The holographic dual of the Penrose transform
Neiman, Yasha
2018-01-01
We consider the holographic duality between type-A higher-spin gravity in AdS4 and the free U( N) vector model. In the bulk, linearized solutions can be translated into twistor functions via the Penrose transform. We propose a holographic dual to this transform, which translates between twistor functions and CFT sources and operators. We present a twistorial expression for the partition function, which makes global higher-spin symmetry manifest, and appears to automatically include all necessary contact terms. In this picture, twistor space provides a fully nonlocal, gauge-invariant description underlying both bulk and boundary spacetime pictures. While the bulk theory is handled at the linear level, our formula for the partition function includes the effects of bulk interactions. Thus, the CFT is used to solve the bulk, with twistors as a language common to both. A key ingredient in our result is the study of ordinary spacetime symmetries within the fundamental representation of higher-spin algebra. The object that makes these "square root" spacetime symmetries manifest becomes the kernel of our boundary/twistor transform, while the original Penrose transform is identified as a "square root" of CPT.
Holographic models with anisotropic scaling
Brynjolfsson, E. J.; Danielsson, U. H.; Thorlacius, L.; Zingg, T.
2013-12-01
We consider gravity duals to d+1 dimensional quantum critical points with anisotropic scaling. The primary motivation comes from strongly correlated electron systems in condensed matter theory but the main focus of the present paper is on the gravity models in their own right. Physics at finite temperature and fixed charge density is described in terms of charged black branes. Some exact solutions are known and can be used to obtain a maximally extended spacetime geometry, which has a null curvature singularity inside a single non-degenerate horizon, but generic black brane solutions in the model can only be obtained numerically. Charged matter gives rise to black branes with hair that are dual to the superconducting phase of a holographic superconductor. Our numerical results indicate that holographic superconductors with anisotropic scaling have vanishing zero temperature entropy when the back reaction of the hair on the brane geometry is taken into account.
Holographic Duals of Quark Gluon Plasmas with Unquenched Flavors
Francesco Bigazzi; Aldo Cotrone; Javier Mas; Daniel Mayerson; Javier Tarrio
2012-01-01
We review the construction of gravitational solutions holographically dual to N = 1 quiver gauge theories with dynamical flavor multiplets. We focus on the D3-D7 construction and consider the finite temperature, finite quark chemical potential case where there is a charged black hole in the dual solution. Discussed physical outputs of the model include its thermodynamics （with susceptibilities） and general hydrodynamic properties.
Exploring holographic Composite Higgs models
Croon, Djuna [Department of Physics and Astronomy, University of Sussex,BN1 9QH Brighton (United Kingdom); Perimeter Institute for Theoretical Physics,Waterloo, ON (Canada); Dillon, Barry M.; Huber, Stephan J.; Sanz, Veronica [Department of Physics and Astronomy, University of Sussex,BN1 9QH Brighton (United Kingdom)
2016-07-13
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, MCHM{sub 5}, 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 MCHM{sub 5} with a small UV cutoff is not in tension with the current experimental data.
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.
Geller, Michael; Telem, Ofri
2015-05-01
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 mKK , naturally allowing for mKK 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.
Adventures in holographic dimer models
Kachru, Shamit; Karch, Andreas; Yaida, Sho
2011-01-01
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.
N.S. Mazhari
2017-03-01
Full Text Available The holographic complexity and fidelity susceptibility have been defined as new quantities dual to different volumes in AdS. In this paper, we will use these new proposals to calculate both of these quantities for a variety of interesting deformations of AdS. We obtain the holographic complexity and fidelity susceptibility for an AdS black hole, Janus solution, a solution with cylindrical symmetry, an inhomogeneous background and a hyperscaling violating background. It is observed that the holographic complexity depends on the size of the subsystem for all these solutions and the fidelity susceptibility does not have any such dependence.
Mazhari, N.S., E-mail: najmemazhari86@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Momeni, Davood, E-mail: davoodmomeni78@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Bahamonde, Sebastian, E-mail: sebastian.beltran.14@ucl.ac.uk [Department of Mathematics, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Faizal, Mir, E-mail: mirfaizalmir@googlemail.com [Irving K. Barber School of Arts and Sciences, University of British Columbia - Okanagan, 3333 University Way, Kelowna, British Columbia, V1V 1V7 (Canada); Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta, T1K 3M4 (Canada); Myrzakulov, Ratbay, E-mail: rmyrzakulov@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan)
2017-03-10
The holographic complexity and fidelity susceptibility have been defined as new quantities dual to different volumes in AdS. In this paper, we will use these new proposals to calculate both of these quantities for a variety of interesting deformations of AdS. We obtain the holographic complexity and fidelity susceptibility for an AdS black hole, Janus solution, a solution with cylindrical symmetry, an inhomogeneous background and a hyperscaling violating background. It is observed that the holographic complexity depends on the size of the subsystem for all these solutions and the fidelity susceptibility does not have any such dependence.
Holographic models and the QCD trace anomaly
Goity, Jose L.; Trinchero, Roberto C.
2012-01-01
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 β-functions are studied. It is shown that in the perturbative case, where the β-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.
Dual-Wavelength Sensitized Photopolymer for Holographic Data Storage
Tao, Shiquan; Zhao, Yuxia; Wan, Yuhong; Zhai, Qianli; Liu, Pengfei; Wang, Dayong; Wu, Feipeng
2010-08-01
Novel photopolymers for holographic storage were investigated by combining acrylate monomers and/or vinyl monomers as recording media and liquid epoxy resins plus an amine harder as binder. In order to improve the holographic performances of the material at blue-green wavelength band two novel dyes were used as sensitizer. The methods of evaluating the holographic performances of the material, including the shrinkage and noise characteristics, are described in detail. Preliminary experiments show that samples with optimized composite have good holographic performances, and it is possible to record dual-wavelength hologram simultaneously in this photopolymer by sharing the same optical system, thus the storage density and data rate can be doubly increased.
Holography and holographic dark energy model
Gong Yungui; Zhang Yuanzhong
2005-01-01
The holographic principle is used to discuss the holographic dark energy model. We find that the Bekenstein-Hawking entropy bound is far from saturation under certain conditions. A more general constraint on the parameter of the holographic dark energy model is also derived
Dual conformal transformations of smooth holographic Wilson loops
Dekel, Amit [Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden)
2017-01-19
We study dual conformal transformations of minimal area surfaces in AdS{sub 5}×S{sup 5} corresponding to holographic smooth Wilson loops and some other related observables. To act with dual conformal transformations we map the string solutions to the dual space by means of T-duality, then we apply a conformal transformation and finally T-dualize back to the original space. The transformation maps between string solutions with different boundary contours. The boundary contours of the minimal surfaces are not mapped back to the AdS boundary, and the regularized area of the surface changes.
No simple dual to the causal holographic information?
Engelhardt, Netta [Department of Physics, Princeton University,Princeton, NJ, 08544 (United States); Wall, Aron C. [Institute for Advanced Study,Einstein Drive, Princeton, NJ, 08540 (United States)
2017-04-21
In AdS/CFT, the fine grained entropy of a boundary region is dual to the area of an extremal surface X in the bulk. It has been proposed that the area of a certain ‘causal surface’ C — i.e. the ‘causal holographic information’ (CHI) — corresponds to some coarse-grained entropy in the boundary theory. We construct two kinds of counterexamples that rule out various possible duals, using (1) vacuum rigidity and (2) thermal quenches. This includes the ‘one-point entropy’ proposed by Kelly and Wall, and a large class of related procedures. Also, any coarse-graining that fixes the geometry of the bulk ‘causal wedge’ bounded by C, fails to reproduce CHI. This is in sharp contrast to the holographic entanglement entropy, where the area of the extremal surface X measures the same information that is found in the ‘entanglement wedge’ bounded by X.
Holographic duals of 3d S-fold CFTs
Assel, Benjamin; Tomasiello, Alessandro
2018-06-01
We construct non-geometric AdS4 solutions of IIB string theory where the fields in overlapping patches are glued by elements of the S-duality group. We obtain them by suitable quotients of compact and non-compact geometric solutions. The quotient procedure suggests CFT duals as quiver theories with links involving the so-called T [U( N)] theory. We test the validity of the non-geometric solutions (and of our proposed holographic duality) by computing the three-sphere partition function Z of the CFTs. A first class of solutions is obtained by an S-duality quotient of Janus-type non-compact solutions and is dual to 3d N=4 SCFTs; for these we manage to compute Z of the dual CFT at finite N, and it agrees perfectly with the supergravity result in the large N limit. A second class has five-branes, it is obtained by a Möbius-like S-quotient of ordinary compact solutions and is dual to 3d N=3 SCFTs. For these, Z agrees with the supergravity result if one chooses the limit carefully so that the effect of the fivebranes does not backreact on the entire geometry. Other limits suggest the existence of IIA duals.
Origin of holographic dark energy models
Myung, Yun Soo; Seo, Min-Gyun
2009-01-01
We investigate the origin of holographic dark energy models which were recently proposed to explain the dark energy-dominated universe. For this purpose, we introduce the spacetime foam uncertainty of δl≥l p α l α-1 . It was argued that the case of α=2/3 could describe the dark energy with infinite statistics, while the case of α=1/2 can describe the ordinary matter with Bose-Fermi statistics. However, two cases may lead to the holographic energy density if the latter recovers from the geometric mean of UV and IR scales. Hence the dark energy with infinite statistics based on the entropy bound is not an ingredient for deriving the holographic dark energy model. Furthermore, it is shown that the agegraphic dark energy models are the holographic dark energy model with different IR length scales
Comparing holographic dark energy models with statefinder
Cui, Jing-Lei; Zhang, Jing-Fei
2014-01-01
We apply the statefinder diagnostic to the holographic dark energy models, including the original holographic dark energy (HDE) model, the new holographic dark energy model, the new agegraphic dark energy (NADE) model, and the Ricci dark energy model. In the low-redshift region the holographic dark energy models are degenerate with each other and with the ΛCDM model in the H(z) and q(z) evolutions. In particular, the HDE model is highly degenerate with the ΛCDM model, and in the HDE model the cases with different parameter values are also in strong degeneracy. Since the observational data are mainly within the low-redshift region, it is very important to break this lowredshift degeneracy in the H(z) and q(z) diagnostics by using some quantities with higher order derivatives of the scale factor. It is shown that the statefinder diagnostic r(z) is very useful in breaking the low-redshift degeneracies. By employing the statefinder diagnostic the holographic dark energy models can be differentiated efficiently in the low-redshift region. The degeneracy between the holographic dark energy models and the ΛCDM model can also be broken by this method. Especially for the HDE model, all the previous strong degeneracies appearing in the H(z) and q(z) diagnostics are broken effectively. But for the NADE model, the degeneracy between the cases with different parameter values cannot be broken, even though the statefinder diagnostic is used. A direct comparison of the holographic dark energy models in the r-s plane is also made, in which the separations between the models (including the ΛCDM model) can be directly measured in the light of the current values {r 0 , s 0 } of the models. (orig.)
Holographic p-wave superconductor models with Weyl corrections
Lu Zhang
2015-04-01
Full Text Available 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.
Holographic dark energy in the DGP model
Cruz, Norman; Lepe, Samuel; Pena, Francisco; Avelino, Arturo
2012-01-01
The braneworld model proposed by Dvali, Gabadadze, and Porrati leads to an accelerated universe without cosmological constant or any other form of dark energy. Nevertheless, we have investigated the consequences of this model when an holographic dark energy is included, taking the Hubble scale as IR cutoff. We have found that the holographic dark energy leads to an accelerated flat universe (de Sitter-like expansion) for the two branches: ε=±1, of the DGP model. Nevertheless, in universes with no null curvature the dark energy presents an EoS corresponding to a phantom fluid during the present era and evolving to a de Sitter-like phase for future cosmic time. In the special case in which the holographic parameter c is equal to one we have found a sudden singularity in closed universes. In this case the expansion is decelerating. (orig.)
Holographic dark energy in the DGP model
Cruz, Norman [Universidad de Santiago, Departamento de Fisica, Facultad de Ciencia, Santiago (Chile); Lepe, Samuel [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Facultad de Ciencias, Valparaiso (Chile); Pena, Francisco [Universidad de La Frontera, Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Avda. Francisco Salazar 01145, Casilla 54-D, Temuco (Chile); Avelino, Arturo [Universidad de Guanajuato, Departamento de Fisica, DCI, Codigo Postal 37150, Leon, Guanajuato (Mexico)
2012-09-15
The braneworld model proposed by Dvali, Gabadadze, and Porrati leads to an accelerated universe without cosmological constant or any other form of dark energy. Nevertheless, we have investigated the consequences of this model when an holographic dark energy is included, taking the Hubble scale as IR cutoff. We have found that the holographic dark energy leads to an accelerated flat universe (de Sitter-like expansion) for the two branches: {epsilon}={+-}1, of the DGP model. Nevertheless, in universes with no null curvature the dark energy presents an EoS corresponding to a phantom fluid during the present era and evolving to a de Sitter-like phase for future cosmic time. In the special case in which the holographic parameter c is equal to one we have found a sudden singularity in closed universes. In this case the expansion is decelerating. (orig.)
Quantum quenches in a holographic Kondo model
Erdmenger, Johanna; Flory, Mario; Newrzella, Max-Niklas; Strydom, Migael; Wu, Jackson M. S.
2017-04-01
We study non-equilibrium dynamics and quantum quenches in a recent gauge/gravity duality model for a strongly coupled system interacting with a magnetic impurity with SU( N ) spin. At large N , it is convenient to write the impurity spin as a bilinear in Abrikosov fermions. The model describes an RG flow triggered by the marginally relevant Kondo operator. There is a phase transition at a critical temperature, below which an operator condenses which involves both an electron and an Abrikosov fermion field. This corresponds to a holographic superconductor in AdS2 and models the impurity screening. We quench the Kondo coupling either by a Gaussian pulse or by a hyperbolic tangent, the latter taking the system from the condensed to the uncondensed phase or vice-versa. We study the time dependence of the condensate induced by this quench. The timescale for equilibration is generically given by the leading quasinormal mode of the dual gravity model. This mode also governs the formation of the screening cloud, which is obtained as the decrease of impurity degrees of freedom with time. In the condensed phase, the leading quasinormal mode is imaginary and the relaxation of the condensate is over-damped. For quenches whose final state is close to the critical point of the large N phase transition, we study the critical slowing down and obtain the combination of critical exponents zν = 1. When the final state is exactly at the phase transition, we find that the exponential ringing of the quasinormal modes is replaced by a power-law behaviour of the form ˜ t - a sin( b log t). This indicates the emergence of a discrete scale invariance.
