 43,000 gallon test tank. Holograms were collected from each object at multiple distances and orientations, with the imager located either outside the tank (looking through a porthole) or submerged (looking downward). The resultant imagery from these holograms was preprocessed to improve dynamic range, mitigate speckle, and segment out the image of the object. A collection of feature descriptors were then extracted from the imagery to characterize various object properties (e.g., shape, reflectivity, texture). The features extracted from images of multiple objects, collected at different imaging geometries, were then used to train statistical models for object recognition tasks. The resulting classification models were used to perform object classification as well as estimation of various parameters of the imaging geometry. This information can then be used to inform the design of autonomous sensing algorithms for UUVs employing holographic imagers.
Retractions of the gingival margins evaluated by holographic methods
NASA Astrophysics Data System (ADS)
Sinescu, Cosmin; Negrutiu, Meda Lavinia; Manole, Marius; de Sabata, Aldo; Rusu, Laura-Cristina; Stratul, Stefan; Dudea, Diana; Dughir, Ciprian; Duma, Virgil-Florin
2015-05-01
The periodontal disease is one of the most common pathological states of the teeth and gums system. The issue is that its evaluation is a subjective one, i.e. it is based on the skills of the dental medical doctor. As for any clinical condition, a quantitative evaluation and monitoring in time of the retraction of the gingival margins is desired. This phenomenon was evaluated in this study with a holographic method by using a He-Ne laser with a power of 13 mW. The holographic system we have utilized - adapted for dentistry applications - is described. Several patients were considered in a comparative study of their state of health - regarding their oral cavity. The impressions of the maxillary dental arch were taken from a patient during his/her first visit and after a period of six months. The hologram of the first model was superposed on the model cast after the second visit. The retractions of the gingival margins could be thus evaluated three-dimensionally in every point of interest. An evaluation of the retraction has thus been made. Conclusions can thus be drawn for the clinical evaluation of the health of the teeth and gums system of each patient.
Holographic quantum liquids in 1+1 dimensions
NASA Astrophysics Data System (ADS)
Hung, Ling-Yan; Sinha, Aninda
2010-01-01
In this paper we initiate the study of holographic quantum liquids in 1+1 dimensions. Since the Landau Fermi liquid theory breaks down in 1+1 dimensions, it is of interest to see what holographic methods have to say about similar models. For theories with a gapless branch, the Luttinger conjecture states that there is an effective description of the physics in terms of a Luttinger liquid which is specified by two parameters. The theory we consider is the defect CFT arising due to a probe D3 brane in the AdS Schwarzschild planar black hole background. We turn on a fundamental string density on the worldvolume. Unlike higher dimensional defects, a persistent dissipationless zero sound mode is found. The thermodynamic aspects of these models are considered carefully and certain subtleties with boundary terms are explained which are unique to 1+1 dimensions. Spectral functions of bosonic and fermionic fluctuations are also considered and quasinormal modes are analysed. A prescription is given to compute spectral functions when there is mixing due to the worldvolume gauge field. We comment on the Luttinger conjecture in the light of our findings.
Propagation phasor approach for holographic image reconstruction
NASA Astrophysics Data System (ADS)
Luo, Wei; Zhang, Yibo; Göröcs, Zoltán; Feizi, Alborz; Ozcan, Aydogan
2016-03-01
To achieve high-resolution and wide field-of-view, digital holographic imaging techniques need to tackle two major challenges: phase recovery and spatial undersampling. Previously, these challenges were separately addressed using phase retrieval and pixel super-resolution algorithms, which utilize the diversity of different imaging parameters. Although existing holographic imaging methods can achieve large space-bandwidth-products by performing pixel super-resolution and phase retrieval sequentially, they require large amounts of data, which might be a limitation in high-speed or cost-effective imaging applications. Here we report a propagation phasor approach, which for the first time combines phase retrieval and pixel super-resolution into a unified mathematical framework and enables the synthesis of new holographic image reconstruction methods with significantly improved data efficiency. In this approach, twin image and spatial aliasing signals, along with other digital artifacts, are interpreted as noise terms that are modulated by phasors that analytically depend on the lateral displacement between hologram and sensor planes, sample-to-sensor distance, wavelength, and the illumination angle. Compared to previous holographic reconstruction techniques, this new framework results in five- to seven-fold reduced number of raw measurements, while still achieving a competitive resolution and space-bandwidth-product. We also demonstrated the success of this approach by imaging biological specimens including Papanicolaou and blood smears.
Testing and inspecting lens by holographic means
Hildebrand, Bernard P.
1976-01-01
Processes for the accurate, rapid and inexpensive testing and inspecting of oncave and convex lens surfaces through holographic means requiring no beamsplitters, mirrors or overpower optics, and wherein a hologram formed in accordance with one aspect of the invention contains the entire interferometer and serves as both a master and illuminating source for both concave and said convex surfaces to be so tested.
Thermal stress studies using optical holographic interferometry
NASA Technical Reports Server (NTRS)
Harris, W. J.; Woods, D. C.
1974-01-01
The application of holography to thermal stress studies is discussed. Interference fringes as produced by holograms and their interpretation are reviewed in relation to workpiece displacement. Three potential mechanisms are given to explain thermal displacement as detected by holographic methods. Results of some thermal stressing studies are reported, including tests on a live rocket motor.
The Holographic Brain: Implications for Training Design.
ERIC Educational Resources Information Center
Jones, James R.
Without special training, most people predominantly process data in one of four ways. Few achieve a coveted whole brain state that integrates such important but separate brain functions as logic and intuition. With new training techniques that exploit the holographic properties of the brain, organizations may be able to tap powerful whole brain…
Full-color holographic 3D printer
NASA Astrophysics Data System (ADS)
Takano, Masami; Shigeta, Hiroaki; Nishihara, Takashi; Yamaguchi, Masahiro; Takahashi, Susumu; Ohyama, Nagaaki; Kobayashi, Akihiko; Iwata, Fujio
2003-05-01
A holographic 3D printer is a system that produces a direct hologram with full-parallax information using the 3-dimensional data of a subject from a computer. In this paper, we present a proposal for the reproduction of full-color images with the holographic 3D printer. In order to realize the 3-dimensional color image, we selected the 3 laser wavelength colors of red (λ=633nm), green (λ=533nm), and blue (λ=442nm), and we built a one-step optical system using a projection system and a liquid crystal display. The 3-dimensional color image is obtained by synthesizing in a 2D array the multiple exposure with these 3 wavelengths made on each 250mm elementary hologram, and moving recording medium on a x-y stage. For the natural color reproduction in the holographic 3D printer, we take the approach of the digital processing technique based on the color management technology. The matching between the input and output colors is performed by investigating first, the relation between the gray level transmittance of the LCD and the diffraction efficiency of the hologram and second, by measuring the color displayed by the hologram to establish a correlation. In our first experimental results a non-linear functional relation for single and multiple exposure of the three components were found. These results are the first step in the realization of a natural color 3D image produced by the holographic color 3D printer.
High sensitive materials in medical holographic microscopy
NASA Astrophysics Data System (ADS)
Osanlou, A.; Snashall, E.; Osanlou, O.; Osanlou, R.; Mirlis, E.; Shi, Lishen; Bjelkhagen, H.
2015-02-01
High sensitivity is defined in relation to the energy required to perform holographic recording. High sensitivity in silver halide materials is their main advantage over other similarly high resolving power holographic recording materials. This work reports progress on the development of silver halide based 'true colour holographic imaging', under a microscope. A thin layer of ultrafine grains of silver halide crystals of around 10 nm average diameter, dispersed in a colloid and coated on a substrate is used as the recording media. The significance of this method so far, is in its ability to produce 'true colour' three-dimensional images of specimen. The recordings have an appreciable depth, permitting the observer to scan through the image under a microscope, as one might with a real specimen sample. Current methods could perform ' True colour holographic imaging' directly under a microscope. The recording methodology has the potential for deeper complex and scattering media imaging, using very small pulses of appropriate laser wavelengths. The methodology, using novel nanosize panchromatic recording media consisting of dispersed fine nano grain crystals, could potentially revolutionise related medical imaging techniques. Future development of digital media will allow it to be utilized in this manner.
Liquid crystals for holographic optical data storage.
Matharu, Avtar S; Jeeva, Shehzad; Ramanujam, P S
2007-12-01
A tutorial review is presented to inform and inspire the reader to develop and integrate strong scientific links between liquid crystals and holographic data storage, from a materials scientist's viewpoint. The principle of holographic data storage as a means of providing a solution to the information storage demands of the 21st century is detailed. Holography is a small subset of the much larger field of optical data storage and similarly, the diversity of materials used for optical data storage is enormous. The theory of polarisation holography which produces holograms of constant intensity, is discussed. Polymeric liquid crystals play an important role in the development of materials for holographic storage and photoresponsive materials based on azobenzene are targeted for discussion due to their ease of photo-reversion between trans- and cis-states. Although the final polymer may not be liquid crystalline, irradiation can induce ordered domains. The mesogens act in a co-operative manner, enhancing refractive indices and birefringences. Surface relief gratings are discussed as a consequence of holographic storage. Cholesteric polymers comprising azobenzene are briefly highlighted. Irradiation causing cis-trans-isomerisation can be used to control helix pitch. A brief mention of liquid crystals is also made since these materials may be of future interest since they are optically transparent and amenable to photo-induced anisotropy. PMID:17982514
Pattern recognition with magnonic holographic memory device
NASA Astrophysics Data System (ADS)
Kozhevnikov, A.; Gertz, F.; Dudko, G.; Filimonov, Y.; Khitun, A.
2015-04-01
In this work, we present experimental data demonstrating the possibility of using magnonic holographic devices for pattern recognition. The prototype eight-terminal device consists of a magnetic matrix with micro-antennas placed on the periphery of the matrix to excite and detect spin waves. The principle of operation is based on the effect of spin wave interference, which is similar to the operation of optical holographic devices. Input information is encoded in the phases of the spin waves generated on the edges of the magnonic matrix, while the output corresponds to the amplitude of the inductive voltage produced by the interfering spin waves on the other side of the matrix. The level of the output voltage depends on the combination of the input phases as well as on the internal structure of the magnonic matrix. Experimental data collected for several magnonic matrixes show the unique output signatures in which maxima and minima correspond to specific input phase patterns. Potentially, magnonic holographic devices may provide a higher storage density compare to optical counterparts due to a shorter wavelength and compatibility with conventional electronic devices. The challenges and shortcoming of the magnonic holographic devices are also discussed.