Quantum quenches in a holographic Kondo model
Erdmenger, Johanna [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, 80805, Munich (Germany); Institut für Theoretische Physik und Astrophysik, Julius-Maximilians-Universität Würzburg,Am Hubland, 97074 Würzburg (Germany); Flory, Mario [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, 80805, Munich (Germany); Institute of Physics, Jagiellonian University,Łojasiewicza 11, 30-348 Kraków (Poland); Newrzella, Max-Niklas; Strydom, Migael [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, 80805, Munich (Germany); Wu, Jackson M. S. [Department of Physics and Astronomy, University of Alabama,Tuscaloosa, AL 35487 (United States)
2017-04-10
We study non-equilibrium dynamics and quantum quenches in a recent gauge/ gravity duality model for a strongly coupled system interacting with a magnetic impurity with SU(N) spin. At large N, it is convenient to write the impurity spin as a bilinear in Abrikosov fermions. The model describes an RG flow triggered by the marginally relevant Kondo operator. There is a phase transition at a critical temperature, below which an operator condenses which involves both an electron and an Abrikosov fermion field. This corresponds to a holographic superconductor in AdS{sub 2} and models the impurity screening. We quench the Kondo coupling either by a Gaussian pulse or by a hyperbolic tangent, the latter taking the system from the condensed to the uncondensed phase or vice-versa. We study the time dependence of the condensate induced by this quench. The timescale for equilibration is generically given by the leading quasinormal mode of the dual gravity model. This mode also governs the formation of the screening cloud, which is obtained as the decrease of impurity degrees of freedom with time. In the condensed phase, the leading quasinormal mode is imaginary and the relaxation of the condensate is over-damped. For quenches whose final state is close to the critical point of the large N phase transition, we study the critical slowing down and obtain the combination of critical exponents zν=1. When the final state is exactly at the phase transition, we find that the exponential ringing of the quasinormal modes is replaced by a power-law behaviour of the form ∼t{sup −a}sin (blog t). This indicates the emergence of a discrete scale invariance.
McFadden, Paul; Skenderis, Kostas
2011-01-01
We investigate the non-Gaussianity of primordial cosmological perturbations within our recently proposed holographic description of inflationary universes. We derive a holographic formula that determines the bispectrum of cosmological curvature perturbations in terms of correlation functions of a holographically dual three-dimensional non-gravitational quantum field theory (QFT). This allows us to compute the primordial bispectrum for a universe which started in a non-geometric holographic phase, using perturbative QFT calculations. Strikingly, for a class of models specified by a three-dimensional super-renormalisable QFT, the primordial bispectrum is of exactly the factorisable equilateral form with f NL equil. = 5/36, irrespective of the details of the dual QFT. A by-product of this investigation is a holographic formula for the three-point function of the trace of the stress-energy tensor along general holographic RG flows, which should have applications outside the remit of this work
Two-point functions in a holographic Kondo model
Erdmenger, Johanna; Hoyos, Carlos; O'Bannon, Andy; Papadimitriou, Ioannis; Probst, Jonas; Wu, Jackson M. S.
2017-03-01
We develop the formalism of holographic renormalization to compute two-point functions in a holographic Kondo model. The model describes a (0 + 1)-dimensional impurity spin of a gauged SU( N ) interacting with a (1 + 1)-dimensional, large- N , strongly-coupled Conformal Field Theory (CFT). We describe the impurity using Abrikosov pseudo-fermions, and define an SU( N )-invariant scalar operator O built from a pseudo-fermion and a CFT fermion. At large N the Kondo interaction is of the form O^{\\dagger}O, which is marginally relevant, and generates a Renormalization Group (RG) flow at the impurity. A second-order mean-field phase transition occurs in which O condenses below a critical temperature, leading to the Kondo effect, including screening of the impurity. Via holography, the phase transition is dual to holographic superconductivity in (1 + 1)-dimensional Anti-de Sitter space. At all temperatures, spectral functions of O exhibit a Fano resonance, characteristic of a continuum of states interacting with an isolated resonance. In contrast to Fano resonances observed for example in quantum dots, our continuum and resonance arise from a (0 + 1)-dimensional UV fixed point and RG flow, respectively. In the low-temperature phase, the resonance comes from a pole in the Green's function of the form - i2, which is characteristic of a Kondo resonance.
Two-point functions in a holographic Kondo model
Erdmenger, Johanna [Institut für Theoretische Physik und Astrophysik, Julius-Maximilians-Universität Würzburg,Am Hubland, D-97074 Würzburg (Germany); Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, D-80805 Munich (Germany); Hoyos, Carlos [Department of Physics, Universidad de Oviedo, Avda. Calvo Sotelo 18, 33007, Oviedo (Spain); O’Bannon, Andy [STAG Research Centre, Physics and Astronomy, University of Southampton,Highfield, Southampton SO17 1BJ (United Kingdom); Papadimitriou, Ioannis [SISSA and INFN - Sezione di Trieste, Via Bonomea 265, I 34136 Trieste (Italy); Probst, Jonas [Rudolf Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Road, Oxford OX1 3NP (United Kingdom); Wu, Jackson M.S. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States)
2017-03-07
We develop the formalism of holographic renormalization to compute two-point functions in a holographic Kondo model. The model describes a (0+1)-dimensional impurity spin of a gauged SU(N) interacting with a (1+1)-dimensional, large-N, strongly-coupled Conformal Field Theory (CFT). We describe the impurity using Abrikosov pseudo-fermions, and define an SU(N)-invariant scalar operator O built from a pseudo-fermion and a CFT fermion. At large N the Kondo interaction is of the form O{sup †}O, which is marginally relevant, and generates a Renormalization Group (RG) flow at the impurity. A second-order mean-field phase transition occurs in which O condenses below a critical temperature, leading to the Kondo effect, including screening of the impurity. Via holography, the phase transition is dual to holographic superconductivity in (1+1)-dimensional Anti-de Sitter space. At all temperatures, spectral functions of O exhibit a Fano resonance, characteristic of a continuum of states interacting with an isolated resonance. In contrast to Fano resonances observed for example in quantum dots, our continuum and resonance arise from a (0+1)-dimensional UV fixed point and RG flow, respectively. In the low-temperature phase, the resonance comes from a pole in the Green’s function of the form −i〈O〉{sup 2}, which is characteristic of a Kondo resonance.
A holographic model for black hole complementarity
Lowe, David A. [Physics Department, Brown University,Providence, RI 02912 (United States); Thorlacius, Larus [University of Iceland, Science Institute,Dunhaga 3, IS-107, Reykjavik (Iceland); The Oskar Klein Centre for Cosmoparticle Physics,Department of Physics, Stockholm University,AlbaNova University Centre, 10691 Stockholm (Sweden)
2016-12-07
We explore a version of black hole complementarity, where an approximate semiclassical effective field theory for interior infalling degrees of freedom emerges holographically from an exact evolution of exterior degrees of freedom. The infalling degrees of freedom have a complementary description in terms of outgoing Hawking radiation and must eventually decohere with respect to the exterior Hamiltonian, leading to a breakdown of the semiclassical description for an infaller. Trace distance is used to quantify the difference between the complementary time evolutions, and to define a decoherence time. We propose a dictionary where the evolution with respect to the bulk effective Hamiltonian corresponds to mean field evolution in the holographic theory. In a particular model for the holographic theory, which exhibits fast scrambling, the decoherence time coincides with the scrambling time. The results support the hypothesis that decoherence of the infalling holographic state and disruptive bulk effects near the curvature singularity are complementary descriptions of the same physics, which is an important step toward resolving the black hole information paradox.
Counterterms and dual holographic anomalies in CS gravity
Banados, Maximo [Departamento de Fisica, P. Universidad Catolica de Chile, Casilla 306, Santiago 22, Chile (Chile); Olea, Rodrigo [Departamento de Fisica, P. Universidad Catolica de Chile, Casilla 306, Santiago 22, Chile (Chile); Theisen, Stefan [Max-Planck-Institut fuer Gravitationphysik, Albert-Einstein-Institut, 14476 Golm (Germany)
2005-10-15
The holographic Weyl anomaly associated to Chern-Simons gravity in 2n+1 dimensions is proportional to the Euler term in 2n dimensions, with no contributions from the Weyl tensor. We compute the holographic energy-momentum tensor associated to Chern-Simons gravity directly from the action, in an arbitrary odd-dimensional spacetime. We show, in particular, that the counterterms rendering the action finite contain only terms of the Lovelock type.
Entanglement entropy in a holographic p-wave superconductor model
Li-Fang Li
2015-05-01
Full Text Available In a recent paper, arXiv:1309.4877, a holographic p-wave model has been proposed in an Einstein–Maxwell-complex vector field theory with a negative cosmological constant. The model exhibits rich phase structure depending on the mass and the charge of the vector field. We investigate the behavior of the entanglement entropy of dual field theory in this model. When the above two model parameters change, we observe the second order, first order and zeroth order phase transitions from the behavior of the entanglement entropy at some intermediate temperatures. These imply that the entanglement entropy can indicate not only the occurrence of the phase transition, but also the order of the phase transition. The entanglement entropy is indeed a good probe to phase transition. Furthermore, the “retrograde condensation” which is a sub-dominated phase is also reflected on the entanglement entropy.
Entanglement entropy in a holographic p-wave superconductor model
Li, Li-Fang, E-mail: lilf@itp.ac.cn [State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China); Cai, Rong-Gen, E-mail: cairg@itp.ac.cn [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Li, E-mail: liliphy@itp.ac.cn [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Shen, Chao, E-mail: sc@nssc.ac.cn [State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)
2015-05-15
In a recent paper, (arXiv:1309.4877), a holographic p-wave model has been proposed in an Einstein–Maxwell-complex vector field theory with a negative cosmological constant. The model exhibits rich phase structure depending on the mass and the charge of the vector field. We investigate the behavior of the entanglement entropy of dual field theory in this model. When the above two model parameters change, we observe the second order, first order and zeroth order phase transitions from the behavior of the entanglement entropy at some intermediate temperatures. These imply that the entanglement entropy can indicate not only the occurrence of the phase transition, but also the order of the phase transition. The entanglement entropy is indeed a good probe to phase transition. Furthermore, the “retrograde condensation” which is a sub-dominated phase is also reflected on the entanglement entropy.
Multitrace Deformations of Vector and Adjoint Theories and their Holographic Duals
Elitzur, S; Porrati, M; Rabinovici, Eliezer
2006-01-01
We present general methods to study the effect of multitrace deformations in conformal theories admitting holographic duals in Anti de Sitter space. In particular, we analyse the case that these deformations introduce an instability both in the bulk AdS space and in the boundary CFT. We also argue that multitrace deformations of the O(N) linear sigma model in three dimensions correspond to nontrivial time-dependent backgrounds in certain theories of infinitely many interacting massless fields on AdS_4, proposed years ago by Fradkin and Vasiliev. We point out that the phase diagram of a truly marginal large-N deformation has an infrared limit in which only an O(N) singlet field survives. We draw from this case lessons on the full string-theoretical interpretation of instabilities of the dual boundary theory and exhibit a toy model that resolves the instability of the O(N) model, generated by a marginal multitrace deformation. The resolution suggests that the instability may not survive in an appropriate UV com...
Very special conformal field theories and their holographic duals
Nakayama, Yu
2018-03-01
Cohen and Glashow introduced the notion of very special relativity as viable space-time symmetry of elementary particle physics. As a natural generalization of their idea, we study the subgroup of the conformal group, dubbed very special conformal symmetry, which is an extension of the very special relativity. We classify all of them and construct field theory examples as well as holographic realization of the very special conformal field theories.
Holographic superconductor in a deformed four-dimensional STU model
Pourhassan, B.; Bagheri-Mohagheghi, M.M. [Damghan University, School of Physics, Damghan (Iran, Islamic Republic of)
2017-11-15
In this paper, we consider a deformed STU model in four dimensions including both electric and magnetic charges. Using the AdS/CFT correspondence, we study holographic superconductors and obtain transport properties like electrical and thermal conductivities. We obtain transport properties in terms of the magnetic charge of the black hole and interpret it as the magnetic monopole of dual field theory. We find that the presence of the magnetic charge is necessary to have maximum conductivities, and the existence of a magnetic monopole with a critical charge (137 e) to reach the maximum superconductivity is important. Also, we show that the thermal conductivity increases with increasing of the magnetic charge. It may be concluded that the origin of superconductivity is the magnetic monopole. (orig.)
Inflation via logarithmic entropy-corrected holographic dark energy model
Darabi, F.; Felegary, F. [Azarbaijan Shahid Madani University, Department of Physics, Tabriz (Iran, Islamic Republic of); Setare, M.R. [University of Kurdistan, Department of Science, Bijar (Iran, Islamic Republic of)
2016-12-15
We study the inflation in terms of the logarithmic entropy-corrected holographic dark energy (LECHDE) model with future event horizon, particle horizon, and Hubble horizon cut-offs, and we compare the results with those obtained in the study of inflation by the holographic dark energy HDE model. In comparison, the spectrum of primordial scalar power spectrum in the LECHDE model becomes redder than the spectrum in the HDE model. Moreover, the consistency with the observational data in the LECHDE model of inflation constrains the reheating temperature and Hubble parameter by one parameter of holographic dark energy and two new parameters of logarithmic corrections. (orig.)
Inflation via logarithmic entropy-corrected holographic dark energy model
Darabi, F.; Felegary, F.; Setare, M.R.
2016-01-01
We study the inflation in terms of the logarithmic entropy-corrected holographic dark energy (LECHDE) model with future event horizon, particle horizon, and Hubble horizon cut-offs, and we compare the results with those obtained in the study of inflation by the holographic dark energy HDE model. In comparison, the spectrum of primordial scalar power spectrum in the LECHDE model becomes redder than the spectrum in the HDE model. Moreover, the consistency with the observational data in the LECHDE model of inflation constrains the reheating temperature and Hubble parameter by one parameter of holographic dark energy and two new parameters of logarithmic corrections. (orig.)
The holographic dual of a Riemann problem in a large number of dimensions
Herzog, Christopher P.; Spillane, Michael [C.N. Yang Institute for Theoretical Physics, Department of Physics and Astronomy,Stony Brook University, Stony Brook, NY 11794 (United States); Yarom, Amos [Department of Physics, Technion,Haifa 32000 (Israel)
2016-08-22
We study properties of a non equilibrium steady state generated when two heat baths are initially in contact with one another. The dynamics of the system we study are governed by holographic duality in a large number of dimensions. We discuss the “phase diagram” associated with the steady state, the dual, dynamical, black hole description of this problem, and its relation to the fluid/gravity correspondence.
Holographic kinetic k-essence model
Cruz, Norman [Departamento de Fisica, Facultad de Ciencia, Universidad de Santiago de Chile, Casilla 307, Santiago (Chile)], E-mail: ncruz@lauca.usach.cl; Gonzalez-Diaz, Pedro F.; Rozas-Fernandez, Alberto [Colina de los Chopos, Instituto de Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 121, 28006 Madrid (Spain)], E-mail: a.rozas@cfmac.csic.es; Sanchez, Guillermo [Departamento de Matematica y Ciencia de la Computacion, Facultad de Ciencia, Universidad de Santiago de Chile, Casilla 307, Santiago (Chile)], E-mail: gsanchez@usach.cl
2009-08-31
We consider a connection between the holographic dark energy density and the kinetic k-essence energy density in a flat FRW universe. With the choice c{>=}1, the holographic dark energy can be described by a kinetic k-essence scalar field in a certain way. In this Letter we show this kinetic k-essential description of the holographic dark energy with c{>=}1 and reconstruct the kinetic k-essence function F(X)
Note on the butterfly effect in holographic superconductor models
Yi Ling
2017-05-01
Full Text Available In this note we remark that the butterfly effect can be used to diagnose the phase transition of superconductivity in a holographic framework. Specifically, we compute the butterfly velocity in a charged black hole background as well as anisotropic backgrounds with Q-lattice structure. In both cases we find its derivative to the temperature is discontinuous at critical points. We also propose that the butterfly velocity can signalize the occurrence of thermal phase transition in general holographic models.
Note on the butterfly effect in holographic superconductor models
Ling, Yi; Liu, Peng; Wu, Jian-Pin
2017-01-01
In this note we remark that the butterfly effect can be used to diagnose the phase transition of superconductivity in a holographic framework. Specifically, we compute the butterfly velocity in a charged black hole background as well as anisotropic backgrounds with Q-lattice structure. In both cases we find its derivative to the temperature is discontinuous at critical points. We also propose that the butterfly velocity can signalize the occurrence of thermal phase transition in general holographic models.
Note on the butterfly effect in holographic superconductor models
Ling, Yi, E-mail: lingy@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai 200444 (China); School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Peng, E-mail: liup51@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wu, Jian-Pin, E-mail: jianpinwu@mail.bnu.edu.cn [Institute of Gravitation and Cosmology, Department of Physics, School of Mathematics and Physics, Bohai University, Jinzhou 121013 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai 200444 (China)
2017-05-10
In this note we remark that the butterfly effect can be used to diagnose the phase transition of superconductivity in a holographic framework. Specifically, we compute the butterfly velocity in a charged black hole background as well as anisotropic backgrounds with Q-lattice structure. In both cases we find its derivative to the temperature is discontinuous at critical points. We also propose that the butterfly velocity can signalize the occurrence of thermal phase transition in general holographic models.
Charged Rényi entropies in CFTs with Einstein-Gauss-Bonnet holographic duals
Pastras, Georgios; Manolopoulos, Dimitrios
2014-11-01
We calculate the Rényi entropy S q ( μ, λ), for spherical entangling surfaces in CFT's with Einstein-Gauss-Bonnet-Maxwell holographic duals. Rényi entropies must obey some interesting inequalities by definition. However, for Gauss-Bonnet couplings λ, larger than specific value, but still allowed by causality, we observe a violation of the inequality , which is related to the existence of negative entropy black holes, providing interesting restrictions in the bulk theory. Moreover, we find an interesting distinction of the behaviour of the analytic continuation of S q ( μ, λ) for imaginary chemical potential, between negative and non-negative λ.
Holographic duals of Kaluza-Klein black holes
Azeyanagi, Tatsuo; Ogawa, Noriaki; Terashima, Seiji
2009-01-01
We apply Brown-Henneaux's method to the 5D extremal rotating Kaluza-Klein black holes essentially following the calculation of the Kerr/CFT correspondence, which is not based on supersymmetry nor string theory. We find that there are two completely different Virasoro algebras that can be obtained as the asymptotic symmetry algebras according to appropriate boundary conditions. The microscopic entropies are calculated by using the Cardy formula for both boundary conditions and they perfectly agree with the Bekenstein-Hawking entropy. The rotating Kaluza-Klein black holes contain a 4D dyonic Reissner-Nordstroem black hole and Myers-Perry black hole. Since the D-brane configurations corresponding to these black holes are known, we expect that our analysis will shed some light on deeper understanding of chiral CFT 2 's dual to extremal black holes.
Entanglement in holographic dark energy models
Horvat, R.
2010-01-01
We study a process of equilibration of holographic dark energy (HDE) with the cosmic horizon around the dark-energy dominated epoch. This process is characterized by a huge amount of information conveyed across the horizon, filling thereby a large gap in entropy between the system on the brink of experiencing a sudden collapse to a black hole and the black hole itself. At the same time, even in the absence of interaction between dark matter and dark energy, such a process marks a strong jump in the entanglement entropy, measuring the quantum-mechanical correlations between the horizon and its interior. Although the effective quantum field theory (QFT) with a peculiar relationship between the UV and IR cutoffs, a framework underlying all HDE models, may formally account for such a huge shift in the number of distinct quantum states, we show that the scope of such a framework becomes tremendously restricted, devoid virtually any application in other cosmological epochs or particle-physics phenomena. The problem of negative entropies for the non-phantom stuff is also discussed.
Entanglement in holographic dark energy models
Horvat, R., E-mail: horvat@lei3.irb.h [Rudjer Boskovic Institute, P.O. Box 180, 10002 Zagreb (Croatia)
2010-10-18
We study a process of equilibration of holographic dark energy (HDE) with the cosmic horizon around the dark-energy dominated epoch. This process is characterized by a huge amount of information conveyed across the horizon, filling thereby a large gap in entropy between the system on the brink of experiencing a sudden collapse to a black hole and the black hole itself. At the same time, even in the absence of interaction between dark matter and dark energy, such a process marks a strong jump in the entanglement entropy, measuring the quantum-mechanical correlations between the horizon and its interior. Although the effective quantum field theory (QFT) with a peculiar relationship between the UV and IR cutoffs, a framework underlying all HDE models, may formally account for such a huge shift in the number of distinct quantum states, we show that the scope of such a framework becomes tremendously restricted, devoid virtually any application in other cosmological epochs or particle-physics phenomena. The problem of negative entropies for the non-phantom stuff is also discussed.
Interacting holographic dark energy models: a general approach
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.
Holographic duals of 3d S-fold CFTs arXiv
Assel, Benjamin
We construct non-geometric AdS$_4$ solutions of IIB string theory where the fields in overlapping patches are glued by elements of the S-duality group. We obtain them by suitable quotients of compact and non-compact geometric solutions. The quotient procedure suggests CFT duals as quiver theories with links involving the so-called $T[U(N)]$ theory. We test the validity of the non-geometric solutions (and of our proposed holographic duality) by computing the three-sphere partition function $Z$ of the CFTs. A first class of solutions is obtained by an S-duality quotient of Janus-type non-compact solutions and is dual to 3d $\\mathcal{N}=4$ SCFTs; for these we manage to compute $Z$ of the dual CFT at finite $N$, and it agrees perfectly with the supergravity result in the large $N$ limit. A second class has five-branes, it is obtained by a M\\"obius-like S-quotient of ordinary compact solutions and is dual to 3d $\\mathcal{N}=3$ SCFTs. For these, $Z$ agrees with the supergravity result if one chooses the limit caref...
Nonlinear evolution dynamics of holographic superconductor model with scalar self-interaction
Li, Ran; Zi, Tieguang; Zhang, Hongbao
2018-04-01
We investigate the holographic superconductor model that is described by the Einstein-Maxwell theory with the self-interaction term λ |Ψ |4 of complex scalar field in asymptotic anti-de Sitter (AdS) spacetime. Below critical temperature Tc, the planar Reissner-Nordström-AdS black hole is unstable due to the near-horizon scalar condensation instability. We study the full nonlinear development of this instability by numerically solving the gravitational dynamics in the asymptotic AdS spacetime, and observe a dynamical process from the perturbed Reissner-Nordström-AdS black hole to a hairy black hole when the initial black hole temperature T process is then holographically dual to the dynamical superconducting phase transition process in the boundary theory. Furthermore, we also study the effect of the scalar self-interaction on time evolution of superconducting condensate operator, event and apparent horizon areas of the final hairy black hole.
Holographic cosmological models on the braneworld
Lepe, Samuel [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Casilla 4950, Valparaiso (Chile); Saavedra, Joel [Instituto de Fisica, Pontificia Universidad Catolica de Valparaiso, Casilla 4950, Valparaiso (Chile)], E-mail: joel.saavedra@ucv.cl; Pena, Francisco [Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Universidad de la Frontera, Avda. Francisco Salazar 01145, Casilla 54-D, Temuco (Chile)
2009-01-26
In this Letter we have studied a closed universe which a holographic energy on the brane whose energy density is described by {rho}(H)=3c{sup 2}H{sup 2} and we obtain an equation for the Hubble parameter. This equation gave us different physical behavior depending if c{sup 2}>1 or c{sup 2}<1 against of the sign of the brane tension.
Holographic shell model: Stack data structure inside black holes?
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.
One-loop effect of null-like cosmology's holographic dual super-Yang-Mills
Lin, F.-L.; Tomino, Dan
2007-01-01
We calculate the 1-loop effect in super-Yang-Mills which preserves 1/4-supersymmetries and is holographically dual to the null-like cosmology with a big-bang singularity. Though the bosonic and fermionic spectra do not agree precisely, we do obtain vanishing 1-loop vacuum energy for generic warped plane-wave type backgrounds with a big-bang singularity. Moreover, we find that the cosmological 'constant' contributed either by bosons or fermions is time-dependent. The issues about the particle production of some background and about the UV structure are also commented. We argue that the effective higher derivative interactions are suppressed as long as the Fourier transform of the time-dependent coupling is UV-finite. Our result holds for scalar configurations that are BPS but with arbitrary time-dependence. This suggests the existence of non-renormalization theorem for such a new class of time-dependent theories. Altogether, it implies that such a super-Yang-Mills is scale-invariant, and that its dual bulk quantum gravity might behave regularly near the big bang
Correlation Functions in Holographic Minimal Models
Papadodimas, Kyriakos
2012-01-01
We compute exact three and four point functions in the W_N minimal models that were recently conjectured to be dual to a higher spin theory in AdS_3. The boundary theory has a large number of light operators that are not only invisible in the bulk but grow exponentially with N even at small conformal dimensions. Nevertheless, we provide evidence that this theory can be understood in a 1/N expansion since our correlators look like free-field correlators corrected by a power series in 1/N . However, on examining these corrections we find that the four point function of the two bulk scalar fields is corrected at leading order in 1/N through the contribution of one of the additional light operators in an OPE channel. This suggests that, to correctly reproduce even tree-level correlators on the boundary, the bulk theory needs to be modified by the inclusion of additional fields. As a technical by-product of our analysis, we describe two separate methods -- including a Coulomb gas type free-field formalism -- that ...
Generalized entropy formalism and a new holographic dark energy model
Sayahian Jahromi, A.; Moosavi, S. A.; Moradpour, H.; Morais Graça, J. P.; Lobo, I. P.; Salako, I. G.; Jawad, A.
2018-05-01
Recently, the Rényi and Tsallis generalized entropies have extensively been used in order to study various cosmological and gravitational setups. Here, using a special type of generalized entropy, a generalization of both the Rényi and Tsallis entropy, together with holographic principle, we build a new model for holographic dark energy. Thereinafter, considering a flat FRW universe, filled by a pressureless component and the new obtained dark energy model, the evolution of cosmos has been investigated showing satisfactory results and behavior. In our model, the Hubble horizon plays the role of IR cutoff, and there is no mutual interaction between the cosmos components. Our results indicate that the generalized entropy formalism may open a new window to become more familiar with the nature of spacetime and its properties.
Cosmology of a holographic induced gravity model with curvature effects
Bouhmadi-Lopez, Mariam; Errahmani, Ahmed; Ouali, Taoufiq
2011-01-01
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.
Quantisation of the holographic Ricci dark energy model
Albarran, Imanol; Bouhmadi-López, Mariam, E-mail: imanol@ubi.pt, E-mail: mbl@ubi.pt [Departamento de Física, Universidade da Beira Interior, 6200 Covilhã (Portugal)
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.
Bu Yanyan; Yang Jinmin
2011-01-01
Motivated by recent studies of deep inelastic scattering off the N=4 super-Yang-Mills (SYM) plasma, holographically dual to an AdS 5 xS 5 black hole, we use the spacelike flavor current to probe the internal structure of one holographic quark-gluon plasma, which is described by the Sakai-Sugimoto model at high temperature phase (i.e., the chiral-symmetric phase). The plasma structure function is extracted from the retarded flavor current-current correlator. Our main aim in this paper is to explore the effect of nonconformality on these physical quantities. As usual, our study is under the supergravity approximation and the limit of large color number. Although the Sakai-Sugimoto model is nonconformal, which makes the calculations more involved than the well-studied N=4 SYM case, the result seems to indicate that the nonconformality has little essential effect on the physical picture of the internal structure of holographic plasma, which is consistent with the intuition from the asymptotic freedom of QCD at high energy. While the physical picture underlying our investigation is same as the deep inelastic scattering off the N=4 SYM plasma with(out) flavor, the plasma structure functions are quantitatively different, especially their scaling dependence on the temperature, which can be recognized as model dependent. As a comparison, we also do the same analysis for the noncritical version of the Sakai-Sugimoto model which is conformal in the sense that it has a constant dilaton vacuum. The result for this noncritical model is quite similar to the conformal N=4 SYM plasma. We therefore attribute the above difference to the effect of nonconformality of the Sakai-Sugimoto model.
Modelling of a holographic interferometry based calorimeter for radiation dosimetry
Beigzadeh, A. M.; Vaziri, M. R. Rashidian; Ziaie, F.
2017-08-01
In this research work, a model for predicting the behaviour of holographic interferometry based calorimeters for radiation dosimetry is introduced. Using this technique for radiation dosimetry via measuring the variations of refractive index due to energy deposition of radiation has several considerable advantages such as extreme sensitivity and ability of working without normally used temperature sensors that disturb the radiation field. We have shown that the results of our model are in good agreement with the experiments performed by other researchers under the same conditions. This model also reveals that these types of calorimeters have the additional and considerable merits of transforming the dose distribution to a set of discernible interference fringes.
Dynamics of holographic vacuum energy in the DGP model
Wu Xing; Zhu Zonghong; Cai Ronggen
2008-01-01
We consider the evolution of the vacuum energy in the Dvali-Gabadadze-Porrati (DGP) model according to the holographic principle under the assumption that the relation linking the IR and UV cutoffs still holds in this scenario. The model is studied when the IR cutoff is chosen to be the Hubble scale H -1 , the particle horizon R ph , and the future event horizon R eh , respectively. The two branches of the DGP model are also taken into account. Through numerical analysis, we find that in the cases of H -1 in the (+) branch and R eh in both branches, the vacuum energy can play the role of dark energy. Moreover, when considering the combination of the vacuum energy and the 5D gravity effect in both branches, the equation of state of the effective dark energy may cross -1, which may lead to the big rip singularity. Besides, we constrain the model with the Type Ia supernovae and baryon oscillation data and find that our model is consistent with current data within 1σ, and that the observations prefer either a pure holographic dark energy or a pure DGP model
Taniguchi, Tadahiro; Sawaragi, Tetsuo
In this paper, a new machine-learning method, called Dual-Schemata model, is presented. Dual-Schemata model is a kind of self-organizational machine learning methods for an autonomous robot interacting with an unknown dynamical environment. This is based on Piaget's Schema model, that is a classical psychological model to explain memory and cognitive development of human beings. Our Dual-Schemata model is developed as a computational model of Piaget's Schema model, especially focusing on sensori-motor developing period. This developmental process is characterized by a couple of two mutually-interacting dynamics; one is a dynamics formed by assimilation and accommodation, and the other dynamics is formed by equilibration and differentiation. By these dynamics schema system enables an agent to act well in a real world. This schema's differentiation process corresponds to a symbol formation process occurring within an autonomous agent when it interacts with an unknown, dynamically changing environment. Experiment results obtained from an autonomous facial robot in which our model is embedded are presented; an autonomous facial robot becomes able to chase a ball moving in various ways without any rewards nor teaching signals from outside. Moreover, emergence of concepts on the target movements within a robot is shown and discussed in terms of fuzzy logics on set-subset inclusive relationships.