Propagation phasor approach for holographic image reconstruction
Luo, Wei; Zhang, Yibo; Göröcs, Zoltán; Feizi, Alborz; Ozcan, Aydogan
2016-01-01
To achieve high-resolution and wide field-of-view, digital holographic imaging techniques need to tackle two major challenges: phase recovery and spatial undersampling. Previously, these challenges were separately addressed using phase retrieval and pixel super-resolution algorithms, which utilize the diversity of different imaging parameters. Although existing holographic imaging methods can achieve large space-bandwidth-products by performing pixel super-resolution and phase retrieval sequentially, they require large amounts of data, which might be a limitation in high-speed or cost-effective imaging applications. Here we report a propagation phasor approach, which for the first time combines phase retrieval and pixel super-resolution into a unified mathematical framework and enables the synthesis of new holographic image reconstruction methods with significantly improved data efficiency. In this approach, twin image and spatial aliasing signals, along with other digital artifacts, are interpreted as noise terms that are modulated by phasors that analytically depend on the lateral displacement between hologram and sensor planes, sample-to-sensor distance, wavelength, and the illumination angle. Compared to previous holographic reconstruction techniques, this new framework results in five- to seven-fold reduced number of raw measurements, while still achieving a competitive resolution and space-bandwidth-product. We also demonstrated the success of this approach by imaging biological specimens including Papanicolaou and blood smears. PMID:26964671
Gravitation from entanglement in holographic CFTs
NASA Astrophysics Data System (ADS)
Faulkner, Thomas; Guica, Monica; Hartman, Thomas; Myers, Robert C.; Van Raamsdonk, Mark
2014-03-01
Entanglement entropy obeys a `first law', an exact quantum generalization of the ordinary first law of thermodynamics. In any CFT with a semiclassical holographic dual, this first law has an interpretation in the dual gravitational theory as a constraint on the spacetimes dual to CFT states. For small perturbations around the CFT vacuum state, we show that the set of such constraints for all ball-shaped spatial regions in the CFT is exactly equivalent to the requirement that the dual geometry satisfy the gravitational equations of motion, linearized about pure AdS. For theories with entanglement entropy computed by the Ryu-Takayanagi formula S = /(4 G N), we obtain the linearized Einstein equations. For theories in which the vacuum entanglement entropy for a ball is computed by more general Wald functionals, we obtain the linearized equations for the associated higher-curvature theories. Using the first law, we also derive the holographic dictionary for the stress tensor, given the holographic formula for entanglement entropy. This method provides a simple alternative to holographic renormalization for computing the stress tensor expectation value in arbitrary higher derivative gravitational theories.
Pattern recognition with magnonic holographic memory device
Kozhevnikov, A.; Dudko, G.; Filimonov, Y.; Gertz, F.; Khitun, A.
2015-04-06
In this work, we present experimental data demonstrating the possibility of using magnonic holographic devices for pattern recognition. The prototype eight-terminal device consists of a magnetic matrix with micro-antennas placed on the periphery of the matrix to excite and detect spin waves. The principle of operation is based on the effect of spin wave interference, which is similar to the operation of optical holographic devices. Input information is encoded in the phases of the spin waves generated on the edges of the magnonic matrix, while the output corresponds to the amplitude of the inductive voltage produced by the interfering spin waves on the other side of the matrix. The level of the output voltage depends on the combination of the input phases as well as on the internal structure of the magnonic matrix. Experimental data collected for several magnonic matrixes show the unique output signatures in which maxima and minima correspond to specific input phase patterns. Potentially, magnonic holographic devices may provide a higher storage density compare to optical counterparts due to a shorter wavelength and compatibility with conventional electronic devices. The challenges and shortcoming of the magnonic holographic devices are also discussed.
Holographic Compact Disk Read-Only Memories
NASA Technical Reports Server (NTRS)
Liu, Tsuen-Hsi
1996-01-01
Compact disk read-only memories (CD-ROMs) of proposed type store digital data in volume holograms instead of in surface differentially reflective elements. Holographic CD-ROM consist largely of parts similar to those used in conventional CD-ROMs. However, achieves 10 or more times data-storage capacity and throughput by use of wavelength-multiplexing/volume-hologram scheme.
Two color holographic interferometry for microgravity application
NASA Technical Reports Server (NTRS)
Trolinger, James D.; Weber, David C.
1995-01-01
Holographic interferometry is a primary candidate for determining temperature and concentration in crystal growth experiments designed for space. The method measures refractive index changes within the fluid of an experimental test cell resulting from temperature and/or concentration changes. When the refractive index changes are caused by simultaneous temperature and concentration changes, the contributions of the two effects cannot be separated by single wavelength interferometry. By using two wavelengths, however, two independent interferograms can provide the additional independent equation required to determine the two unknowns. There is no other technique available that provides this type of information. The primary objectives of this effort were to experimentally verify the mathematical theory of two color holographic interferometry (TCHI) and to determine the practical value of this technique for space application. In the foregoing study, the theory of TCHI has been tested experimentally over a range of interest for materials processing in space where measurements of temperature and concentration in a solution are required. New techniques were developed and applied to stretch the limits beyond what could be done with existing procedures. The study resulted in the production of one of the most advanced, enhanced sensitivity holographic interferometers in existence. The interferometric measurements made at MSFC represent what is believed to be the most accurate holographic interferometric measurements made in a fluid to date. The tests have provided an understanding of the limitations of the technique in practical use.
Holographic reflection gratings in photopolymerizable solgel materials.
Murciano, A; Blaya, S; Carretero, L; Madrigal, R F; Fimia, A
2006-08-01
The recording of holographic reflection gratings with a spatial frequency higher than 5400 lines/mm in photopolymerizable solgel materials is experimentally demonstrated. Diffraction efficiencies near 60% and a FWHM of 2.5 nm centered at 531.5 nm are achieved. Moreover, the effect of the energetic exposure is characterized at different recording intensities. PMID:16832471
Holographic reflection gratings in photopolymerizable solgel materials
NASA Astrophysics Data System (ADS)
Murciano, A.; Blaya, S.; Carretero, L.; Madrigal, R. F.; Fimia, A.
2006-08-01
The recording of holographic reflection gratings with a spatial frequency higher than 5400 lines/mm in photopolymerizable solgel materials is experimentally demonstrated. Diffraction efficiencies near 60% and a FWHM of 2.5 nm centered at 531.5 nm are achieved. Moreover, the effect of the energetic exposure is characterized at different recording intensities.
Photorefractive phase-conjugation digital holographic microscopy
NASA Astrophysics Data System (ADS)
Chang, Chi-Ching; Chan, Huang-Tian; Shiu, Min-Tzung; Chew, Yang-Kun
2015-05-01
In this work, we propose an innovative method for digital holographic microscopy named as photorefractive phaseconjugation digital holographic microscopy (PPCDHM) technique based on the phase conjugation dynamic holographic process in photorefractive BaTiO3 crystal and the retrieval of phase and amplitude of the object wave were performed by a reflection-type digital holographic method. Both amplitude and phase reconstruction benefit from the prior amplification by self-pumped conjugation (SPPC) as they have an increased SNR. The interest of the PPCDHM is great, because its hologram is created by interfered the amplified phase-conjugate wave field generated from a photorefractive phase conjugator (PPC) correcting the phase aberration of the imaging system and the reference wave onto the digital CCD camera. Therefore, a precise three-dimensional description of the object with high SNR can be obtained digitally with only one hologram acquisition. The method requires the acquisition of a single hologram from which the phase distribution can be obtained simultaneously with distribution of intensity at the surface of the object.
Holographic analysis as an inspection method for welded thin-wall tubing
NASA Technical Reports Server (NTRS)
Brooks, Lawrence; Mulholland, John; Genin, Joseph; Matthews, Larryl
1990-01-01
The feasibility of using holographic interferometry for locating flaws in welded tubing is explored. Two holographic techniques are considered: traditional holographic interferometry and electronic speckle pattern interferometry. Several flaws including cold laps, discontinuities, and tube misalignments are detected.
Light-front holographic QCD with generic dilaton profile
NASA Astrophysics Data System (ADS)
Guo, Zhaoheng; Liu, Tianbo; Ma, Bo-Qiang
2016-04-01
We generalize the soft-wall and hard-wall models to a light-front holographic QCD model with a generic dilaton profile. The effective potential induced by a higher power dilaton profile is interpreted as a stronger color confinement at long distance, and it gradually evolves to the hard-wall model when the power increases to infinity. As an application, we investigate the exotic meson states recently discovered in experiments in the generic soft-wall model with a higher power dilaton profile, and the results are in agreement with the spectra of the exotic mesons. Our calculation indicates a weaker interaction at short distance and a stronger interaction at large distance for the components in the exotic mesons. The generic dilaton profile deserves further scrutiny for understanding the strong interaction and for applications.
NASA Astrophysics Data System (ADS)
Fein, Howard
2003-09-01
Holographic Interferometry has been successfully employed to characterize the materials and behavior of diverse types of structures under dynamic stress. Specialized variations of this technology have also been applied to define dynamic and vibration related structural behavior. Such applications of holographic technique offer some of the most effective methods of modal and dynamic analysis available. Real-time dynamic testing of the modal and mechanical behavior of jet engine turbine, rotor, vane, and compressor structures has always required advanced instrumentation for data collection in either simulated flight operation test or computer-based modeling and simulations. Advanced optical holography techniques are alternate methods which result in actual full-field behavioral data in a noninvasive, noncontact environment. These methods offer significant insight in both the development and subsequent operational test and modeling of advanced jet engine turbine and compressor rotor structures and their integration with total vehicle system dynamics. Structures and materials can be analyzed with very low amplitude excitation and the resultant data can be used to adjust the accuracy of mathematically derived structural and behavioral models. Holographic Interferometry offers a powerful tool to aid in the developmental engineering of turbine rotor and compressor structures for high stress applications. Aircraft engine applications in particular most consider operational environments where extremes in vibration and impulsive as well as continuous mechanical stress can affect both operation and structural stability. These considerations present ideal requisites for analysis using advanced holographic methods in the initial design and test of turbine rotor components. Holographic techniques are nondestructive, real-time, and definitive in allowing the identification of vibrational modes, displacements, and motion geometries. Such information can be crucial to the
NASA Astrophysics Data System (ADS)
Fein, Howard
2003-05-01
Holographic Interferometry has been successfully employed to characterize the materials and behavior of diverse types of structures under dynamic stress 1,2,3,4. Specialized variations of this technology have also been applied to define dynamic and vibration related structural behavior 5. Such applications of holographic technique offer some of the most effective methods of modal and dynamic analysis available. Real-time dynamic testing of the modal and mechanical behavior of jet engine turbine, rotor, vane, and compressor structures has always required advanced instrumentation for data collection in either simulated flight operation test or computer-based modeling and simulations. Advanced optical holography techniques are alternate methods which result in actual full-field behavioral data in a noninvasive, noncontact environment 6. These methods offer significant insight in both the development and subsequent operational test and modeling of advanced jet engine turbine and compressor rotor structures and their integration with total vehicle system dynamics. Structures and materials can be analyzed with very low amplitude excitation and the resultant data can be used to adjust the accuracy of mathematically derived structural and behavioral models. Holographic Interferometry offers a powerful tool to aid in the developmental engineering of turbine rotor and compressor structures for high stress applications. Aircraft engine applications in particular must consider operational environments where extremes in vibration and impulsive as well as continuous mechanical stress can affect both operation and structural stability. These considerations present ideal requisites for analysis using advanced holographic methods in the initial design and test of turbine rotor components. Holographic techniques are nondestructive, real-time, and definitive in allowing the identification of vibrational modes, displacements, and motion geometries. Such information can be crucial to
Holographic dark energy in Brans-Dicke theory with logarithmic correction
NASA Astrophysics Data System (ADS)
Sheykhi, A.; Karami, K.; Jamil, M.; Kazemi, E.; Haddad, M.