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
2013-01-01
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)
Quantum chaos and holographic tensor models
Krishnan, Chethan [Center for High Energy Physics, Indian Institute of Science,Bangalore 560012 (India); Sanyal, Sambuddha [International Center for Theoretical Sciences, Tata Institute of Fundamental Research,Bangalore 560089 (India); Subramanian, P.N. Bala [Center for High Energy Physics, Indian Institute of Science,Bangalore 560012 (India)
2017-03-10
A class of tensor models were recently outlined as potentially calculable examples of holography: their perturbative large-N behavior is similar to the Sachdev-Ye-Kitaev (SYK) model, but they are fully quantum mechanical (in the sense that there is no quenched disorder averaging). These facts make them intriguing tentative models for quantum black holes. In this note, we explicitly diagonalize the simplest non-trivial Gurau-Witten tensor model and study its spectral and late-time properties. We find parallels to (a single sample of) SYK where some of these features were recently attributed to random matrix behavior and quantum chaos. In particular, the spectral form factor exhibits a dip-ramp-plateau structure after a running time average, in qualitative agreement with SYK. But we also observe that even though the spectrum has a unique ground state, it has a huge (quasi-?)degeneracy of intermediate energy states, not seen in SYK. If one ignores the delta function due to the degeneracies however, there is level repulsion in the unfolded spacing distribution hinting chaos. Furthermore, there are gaps in the spectrum. The system also has a spectral mirror symmetry which we trace back to the presence of a unitary operator with which the Hamiltonian anticommutes. We use it to argue that to the extent that the model exhibits random matrix behavior, it is controlled not by the Dyson ensembles, but by the BDI (chiral orthogonal) class in the Altland-Zirnbauer classification.
Quantum chaos and holographic tensor models
Krishnan, Chethan; Sanyal, Sambuddha; Subramanian, P.N. Bala
2017-01-01
A class of tensor models were recently outlined as potentially calculable examples of holography: their perturbative large-N behavior is similar to the Sachdev-Ye-Kitaev (SYK) model, but they are fully quantum mechanical (in the sense that there is no quenched disorder averaging). These facts make them intriguing tentative models for quantum black holes. In this note, we explicitly diagonalize the simplest non-trivial Gurau-Witten tensor model and study its spectral and late-time properties. We find parallels to (a single sample of) SYK where some of these features were recently attributed to random matrix behavior and quantum chaos. In particular, the spectral form factor exhibits a dip-ramp-plateau structure after a running time average, in qualitative agreement with SYK. But we also observe that even though the spectrum has a unique ground state, it has a huge (quasi-?)degeneracy of intermediate energy states, not seen in SYK. If one ignores the delta function due to the degeneracies however, there is level repulsion in the unfolded spacing distribution hinting chaos. Furthermore, there are gaps in the spectrum. The system also has a spectral mirror symmetry which we trace back to the presence of a unitary operator with which the Hamiltonian anticommutes. We use it to argue that to the extent that the model exhibits random matrix behavior, it is controlled not by the Dyson ensembles, but by the BDI (chiral orthogonal) class in the Altland-Zirnbauer classification.
Coupling constant corrections in a holographic model of heavy ion collisions
Grozdanov, Sašo; Schee, Wilke van der
2017-01-01
We initiate a holographic study of coupling-dependent heavy ion collisions by analysing for the first time the effects of leading-order, inverse coupling constant corrections. In the dual description, this amounts to colliding gravitational shock waves in a theory with curvature-squared terms. We
A holographic view on matrix model of black hole
Suyama, Takao; Yi Piljin
2004-01-01
We investigate a deformed matrix model proposed by Kazakov et.al. in relation to Witten's two-dimensional black hole. The existing conjectures assert the equivalence of the two by mapping each to a deformed c=1 theory called the sine-Liouville theory. We point out that the matrix theory in question may be naturally interpreted as a gauged quantum mechanics deformed by insertion of an exponentiated Wilson loop operator, which gives us more direct and holographic map between the two sides. The matrix model in the usual scaling limit must correspond to the bosonic SL(2,R)/U(1) theory in genus expansion but exact in α'. We successfully test this by computing the Wilson loop expectation value and comparing it against the bulk computation. For the latter, we employ the α'-exact geometry proposed by Dijkgraaf, Verlinde, and Verlinde, which was further advocated by Tseytlin. We close with comments on open problems. (author)
Entropic information of dynamical AdS/QCD holographic models
Bernardini, Alex E., E-mail: alexeb@ufscar.br [Departamento de Física, Universidade Federal de São Carlos, PO Box 676, 13565-905, São Carlos, SP (Brazil); Rocha, Roldão da, E-mail: roldao.rocha@ufabc.edu.br [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, UFABC, 09210-580, Santo André (Brazil)
2016-11-10
The Shannon based conditional entropy that underlies five-dimensional Einstein–Hilbert gravity coupled to a dilaton field is investigated in the context of dynamical holographic AdS/QCD models. Considering the UV and IR dominance limits of such AdS/QCD models, the conditional entropy is shown to shed some light onto the meson classification schemes, which corroborate with the existence of light-flavor mesons of lower spins in Nature. Our analysis is supported by a correspondence between statistical mechanics and information entropy which establishes the physical grounds to the Shannon information entropy, also in the context of statistical mechanics, and provides some specificities for accurately extending the entropic discussion to continuous modes of physical systems. From entropic informational grounds, the conditional entropy allows one to identify the lower experimental/phenomenological occurrence of higher spin mesons in Nature. Moreover, it introduces a quantitative theoretical apparatus for studying the instability of high spin light-flavor mesons.
Thermodynamical Aspects of Modified Holographic Dark Energy Model
Li Hui; Zhang Yi
2014-01-01
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 r c of the 5-dimensional DGP model. (geophysics, astronomy, and astrophysics)
A more general interacting model of holographic dark energy
Yu Fei; Zhang Jingfei; Lu Jianbo; Wang Wei; Gui Yuanxing
2010-01-01
So far, there have been no theories or observational data that deny the presence of interaction between dark energy and dark matter. We extend naturally the holographic dark energy (HDE) model, proposed by Granda and Oliveros, in which the dark energy density includes not only the square of the Hubble scale, but also the time derivative of the Hubble scale to the case with interaction and the analytic forms for the cosmic parameters are obtained under the specific boundary conditions. The various behaviors concerning the cosmic expansion depend on the introduced numerical parameters which are also constrained. The more general interacting model inherits the features of the previous ones of HDE, keeping the consistency of the theory.
Bao, Ning [Institute for Quantum Information and Matter, California Institute of Technology,Pasadena, CA 91125 (United States); Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Nezami, Sepehr [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94305 (United States); Ooguri, Hirosi [Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Kavli Institute for the Physics and Mathematics of the Universe, University of Tokyo,Kashiwa 277-8583 (Japan); Stoica, Bogdan [Walter Burke Institute for Theoretical Physics, California Institute of Technology,452-48, Pasadena, CA 91125 (United States); Sully, James [Theory Group, SLAC National Accelerator Laboratory, Stanford University,Menlo Park, CA 94025 (United States); Walter, Michael [Stanford Institute for Theoretical Physics, Stanford University,Stanford, CA 94305 (United States)
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
2015-01-01
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.
SVZ⊕1/q{sup 2}-expansion versus some QCD holographic models
Jugeau, F., E-mail: frederic.jugeau@if.ufrj.br [Instituto de Física, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, RJ 21941-972, Rio de Janeiro (Brazil); Narison, S., E-mail: snarison@yahoo.fr [Laboratoire Particules et Univers de Montpellier, CNRS-IN2P3, Case 070, Place Eugène Bataillon, 34095 Montpellier (France); Ratsimbarison, H., E-mail: herysedra@yahoo.fr [Institute of High-Energy Physics of Madagascar (iHEP-MAD), University of Antananarivo (Madagascar)
2013-05-13
Considering the classical two-point correlators built from (axial-) vector, scalar q{sup ¯}q and gluonium currents, we confront results obtained using the SVZ⊕1/q{sup 2}-expansion to the ones from some QCD holographic models in the Euclidean region and with negative dilaton Φ{sub i}(z)=−|c{sub i}{sup 2}|z{sup 2}. We conclude that the presence of the 1/q{sup 2}-term in the SVZ-expansion due to a tachyonic gluon mass appears naturally in the Minimum Soft-Wall (MSW) and the Gauge/String Dual (GSD) models which can also reproduce semi-quantitatively some of the higher dimension condensate contributions appearing in the OPE. The Hard-Wall model shows a large departure from the SVZ⊕1/q{sup 2}-expansion in the vector, scalar and gluonium channels due to the absence of any power corrections. The equivalence of the MSW and GSD models is manifest in the vector channel through the relation of the dilaton parameter with the tachyonic gluon mass. For approximately reproducing the phenomenological values of the dimension d=4,6 condensates, the holographic models require a tachyonic gluon mass (α{sub s}/π)λ{sup 2}≈−(0.12–0.14) GeV{sup 2}, which is about twice the fitted phenomenological value from e{sup +}e{sup −} data. The relation of the inverse length parameter c{sub i} to the tachyonic gluon mass also shows that c{sub i} is channel dependent but not universal for a given holographic model. Using the MSW model and M{sub ρ}=0.78 GeV as input, we predict a scalar q{sup ¯}q mass M{sub S}≈(0.95–1.10) GeV and a scalar gluonium mass M{sub G}≈(1.1–1.3) GeV.
Holographic multiverse and conformal invariance
Garriga, Jaume [Departament de Física Fonamental i Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, 08193 Barcelona (Spain); Vilenkin, Alexander, E-mail: jaume.garriga@ub.edu, E-mail: vilenkin@cosmos.phy.tufts.edu [Institute of Cosmology, Department of Physics and Astronomy, Tufts University, 212 College Ave., Medford, MA 02155 (United States)
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.
Holographic multiverse and conformal invariance
Garriga, Jaume; Vilenkin, Alexander
2009-01-01
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
Model-based magnetization retrieval from holographic phase images
Röder, Falk, E-mail: f.roeder@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, Bautzner Landstr. 400, D-01328 Dresden (Germany); Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Vogel, Karin [Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Wolf, Daniel [Helmholtz-Zentrum Dresden-Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, Bautzner Landstr. 400, D-01328 Dresden (Germany); Triebenberg Labor, Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden (Germany); Hellwig, Olav [Helmholtz-Zentrum Dresden-Rossendorf, Institut für Ionenstrahlphysik und Materialforschung, Bautzner Landstr. 400, D-01328 Dresden (Germany); AG Magnetische Funktionsmaterialien, Institut für Physik, Technische Universität Chemnitz, D-09126 Chemnitz (Germany); HGST, A Western Digital Company, 3403 Yerba Buena Rd., San Jose, CA 95135 (United States); Wee, Sung Hun [HGST, A Western Digital Company, 3403 Yerba Buena Rd., San Jose, CA 95135 (United States); Wicht, Sebastian; Rellinghaus, Bernd [IFW Dresden, Institute for Metallic Materials, P.O. Box 270116, D-01171 Dresden (Germany)
2017-05-15
The phase shift of the electron wave is a useful measure for the projected magnetic flux density of magnetic objects at the nanometer scale. More important for materials science, however, is the knowledge about the magnetization in a magnetic nano-structure. As demonstrated here, a dominating presence of stray fields prohibits a direct interpretation of the phase in terms of magnetization modulus and direction. We therefore present a model-based approach for retrieving the magnetization by considering the projected shape of the nano-structure and assuming a homogeneous magnetization therein. We apply this method to FePt nano-islands epitaxially grown on a SrTiO{sub 3} substrate, which indicates an inclination of their magnetization direction relative to the structural easy magnetic [001] axis. By means of this real-world example, we discuss prospects and limits of this approach. - Highlights: • Retrieval of the magnetization from holographic phase images. • Magnetostatic model constructed for a magnetic nano-structure. • Decomposition into homogeneously magnetized components. • Discretization of a each component by elementary cuboids. • Analytic solution for the phase of a magnetized cuboid considered. • Fitting a set of magnetization vectors to experimental phase images.
A holographic model for the fractional quantum Hall effect
Lippert, Matthew [Institute for Theoretical Physics, University of Amsterdam,Science Park 904, 1090GL Amsterdam (Netherlands); Meyer, René [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo,Kashiwa, Chiba 277-8568 (Japan); Taliotis, Anastasios [Theoretische Natuurkunde, Vrije Universiteit Brussel andThe International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium)
2015-01-08
Experimental data for fractional quantum Hall systems can to a large extent be explained by assuming the existence of a Γ{sub 0}(2) modular symmetry group commuting with the renormalization group flow and hence mapping different phases of two-dimensional electron gases into each other. Based on this insight, we construct a phenomenological holographic model which captures many features of the fractional quantum Hall effect. Using an SL(2,ℤ)-invariant Einstein-Maxwell-axio-dilaton theory capturing the important modular transformation properties of quantum Hall physics, we find dyonic diatonic black hole solutions which are gapped and have a Hall conductivity equal to the filling fraction, as expected for quantum Hall states. We also provide several technical results on the general behavior of the gauge field fluctuations around these dyonic dilatonic black hole solutions: we specify a sufficient criterion for IR normalizability of the fluctuations, demonstrate the preservation of the gap under the SL(2,ℤ) action, and prove that the singularity of the fluctuation problem in the presence of a magnetic field is an accessory singularity. We finish with a preliminary investigation of the possible IR scaling solutions of our model and some speculations on how they could be important for the observed universality of quantum Hall transitions.
A holographic model for the fractional quantum Hall effect
Lippert, Matthew; Meyer, René; Taliotis, Anastasios
2015-01-01
Experimental data for fractional quantum Hall systems can to a large extent be explained by assuming the existence of a Γ0(2) modular symmetry group commuting with the renormalization group flow and hence mapping different phases of two-dimensional electron gases into each other. Based on this insight, we construct a phenomenological holographic model which captures many features of the fractional quantum Hall effect. Using an -invariant Einstein-Maxwell-axio-dilaton theory capturing the important modular transformation properties of quantum Hall physics, we find dyonic diatonic black hole solutions which are gapped and have a Hall conductivity equal to the filling fraction, as expected for quantum Hall states. We also provide several technical results on the general behavior of the gauge field fluctuations around these dyonic dilatonic black hole solutions: we specify a sufficient criterion for IR normalizability of the fluctuations, demonstrate the preservation of the gap under the action, and prove that the singularity of the fluctuation problem in the presence of a magnetic field is an accessory singularity. We finish with a preliminary investigation of the possible IR scaling solutions of our model and some speculations on how they could be important for the observed universality of quantum Hall transitions.
Holographic effective field theories
Martucci, Luca [Dipartimento di Fisica ed Astronomia “Galileo Galilei' , Università di Padova,and INFN - Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Zaffaroni, Alberto [Dipartimento di Fisica, Università di Milano-Bicocca,and INFN - Sezione di Milano-Bicocca, I-20126 Milano (Italy)
2016-06-28
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.
On the internal consistency of holographic dark energy models
Horvat, R
2008-01-01
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
Bulk viscosity in holographic Lifshitz hydrodynamics
Hoyos, Carlos; Kim, Bom Soo; Oz, Yaron
2014-01-01
We compute the bulk viscosity in holographic models dual to theories with Lifshitz scaling and/or hyperscaling violation, using a generalization of the bulk viscosity formula derived in arXiv:1103.1657 from the null focusing equation. We find that only a class of models with massive vector fields are truly Lifshitz scale invariant, and have a vanishing bulk viscosity. For other holographic models with scalars and/or massless vector fields we find a universal formula in terms of the dynamical exponent and the hyperscaling violation exponent
Probing interaction and spatial curvature in the holographic dark energy model
Li, Miao; Li, Xiao-Dong; Wang, Shuang; Wang, Yi; Zhang, Xin
2009-01-01
In this paper we place observational constraints on the interaction and spatial curvature in the holographic dark energy model. We consider three kinds of phenomenological interactions between holographic dark energy and matter, i.e., the interaction term Q is proportional to the energy densities of dark energy (ρ Λ ), matter (ρ m ), and matter plus dark energy (ρ m +ρ Λ ). For probing the interaction and spatial curvature in the holographic dark energy model, we use the latest observational data including the type Ia supernovae (SNIa) Constitution data, 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). Our results show that the interaction and spatial curvature in the holographic dark energy model are both rather small. Besides, it is interesting to find that there exists significant degeneracy between the phenomenological interaction and the spatial curvature in the holographic dark energy model
The effect of anisotropy on the thermodynamics of the interacting holographic dark energy model
Hossienkhani, H.; Jafari, A.; Fayaz, V.; Ramezani, A. H.