2012-03-01
In the derivation of holographic dark energy density, the area law of the black hole entropy plays a crucial role. However, the entropy-area relation can be modified from the inclusion of quantum effects, motivated from the loop quantum gravity, string theory and black hole physics. In this paper, we study cosmological implication of the interacting entropy-corrected holographic dark energy model in the framework of Brans-Dicke cosmology. We obtain the equation of state and the deceleration parameters of the entropy-corrected holographic dark energy in a non-flat Universe. As system's IR cutoff we choose the radius of the event horizon measured on the sphere of the horizon, defined as L = ar( t). We find out that when the entropy-corrected holographic dark energy is combined with the Brans-Dicke field, the transition from normal state where w D > -1 to the phantom regime where w D < -1 for the equation of state of interacting dark energy can be more easily achieved for than when resort to the Einstein field equations is made.
HOMER: the Holographic Optical Microscope for Education and Research
NASA Astrophysics Data System (ADS)
Luviano, Anali
Holography was invented in 1948 by Dennis Gabor and has undergone major advancements since the 2000s leading to the development of commercial digital holographic microscopes (DHM). This noninvasive form of microscopy produces a three-dimensional (3-D) digital model of a sample without altering or destroying the sample, thus allowing the same sample to be studied multiple times. HOMER-the Holographic Optical Microscope for Education and Research-produces a 3-D image from a two-dimensional (2-D) interference pattern captured by a camera that is then put through reconstruction software. This 2-D pattern is created when a reference wave interacts with the sample to produce a secondary wave that interferes with the unaltered part of the reference wave. I constructed HOMER to be an efficient, portable in-line DHM using inexpensive material and free reconstruction software. HOMER uses three different-colored LEDs as light sources. I am testing the performance of HOMER with the goal of producing tri-color images of samples. I'm using small basic biological samples to test the effectiveness of HOMER and plan to transition to complex cellular and biological specimens as I pursue my interest in biophysics. Norwich University.
Infrared behavior of scalar condensates in effective holographic theories
NASA Astrophysics Data System (ADS)
Cadoni, Mariano; Pani, Paolo; Serra, Matteo
2013-06-01
We investigate the infrared behavior of the spectrum of scalar-dressed, asymptotically Anti de Sitter (AdS) black brane (BB) solutions of effective holographic models. These solutions describe scalar condensates in the dual field theories. We show that for zero charge density the ground state of these BBs must be degenerate with the AdS vacuum, must satisfy conformal boundary conditions for the scalar field and it is isolated from the continuous part of the spectrum. When a finite charge density is switched on, the ground state is not anymore isolated and the degeneracy is removed. Depending on the coupling functions, the new ground state may possibly be energetically preferred with respect to the extremal Reissner-Nordstrom AdS BB. We derive several properties of BBs near extremality and at finite temperature. As a check and illustration of our results we derive and discuss several analytic and numerical, BB solutions of Einstein-scalar-Maxwell AdS gravity with different coupling functions and different potentials. We also discuss how our results can be used for understanding holographic quantum critical points, in particular their stability and the associated quantum phase transitions leading to superconductivity or hyperscaling violation.
Zero temperature holographic superfluids with two competing orders
NASA Astrophysics Data System (ADS)
Ran, Li; Tian, Yu; Zhang, Hongbao; Zhao, Junkun
2016-08-01
We initiate the investigation of the zero temperature holographic superfluids with two competing orders, where besides the vacuum phase, two one component superfluid phases, the coexistent superfluid phase has also been found in the anti-de Sitter soliton background for the first time. We construct the complete phase diagram in the e - μ plane by numerics, which is consistent with our qualitative analysis. Furthermore, we calculate the corresponding optical conductivity and sound speed by the linear response theory. The onset of the pole of optical conductivity at ω =0 indicates that the spontaneous breaking phase always represents the superfluid phase, and the residue of the pole is increased with the chemical potential, which is consistent with the fact that the particle density is essentially the superfluid density for zero temperature superfluids. In addition, the resulting sound speed demonstrates the nonsmoothness at the critical points as the order parameter of the condensate, which indicates that the phase transitions can also be identified by the behavior of the sound speed. Moreover, as expected from the boundary conformal field theory, the sound speed saturates to 1/√{2 } at the large chemical potential limit for our two component holographic superfluid model.
Realization of chiral symmetry breaking and restoration in holographic QCD
NASA Astrophysics Data System (ADS)
Chelabi, Kaddour; Fang, Zhen; Huang, Mei; Li, Danning; Wu, Yue-Liang
2016-05-01
With proper profiles of the scalar potential and the dilaton field, for the first time, the spontaneous chiral symmetry breaking in the vacuum and its restoration at finite temperature are correctly realized in the holographic QCD framework. In the chiral limit, a nonzero chiral condensate develops in the vacuum and decreases with temperature, and the phase transition is of the second order for a two-flavor case and of the first order for a three-flavor case. In the case of explicit chiral symmetry breaking, in the two-flavor case, the second-order phase transition turns into a crossover with any nonzero current quark mass, and in the three-flavor case, the first-order phase transition turns into a crossover at a finite current quark mass. The correct description of chiral symmetry breaking and restoration makes the holographic QCD models more powerful in dealing with nonperturbative QCD phenomena. This framework can be regarded as a general setup in an application of AdS/CFT to describe conventional Ginzburg-Landau-Wilson-type phase transitions, e.g. in condensed matter and cosmology systems.
Universal far-from-equilibrium dynamics of a holographic superconductor.
Sonner, Julian; Del Campo, Adolfo; Zurek, Wojciech H
2015-01-01
Symmetry-breaking phase transitions are an example of non-equilibrium processes that require real-time treatment, a major challenge in strongly coupled systems without long-lived quasiparticles. Holographic duality provides such an approach by mapping strongly coupled field theories in D dimensions into weakly coupled quantum gravity in D+1 anti-de Sitter spacetime. Here we use holographic duality to study the formation of topological defects-winding numbers-in the course of a superconducting transition in a strongly coupled theory in a 1D ring. When the system undergoes the transition on a given quench time, the condensate builds up with a delay that can be deduced using the Kibble-Zurek mechanism from the quench time and the universality class of the theory, as determined from the quasinormal mode spectrum of the dual model. Typical winding numbers deposited in the ring exhibit a universal fractional power law dependence on the quench time, also predicted by the Kibble-Zurek Mechanism. PMID:26100330
Robust Topological and Holographic Degeneracies of Classical Systems
NASA Astrophysics Data System (ADS)
Vaezi, Seyyed Mohammad Sadegh; Nussinov, Zohar; Ortiz, Gerardo
We challenge the hypothesis that the ground states of a physical system whose degeneracy depends on topology must necessarily realize topological quantum order and display non-local entanglement. To this end, we introduce and study a classical rendition of the Toric Code model embedded on Riemann surfaces of different genus numbers. We find that the minimal ground state degeneracy (and those of all levels) depends on the topology of the embedding surface alone. As the ground states of this classical system may be distinguished by local measurements, a characteristic of Landau orders, this example illustrates that topological degeneracy is not a sufficient condition for topological quantum order. This conclusion is generic and, as shown, it applies to many other models. We also demonstrate that in certain lattice realizations of these models, and other theories, one can find a ground state entropy that is ''holographic'', i.e., extensive in the system's boundary.
Supercurrent in a p-wave holographic superconductor
Zeng Huabi; Sun Weimin; Zong Hongshi
2011-02-15
The p-wave and p+ip-wave holographic superconductors with fixed DC supercurrent are studied by introducing a nonvanishing vector potential. We find that close to the critical temperature T{sub c} of zero current, the numerical results of both the p-wave model and the p+ip model are the same as those of Ginzburg-Landau (GL) theory; for example, the critical current is j{sub c}{approx}(T{sub c}-T){sup 3/2} and the phase transition in the presence of a DC current is a first-order transition. Beside the similar results between both models, the p+ip superconductor shows isotropic behavior for the supercurrent, while the p-wave superconductor shows anisotropic behavior for the supercurrent.
Holographic kinetics for mixed volume gratings in gold nanoparticles doped photopolymer.
Li, Chengmingyue; Cao, Liangcai; He, Qingsheng; Jin, Guofan
2014-03-10
A holographic kinetic model is proposed to quantitatively represent the dynamics of mixed volume gratings in a bulk gold nanoparticles (NPs) doped photopolymer. Due to the polymerization-driven multicomponent diffusion, the volume refractive index grating is induced by the periodic spatial distribution of photoproduct while the absorption grating is formed by the periodic spatial distribution of gold NPs. By simulating this model with the characterization of time varying absorption modulation, it is capable to describe the behavior of gold NPs in both the polymerization and the multicomponent diffusion process. The temporal evolution of refractive index modulation and absorption modulation can be extracted, respectively, from a diffraction efficiency curve by fitting the model. The established model could be an effective method for understanding the photophysical and photochemical mechanism of holographic nanocomposite. PMID:24663840
Silver-doped photopolymer media for holographic recording.
Pramitha, V; Nimmi, K P; Subramanyan, N V; Joseph, Rani; Sreekumar, K; Kartha, C Sudha
2009-04-20
Incorporation of silver ions into a dye-sensitized poly(vinyl alcohol)/acrylamide photopolymer is observed to give better performance compared to other metal-ion-doped photopolymer holographic recording media. Plane-wave transmission gratings were recorded in the photopolymer films using a He-Ne laser, and various holographic parameters were optimized so as to explore maximum potential of the material for various holographic applications. Silver-doped films showed good energy sensitivity, and gratings recorded in optimized film exhibited a diffraction efficiency of more than 75%. The potential of the material for holographic data storage applications is also studied using peristrophic multiplexing. PMID:19381175
Violation of the holographic principle in the loop quantum gravity
NASA Astrophysics Data System (ADS)
Sargın, Ozan; Faizal, Mir
2016-02-01
In this paper, we analyze the holographic principle using loop quantum gravity (LQG). This will be done by using polymeric quantization for analysing Yurtsever's holographic bound on the entropy, which is obtained from local quantum field theories. As the polymeric quantization is the characteristic feature of loop quantum gravity, we will argue that this calculation will indicate the effect of loop quantum gravity on the holographic principle. Thus, we will be able to explicitly demonstrate the violation of the holographic principle in the loop quantum gravity.
Photosensitive holographic material with a medium of fluorescent ink
NASA Astrophysics Data System (ADS)
Olivares-Pérez, A.; Toxqui-López, S.; Fuentes-Tapia, I.; Ortiz-Gutiérrez, M.; Mellado-Villaseñor, G.
2012-03-01
Recent researches have been reported that is possible increase the diffraction efficiency parameter from holographic gratings when photosensitive material (PVA with ammonium dichromate) it is painted after register the hologram with commercial fluorescent ink. In this research we shown that PVA as a binder, with the fluorescent ink and ammonium dichromate, this mixed can be used as recording medium. We characterize this material by implementing holographic films in which holographic gratings are recorded with a He- Cd laser at 442nm, and measuring holographic parameters such as diffraction efficiency. We get increased the diffraction efficiency and also the lifetime of the film.
Modulation of the characteristics of complex holographic gratings under an additional laser pulse
Kucherenko, M G; Rusinov, A P; Fedorov, D S
2012-08-31
Recording of elementary holographic gratings in polymer films and solutions coloured with organic dyes has been investigated. Possible mechanisms of modifying a recorded grating by an additional laser pulse are considered. A theoretical model is proposed to describe the processes of recording/relaxation and modification of gratings recorded on triplet states of photochrome molecules; the predictions of this model are found to be in good agreement with the experimental data. (holography)
Spatial modulation and conductivities in effective holographic theories
NASA Astrophysics Data System (ADS)
Rangamani, Mukund; Rozali, Moshe; Smyth, Darren
2015-07-01
We analyze a class of bottom-up holographic models for low energy thermo-electric transport. The models we focus on belong to a family of Einstein-Maxwell-dilaton theories parameterized by two scalar functions, characterizing the dilaton self-interaction and the gauge coupling function. We impose spatially inhomogeneous lattice boundary conditions for the dilaton on the AdS boundary and study the resulting phase structure attained at low energies. We find that as we dial the scalar functions at our disposal (changing thus the theory under consideration), we obtain either (i) coherent metallic, or (ii) insulating, or (iii) incoherent metallic phases. We chart out the domain where the incoherent metals appear in a restricted parameter space of theories. We also analyze the optical conductivity, noting that non-trivial scaling behaviour at intermediate frequencies appears to only be possible for very narrow regions of parameter space.
Deformation of a holographic image in space
Schumann, W.; Cuche, D.
1982-01-01
In the preliminary part of this paper, the third-order aberrations (coma) of the points of a modified holographic image are investigated by means of the seocond-order terms in the transverse-ray equation. In the main part, however, the deformation of the holographic image as a whole (more precisely, the deformation of the vicinity of each point) is treated: First a duality concept is used; then it is outlined in such a way that the same third-order tensor as the one describing the coma appears in the deformation in space. This third-order tensor contains both the derivative and the square of the second-order tensor that describes the astigmatism.
Compression of digital holographic data: an overview
NASA Astrophysics Data System (ADS)
Dufaux, Frederic; Xing, Yafei; Pesquet-Popescu, Beatrice; Schelkens, Peter
2015-09-01
Holography has the potential to become the ultimate 3D experience. Nevertheless, in order to achieve practical working systems, major scientific and technological challenges have to be tackled. In particular, as digital holographic data represents a huge amount of information, the development of efficient compression techniques is a key component. This problem has gained significant attention by the research community during the last 10 years. Given that holograms have very different signal properties when compared to natural images and video sequences, existing compression techniques (e.g. JPEG or MPEG) remain suboptimal, calling for innovative compression solutions. In this paper, we will review and analyze past and on-going work for the compression of digital holographic data.
Conformal quantum mechanics and holographic quench
NASA Astrophysics Data System (ADS)
Järvelä, Jarkko; Keränen, Ville; Keski-Vakkuri, Esko
2016-02-01
Recently, there has been much interest in holographic computations of two-point nonequilibrium Green functions from anti-de Sitter- (AdS-)Vaidya backgrounds. In the strongly coupled quantum field theory on the boundary, the dual interpretation of the background is an equilibration process called a holographic quench. The two-dimensional AdS-Vaidya spacetime is a special case, dual to conformal quantum mechanics. We study how the quench is incorporated into a Hamiltonian H +θ (t )Δ H and into correlation functions. With the help of recent work on correlation functions in conformal quantum mechanics, we first rederive the known two-point functions, and then compute nonequilibrium three- and four-point functions. We also compute the three-point function Witten diagram in the two-dimensional AdS-Vaidya background, and find agreement with the conformal quantum mechanics result.
Holographic representation of higher spin gauge fields
NASA Astrophysics Data System (ADS)
Sarkar, Debajyoti; Xiao, Xiao
2015-04-01
Extending the results of [1,2] on the holographic representation of local gauge field operators in anti-de Sitter space, here we construct the bulk operators for higher spin gauge fields at the leading order in 1/N expansion. Working in the holographic gauge for higher spin gauge fields, we show that gauge field operators with integer spin s >1 can be represented by an integration over a ball region, which is the interior region of the spacelike bulk light cone on the boundary. The construction is shown to be anti-de Sitter covariant up to gauge transformations, and the two-point function between higher spin gauge fields and the boundary higher spin current exhibits singularities on both bulk and boundary light cones. We also comment on a possible extension to the level of three-point functions and carry out a causal construction for higher spin fields in de Sitter spacetime.
Holographic Reconstruction Of A Synthetised Subpicosecond Pulse
NASA Astrophysics Data System (ADS)
Tribillon, G.; Salazar, R.
1983-10-01
Subpicosecond pulses have been synthetized with a dye laser. The 8000 GHz broadband source corresponds to a temporal resolution of ▵t = 1/▵ν = 0,12 ps. The holographic recording set-up proposed by N. Abramson has been used to visualize the light in flight, but the wavelength dependence of the hologram introduces a disper sion in the reconstructed image. Compensation techniques have been applied and an other recording system has been developed. Experimental results of the reconstructed holographic wavefront are presented. The interesting possibility to obtain a reconstruction in white light is compared with the coherent case. The signal-to-noise ratio of the image is discussed.
Very general holographic superconductors and entanglement thermodynamics
NASA Astrophysics Data System (ADS)
Dey, Anshuman; Mahapatra, Subhash; Sarkar, Tapobrata
2014-12-01
We construct and analyze holographic superconductors with generalized higher derivative couplings, in single R-charged black hole backgrounds in four and five dimensions. These systems, which we call very general holographic superconductors, have multiple tuning parameters and are shown to exhibit a rich phase structure. We establish the phase diagram numerically as well as by computing the free energy, and then validated the results by calculating the entanglement entropy for these systems. The entanglement entropy is shown to be a perfect indicator of the phase diagram. The differences in the nature of the entanglement entropy in R-charged backgrounds compared to the AdS-Schwarzschild cases are pointed out. We also compute the analogue of the entangling temperature for a subclass of these systems and compare the results with non-hairy backgrounds.
More holographic Berezinskii-Kosterlitz-Thouless transitions
Jensen, Kristan
2010-08-15
We find two systems via holography that exhibit quantum Berezinskii-Kosterlitz-Thouless (BKT) phase transitions. The first is the ABJM theory with flavor and the second is a flavored (1, 1) little string theory. In each case the transition occurs at nonzero density and magnetic field. The BKT transition in the little string theory is the first example of a quantum BKT transition in (3+1) dimensions. As in the 'original' holographic BKT transition in the D3/D5 system, the exponential scaling is destroyed at any nonzero temperature and the transition becomes second order. Along the way we construct holographic renormalization for probe branes in the ABJM theory and propose a scheme for the little string theory. Finally, we obtain the embeddings and (half of) the meson spectrum in the ABJM theory with massive flavor.
Holographic Optical Storage Using Photorefractive Polymers
NASA Technical Reports Server (NTRS)
Hayden, L. Michael; Strutz, Shane J.; Harris, Kristi; Ayachitula, Rajani
2000-01-01
The task for this report is to perform the basic research and develop a prototype benchtop holographic optical storage system based on photochromic and/or photorefractive polymers so that both permanent and erasable images may be stored and retrieved in the same mixed polymer medium. The task consist of: assembly and setup of the benchtop holographic storage system, including lasers, optics, and other ancillary equipment in a laboratory setting; and research and development of a suitable polymer matrix that will allow practical storage and retrieval of digital data. This will necessitate molecular design of the matrices involved and subsequent physics test to verify the characteristics of the matrices provide practical storage and retrieval.
Exploring unconventional capabilities of holographic tweezers
NASA Astrophysics Data System (ADS)
Hernandez, R. J.; Pagliusi, P.; Provenzano, C.; Cipparrone, G.
2011-06-01
We report an investigation of manipulation and trapping capabilities of polarization holographic tweezers. A polarization gradient connected with a modulation of the ellipticity shows an optical force related to the polarization of the light that can influence optically isotropic particles. While in the case of birefringent particles an unconventional trapping in circularly polarized fringes is observed. A liquid crystal emulsion has been adopted to investigate the capabilities of the holographic tweezers. The unusual trapping observed for rotating bipolar nematic droplets has suggested the involvement of the lift hydrodynamic force responsible of the Magnus effect, originating from the peculiar optical force field. We show that the Magnus force which is ignored in the common approach can contribute to unconventional optohydrodynamic trapping and manipulation.
Development of 3D holographic endoscope
NASA Astrophysics Data System (ADS)
Özcan, Meriç; Önal Tayyar, Duygu
2016-03-01
Here we present the development of a 3D holographic endoscope with an interferometer built around a commercial rigid endoscope. We consider recording the holograms with coherent and incoherent light separately without compromising the white light imaging capacity of the endoscope. In coherent light based recording, reference wave required for the hologram is obtained in two different ways. First, as in the classical holography, splitting the laser beam before the object illumination, and secondly creating the reference beam from the object beam itself. This second method does not require path-length matching between the object wave and the reference wave, and it allows the usage of short coherence length light sources. For incoherent light based holographic recordings various interferometric configurations are considered. Experimental results on both illumination conditions are presented.
Holographic NDT of thin titanium plate described
NASA Astrophysics Data System (ADS)
Yang, R.
1986-01-01
Holography is a technique for recording the amplitude and phase changes of an object on a photographic plate in the form of interference fringes. Because the holographic interference method can examine a component in the noncontact mode and is not bothered by complicated part shape or surface roughness, it has been widely used in nondestructive testing. In the rapidly developing aerospace industry, titanium and titanium alloy thin plates are used more and more but local delamination has been found in the production process of bonded titanium plates. Using ultrasonic methods, such defects are difficult to detect and large area delaminations with tightly closed edges can easily be missed. Other testing methods are also unsuccessful. A holographic method was developed for detecting defects in thin titanium plates and several high temperature alloy plates were tested. The testing equipment, methods and results are discussed.
Measurements of Holographic Properties of Bacteriorhodopsin Films
NASA Technical Reports Server (NTRS)
Downie, John D.; Swietek, Gregory E. (Technical Monitor)
1995-01-01
Several different bacteriorhodopsin (BR) films are characterized with respect to general holographic properties. Experimental measurements include diffraction efficiency and sensitivity as functions of writing intensity and grating frequency, hologram thermal decay behavior, diffraction efficiency as a function of grating tilt within the film and modulation depth, and estimates of the refractive index change from the diffraction efficiency data. The films studied include those made from wildtype BR and the genetic variants D96N and D96N/T46V. The maximum diffraction efficiency measured was just over 3% for a hydrated wildtype BR film. The films' holographic properties were found to be relatively insensitive to grating frequency and grating tilt angle. The diffraction efficiency dropped off more sharply as a function of modulation depth than a purely linear medium, and only the hydrated wildtype film exhibited significant behavior variation with different writing intensities.