2018-02-01
By considering a holographic model for the dark energy in an anisotropic universe, the thermodynamics of a scheme of dark matter and dark energy interaction has been investigated. The results suggest that when holographic dark energy and dark matter evolve separately, each of them remains in thermodynamic equilibrium, therefore the interaction between them may be viewed as a stable thermal fluctuation that brings a logarithmic correction to the equilibrium entropy. Also the relation between the interaction term of the dark components and this thermal fluctuation has been obtained. Additionally, for a cosmological interaction as a free function, the anisotropy effects on the generalized second law of thermodynamics have been studied. By using the latest observational data on the holographic dark energy models as the unification of dark matter and dark energy, the observational constraints have been probed. To do this, we focus on observational determinations of the Hubble expansion rate H( z). Finally, we evaluate the anisotropy effects (although low) on various topics, such as the evolution of the statefinder diagnostic, the distance modulus and the spherical collapse from the holographic dark energy model and compare them with the results of the holographic dark energy of the Friedmann-Robertson-Walker and Λ CDM models.
Intelligent holographic databases
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
Holographic dark energy models: a comparison from the latest observational data
Li, Miao; Li, Xiao-Dong; Wang, Shuang; Zhang, Xin
2009-01-01
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 min 2 = 465.912; for RDE, χ min 2 = 483.130; for ADE, χ min 2 = 481.694. Among these models, HDE model can give the smallest χ 2 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
Reconstructing an interacting holographic polytropic gas model in a non-flat FRW universe
Karami, K; Abdolmaleki, A
2010-01-01
We study the correspondence between the interacting holographic dark energy and the polytropic gas model of dark energy in a non-flat FRW universe. This correspondence allows one to reconstruct the potential and the dynamics for the scalar field of the polytropic model, which describe accelerated expansion of the universe.
Reconstructing an interacting holographic polytropic gas model in a non-flat FRW universe
Karami, K; Abdolmaleki, A, E-mail: KKarami@uok.ac.i [Department of Physics, University of Kurdistan, Pasdaran Street, Sanandaj (Iran, Islamic Republic of)
2010-05-01
We study the correspondence between the interacting holographic dark energy and the polytropic gas model of dark energy in a non-flat FRW universe. This correspondence allows one to reconstruct the potential and the dynamics for the scalar field of the polytropic model, which describe accelerated expansion of the universe.
Peng, Yan, E-mail: yanpengphy@163.com [School of Mathematical Sciences, Qufu Normal University, Qufu, Shandong 273165 (China); School of Mathematics and Computer Science, Shaanxi Sci-Tech University, Hanzhong, Shaanxi 723000 (China); Pan, Qiyuan, E-mail: panqiyuan@126.com [Department of Physics, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, Hunan 410081 (China); Liu, Yunqi, E-mail: liuyunqi@hust.edu.cn [School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)
2017-02-15
We investigate holographic phase transitions with dark matter sector in the AdS soliton background away from the probe limit. In cases of weak backreaction, we find that the larger coupling parameter α makes the gap of condensation shallower and the critical chemical potential keeps as a constant. In contrast, for very heavy backreaction, the dark matter sector could affect the critical chemical potential and the order of phase transitions. We also find the jump of the holographic topological entanglement entropy corresponds to a first order transition between superconducting states in this model with dark matter sector. More importantly, for certain sets of parameters, we observe novel phenomenon of retrograde condensation. In a word, the dark matter sector provides richer physics in the phase structure and the holographic superconductor properties are helpful in understanding dark matter.
Peng, Yan; Pan, Qiyuan; Liu, Yunqi
2017-01-01
We investigate holographic phase transitions with dark matter sector in the AdS soliton background away from the probe limit. In cases of weak backreaction, we find that the larger coupling parameter α makes the gap of condensation shallower and the critical chemical potential keeps as a constant. In contrast, for very heavy backreaction, the dark matter sector could affect the critical chemical potential and the order of phase transitions. We also find the jump of the holographic topological entanglement entropy corresponds to a first order transition between superconducting states in this model with dark matter sector. More importantly, for certain sets of parameters, we observe novel phenomenon of retrograde condensation. In a word, the dark matter sector provides richer physics in the phase structure and the holographic superconductor properties are helpful in understanding dark matter.
Yan Peng
2017-02-01
Full Text Available We investigate holographic phase transitions with dark matter sector in the AdS soliton background away from the probe limit. In cases of weak backreaction, we find that the larger coupling parameter α makes the gap of condensation shallower and the critical chemical potential keeps as a constant. In contrast, for very heavy backreaction, the dark matter sector could affect the critical chemical potential and the order of phase transitions. We also find the jump of the holographic topological entanglement entropy corresponds to a first order transition between superconducting states in this model with dark matter sector. More importantly, for certain sets of parameters, we observe novel phenomenon of retrograde condensation. In a word, the dark matter sector provides richer physics in the phase structure and the holographic superconductor properties are helpful in understanding dark matter.
Anomalous transport and holographic momentum relaxation
Copetti, Christian; Fernández-Pendás, Jorge; Landsteiner, Karl; Megías, Eugenio
2017-09-01
The chiral magnetic and vortical effects denote the generation of dissipationless currents due to magnetic fields or rotation. They can be studied in holographic models with Chern-Simons couplings dual to anomalies in field theory. We study a holographic model with translation symmetry breaking based on linear massless scalar field backgrounds. We compute the electric DC conductivity and find that it can vanish for certain values of the translation symmetry breaking couplings. Then we compute the chiral magnetic and chiral vortical conductivities. They are completely independent of the holographic disorder couplings and take the usual values in terms of chemical potential and temperature. To arrive at this result we suggest a new definition of energy-momentum tensor in presence of the gravitational Chern-Simons coupling.
Holographic dual of de Sitter universe with AdS bubbles
Kanno, Sugumi; Sasaki, Misao; Soda, Jiro
2012-01-01
We study the proposal that a de Sitter (dS) universe with an Anti-de Sitter (AdS) bubble can be replaced by a dS universe with a boundary CFT. To explore this duality, we consider incident gravitons coming from the dS universe through the bubble wall into the AdS bubble in the original picture. In the dual picture, this process has to be identified with the absorption of gravitons by CFT matter. We have obtained a general formula for the absorption probability in general d+1 spacetime dimensions. The result shows the different behavior depending on whether spacetime dimensions are even or odd. We find that the absorption process of gravitons from the dS universe by CFT matter is controlled by localized gravitons (massive bound state modes in the Kaluza-Klein decomposition) in the dS universe. The absorption probability is determined by the effective degrees of freedom of the CFT matter and the effective gravitational coupling constant which encodes information of localized gravitons. We speculate that the dual of (d+1)-dimensional dS universe with an AdS bubble is also dual to a d-dimensional dS universe with CFT matter.
Wu, Jingjing; Wu, Xinming; Li, Pengfei; Li, Nan; Mao, Xiaomei; Chai, Lihe
2017-04-01
Meridian system is not only the basis of traditional Chinese medicine (TCM) method (e.g. acupuncture, massage), but also the core of TCM's basic theory. This paper has introduced a new informational perspective to understand the reality and the holographic field of meridian. Based on maximum information entropy principle (MIEP), a dynamic equation for the holographic field has been deduced, which reflects the evolutionary characteristics of meridian. By using self-organizing artificial neural network as algorithm, the evolutionary dynamic equation of the holographic field can be resolved to assess properties of meridians and clinically diagnose the health characteristics of patients. Finally, through some cases from clinical patients (e.g. a 30-year-old male patient, an apoplectic patient, an epilepsy patient), we use this model to assess the evolutionary properties of meridians. It is proved that this model not only has significant implications in revealing the essence of meridian in TCM, but also may play a guiding role in clinical assessment of patients based on the holographic field of meridians.
Collapse and revival in holographic quenches
Silva, Emilia da; Lopez, Esperanza; Mas, Javier; Serantes, Alexandre
2015-01-01
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.
Holographic Chern-Simons defects
Fujita, Mitsutoshi; Melby-Thompson, Charles M.; Meyer, René; Sugimoto, Shigeki
2016-01-01
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.
Karami, K; Khaledian, M S [Department of Physics, University of Kurdistan, Pasdaran Street, Sanandaj (Iran, Islamic Republic of); Jamil, Mubasher, E-mail: KKarami@uok.ac.ir, E-mail: MS.Khaledian@uok.ac.ir, E-mail: mjamil@camp.nust.edu.pk [Center for Advanced Mathematics and Physics (CAMP), National University of Sciences and Technology (NUST), Islamabad (Pakistan)
2011-02-15
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.
Zhang, Xiaolei; Zhang, Xiangchao; Yuan, He; Zhang, Hao; Xu, Min
2018-02-01
Digital holography is a promising measurement method in the fields of bio-medicine and micro-electronics. But the captured images of digital holography are severely polluted by the speckle noise because of optical scattering and diffraction. Via analyzing the properties of Fresnel diffraction and the topographies of micro-structures, a novel reconstruction method based on the dual-tree complex wavelet transform (DT-CWT) is proposed. This algorithm is shiftinvariant and capable of obtaining sparse representations for the diffracted signals of salient features, thus it is well suited for multiresolution processing of the interferometric holograms of directional morphologies. An explicit representation of orthogonal Fresnel DT-CWT bases and a specific filtering method are developed. This method can effectively remove the speckle noise without destroying the salient features. Finally, the proposed reconstruction method is compared with the conventional Fresnel diffraction integration and Fresnel wavelet transform with compressive sensing methods to validate its remarkable superiority on the aspects of topography reconstruction and speckle removal.
Vacuum transitions in dual models
Pashnev, A.I.; Volkov, D.V.; Zheltukhin, A.A.
1976-01-01
The investigation is continued of the spontaneous vacuum transition problem in the Neview-Schwartz dual model (NSDM). It is shown that vacuum transitions allow disclosing of supplementary degeneration in the resonance state spectrum. The dual amplitudes possess an internal structure corresponding to the presence of an infinite number of quarks with increasing masses and retained charges. The Adler principle holds. Analytic continuation on the constant of induced vacuum transitions makes it possible to establish the existence of spontaneous vacuum transitions in the NSDM. The consequence of this fact is the exact SU(2) symmetry of π, rho meson trajectories and the Higgs mechanism in the model. In this case the ratios of masses of particles leading trajectories are analogous to those obtained in the current algebra. It is shown that in the NSDM there arises chiral SU(2) x SU(2) x U(1) x U(1) x ... symmetry resulting from spontaneous vacuum transitions
Sutherland, Richard L.
2002-12-01
Polarization properties and electro-optical switching behavior of holographic polymer-dispersed liquid-crystal (HPDLC) reflection and transmission gratings are studied. A theoretical model is developed that combines anisotropic coupled-wave theory with an elongated liquid-crystal-droplet switching model and includes the effects of a statistical orientational distribution of droplet-symmetry axes. Angle- and polarization-dependent switching behaviors of HPDLC gratings are elucidated, and the effects on dynamic range are described. A new type of electro-optical switching not seen in ordinary polymer-dispersed liquid crystals, to the best of the author's knowledge, is presented and given a physical interpretation. The model provides valuable insight to the physics of these gratings and can be applied to the design of HPDLC holographic optical elements.
Salty popcorn in a homogeneous low-dimensional toy model of holographic QCD
Elliot-Ripley, Matthew
2017-01-01
Recently, a homogeneous ansatz has been used to study cold dense nuclear matter in the Sakai–Sugimoto model of holographic QCD. To justify this homogeneous approximation we here investigate a homogeneous ansatz within a low-dimensional toy version of Sakai–Sugimoto to study finite baryon density configurations and compare it to full numerical solutions. We find the ansatz corresponds to enforcing a dyon salt arrangement in which the soliton solutions are split into half-soliton layers. Within this ansatz we find analogues of the proposed baryonic popcorn transitions, in which solutions split into multiple layers in the holographic direction. The homogeneous results are found to qualitatively match the full numerical solutions, lending confidence to the homogeneous approximations of the full Sakai–Sugimoto model. In addition, we find exact compact solutions in the high density, flat space limit which demonstrate the existence of further popcorn transitions to three layers and beyond. (paper)
Alberte, Lasma; Ammon, Martin; Jiménez-Alba, Amadeo; Baggioli, Matteo; Pujolàs, Oriol
2018-04-01
We present a class of holographic massive gravity models that realize a spontaneous breaking of translational symmetry—they exhibit transverse phonon modes whose speed relates to the elastic shear modulus according to elasticity theory. Massive gravity theories thus emerge as versatile and convenient theories to model generic types of translational symmetry breaking: explicit, spontaneous, and a mixture of both. The nature of the breaking is encoded in the radial dependence of the graviton mass. As an application of the model, we compute the temperature dependence of the shear modulus and find that it features a glasslike melting transition.
P-T phase diagram of a holographic s+p model from Gauss-Bonnet gravity
Nie, Zhang-Yu; Zeng, Hui
2015-01-01
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.
Reheating of the Universe as holographic thermalization
Kawai, Shinsuke, E-mail: shinsuke.kawai@gmail.com [Department of Physics, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Nakayama, Yu [California Institute of Technology, 452-48, Pasadena, CA 91125 (United States); Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, Kashiwa, Chiba 277-8583 (Japan)
2016-08-10
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.
Reheating of the Universe as holographic thermalization
Shinsuke Kawai
2016-08-01
Full Text Available 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.
Forte, Monica [Universidad de Buenos Aires, Departamento de Fisica, Facultad de ciencias Exactas y Naturales, Buenos Aires (Argentina)
2016-12-15
We make a scalar representation of interactive models with cold dark matter and modified holographic Ricci dark energy through unified models driven by scalar fields with non-canonical kinetic term. These models are applications of the formalism of exotic k-essences generated by the global description of cosmological models with two interactive fluids in the dark sector and in these cases they correspond to the usual k-essences. The formalism is applied to the cases of constant potential in Friedmann-Robertson-Walker geometries. (orig.)
Viscous cosmology in new holographic dark energy model and the cosmic acceleration
Singh, C.P.; Srivastava, Milan
2018-01-01
In this work, we study a flat Friedmann-Robertson-Walker universe filled with dark matter and viscous new holographic dark energy. We present four possible solutions of the model depending on the choice of the viscous term. We obtain the evolution of the cosmological quantities such as scale factor, deceleration parameter and transition redshift to observe the effect of viscosity in the evolution. We also emphasis upon the two independent geometrical diagnostics for our model, namely the statefinder and the Om diagnostics. In the first case we study new holographic dark energy model without viscous and obtain power-law expansion of the universe which gives constant deceleration parameter and statefinder parameters. In the limit of the parameter, the model approaches to ΛCDM model. In new holographic dark energy model with viscous, the bulk viscous coefficient is assumed as ζ = ζ 0 + ζ 1 H, where ζ 0 and ζ 1 are constants, and H is the Hubble parameter. In this model, we obtain all possible solutions with viscous term and analyze the expansion history of the universe. We draw the evolution graphs of the scale factor and deceleration parameter. It is observed that the universe transits from deceleration to acceleration for small values of ζ in late time. However, it accelerates very fast from the beginning for large values of ζ. By illustrating the evolutionary trajectories in r - s and r - q planes, we find that our model behaves as an quintessence like for small values of viscous coefficient and a Chaplygin gas like for large values of bulk viscous coefficient at early stage. However, model has close resemblance to that of the ΛCDM cosmology in late time. The Om has positive and negative curvatures for phantom and quintessence models, respectively depending on ζ. Our study shows that the bulk viscosity plays very important role in the expansion history of the universe. (orig.)
Viscous cosmology in new holographic dark energy model and the cosmic acceleration
Singh, C. P.; Srivastava, Milan
2018-03-01
In this work, we study a flat Friedmann-Robertson-Walker universe filled with dark matter and viscous new holographic dark energy. We present four possible solutions of the model depending on the choice of the viscous term. We obtain the evolution of the cosmological quantities such as scale factor, deceleration parameter and transition redshift to observe the effect of viscosity in the evolution. We also emphasis upon the two independent geometrical diagnostics for our model, namely the statefinder and the Om diagnostics. In the first case we study new holographic dark energy model without viscous and obtain power-law expansion of the universe which gives constant deceleration parameter and statefinder parameters. In the limit of the parameter, the model approaches to Λ CDM model. In new holographic dark energy model with viscous, the bulk viscous coefficient is assumed as ζ =ζ 0+ζ 1H, where ζ 0 and ζ 1 are constants, and H is the Hubble parameter. In this model, we obtain all possible solutions with viscous term and analyze the expansion history of the universe. We draw the evolution graphs of the scale factor and deceleration parameter. It is observed that the universe transits from deceleration to acceleration for small values of ζ in late time. However, it accelerates very fast from the beginning for large values of ζ . By illustrating the evolutionary trajectories in r-s and r-q planes, we find that our model behaves as an quintessence like for small values of viscous coefficient and a Chaplygin gas like for large values of bulk viscous coefficient at early stage. However, model has close resemblance to that of the Λ CDM cosmology in late time. The Om has positive and negative curvatures for phantom and quintessence models, respectively depending on ζ . Our study shows that the bulk viscosity plays very important role in the expansion history of the universe.
New holographic scalar field models of dark energy in non-flat universe
Karami, K., E-mail: KKarami@uok.ac.i [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Fehri, J. [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of)
2010-02-08
Motivated by the work of Granda and Oliveros [L.N. Granda, A. Oliveros, Phys. Lett. B 671 (2009) 199], we generalize their work to the non-flat case. We study the correspondence between the quintessence, tachyon, K-essence and dilaton scalar field models with the new holographic dark energy model in the non-flat FRW universe. We reconstruct the potentials and the dynamics for these scalar field models, which describe accelerated expansion of the universe. In the limiting case of a flat universe, i.e. k=0, all results given in [L.N. Granda, A. Oliveros, Phys. Lett. B 671 (2009) 199] are obtained.
New holographic scalar field models of dark energy in non-flat universe
Karami, K.; Fehri, J.
2010-01-01
Motivated by the work of Granda and Oliveros [L.N. Granda, A. Oliveros, Phys. Lett. B 671 (2009) 199], we generalize their work to the non-flat case. We study the correspondence between the quintessence, tachyon, K-essence and dilaton scalar field models with the new holographic dark energy model in the non-flat FRW universe. We reconstruct the potentials and the dynamics for these scalar field models, which describe accelerated expansion of the universe. In the limiting case of a flat universe, i.e. k=0, all results given in [L.N. Granda, A. Oliveros, Phys. Lett. B 671 (2009) 199] are obtained.
Reconstructing an f(R) model from holographic dark energy: using the observational evidence
Saaidi, Kh; Aghamohammadi, A
2012-01-01
We investigate the correspondence relation between f(R) gravity and an interacting holographic dark energy (HDE). By obtaining the conditions needed for some observational evidence such as positive acceleration expansion of the Universe, crossing the phantom divide line and validity of the thermodynamics second law in an interacting HDE model and corresponding it with the f(R) model of gravity, we find a viable f(R) model that can explain the present Universe. We also obtain the explicit evolutionary forms of the corresponding scalar field, potential and scale factor of the Universe. (paper)
Communicative Modelling of Cultural Transmission and Evolution Through a Holographic Cognition Model
Ambjörn Naeve
2012-12-01
Full Text Available This article presents communicative ways to model the transmission and evolution of the processes and artefacts of a culture as the result of ongoing interactions between its members - both at the tacit and the explicit level. The purpose is not to model the entire cultural process, but to provide semantically rich “conceptual placeholders” for modelling any cultural activity that is considered important enough within a certain context. The general purpose of communicative modelling is to create models that improve the quality of communication between people. In order to capture the subjective aspects of Gregory Bateson’s definition of information as “a difference that makes a difference,” the article introduces a Holographic Cognition Model that uses optical holography as an analogy for human cognition, with the object beam of holography corresponding to the first difference (the situation that the cognitive agent encounters, and the reference beam of holography corresponding to the subjective experiences and biases that the agent brings to the situation, and which makes the second difference (the interference/interpretation pattern unique for each agent. By combining the HCM with a semantically rich and recursive form of process modelling, based on the SECI-theory of knowledge creation, we arrive at way to model the cultural transmission and evolution process that is consistent with the Unified Theory of Information (the Triple-C model with its emphasis on intra-, inter- and supra-actions.
From strong to weak coupling in holographic models of thermalization
Grozdanov, Sašo; Kaplis, Nikolaos [Instituut-Lorentz for Theoretical Physics, Leiden University,Niels Bohrweg 2, Leiden 2333 CA (Netherlands); Starinets, Andrei O. [Rudolf Peierls Centre for Theoretical Physics, University of Oxford,1 Keble Road, Oxford OX1 3NP (United Kingdom)
2016-07-29
We investigate the analytic structure of thermal energy-momentum tensor correlators at large but finite coupling in quantum field theories with gravity duals. We compute corrections to the quasinormal spectra of black branes due to the presence of higher derivative R{sup 2} and R{sup 4} terms in the action, focusing on the dual to N=4 SYM theory and Gauss-Bonnet gravity. We observe the appearance of new poles in the complex frequency plane at finite coupling. The new poles interfere with hydrodynamic poles of the correlators leading to the breakdown of hydrodynamic description at a coupling-dependent critical value of the wave-vector. The dependence of the critical wave vector on the coupling implies that the range of validity of the hydrodynamic description increases monotonically with the coupling. The behavior of the quasinormal spectrum at large but finite coupling may be contrasted with the known properties of the hierarchy of relaxation times determined by the spectrum of a linearized kinetic operator at weak coupling. We find that the ratio of a transport coefficient such as viscosity to the relaxation time determined by the fundamental non-hydrodynamic quasinormal frequency changes rapidly in the vicinity of infinite coupling but flattens out for weaker coupling, suggesting an extrapolation from strong coupling to the kinetic theory result. We note that the behavior of the quasinormal spectrum is qualitatively different depending on whether the ratio of shear viscosity to entropy density is greater or less than the universal, infinite coupling value of ℏ/4πk{sub B}. In the former case, the density of poles increases, indicating a formation of branch cuts in the weak coupling limit, and the spectral function shows the appearance of narrow peaks. We also discuss the relation of the viscosity-entropy ratio to conjectured bounds on relaxation time in quantum systems.
Constraining holographic cosmology using Planck data
Afshordi, Niayesh; Gould, Elizabeth; Skenderis, Kostas
2017-06-01
Holographic cosmology offers a novel framework for describing the very early Universe in which cosmological predictions are expressed in terms of the observables of a three-dimensional quantum field theory (QFT). This framework includes conventional slow-roll inflation, which is described in terms of a strongly coupled QFT, but it also allows for qualitatively new models for the very early Universe, where the dual QFT may be weakly coupled. The new models describe a universe which is nongeometric at early times. While standard slow-roll inflation leads to a (near-) power-law primordial power spectrum, perturbative super-renormalizable QFTs yield a new holographic spectral shape. Here, we compare the two predictions against cosmological observations. We use CosmoMC to determine the best fit parameters, and MultiNest for Bayesian evidence, comparing the likelihoods. We find that the dual QFT should be nonperturbative at the very low multipoles (l ≲30 ), while for higher multipoles (l ≳30 ) the new holographic model, based on perturbative QFT, fits the data just as well as the standard power-law spectrum assumed in Λ CDM cosmology. This finding opens the door to applications of nonperturbative QFT techniques, such as lattice simulations, to observational cosmology on gigaparsec scales and beyond.
Holographic complexity in gauge/string superconductors
Davood Momeni
2016-05-01
Full Text Available 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
Holographic renormalization and supersymmetry
Genolini, Pietro Benetti [Mathematical Institute, University of Oxford,Woodstock Road, Oxford OX2 6GG (United Kingdom); Cassani, Davide [LPTHE, Sorbonne Universités UPMC Paris 6 and CNRS, UMR 7589,F-75005, Paris (France); Martelli, Dario [Department of Mathematics, King’s College London,The Strand, London, WC2R 2LS (United Kingdom); Sparks, James [Mathematical Institute, University of Oxford,Woodstock Road, Oxford OX2 6GG (United Kingdom)
2017-02-27
Holographic renormalization is a systematic procedure for regulating divergences in observables in asymptotically locally AdS spacetimes. For dual boundary field theories which are supersymmetric it is natural to ask whether this defines a supersymmetric renormalization scheme. Recent results in localization have brought this question into sharp focus: rigid supersymmetry on a curved boundary requires specific geometric structures, and general arguments imply that BPS observables, such as the partition function, are invariant under certain deformations of these structures. One can then ask if the dual holographic observables are similarly invariant. We study this question in minimal N=2 gauged supergravity in four and five dimensions. In four dimensions we show that holographic renormalization precisely reproduces the expected field theory results. In five dimensions we find that no choice of standard holographic counterterms is compatible with supersymmetry, which leads us to introduce novel finite boundary terms. For a class of solutions satisfying certain topological assumptions we provide some independent tests of these new boundary terms, in particular showing that they reproduce the expected VEVs of conserved charges.
f(R in Holographic and Agegraphic Dark Energy Models and the Generalized Uncertainty Principle
Barun Majumder
2013-01-01
Full Text Available We studied a unified approach with the holographic, new agegraphic, and f(R dark energy model to construct the form of f(R which in general is responsible for the curvature driven explanation of the very early inflation along with presently observed late time acceleration. We considered the generalized uncertainty principle in our approach which incorporated the corrections in the entropy-area relation and thereby modified the energy densities for the cosmological dark energy models considered. We found that holographic and new agegraphic f(R gravity models can behave like phantom or quintessence models in the spatially flat FRW universe. We also found a distinct term in the form of f(R which goes as R 3 / 2 due to the consideration of the GUP modified energy densities. Although the presence of this term in the action can be important in explaining the early inflationary scenario, Capozziello et al. recently showed that f(R ~ R 3 / 2 leads to an accelerated expansion, that is, a negative value for the deceleration parameter q which fits well with SNeIa and WMAP data.
Λ(t)CDM model as a unified origin of holographic and agegraphic dark energy models
Chen Yun; Zhu Zonghong; Xu Lixin; Alcaniz, J.S.
2011-01-01
Motivated by the fact that any nonzero Λ can introduce a length scale or a time scale into Einstein's theory, r Λ =ct Λ =√(3/|Λ|). Conversely, any cosmological length scale or time scale can introduce a Λ(t), Λ(t)=3/r Λ 2 (t)=3/(c 2 t Λ 2 (t)). In this Letter, we investigate the time varying Λ(t) corresponding to the length scales, including the Hubble horizon, the particle horizon and the future event horizon, and the time scales, including the age of the universe and the conformal time. It is found out that, in this scenario, the Λ(t)CDM model can be taken as the unified origin of the holographic and agegraphic dark energy models with interaction between the matter and the dark energy, where the interacting term is determined by Q=-ρ . Λ . We place observational constraints on the Λ(t)CDM models originating from different cosmological length scales and time scales with the recently compiled 'Union2 compilation' which consists of 557 Type Ia supernovae (SNIa) covering a redshift range 0.015≤z≤1.4. In conclusion, an accelerating expansion universe can be derived in the cases taking the Hubble horizon, the future event horizon, the age of the universe and the conformal time as the length scale or the time scale.
Effect of quintessence on holographic fermionic spectrum
Kuang, Xiao-Mei [Yangzhou University, Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou (China); Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Valparaiso (Chile); Wu, Jian-Pin [Bohai University, Institute of Gravitation and Cosmology, Department of Physics, School of Mathematics and Physics, Jinzhou (China)
2017-10-15
In this letter, we investigate the holographic fermionic spectrum without/with dipole coupling dual to the Reissner-Nordstroem anti-de Sitter (RN-AdS) black brane surrounded by quintessence. We find that the low energy excitation of this fermionic system without dipole coupling behaves as a non-Fermi liquid. In particular, the introduction of quintessence aggravates the degree of deviation from a Fermi liquid. For the system with dipole coupling, the phase transition from (non-)Fermi liquid to Mott phase can be observed. The ratio between the width of gap and the critical temperature, beyond which the gap closes, is also worked out. We find that this ratio is larger than that of the holographic fermionic system dual to the RN-AdS black brane and even the material of V O{sub 2}. It means that our holographic system with quintessence can model new phenomena of the condensed matter system and provide some new insights in their regard. (orig.)
Ramanujam, P.S.; Berg, R.H.; Hvilsted, Søren
1999-01-01
A Two-dimensional holographic memory for archival storage is described. Assuming a coherent transfer function, an A4 page can be stored at high resolution in an area of 1 mm(2). Recently developed side-chain liquid crystalline azobenzene polyesters are found to be suitable media for holographic...
Instability in interacting dark sector: an appropriate holographic Ricci dark energy model
Herrera, Ramón [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2950, Casilla 4059, Valparaíso (Chile); Hipólito-Ricaldi, W.S. [Departamento de Ciências Naturais, Universidade Federal do Espírito Santo, Rodovia BR 101 Norte, km. 60, São Mateus, Espírito Santo (Brazil); Videla, Nelson, E-mail: ramon.herrera@pucv.cl, E-mail: wiliam.ricaldi@ufes.br, E-mail: nelson.videla@ing.uchile.cl [Departamento de Física, Universidad de Chile, FCFM, Blanco Encalada 2008, Santiago (Chile)
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.
Soft Pomeron in Holographic QCD
Ballon-Bayona, Alfonso; Costa, Miguel S; Djurić, Marko
2016-01-01
We study the graviton Regge trajectory in Holographic QCD as a model for high energy scattering processes dominated by soft pomeron exchange. This is done by considering spin J fields from the closed string sector that are dual to glueball states of even spin and parity. In particular, we construct a model that governs the analytic continuation of the spin J field equation to the region of real J < 2, which includes the scattering domain of negative Maldelstam variable t. The model leads to approximately linear Regge trajectories and is compatible with the measured values of 1.08 for the intercept and 0.25 GeV$^{-2}$ for the slope of the soft pomeron. The intercept of the secondary pomeron trajectory is in the same region of the subleading trajectories, made of mesons, proposed by Donnachie and Landshoff, and should therefore be taken into account.