Advanced Compact Holographic Data Storage System
NASA Technical Reports Server (NTRS)
Chao, Tien-Hsin; Zhou, Hanying; Reyes, George
2000-01-01
JPL, under current sponsorship from NASA Space Science and Earth Science Programs, is developing a high-density, nonvolatile and rad-hard Advanced Holographic Memory (AHM) 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 electro-optic 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 highspeed. The nonvolatile, rad-hard characteristics of the holographic memory will provide a revolutionary memory technology to enhance mission capabilities for all NASA's Earth Science Mission. In this paper, recent technology progress in developing this CHDS at JPL will be presented.
Holographic vector-wave femtosecond laser processing
NASA Astrophysics Data System (ADS)
Hayasaki, Yoshio; Hasegawa, Satoshi
2016-03-01
Arbitrary and variable beam shaping of femtosecond pulses by a computer-generated hologram (CGH) displayed on a spatial light modulator (SLM) have been applied to femtosecond laser processing. The holographic femtosecond laser processing has been widely used in many applications such as two-photon polymerization, optical waveguide fabrication, fabrication of volume phase gratings in polymers, and surface nanostructuring. A vector wave that has a spatial distribution of polarization states control of femtosecond pulses gives good performances for the femtosecond laser processing. In this paper, an in- system optimization of a CGH for massively-parallel femtosecond laser processing, a dynamic control of spatial spectral dispersion to improve the focal spot shape, and the holographic vector-wave femtosecond laser processing are demonstrated.
Holographic vortex liquids and superfluid turbulence.
Chesler, Paul M; Liu, Hong; Adams, Allan
2013-07-26
Superfluid turbulence is a fascinating phenomenon for which a satisfactory theoretical framework is lacking. Holographic duality provides a systematic approach to studying such quantum turbulence by mapping the dynamics of a strongly interacting quantum liquid into the dynamics of classical gravity. We use this gravitational description to numerically construct turbulent flows in a holographic superfluid in two spatial dimensions. We find that the superfluid kinetic energy spectrum obeys the Kolmogorov -5/3 scaling law, with energy injected at long wavelengths undergoing a direct cascade to short wavelengths where dissipation by vortex annihilation and vortex drag becomes efficient. This dissipation has a simple gravitational interpretation as energy flux across a black hole event horizon. PMID:23888034
Biometric Identification Using Holographic Radar Imaging Techniques
McMakin, Douglas L.; Sheen, David M.; Hall, Thomas E.; Kennedy, Mike O.; Foote, Harlan P.
2007-04-01
Pacific Northwest National Laboratory researchers have been at the forefront of developing innovative screening systems to enhance security and a novel imaging system to provide custom-fit clothing using holographic radar imaging techniques. First-of-a-kind cylindrical holographic imaging systems have been developed to screen people at security checkpoints for the detection of concealed, body worn, non-metallic threats such as plastic and liquid explosives, knifes and contraband. Another embodiment of this technology is capable of obtaining full sized body measurements in near real time without the person under surveillance removing their outer garments. Radar signals readily penetrate clothing and reflect off the water in skin. This full body measurement system is commercially available for best fitting ready to wear clothing, which was the first “biometric” application for this technology. One compelling feature of this technology for security biometric applications is that it can see effectively through disguises, appliances and body hair.
Transonic flow visualization using holographic interferometry
NASA Technical Reports Server (NTRS)
Bryanston-Cross, Peter J.
1987-01-01
An account is made of some of the applications of holographic interferometry to the visualization of transonic flows. In the case of the compressor shock visualization, the method is used regularly and has moved from being a research department invention to a design test tool. With the implementation of automatic processing and simple digitization systems, holographic vibrational analysis has also moved into routine nondestructive testing. The code verification interferograms were instructive, but the main turbomachinery interest is now in 3 dimensional flows. A major data interpretation effort will be required to compute tomographically the 3 dimensional flow around the leading or the trailing edges of a rotating blade row. The bolt on approach shows the potential application to current unsteady flows of interest. In particular that of the rotor passing and vortex interaction effects is experienced by the new generation of unducted fans. The turbocharger tests presents a new area for the application of holography.
Multidimensional optical fractionation with holographic verification
NASA Astrophysics Data System (ADS)
Xiao, Ke; Grier, David
2010-03-01
Colloidal particles driven through a periodic potential energy landscape can become kinetically locked in to symmetry-selected directions. The path a given particle follows has been predicted to depend sensitively on such properties as the particle's size and refractive index. These predictions, however, have not been tested experimentally. We present experimental observations of colloidal silica spheres' trajectories through specially structured arrays of holographic optical traps, using quantitative methods of holographic video microscopy to track the particles' motions in three dimensions and simultaneously to measure their radii and refractive indexes with part-per-thousand resolution. Single-particle tracking and characterization enable us to demonstrate sorting of colloidal particles into spatially separated fractions with part-per-thousand resolution in either particle size or refractive index. Even more dramatically, these results agree quantitatively with previously untested predictions for the threshold of kinetically locked-in transport.
Improvements to the modal holographic wavefront sensor.
Kong, Fanpeng; Lambert, Andrew
2016-05-01
The Zernike coefficients of a light wavefront can be calculated directly by intensity ratios of pairs of spots in the reconstructed image plane of a holographic wavefront sensor (HWFS). However, the response curve of the HWFS heavily depends on the position and size of the detector for each spot and the distortions introduced by other aberrations. In this paper, we propose a method to measure the intensity of each spot by setting a threshold to select effective pixels and using the weighted average intensity within a selected window. Compared with using the integral intensity over a small window for each spot, we show through a numerical simulation that the proposed method reduces the dependency of the HWFS's response curve on the selection of the detector window. We also recorded a HWFS on a holographic plate using a blue laser and demonstrated its capability to detect the strength of encoded Zernike terms in an aberrated beam. PMID:27140379
Cold holographic matter in the Higgs branch
NASA Astrophysics Data System (ADS)
Itsios, Georgios; Jokela, Niko; Ramallo, Alfonso V.
2015-07-01
We study collective excitations of cold (2 + 1)-dimensional fundamental matter living on a defect of the four-dimensional N = 4 super Yang-Mills theory in the Higgs branch. This system is realized holographically as a D3-D5 brane intersection, in which the D5-brane is treated as a probe with a non-zero gauge flux across the internal part of its worldvolume. We study the holographic zero sound mode in the collisionless regime at low temperature and find a simple analytic result for its dispersion relation. We also find the diffusion constant of the system in the hydrodynamic regime at higher temperature. In both cases we study the dependence on the flux parameter which determines the amount of Higgs symmetry breaking. We also discuss the anyonization of this construction.
Note on zero temperature holographic superfluids
NASA Astrophysics Data System (ADS)
Guo, Minyong; Lan, Shanquan; Niu, Chao; Tian, Yu; Zhang, Hongbao
2016-06-01
In this note, we have addressed various issues on zero temperature holographic superfluids. First, inspired by our numerical evidence for the equality between the superfluid density and particle density, we provide an elegant analytic proof for this equality by a boost trick. Second, using not only the frequency domain analysis but also the time domain analysis from numerical relativity, we identify the hydrodynamic normal modes and calculate out the sound speed, which is shown to increase with the chemical potential and saturate to the value predicted by the conformal field theory in the large chemical potential limit. Third, the generic non-thermalization is demonstrated by the fully nonlinear time evolution from a non-equilibrium state for our zero temperature holographic superfluid. Furthermore, a conserved Noether charge is proposed in support of this behavior.
Fast holographic-like stereogram display using shell rendering and a holographic screen
NASA Astrophysics Data System (ADS)
de Mendonca, Candido F. X.; Falcao, Alexandre X.; Vannini, Cesar Augusto D. C.; Lunazzi, Jose J.
1999-05-01
Display systems relying on computer graphics techniques usually create 2.5D image display on a 2D screen. To obtain 3D image display, most system uses auxiliary devices or viewing tricks, such as polarized glasses, virtual reality helmet, detection of observer's location, divergent viewing, etc. We call these systems stereoscopic. A system that can display 3D images in a natural way is called a self- stereoscopic system. We know that stereoscopic system do not have horizontal parallax such as seen in holograms, which display continuum parallax. In this paper, we introduce a new technique based on shell rendering to discretize horizontal parallax by coding several views of the object forming a holographic-like stereogram and a new self- stereoscopic 3D display system to visualize holographic stereograms on a holographic screen. We also demonstrate the new system using medical image data.
Innovative re-creation of realities in a holographic digital form
NASA Astrophysics Data System (ADS)
Wang, Shuo; Hebblewhite, Richard; Osanlou, Ardieshir; Excell, Peter; Di Gennaro, Sonia; Shi, Lishen
2014-02-01
Only nature can create, whereas humans can only re-create. This article is an exploration of synergies between art and science in digital holography in relation to art practice and the making of holograms as art works. This is achieved through involvement in the re-creation of a real object (a telescope) as a case study. A digital three-dimensional model suitable for holographic hard copy re-creation is produced. To explore special and immersive environment, real geographical landscape background from Google Earth is added to the model. After a brief introduction to visual art within the context of two and three-dimensional imaging in the form photography and holography, the whole process of producing the three-dimensional model and the environment in which it should be presented, ready for holographic printing is explained.
A 5D holographic dark energy in DGP-BRANE cosmology
NASA Astrophysics Data System (ADS)
Farajollahi, H.; Ravanpak, A.
2014-02-01
This paper is aimed to investigate 5D holographic dark energy (HDE) in DGP-Brane cosmology by employing a combination of Sne Ia, BAO and CMB observational data and constraining cosmological parameters. The FRW dynamics for the normal branch ( ɛ=+1) solution of induced gravity brane-world model is taken with the assumption that matter in 5D bulk is HDE such that its holographic nature is reproduced effectively in 4D universe. In the HDE model, we used Hubble horizon as IR cutoff instead of future event horizon. This way, while the model predicts current universe acceleration, it also removes the problem of circular reasoning and causality observed in using future event horizon as IR cutoff.
Analytical holographic superconductors in AdSN-Lifshitz topological black holes
NASA Astrophysics Data System (ADS)
Momeni, D.; Myrzakulov, R.; Sebastiani, L.; Setare, M. R.
2015-11-01
We present the analytic Lifshitz solutions for a scalar field model minimally coupled with the abelian gauge field in N-dimensions. We also consider the presence of cosmological constant Λ. The Lifshitz parameter z appearing in the solution plays the role of the Lorentz breaking parameter of the model. We investigate the thermodynamical properties of the solutions and discuss the energy issue. Furthermore, we study the hairy black hole solutions in which the abelian gauge field breaks the symmetry near to the horizon. In the holographic picture, it is equivalent to a second-order phase transition. Explicitly we show that there exists a critical temperature which is a function of the Lifshitz parameter z. The system below the critical temperature becomes superconductor, but the critical exponent of the model remains the same of the usual holographic superconductors without the higher-order gravitational corrections, in agreement with Ginzburg-Landau theories.