Schwinger effect and negative differential conductivity in holographic models
Shankhadeep Chakrabortty
2015-01-01
Full Text Available The consequences of the Schwinger effect for conductivity are computed for strong coupling systems using holography. The one-loop diagram on the flavor brane introduces an O(λNc imaginary part in the effective action for a Maxwell flavor gauge field. This in turn introduces a real conductivity in an otherwise insulating phase of the boundary theory. Moreover, in certain regions of parameter space the differential conductivity is negative. This is computed in the context of the Sakai–Sugimoto model.
Holographic dark energy from fluid/gravity duality constraint by cosmological observations
Pourhassan, Behnam; Bonilla, Alexander; Faizal, Mir; Abreu, Everton M. C.
2018-06-01
In this paper, we obtain a holographic model of dark energy using the fluid/gravity duality. This model will be dual to a higher dimensional Schwarzschild black hole, and we would use fluid/gravity duality to relate to the parameters of this black hole to such a cosmological model. We will also analyze the thermodynamics of such a solution, and discuss the stability model. Finally, we use cosmological data to constraint the parametric space of this dark energy model. Thus, we will use observational data to perform cosmography for this holographic model based on fluid/gravity duality.
Combined constraints on holographic bosonic technicolor
Carone, Christopher D.; Primulando, Reinard
2010-01-01
We consider a model of strong electroweak symmetry breaking in which the expectation value of an additional, possibly composite, scalar field is responsible for the generation of fermion masses. The dynamics of the strongly coupled sector is defined and studied via its holographic dual, and does not correspond to a simple, scaled-up version of QCD. We consider the bounds from perturbative unitarity, the S parameter, and the mass of the Higgs-like scalar. We show that the combination of these constraints leaves a relatively limited region of parameter space viable, and suggests the qualitative features of the model that might be probed at the LHC.
Dual model for parton densities
El Hassouni, A.; Napoly, O.
1981-01-01
We derive power-counting rules for quark densities near x=1 and x=0 from parton interpretations of one-particle inclusive dual amplitudes. Using these rules, we give explicit expressions for quark distributions (including charm) inside hadrons. We can then show the compatibility between fragmentation and recombination descriptions of low-p/sub perpendicular/ processes
Wave optics modeling of real-time holographic wavefront compensation systems using OSSim
Carbon, Margarita A.; Guthals, Dennis M.; Logan, Jerry D.
2005-08-01
OSSim (Optical System Simulation) is a wave-optics, time-domain simulation toolbox with both optical and data processing components developed for adaptive optics (AO) systems. Diffractive wavefront control elements have recently been added that accurately model optically and electrically addressed spatial light modulators as real time holographic (RTH) devices in diffractive wavefront control systems. The developed RTH toolbox has found multiple applications for a variety of Boeing programs in solving problems of AO system analysis and design. Several complex diffractive wavefront control systems have been modeled for compensation of static and dynamic aberrations such as imperfect segmented primary mirrors and atmospheric and boundary layer turbulence. The results of OSSim simulations of RTH wavefront compensation show very good agreement with available experimental data.
Nonword Reading: Comparing Dual-Route Cascaded and Connectionist Dual-Process Models with Human Data
Pritchard, Stephen C.; Coltheart, Max; Palethorpe, Sallyanne; Castles, Anne
2012-01-01
Two prominent dual-route computational models of reading aloud are the dual-route cascaded (DRC) model, and the connectionist dual-process plus (CDP+) model. While sharing similarly designed lexical routes, the two models differ greatly in their respective nonlexical route architecture, such that they often differ on nonword pronunciation. Neither…
Interacting cosmic fluids and phase transitions under a holographic modeling for dark energy
Lepe, Samuel [Pontificia Universidad Catolica de Valparaiso, Instituto de Fisica, Facultad de Ciencias, Valparaiso (Chile); Pena, Francisco [Universidad de La Frontera, Departamento de Ciencias Fisicas, Facultad de Ingenieria y Ciencias, Temuco (Chile)
2016-09-15
We discuss the consequences of possible sign changes of the Q-function which measures the transfer of energy between dark energy and dark matter. We investigate this scenario from a holographic perspective by modeling dark energy by a linear parametrization and CPL-parametrization of the equation of state (ω). By imposing the strong constraint of the second law of thermodynamics, we show that the change of sign for Q, due to the cosmic evolution, imply changes in the temperatures of dark energy and dark matter. We also discuss the phase transitions, in the past and future, experienced by dark energy and dark matter (or, equivalently, the sign changes of their heat capacities). (orig.)
Direct phase derivative estimation using difference equation modeling in holographic interferometry
Kulkarni, Rishikesh; Rastogi, Pramod
2014-01-01
A new method is proposed for the direct phase derivative estimation from a single spatial frequency modulated carrier fringe pattern in holographic interferometry. The fringe intensity in a given row/column is modeled as a difference equation of intensity with spatially varying coefficients. These coefficients carry the information on the phase derivative. Consequently, the accurate estimation of the coefficients is obtained by approximating the coefficients as a linear combination of the predefined linearly independent basis functions. Unlike Fourier transform based fringe analysis, the method does not call for performing the filtering of the Fourier spectrum of fringe intensity. Moreover, the estimation of the carrier frequency is performed by applying the proposed method to a reference interferogram. The performance of the proposed method is insensitive to the fringe amplitude modulation and is validated with the simulation results. (paper)
Interacting cosmic fluids and phase transitions under a holographic modeling for dark energy
Lepe, Samuel; Pena, Francisco
2016-01-01
We discuss the consequences of possible sign changes of the Q-function which measures the transfer of energy between dark energy and dark matter. We investigate this scenario from a holographic perspective by modeling dark energy by a linear parametrization and CPL-parametrization of the equation of state (ω). By imposing the strong constraint of the second law of thermodynamics, we show that the change of sign for Q, due to the cosmic evolution, imply changes in the temperatures of dark energy and dark matter. We also discuss the phase transitions, in the past and future, experienced by dark energy and dark matter (or, equivalently, the sign changes of their heat capacities). (orig.)
Holographic collisions in non-conformal theories
Attems, Maximilian; Casalderrey-Solana, Jorge; Mateos, David; Santos-Oliván, Daniel; Sopuerta, Carlos F.; Triana, Miquel; Zilhão, Miguel
2017-01-01
We numerically simulate gravitational shock wave collisions in a holographic model dual to a non-conformal four-dimensional gauge theory. We find two novel effects associated to the non-zero bulk viscosity of the resulting plasma. First, the hydrodynamization time increases. Second, if the bulk viscosity is large enough then the plasma becomes well described by hydrodynamics before the energy density and the average pressure begin to obey the equilibrium equation of state. We discuss implications for the quark-gluon plasma created in heavy ion collision experiments.
Wang, Yuting; Xu, Lixin
2010-01-01
In this paper, the holographic dark energy model with new infrared (IR) cut-off for both the flat case and the non-flat case are confronted with the combined constraints of current cosmological observations: type Ia Supernovae, Baryon Acoustic Oscillations, current Cosmic Microwave Background, and the observational hubble data. By utilizing the Markov Chain Monte Carlo (MCMC) method, we obtain the best fit values of the parameters with $1\\sigma, 2\\sigma$ errors in the flat model: $\\Omega_{b}h...
Animal Modeling and Neurocircuitry of Dual Diagnosis
Chambers, R. Andrew
2010-01-01
Dual diagnosis is a problem of tremendous depth and scope, spanning many classes of mental disorders and addictive drugs. Animal models of psychiatric disorders studied in addiction paradigms suggest a unitary nature of mental illness and addiction vulnerability both on the neurocircuit and clinical-behavioral levels. These models provide platforms for exploring the interactive roles of biological, environmental and developmental factors on neurocircuits commonly involved in psychiatric and addiction diseases. While suggestive of the artifice of segregated research, training, and clinical cultures between psychiatric and addiction fields, this research may lead to more parsimonious, integrative and preventative treatments for dual diagnosis. PMID:20585464
Dual resonance models and their currents
Johnson, E.A.
1978-01-01
It is shown how dual resonance models were rederived from the concept of a string tracing out a surface in space-time. Thus, interacting strings reproduce the dual amplitudes. A scheme for tackling the unitarity problem began to develop. As a consistent theory of hadronic processes began to be built, workers at the same time were naturally led to expect that leptons could be included with hadrons in a unified dual theory. Thus, there is a search for dual amplitudes which would describe interactions between hadrons and currents (for example, electrons), as well as interactions involving only hadrons. Such amplitudes, it is believed, will be the correct ones, describing the real world. Such amplitudes will provide valuable information concerning such things as hadronic form factors. The great difficulties in building current-amplitudes with the required properties of proper factorization on a good spectrum, duality, current algebra, and proper asymptotic behavior are described. Dual models at the present time require for consistency, an intercept value of α 0 = 1 and a dimension value of d = 26 (or d = 10). There have been speculations that the unphysical dimension may be made physical by associating the ''extra dimensions'' with certain internal degrees of freedom. However, it is desired that the theory itself, force the dimension d = 4. It is quite possible that the dimension problem and the intercept problem are tied together and that resolving either problem will resolve the other. Order by order, a new dual current is constructed that is manifestly factorizable and which appears to be valid for arbitrary space-time dimension. The fact that this current is not bound at d = 26, leads to interesting speculations on the nature of dual currents
Li, Hai-Li; Zhang, Jing-Fei; Feng, Lu [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Zhang, Xin [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Peking University, Center for High Energy Physics, Beijing (China)
2017-12-15
In this paper, we make a deep analysis for the five typical interacting holographic dark energy models with the interaction terms Q = 3βH{sub 0}ρ{sub de}, Q = 3βH{sub 0}ρ{sub c}, Q = 3βH{sub 0}(ρ{sub de} + ρ{sub c}), Q = 3βH{sub 0}√(ρ{sub de}ρ{sub c}), and Q = 3βH{sub 0}(ρ{sub de}ρ{sub c})/(ρ{sub de}+ρ{sub c}), respectively. We obtain observational constraints on these models by using the type Ia supernova data (the Joint Light-Curve Analysis sample), the cosmic microwave background data (Planck 2015 distance priors), the baryon acoustic oscillations data, and the direct measurement of the Hubble constant. We find that the values of χ{sub min}{sup 2} for all the five models are almost equal (around 699), indicating that the current observational data equally favor these IHDE models. In addition, a comparison with the cases of an interaction term involving the Hubble parameter H is also made. (orig.)
Dual elaboration models in attitude change processes
Žeželj Iris
2005-01-01
Full Text Available This article examines empirical and theoretical developments in research on attitude change in the past 50 years. It focuses the period from 1980 till present as well as cognitive response theories as the dominant theoretical approach in the field. The postulates of Elaboration Likelihood Model, as most-researched representative of dual process theories are studied, based on review of accumulated research evidence. Main research findings are grouped in four basic factors: message source, message content, message recipient and its context. Most influential criticisms of the theory are then presented regarding its empirical base and dual process assumption. Some possible applications and further research perspectives are discussed at the end.
Distributed Model Predictive Control via Dual Decomposition
Biegel, Benjamin; Stoustrup, Jakob; Andersen, Palle
2014-01-01
This chapter presents dual decomposition as a means to coordinate a number of subsystems coupled by state and input constraints. Each subsystem is equipped with a local model predictive controller while a centralized entity manages the subsystems via prices associated with the coupling constraints...
Holographic magnetisation density waves
Donos, Aristomenis [Centre for Particle Theory and Department of Mathematical Sciences, Durham University,Stockton Road, Durham, DH1 3LE (United Kingdom); Pantelidou, Christiana [Departament de Fisica Quantica i Astrofisica & Institut de Ciencies del Cosmos (ICC),Universitat de Barcelona,Marti i Franques 1, 08028 Barcelona (Spain)
2016-10-10
We numerically construct asymptotically AdS black brane solutions of D=4 Einstein theory coupled to a scalar and two U(1) gauge fields. The solutions are holographically dual to d=3 CFTs in a constant external magnetic field along one of the U(1)’s. Below a critical temperature the system’s magnetisation density becomes inhomogeneous, leading to spontaneous formation of current density waves. We find that the transition can be of second order and that the solutions which minimise the free energy locally in the parameter space of solutions have averaged stressed tensor of a perfect fluid.
Holographic Renormalization in Dense Medium
Park, Chanyong
2014-01-01
The holographic renormalization of a charged black brane with or without a dilaton field, whose dual field theory describes a dense medium at finite temperature, is investigated in this paper. In a dense medium, two different thermodynamic descriptions are possible due to an additional conserved charge. These two different thermodynamic ensembles are classified by the asymptotic boundary condition of the bulk gauge field. It is also shown that in the holographic renormalization regularity of all bulk fields can reproduce consistent thermodynamic quantities and that the Bekenstein-Hawking entropy is nothing but the renormalized thermal entropy of the dual field theory. Furthermore, we find that the Reissner-Nordström AdS black brane is dual to a theory with conformal matter as expected, whereas a charged black brane with a nontrivial dilaton profile is mapped to a theory with nonconformal matter although its leading asymptotic geometry still remains as AdS space
Living on the edge: a toy model for holographic reconstruction of algebras with centers
Donnelly, William; Marolf, Donald; Michel, Ben; Wien, Jason [Department of Physics, University of California,Santa Barbara, CA 93106 (United States)
2017-04-18
We generalize the Pastawski-Yoshida-Harlow-Preskill (HaPPY) holographic quantum error-correcting code to provide a toy model for bulk gauge fields or linearized gravitons. The key new elements are the introduction of degrees of freedom on the links (edges) of the associated tensor network and their connection to further copies of the HaPPY code by an appropriate isometry. The result is a model in which boundary regions allow the reconstruction of bulk algebras with central elements living on the interior edges of the (greedy) entanglement wedge, and where these central elements can also be reconstructed from complementary boundary regions. In addition, the entropy of boundary regions receives both Ryu-Takayanagi-like contributions and further corrections that model the ((δArea)/(4G{sub N})) term of Faulkner, Lewkowycz, and Maldacena. Comparison with Yang-Mills theory then suggests that this ((δArea)/(4G{sub N})) term can be reinterpreted as a part of the bulk entropy of gravitons under an appropriate extension of the physical bulk Hilbert space.
Living on the edge: a toy model for holographic reconstruction of algebras with centers
Donnelly, William; Marolf, Donald; Michel, Ben; Wien, Jason
2017-01-01
We generalize the Pastawski-Yoshida-Harlow-Preskill (HaPPY) holographic quantum error-correcting code to provide a toy model for bulk gauge fields or linearized gravitons. The key new elements are the introduction of degrees of freedom on the links (edges) of the associated tensor network and their connection to further copies of the HaPPY code by an appropriate isometry. The result is a model in which boundary regions allow the reconstruction of bulk algebras with central elements living on the interior edges of the (greedy) entanglement wedge, and where these central elements can also be reconstructed from complementary boundary regions. In addition, the entropy of boundary regions receives both Ryu-Takayanagi-like contributions and further corrections that model the ((δArea)/(4G N )) term of Faulkner, Lewkowycz, and Maldacena. Comparison with Yang-Mills theory then suggests that this ((δArea)/(4G N )) term can be reinterpreted as a part of the bulk entropy of gravitons under an appropriate extension of the physical bulk Hilbert space.
More on the holographic Ricci dark energy model: smoothing Rips through interaction effects?