Quantitative roadmap of holographic media performance
NASA Astrophysics Data System (ADS)
Kowalski, Benjamin A.; McLeod, Robert R.
2015-09-01
For holographic photopolymer media, the "formula limit" concept enables facile calculation of the fraction of writing chemistry that is usefully patterned, and the fraction that is wasted. This provides a quantitative context to compare the performance of a diverse range of media formulations from the literature, using only information already reported in the original works. Finally, this analysis is extended to estimate the scope of achievable future performance improvements.
Holographic consequences of a no transmission principle
NASA Astrophysics Data System (ADS)
Engelhardt, Netta; Horowitz, Gary T.
2016-01-01
Two quantum field theories whose Hilbert spaces do not overlap cannot transmit a signal to one another. From this simple principle, we deduce some highly nontrivial consequences for holographic quantum gravity. These include: (i) certain cosmological bounces are forbidden, (ii) generic singularities inside black holes cannot be resolved, and (iii) traversable wormholes do not exist. At the classical level, this principle rules out certain types of naked singularities and suggests that new singularity theorems should exist.
Using a portable holographic camera in cosmetology
NASA Astrophysics Data System (ADS)
Bakanas, R.; Gudaitis, G. A.; Zacharovas, S. J.; Ratcliffe, D. B.; Hirsch, S.; Frey, S.; Thelen, A.; Ladrière, N.; Hering, P.
2006-07-01
The HSF-MINI portable holographic camera is used to record holograms of the human face. The recorded holograms are analyzed using a unique three-dimensional measurement system that provides topometric data of the face with resolution less than or equal to 0.5 mm. The main advantages of this method over other, more traditional methods (such as laser triangulation and phase-measurement triangulation) are discussed.
Holographic Helmet-Mounted Display Unit
NASA Technical Reports Server (NTRS)
Burley, James R., II; Larussa, Joseph A.
1995-01-01
Helmet-mounted display unit designed for use in testing innovative concepts for display of information to aircraft pilots. Operates in conjunction with computers generating graphical displays. Includes two ocular subunits containing miniature cathoderay tubes and optics providing 40 degrees vertical, 50 degrees horizontal field of view to each eye, with or without stereopsis. In future color application, each ocular subunit includes trichromatic holographic combiner tuned to red, green, and blue wavelengths of phosphors used in development of miniature color display devices.
Magnetic oscillations in a holographic liquid
NASA Astrophysics Data System (ADS)
Giangreco M. Puletti, V.; Nowling, S.; Thorlacius, L.; Zingg, T.
2015-04-01
We present a holographic perspective on magnetic oscillations in strongly correlated electron systems via a fluid of charged spin 1 /2 particles outside a black brane in an asymptotically anti-de-Sitter spacetime. The resulting backreaction on the spacetime geometry and bulk gauge field gives rise to magnetic oscillations in the dual field theory, which can be directly studied without introducing probe fermions, and which differ from those predicted by Fermi liquid theory.
Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE)
NASA Technical Reports Server (NTRS)
Schwemmer, Geary K.
1998-01-01
Scanning holographic lidar receivers are currently in use in two operational lidar systems, PHASERS (Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing) and now HARLIE (Holographic Airborne Rotating Lidar Instrument Experiment). These systems are based on volume phase holograms made in dichromated gelatin (DCG) sandwiched between 2 layers of high quality float glass. They have demonstrated the practical application of this technology to compact scanning lidar systems at 532 and 1064 nm wavelengths, the ability to withstand moderately high laser power and energy loading, sufficient optical quality for most direct detection systems, overall efficiencies rivaling conventional receivers, and the stability to last several years under typical lidar system environments. Their size and weight are approximately half of similar performing scanning systems using reflective optics. The cost of holographic systems will eventually be lower than the reflective optical systems depending on their degree of commercialization. There are a number of applications that require or can greatly benefit from a scanning capability. Several of these are airborne systems, which either use focal plane scanning, as in the Laser Vegetation Imaging System or use primary aperture scanning, as in the Airborne Oceanographic Lidar or the Large Aperture Scanning Airborne Lidar. The latter class requires a large clear aperture opening or window in the aircraft. This type of system can greatly benefit from the use of scanning transmission holograms of the HARLIE type because the clear aperture required is only about 25% larger than the collecting aperture as opposed to 200-300% larger for scan angles of 45 degrees off nadir.
Broadband Hybrid Holographic Multiplexing with Geometric Metasurfaces.
Huang, Lingling; Mühlenbernd, Holger; Li, Xiaowei; Song, Xu; Bai, Benfeng; Wang, Yongtian; Zentgraf, Thomas
2015-11-01
An effective way for broadband holographic multiplexing based on geometric metasurfaces is demonstrated by the integration of several recording channels into a single device. Each image can be individually addressed with a unique set of parameters, such as circular polarization, position, and angle. Such a technique paves the way for a wide range of applications related to optical patterning, encryption, and information processing. PMID:26398589
Holographic center high-mounted stoplight
NASA Astrophysics Data System (ADS)
Smith, Ronald T.
1991-07-01
The holographic center high mounted stoplight achieves the required performance of a conventional center high mounted stoplight, but without the obstruction to the driver's view through the rear window. A lamp located in the roof illuminates a transmission image hologram mounted on the inner surface of the automobile rear window. The hologram strongly diffracts the incident light rearward but is transparent to the driver looking in his rearview mirror.
Optical Correlator With Complex Holographic Filter
NASA Technical Reports Server (NTRS)
Chao, Tien-Hsin
1992-01-01
Experimental real-time optical correlator includes complex-valued holographic filter computed from one of two input scenes. Made more tolerant of errors in patterns to be recognized. Filter function essentially coded hologram computed by Burchhardt's method, in which complex value of each pixel of fast Fourier transform of image represented by three real, nonnegative numbers. In generating optical correlator according to method, phasor of each pixel in Fourier transform represented by intensities in three adjacent pixels.
Holographic interferometric tomography for reconstructing flow fields
NASA Technical Reports Server (NTRS)
Cha, Soyoung S.
1994-01-01
Holographic interferometric tomography is a technique for instantaneously capturing and quantitatively reconstructing three-dimensional flow fields. It has a very useful application potential for high-speed aerodynamics. However, three major challenging tasks need to be accomplished before its practical applications. First, fluid flows are mostly unsteady or at least non repeatable. Consequently, a means for Instantaneously recording three-dimensional flow fields, that is, a simple holographic technique for simultaneously recording multi-directional projections, needs to be developed. Second, while holographic interferometry provides enormous data storage capabilities, expeditious data extraction from complicated interferograms is very important for timely near real-time applications. Third, unlike medical applications, flow tomography does not provide complete data sets but instead involves ill-posed reconstruction problems of incomplete projection and limited angular scanning. During this summer research period, new experimental techniques and corresponding hardware were developed and tested to address the above mentioned tasks. The first task was achieved by diffuser illumination. This concept allows instantaneous capture of many projections with a conventional setup for single-projection recording. For the second task, a phase-shifting technique was incorporated. This technique allows one to acquire multiple phase-stepped interferograms for a single projection and thus to extract phase information from intensity data almost at real-time. For the third task, the research that has been extensively conducted previously was utilized. In this research period, a complete experimental setup that provides the above three major capabilities was designed, built, and tested by integrating all the techniques. A simple laboratory experiment for simulating wind-tunnel testing was then conducted. A test flow was produced by employing a relatively simple device that generated
Stereo multiplexed holographic particle image velocimeter
Adrian, R.J.; Barnhart, D.H.; Papen, G.A.
1996-08-20
A holographic particle image velocimeter employs stereoscopic recording of particle images, taken from two different perspectives and at two distinct points in time for each perspective, on a single holographic film plate. The different perspectives are provided by two optical assemblies, each including a collecting lens, a prism and a focusing lens. Collimated laser energy is pulsed through a fluid stream, with elements carried in the stream scattering light, some of which is collected by each collecting lens. The respective focusing lenses are configured to form images of the scattered light near the holographic plate. The particle images stored on the plate are reconstructed using the same optical assemblies employed in recording, by transferring the film plate and optical assemblies as a single integral unit to a reconstruction site. At the reconstruction site, reconstruction beams, phase conjugates of the reference beams used in recording the image, are directed to the plate, then selectively through either one of the optical assemblies, to form an image reflecting the chosen perspective at the two points in time. 13 figs.
Stereo multiplexed holographic particle image velocimeter
Adrian, Ronald J.; Barnhart, Donald H.; Papen, George A.
1996-01-01
A holographic particle image velocimeter employs stereoscopic recording of particle images, taken from two different perspectives and at two distinct points in time for each perspective, on a single holographic film plate. The different perspectives are provided by two optical assemblies, each including a collecting lens, a prism and a focusing lens. Collimated laser energy is pulsed through a fluid stream, with elements carried in the stream scattering light, some of which is collected by each collecting lens. The respective focusing lenses are configured to form images of the scattered light near the holographic plate. The particle images stored on the plate are reconstructed using the same optical assemblies employed in recording, by transferring the film plate and optical assemblies as a single integral unit to a reconstruction site. At the reconstruction site, reconstruction beams, phase conjugates of the reference beams used in recording the image, are directed to the plate, then selectively through either one of the optical assemblies, to form an image reflecting the chosen perspective at the two points in time.
Holographic display with tilted spatial light modulator.
Kozacki, Tomasz
2011-07-10
In this paper, we analyze a holographic display system utilizing a phase-only spatial light modulator (SLM) based on liquid crystal on silicon (LCoS). An LCoS SLM works in reflection, and, in some applications, it is convenient to use with an inclined illumination. Even with a highly inclined illumination, the holographic display is capable of good-quality image generation. We show that the key to obtain high-quality reconstructions is the tilt-dependent calibration and algorithms. Typically, an LCoS SLM is illuminated with a plane wave with normal wave vector. We use inclined illumination, which requires development of new algorithms and display characterization. In this paper we introduce two algorithms. The first one is designed to process a digital hologram captured in CCD normal configuration, so it can be displayed in SLM tilted geometry, while the second one is capable of synthetic hologram generation for tilted SLM configuration. The inclined geometry asymmetrically changes the field of view of a holographic display. The presented theoretical analysis of the aliasing effect provides a formula for the field of view as a function of SLM tilt. The incidence angle affects SLM performance. Both elements of SLM calibration, i.e., pixel phase response and wavefront aberrations, strongly depend on SLM tilt angle. The effect is discussed in this paper. All of the discussions are accompanied with experimental results. PMID:21743569
A shape dynamical approach to holographic renormalization
NASA Astrophysics Data System (ADS)
Gomes, Henrique; Gryb, Sean; Koslowski, Tim; Mercati, Flavio; Smolin, Lee
2015-01-01
We provide a bottom-up argument to derive some known results from holographic renormalization using the classical bulk-bulk equivalence of General Relativity and Shape Dynamics, a theory with spatial conformal (Weyl) invariance. The purpose of this paper is twofold: (1) to advertise the simple classical mechanism, trading off gauge symmetries, that underlies the bulk-bulk equivalence of General Relativity and Shape Dynamics to readers interested in dualities of the type of AdS/conformal field theory (CFT); and (2) to highlight that this mechanism can be used to explain certain results of holographic renormalization, providing an alternative to the AdS/CFT conjecture for these cases. To make contact with the usual semiclassical AdS/CFT correspondence, we provide, in addition, a heuristic argument that makes it plausible that the classical equivalence between General Relativity and Shape Dynamics turns into a duality between radial evolution in gravity and the renormalization group flow of a CFT. We believe that Shape Dynamics provides a new perspective on gravity by giving conformal structure a primary role within the theory. It is hoped that this work provides the first steps toward understanding what this new perspective may be able to teach us about holographic dualities.
Holographic Optical Elements as Scanning Lidar Telescopes
NASA Technical Reports Server (NTRS)
Schwemmer, Geary K.; Rallison, Richard D.; Wilkerson, Thomas D.; Guerra, David V.
2005-01-01
We have developed and investigated the use of holographic optical elements (HOEs) and holographic transmission gratings for scanning lidar telescopes. For example, rotating a flat HOE in its own plane with the focal spot on the rotation axis makes a very simple and compact conical scanning telescope. We developed and tested transmission and reflection HOEs for use at the first three harmonic wavelengths of Nd:YAG lasers. The diffraction efficiency, diffraction angle, focal length, focal spot size and optical losses were measured for several HOEs and holographic gratings, and found to be suitable for use as lidar receiver telescopes, and in many cases could also serve as the final collimating and beam steering optic for the laser transmitter. Two lidar systems based on this technology have been designed, built, and successfully tested in atmospheric science applications. This technology will enable future spaceborne lidar missions by significantly lowering the size, weight, power requirement and cost of a large aperture, narrow field of view scanning telescope.
Holographic Hall conductivities from dyonic backgrounds
NASA Astrophysics Data System (ADS)
Lindgren, Jonathan; Papadimitriou, Ioannis; Taliotis, Anastasios; Vanhoof, Joris
2015-07-01
We develop a general framework for computing the holographic 2-point functions and the corresponding conductivities in asymptotically locally AdS backgrounds with an electric charge density, a constant magentic field, and possibly non-trivial scalar profiles, for a broad class of Einstein-Maxwell-Axion-Dilaton theories, including certain Chern-Simons terms. Holographic renormalization is carried out for any theory in this class and the computation of the renormalized AC conductivities at zero spatial momentum is reduced to solving a single decoupled first order Riccati equation. Moreover, we develop a first order fake supergravity formulalism for dyonic renormalization group flows in four dimensions, allowing us to construct analytically infinite families of such backgrounds by specifying a superpotential at will. These RG flows interpolate between AdS4 in the UV and a hyperscaling violating Lifshitz geometry in the IR with exponents 1 < z < 3 and θ = z + 1. For 1 < z < 2 the spectrum of fluctuations is gapped and discrete. Our hope and intention is that this analysis can serve as a manual for computing the holographic 1- and 2-point functions and the corresponding transport coefficients in any dyonic background, both in the context of AdS/CMT and AdS/QCD.
Holographic Flow Visualization at NASA Langley
NASA Technical Reports Server (NTRS)
Burner, A. W.; Goad, W. K.
2005-01-01
Holographic flow visualization systems at two NASA Langley facilities, a hypersonic blow-down tunnel using CF4 gas and an expansion tube with very short test time, are described. A pulsed ruby laser is used at a CF4 tunnel for single pulse holography, double pulse with several minutes between exposures, and dual plate holographic interferometry. Shadow-graph, schlieren, and interferograms are reconstructed from the holograms in a separate reconstruction lab. At the expansion tube the short run time of 200 microseconds requires precise triggering of its double pulsed ruby laser. With pulse separation, one pulse can occur before and one after flow is established to obtain fringe free background interferograms (perfect infinite fringe) or both pulses can occur during flow in order to study flow instabilities. Holograms are reconstructed at the expansion tube with an in-place setup which makes use of a high power CW Argon laser and common optics for both recording and reconstructing the holograms. The holographic systems at the CF4 tunnel and expansion tube are operated routinely for flow visualization by tunnel technicians. Typical flow visualization photographs from both facilities are presented.
Two color holographic interferometry for microgravity application
NASA Technical Reports Server (NTRS)
Trolinger, James D.
1993-01-01
Holographic interferometry is a primary candidate for the measurement of temperature and concentration in various crystal growth experiments destined for space. The method measures refractive index changes in the experiment test cell. A refractive index change can be caused by concentration changes, temperature changes, or a combination of temperature and concentration changes. If the refractive index changes are caused by temperature and concentration changes occurring simultaneously in the experiment test cell, the contributions by the two effects cannot be separated by conventional measurement methods. By using two wavelengths, two independent interferograms can be produced from the reconstruction of the hologram. The two interferograms will be different due to dispersion properties of fluid materials. These differences provide the additional information that allows the separation of simultaneously occurring temperature and concentration gradients. There is no other technique available that can provide this type of information. The primary objectives of this effort are to experimentally verify the mathematical theory of two color holographic interferometry and to determine the practical value of this technique for space application. To achieve these objectives, the accuracy and sensitivity of the technique must be determined for geometry's and materials that are relevant to the Materials Processing in the Space program of NASA. This will be achieved through the use of a specially designed two-color holographic interferometry breadboard optical system. In addition to experiments to achieve the primary goals, the breadboard will also provide inputs to the design of an optimum space flight system.
Drawing Lines with Light in Holographic Space
NASA Astrophysics Data System (ADS)
Chang, Yin-Ren; Richardson, Martin
2013-02-01
This paper explores the dynamic and expressive possibilities of holographic art through a comparison of art history and technical media such as photography, film and holographic technologies. Examples of modern art and creative expression of time and motions are examined using the early 20th century art movement, Cubism, where subjects are portrayed to be seen simultaneously from different angles. Folding space is represented as subject matter as it can depict space from multiple points of time. The paper also investigates the way holographic art has explored time and space. The lenticular lens-based media reveal a more subjective poetic art in the form of the lyrical images and messages as spectators pass through time, or walk along with the piece of work through an interactive process. It is argued that photographic practice is another example of artistic representation in the form of aesthetic medium of time movement and as such shares a common ground with other dynamic expression that require time based interaction.
The techniques of holographic particle sizing
NASA Technical Reports Server (NTRS)
Kurtz, R. L.
1973-01-01
Depending on the mechanism of particle production, the resultant particle size and velocity distribution may range over several orders of magnitude. In general, if particle size information is desired from a given type generator, one must resort to some form of experimental determination of the distribution. If the source of particle production is a dynamic one involving a reasonable volume, holography provides a tailor-made particle size and velocity distribution detector. This is evidenced by the fact that holography allows the entire volume to be recorded on one exposure without any interference with the volume of interest. Herein lies a very important characteristic of the holographic particle detection technique: It provides a holographic nondestructive testing technique in the fullest sense of the definition of nondestructive testing. This report provides a description of three different systems useful in this technique and includes the experimental results from one of the holographic systems which was used to detect particle size and velocity distribution from the Skylab waste tank.
Real-time holographic camera system
NASA Astrophysics Data System (ADS)
Bazhenov, Mikhail Y.; Grabovski, Vitaly V.; Stolyarenko, Alexandr V.; Zahaykevich, George A.
1997-04-01
The holographic camera system for surface-relief hologram multiple reversible registration is presented. Photosensitive media is a single-layer photothermoplastic polymer on a glass substrate with conductive layer. This exclude a charges accumulation in the polymer volume and permits to realize an efficient enhancement of latent electrostatic image and its fast pulse heating development. The processes of charging, photogeneration, carriers transport, fast development and erasing, image enhancement were studied in detail and optimized. In order to improve some defects of photothermoplastic recording, originating from influences of circumstances and recording conditions, some new processes were developed: (1) fast charging with pulses corona in closed dielectric volume, (2) optoelectronic enhancement of electrostatic image, and (3) fast pulsed development with automatically controlled temperature rate. The dust-proof recording camera with built-in highvoltage power supply, thermo- and photosensors was designed to meet the needs of real-time or multiple- exposure interferometry, holographic training recording, holographic storage systems, correlation investigations and pattern recognition.
Simonov, A N; Larichev, A V; Shibaev, Valerii P
2000-07-31
The dynamics of holographic recording in a film of azo-containing liquid-crystal polymer is studied both experimentally and theoretically in the presence of the orienting electric field. The possibility is demonstrated to efficiently control the optical recording regime by varying the applied field. The specificity of hologram formation in the case of different polarisation of the interacting light beams is considered. A theoretical model describing the holographic recording dynamics in a film of azo-containing nematic polymer is presented; numerical simulation of the processes of recording and read-out in anisotropic holograms is carried out as well. (laser applications and other topics in quantum electronics)
Possibilities of holographic techniques in laser scanning microscopy
NASA Astrophysics Data System (ADS)
Zakharov, Yu.; Muravyeva, M.; Dudenkova, V.; Mukhina, I.; Meglinski, I.
2015-07-01
Holographic scanning microscopy - novel technique both in laser scanning microscopy and digital holographic microscopy allow multimodal approach to cell and tissue investigation in biomedical applications promising new advantages (quantitative phase imaging, superresolution, computerized tomography), but regular reconstruction leads to incorrectness. Analysis of light propagation through the schematics allows to offer reconstruction procedures depending on recording conditions.
Designing the Holographic Whole Language Program. Opinion Paper.
ERIC Educational Resources Information Center
Fluellen, Jerry
A paper describes how David Bohm's holographic world view can be used to design a whole language program. Characterized by interconnectedness and multidimensionality, Bohm's holographic paradigm joins Eastern and Western belief systems in an old fashion pursuit of wisdom, on the one hand, and a new fashion pursuit of solutions to nonlinear…
NASA Astrophysics Data System (ADS)
You, Yi-Zhuang; Qi, Xiao-Liang; Xu, Cenke
We introduce the spectrum bifurcation renormalization group (SBRG) as a generalization of the real-space renormalization group for the many-body localized (MBL) system without truncating the Hilbert space. Starting from a disordered many-body Hamiltonian in the full MBL phase, the SBRG flows to the MBL fixed-point Hamiltonian, and generates the local conserved quantities and the matrix product state representations for all eigenstates. The method is applicable to both spin and fermion models with arbitrary interaction strength on any lattice in all dimensions, as long as the models are in the MBL phase. In particular, we focus on the 1 d interacting Majorana chain with strong disorder, and map out its phase diagram using the entanglement entropy. The SBRG flow also generates an entanglement holographic mapping, which duals the MBL state to a fragmented holographic space decorated with small blackholes.
Qualitative holographic study of hemi-pelvic deformation caused by loading different hip prostheses.
Spirakis, A; Learmonth, I D; Gryzagoridis, J; Davis, B L
1992-03-01
The dynamic biological response of bone can materially influence the longevity of artificial implants. This paper presents a series of in vitro experiments conducted on epoxy resin models of human hemi-pelves. Different commercially available acetabular components were implanted and used for the construction of simplified three-dimensional models of the artificial hip joint. Boundary conditions included simulation of muscle groups and femoral loading. Real-time holographic interferometry, a stress analysis technique permitting whole-field simultaneous inspection of deformation patterns, was used as the experimental method. The holographic interferograms were interpreted qualitatively rather than quantitatively. High stresses were identified in the hemi-pelvis and it is postulated that these stresses may be implicated in the mechanical pathogenesis of loosening. The observed changes in the detected stress levels could influence both future design of acetabular prostheses and surgical techniques. PMID:1306037
Holographic flow visualisation applied to very small flow sections in turbomachinery research
NASA Astrophysics Data System (ADS)
Parker, R. J.; Brownell, J. B.
1986-01-01
Holographic flow visualization has been successfully employed by Rolls-Royce to investigate three dimensional flows in rotating aero-engine fans and two dimensional flows in cascades of blades in wind tunnels. In a development of the latter technique, flow fields in life-size models of labyrinth seals have been investigated. These tiny components are used to block gas flow between rotating and stationary parts of the engine without physical contact. The models are typically 20 mm across with gaps of less than 0.5 mm. Careful design of the optical system and the use of broadband reconstruction techniques minimize the deleterious effects of diffraction and laser speckle. High resolution interferograms of the complicated flow field can be achieved. The paper discusses the optical system and presents examples of the holographic reconstructions.
Yonetani, Yusuke; Nitta, Kouichi; Matoba, Osamu
2010-02-01
We evaluate numerically the effect of shrinkage of photopolymer on the bit error rate or signal-to-noise ratio in a reflection-type holographic data storage system with angular multiplexing. In the evaluation, we use a simple model where the material is divided into layered structures and then the shrinkage rate is proportional to the intensity in each layer. We present the effectiveness of the proposed model from the experimental results in the recording of the plane waves both in a transmission-type hologram and a reflection-type one. Several kinds of shrinkage rates are used to evaluate the characteristics of angular multiplexing in the reflection-type holographic memory. PMID:20119021
Reconstructing f(R, t) Gravity from Holographic Dark Energy
NASA Astrophysics Data System (ADS)
Houndjo, M. J. S.; Piattella, Oliver F.
2012-03-01
We consider cosmological scenarios based on f(R, T) theories of gravity (R is the Ricci scalar and T is the trace of the energy-momentum tensor) and numerically reconstruct the function f(R, T) which is able to reproduce the same expansion history generated, in the standard General Relativity theory, by dark matter and holographic dark energy. We consider two special f(R, T) models: in the first instance, we investigate the modification R + 2f(T), i.e. the usual Einstein-Hilbert term plus a f(T) correction. In the second instance, we consider a f(R) + λT theory, i.e. a T correction to the renown f(R) theory of gravity.
A Holographic c-Theorem for Schrodinger Spacetimes
NASA Astrophysics Data System (ADS)
Zhong, Weishun; Liu, James
2016-03-01
We prove a c-theorem for holographic renormalization group flows in a Schrodinger spacetime that demonstrates that the effective radius L (r) monotonically decreases from the UV to the IR, where r is the bulk radial coordinate. This result assumes that the bulk matter satisfies the null energy condition, but holds regardless of the value of the critical exponent z. We also construct several numerical examples in a model where the Schrodinger background is realized by a massive vector coupled to a real scalar. The full Schrodinger group is realized when z = 2 , and in this case it is possible to construct solutions with constant effective z (r) = 2 along the entire flow.
Holographic vortices in the presence of dark matter sector
NASA Astrophysics Data System (ADS)
Rogatko, Marek; Wysokinski, Karol I.
2015-12-01
The dark matter seem to be an inevitable ingredient of the total matter configuration in the Universe and the knowledge how the dark matter affects the properties of superconductors is of vital importance for the experiments aimed at its direct detection. The homogeneous magnetic field acting perpendicularly to the surface of (2+1) dimensional s-wave holographic superconductor in the theory with dark matter sector has been modeled by the additional U(1)-gauge field representing dark matter and coupled to the Maxwell one. As expected the free energy for the vortex configuration turns out to be negative. Importantly its value is lower in the presence of dark matter sector. This feature can explain why in the Early Universe first the web of dark matter appeared and next on these gratings the ordinary matter forming cluster of galaxies has formed.
P-wave holographic superconductor/insulator phase transitions affected by dark matter sector
NASA Astrophysics Data System (ADS)
Rogatko, Marek; Wysokinski, Karol I.
2016-03-01
The holographic approach to building the p-wave superconductors results in three different models: the Maxwell-vector, the SU(2) Yang-Mills and the helical. In the probe limit approximation, we analytically examine the properties of the first two models in the theory with dark matter sector. It turns out that the effect of dark matter on the Maxwell-vector p-wave model is the same as on the s-wave superconductor studied earlier. For the non-Abelian model we study the phase transitions between p-wave holographic insulator/superconductor and metal/superconductor. Studies of marginally stable modes in the theory under consideration allow us to determine features of p-wave holographic droplet in a constant magnetic field. The dependence of the superconducting transition temperature on the coupling constant α to the dark matter sector is affected by the dark matter density ρD . For ρ D > ρ the transition temperature is a decreasing function of α. The critical chemical potential μ c for the quantum phase transition between insulator and metal depends on the chemical potential of dark matter μ D and for μ D = 0 is a decreasing function of α.
NASA Astrophysics Data System (ADS)
Stratul, Stefan-Ioan; Sinescu, Cosmin; Negrutiu, Meda; de Sabata, Aldo; Rominu, Mihai; Ogodescu, Alexandru; Rusu, Darian
2014-01-01
Holographic evaluations count among recent measurement tools in orthodontics and prosthodontics. This research introduces holography as an assessment method of 3D variations of gingival retractions. The retraction of gingiva on frontal regions of 5 patients with periodontitis was measured in six points and was evaluated by holographic methods using a He-Ne laser device (1mV, Superlum, Carrigtwohill, Ireland) inside a holographic bank of 200 x 100cm. Impressions were taken during first visit and cast models were manufactured. Six months after the end of periodontal treatment, clinical measurements were repeated and the hologram of the first model was superimposed on a final model cast, by using reference points, while maintaining the optical geometric perimeters. The retractions were evaluated 3D in every point using a dedicated software (Sigma Scan Pro,Systat Software, SanJose, CA, USA). The Wilcoxon test was used to compare the mean recession changes between baseline and six months after treatment, and between values in vivo and the values on hologram. No statistically significant differences between values in vivo and on the hologram were found. In conclusion, holography provides a valuable tool for assessing gingival retractions on virtual models. The data can be stored, reproduced, transmitted and compared at a later time point with accuracy.
Nondestructive testing of composite materials by holographic interferometry
NASA Astrophysics Data System (ADS)
Ebbeni, J.; de Smet, M.-A.
Techniques for the nondestructive testing of composites by holographic interferometry are discussed, and results from tests analyzing carbon/epoxy composites for two types of defects, resulting from the impact of steel rods and the introduction of mylar inhomogeneities, are presented. Holographic techniques for the interferometric real-time observation of the superposition of the object and the holographic image, and for the recording on two photosensitively different plates of holographic images of the object in the neutral and deformed states, are discussed. Results show that a defect of 0.02 mm, situated at less than three layers below the observed surface, could be precisely characterized, and that for certain cases of 3-12 layers, defects could be detected by a fringe deviation. Better definition of the zone of impact was obtained by the holographic method than by an ultrasound method.
Depth perception and user interface in digital holographic television
NASA Astrophysics Data System (ADS)
Barabas, James; Jolly, Sundeep; Smalley, Daniel E.; Bove, V. Michael, Jr.
2012-03-01
A holographic television system, featuring realtime incoherent 3D capture and live holographic display is used for experiments in depth perception. Holographic television has the potential to provide more complete visual representations, including latency-free motion parallax and more natural affordances for accommodation. Although this technology has potential to improve realism in many display applications, we investigate benefits in uses where direct vision of a workspace is not possible. Applications of this nature include work with hazardous materials, teleoperation over distance, and laparoscopic surgery. In this study, subjects perform manual 3D object manipulation tasks where they can only see the workspace through holographic closed-circuit television. This study is designed to compare performance at manual tasks using holographic television compared to performance with displays that mimic 2D, and stereoscopic television.
Optical properties of a photopolymer film for digital holographic storage
NASA Astrophysics Data System (ADS)
Shin, Changwon; Kim, Junghoi; Kim, Nam; Lee, Hyojin; Kim, Eunkyoung
2005-09-01
Tir- and mono functional monomers were dispersed in a solution of polysulfone in organic solvent containing a photo initiator and other additives. New photopolymer film was prepared by dispersing acrylic monomer in a polysulfone matrix. The Polysulfone was adopted as a binder since it affords transparent thick films with low dimensional changes during holographic recording. Optical property of the photopolymer showed high diffraction efficiency (>90%) under an optimized optical condition at 532nm laser. The angular selectivity for angular multiplexing page oriented holographic memories (POHMs), the maximum diffraction efficiency of the material during holographic recording, the diffraction efficiency of the films as a function of an incident angle of two beams, exposure energy for saturation of the holographic material and application for holographic data storage will be discussed.
Research on copying system of dynamic multiplex holographic stereograms
NASA Astrophysics Data System (ADS)
Fu, Huaiping; Yang, Hong; Zheng, Tong
2003-05-01
The most important advantage of holographic stereograms over conventional hologram is that they can produce 3D images at any desired scale with movement, holographers in many countries involved in the studies towards it. We began our works in the early 80's and accomplished two research projects automatic system for making synthetic holograms and multiplex synthetic rainbow holograms, Based on these works, a large scale holographic stereogram of an animated goldfish was made by us for practical advertisement. In order to meet the needs of the market, a copying system for making multiplex holographic stereograms, and a special kind of silver halide holographic film developed by us recently. The characteristic of the copying system and the property of the special silver-halide emulsion are introduced in this paper.
Holographic illuminator for synchrotron-based projection lithography systems
Naulleau, Patrick P.
2005-08-09
The effective coherence of a synchrotron beam line can be tailored to projection lithography requirements by employing a moving holographic diffuser and a stationary low-cost spherical mirror. The invention is particularly suited for use in an illuminator device for an optical image processing system requiring partially coherent illumination. The illuminator includes: (1) a synchrotron source of coherent or partially coherent radiation which has an intrinsic coherence that is higher than the desired coherence, (2) a holographic diffuser having a surface that receives incident radiation from said source, (3) means for translating the surface of the holographic diffuser in two dimensions along a plane that is parallel to the surface of the holographic diffuser wherein the rate of the motion is fast relative to integration time of said image processing system; and (4) a condenser optic that re-images the surface of the holographic diffuser to the entrance plane of said image processing system.