Bouhmadi-López, Mariam; Errahmani, Ahmed; Ouali, Taoufik; Tavakoli, Yaser
2018-04-01
The background cosmological dynamics of the late Universe is analysed on the framework of a dark energy model described by an holographic Ricci dark energy component. Several kind of interactions between the dark energy and the dark matter components are considered herein. We solve the background cosmological dynamics for the different choices of interactions with the aim to analyse not only the current evolution of the universe but also its asymptotic behaviour and, in particular, possible future singularities removal. We show that in most of the cases, the Big Rip singularity, a finger print of this model in absence of an interaction between the dark sectors, is substituted by a de Sitter or a Minkowski state. Most importantly, we found two new future bouncing solutions leading to two possible asymptotic behaviours, we named Little Bang and Little Sibling of the Big Bang. At a Little Bang, as the size of the universe shrinks to zero in an infinite cosmic time, the Hubble rate and its cosmic time derivative blow up. In addition, at a Little sibling of the Big Bang, as the size of the universe shrinks to zero in an infinite cosmic time, the Hubble rate blows up but its cosmic time derivative is finite. These two abrupt events can happen as well in the past.
Amer, E., E-mail: eynas.amer@ltu.se [Lulea University of Technology, Department of Applied Physics and Mechanical Engineering, SE-971 87 Lulea (Sweden); Gren, P.; Kaplan, A.F.H.; Sjoedahl, M. [Lulea University of Technology, Department of Applied Physics and Mechanical Engineering, SE-971 87 Lulea (Sweden)
2009-08-15
Pulsed digital holographic interferometry has been used to study the effect of the laser spot diameter on the shock wave generated in the ablation process of an Nd:YAG laser pulse on a Zn target under atmospheric pressure. For different laser spot diameters and time delays, the propagation of the expanding vapour and of the shock wave were recorded by intensity maps calculated using the recorded digital holograms. From the latter, the phase maps, the refractive index and the density field can be derived. A model was developed that approaches the density distribution, in particular the ellipsoidal expansion characteristics. The induced shock wave has an ellipsoid shape that approaches a sphere for decreasing spot diameter. The ellipsoidal shock waves have almost the same centre offset towards the laser beam and the same aspect ratio for different time steps. The model facilitates the derivation of the particle velocity field. The method provides valuable quantitative results that are discussed, in particular in comparison with the simpler point source explosion theory.
More on the holographic Ricci dark energy model: smoothing Rips through interaction effects?
Bouhmadi-López, Mariam; Errahmani, Ahmed; Ouali, Taoufik; Tavakoli, Yaser
2018-01-01
The background cosmological dynamics of the late Universe is analysed on the framework of a dark energy model described by an holographic Ricci dark energy component. Several kind of interactions between the dark energy and the dark matter components are considered herein. We solve the background cosmological dynamics for the different choices of interactions with the aim to analyse not only the current evolution of the universe but also its asymptotic behaviour and, in particular, possible future singularities removal. We show that in most of the cases, the Big Rip singularity, a finger print of this model in absence of an interaction between the dark sectors, is substituted by a de Sitter or a Minkowski state. Most importantly, we found two new future bouncing solutions leading to two possible asymptotic behaviours, we named Little Bang and Little Sibling of the Big Bang. At a Little Bang, as the size of the universe shrinks to zero in an infinite cosmic time, the Hubble rate and its cosmic time derivative blow up. In addition, at a Little sibling of the Big Bang, as the size of the universe shrinks to zero in an infinite cosmic time, the Hubble rate blows up but its cosmic time derivative is finite. These two abrupt events can happen as well in the past.
On Goldstone particles and the Adler principle in dual models
Volkov, D.V.; Zheltukhin, A.A.; Pashnev, A.I.
1975-01-01
The results that have been obtained on the basis of considering the spontaneous vacuum transitions for the cases of Veneziano dual model and dual M-model are generalized to model containing internal quantum numbers of SU(N)-group. This generalization allows to consider how in dual models the spontaneous violation of symmetry occurs, which Goldstone particles appear in this process, how Adler's principle is realized for dual amplitudes and their topics related of spontaneous violation of symmetry
Fidelity susceptibility as holographic PV-criticality
Momeni, Davood, E-mail: davoodmomeni78@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Faizal, Mir, E-mail: mirfaizalmir@googlemail.com [Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada); Irving K. Barber School of Arts and Sciences, University of British Columbia – Okanagan, 3333 University Way, Kelowna, British Columbia V1V 1V7 (Canada); Myrzakulov, Kairat, E-mail: kairatmyrzakul@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Myrzakulov, Ratbay, E-mail: rmyrzakulov@gmail.com [Eurasian International Center for Theoretical Physics and Department of General & Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan)
2017-02-10
It is well known that entropy can be used to holographically establish a connection among geometry, thermodynamics and information theory. In this paper, we will use complexity to holographically establish a connection among geometry, thermodynamics and information theory. Thus, we will analyze the relation among holographic complexity, fidelity susceptibility, and thermodynamics in extended phase space. We will demonstrate that fidelity susceptibility (which is the informational complexity dual to a maximum volume in AdS) can be related to the thermodynamical volume (which is conjugate to the cosmological constant in the extended thermodynamic phase space). Thus, this letter establishes a relation among geometry, thermodynamics, and information theory, using complexity.
Dual superconductor models of color confinement
Ripka, Georges
2004-01-01
The lectures, delivered at ECT (European Centre for Theoretical Studies in Nuclear Physics and Related Areas) in Trento (Italy) in 2002 and 2003, are addressed to physicists who wish to acquire a minimal background to understand present day attempts to model the confinement of quantum chromo-dynamics (QCD) in terms of dual superconductors. The lectures focus more on the models than on attempts to derive them from QCD. They discuss the Dirac theory of magnetic monopoles, the world sheet swept out by Dirac strings, deformations of Dirac strings and charge quantization, gauge fields associated to the field tensor and to the dual field tensor, the Landau-Ginzburg (Abelian Higgs) model of a dual superconductor, the flux tube joining two equal and opposite color-electric charges, the Abrikosov-Nielsen-Olesen vortex, the divergencies of the London limit, the comparison of the calculated flux tube and string tension with lattice data, duality transformations and the use of Kalb-Ramond fields, the two-potential Zwanzi...
On holographic disorder-driven metal-insulator transitions
Baggioli, Matteo; Pujolàs, Oriol [Institut de Física d’Altes Energies (IFAE), Universitat Autònoma de Barcelona,The Barcelona Institute of Science and Technology,Campus UAB, 08193 Bellaterra (Barcelona) (Spain)
2017-01-10
We give a minimal holographic model of a disorder-driven metal-insulator transition. It consists in a CFT with a charge sector and a translation-breaking sector that interact in the most generic way allowed by the symmetries and by dynamical consistency. In the gravity dual, it reduces to a Massive Gravity-Maxwell model with a new direct coupling between the gauge field and the metric that is allowed when gravity is massive. We show that the effect of this coupling is to decrease the DC electrical conductivity generically. This gives a nontrivial check that holographic massive gravity can be consistently interpreted as disorder from the CFT perspective. The suppression of the conductivity happens to such an extent that it does not obey any lower bound and it can be very small in the insulating phase. In some cases, the large disorder limit produces gradient instabilities that hint at the formation of modulated phases.
On holographic disorder-driven metal-insulator transitions
Baggioli, Matteo; Pujolàs, Oriol
2017-01-01
We give a minimal holographic model of a disorder-driven metal-insulator transition. It consists in a CFT with a charge sector and a translation-breaking sector that interact in the most generic way allowed by the symmetries and by dynamical consistency. In the gravity dual, it reduces to a Massive Gravity-Maxwell model with a new direct coupling between the gauge field and the metric that is allowed when gravity is massive. We show that the effect of this coupling is to decrease the DC electrical conductivity generically. This gives a nontrivial check that holographic massive gravity can be consistently interpreted as disorder from the CFT perspective. The suppression of the conductivity happens to such an extent that it does not obey any lower bound and it can be very small in the insulating phase. In some cases, the large disorder limit produces gradient instabilities that hint at the formation of modulated phases.
Intelligent interaction based on holographic personalized portal
Yadong Huang
2017-06-01
Full Text Available Purpose – The purpose of this paper is to study the architecture of holographic personalized portal, user modeling, commodity modeling and intelligent interaction. Design/methodology/approach – In this paper, the authors propose crowd-science industrial ecological system based on holographic personalized portal and its interaction. The holographic personality portal is based on holographic enterprises, commodities and consumers, and the personalized portal consists of accurate ontology, reliable supply, intelligent demand and smart cyberspace. Findings – The personalized portal can realize the information acquisition, characteristic analysis and holographic presentation. Then, the intelligent interaction, e.g. demand decomposition, personalized search, personalized presentation and demand prediction, will be implemented within the personalized portal. Originality/value – The authors believe that their work on intelligent interaction based on holographic personalized portal, which has been first proposed in this paper, is innovation focusing on the interaction between intelligence and convenience.
Betin, A Yu; Bobrinev, V I; Verenikina, N M; Donchenko, S S; Odinokov, S B [Research Institute ' Radiotronics and Laser Engineering' , Bauman Moscow State Technical University, Moscow (Russian Federation); Evtikhiev, N N; Zlokazov, E Yu; Starikov, S N; Starikov, R S [National Reseach Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)
2015-08-31
A multiplex method of recording computer-synthesised one-dimensional Fourier holograms intended for holographic memory devices is proposed. The method potentially allows increasing the recording density in the previously proposed holographic memory system based on the computer synthesis and projection recording of data page holograms. (holographic memory)
Zhai, Zhong-Xu; Liu, Wen-Biao [Department of Physics, Institute of Theoretical Physics, Beijing Normal University, Beijing, 100875 (China); Zhang, Tong-Jie, E-mail: zzx@mail.bnu.edu.cn, E-mail: tjzhang@bnu.edu.cn, E-mail: wbliu@bnu.edu.cn [Department of Astronomy, Beijing Normal University, Beijing, 100875 (China)
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.
Momentum analyticity of the holographic electric polarizability in 2+1 dimensions
Yin, Lei [Institute of Physics, Academic Sinica,No. 128, Sec. 2, Academia Rd., Nangang Dist., Taipei, R.O.C. (China); Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOS), Central China Normal University, No. 152 Luoyu Rd., Hongshan Dist., Wuhan (China); Ren, Hai-cang [Physics Department, The Rockefeller University,1230 York Avenue, New York, 10021-6399 (United States); Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOS), Central China Normal University, No. 152 Luoyu Rd., Hongshan Dist., Wuhan (China); Lee, Ting-Kuo [Institute of Physics, Academic Sinica,No. 128, Sec. 2, Academia Rd., Nangang Dist., Taipei, Taiwan (China); Hou, Defu [Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOS), Central China Normal University, No. 152 Luoyu Rd., Hongshan Dist., Wuhan (China)
2017-04-21
The static electric polarization of a holographic field theory dual to the Einstein-Maxwell theory in the background of AdS{sub 4} with a Reissner-Nordström (AdS-RN) black hole is investigated. We prove that the holographic polarization is a meromorphic functions in complex momentum plane and locate analytically the asymptotic distribution of the poles along two straight lines parallel to the imaginary axis for a large momentum magnitude. The results are compared with the numerical result on Friedel-like poles of the same holographic model reported in the literature and with the momentum singularities of the one-loop polarization in weak-coupling spinor QED{sub 3} and scalar QED{sub 3} with the similarities and differences discussed.
Holographic QCD with topologically charged domain-wall/membranes
Lin Fengli; Wu Shangyu
2008-01-01
We study the thermodynamical phase structures of holographic QCD with nontrivial topologically charged domain-wall/membranes which are originally related to the multiple θ-vacua in the large N c limit. We realize the topologically charged membranes as the holographic D6-brane fluxes in the Sakai-Sugimoto model. The D6-brane fluxes couple to the probe D8-D8-bar via Chern-Simon term, and act as the source for the baryonic current density of QCD. We find rich phase structures of the dual meson system by varying asymptotic separation of D8 and D8-bar. Especially, there can be a thermodynamically favored and stable phase of finite baryonic current density. This provides the supporting evidence for the discovery of the topologically charged membranes found in the lattice QCD calculations. We also find a crossover phase with the limiting baryonic current density and temperature which suggest a Hagedorn-like phase transition of meson dissociation.
On effective holographic Mott insulators
Baggioli, Matteo; Pujolàs, Oriol [Institut de Física d’Altes Energies (IFAE), Universitat Autònoma de Barcelona,The Barcelona Institute of Science and Technology,Campus UAB, 08193 Bellaterra (Barcelona) (Spain)
2016-12-20
We present a class of holographic models that behave effectively as prototypes of Mott insulators — materials where electron-electron interactions dominate transport phenomena. The main ingredient in the gravity dual is that the gauge-field dynamics contains self-interactions by way of a particular type of non-linear electrodynamics. The electrical response in these models exhibits typical features of Mott-like states: i) the low-temperature DC conductivity is unboundedly low; ii) metal-insulator transitions appear by varying various parameters; iii) for large enough self-interaction strength, the conductivity can even decrease with increasing doping (density of carriers) — which appears as a sharp manifestation of ‘traffic-jam’-like behaviour; iv) the insulating state becomes very unstable towards superconductivity at large enough doping. We exhibit some of the properties of the resulting insulator-superconductor transition, which is sensitive to the momentum dissipation rate in a specific way. These models imply a clear and generic correlation between Mott behaviour and significant effects in the nonlinear electrical response. We compute the nonlinear current-voltage curve in our model and find that indeed at large voltage the conductivity is largely reduced.
On effective holographic Mott insulators
Baggioli, Matteo; Pujolàs, Oriol
2016-01-01
We present a class of holographic models that behave effectively as prototypes of Mott insulators — materials where electron-electron interactions dominate transport phenomena. The main ingredient in the gravity dual is that the gauge-field dynamics contains self-interactions by way of a particular type of non-linear electrodynamics. The electrical response in these models exhibits typical features of Mott-like states: i) the low-temperature DC conductivity is unboundedly low; ii) metal-insulator transitions appear by varying various parameters; iii) for large enough self-interaction strength, the conductivity can even decrease with increasing doping (density of carriers) — which appears as a sharp manifestation of ‘traffic-jam’-like behaviour; iv) the insulating state becomes very unstable towards superconductivity at large enough doping. We exhibit some of the properties of the resulting insulator-superconductor transition, which is sensitive to the momentum dissipation rate in a specific way. These models imply a clear and generic correlation between Mott behaviour and significant effects in the nonlinear electrical response. We compute the nonlinear current-voltage curve in our model and find that indeed at large voltage the conductivity is largely reduced.
Higher order corrections to holographic black hole chemistry
Sinamuli, Musema; Mann, Robert B.
2017-10-01
We investigate the holographic Smarr relation beyond the large N limit. By making use of the holographic dictionary, we find that the bulk correlates of subleading 1 /N corrections to this relation are related to the couplings in Lovelock gravity theories. We likewise obtain a holographic equation of state and check its validity for a variety of interesting and nontrivial black holes, including rotating planar black holes in Gauss-Bonnet-Born-Infeld gravity, and nonextremal rotating black holes in minimal five-dimensional gauged supergravity. We provide an explanation of the N -dependence of the holographic Smarr relation in terms of contributions due to planar and nonplanar diagrams in the dual theory.
Peng, Yan
2017-07-01
We study a general flat space/boson star transition model in quasi-local ensemble through approaches familiar from holographic superconductor theories. We manage to find a parameter ψ 2, which is proved to be useful in disclosing properties of phase transitions. In this work, we explore effects of the scalar mass, scalar charge and Stückelberg mechanism on the critical phase transition points and the order of transitions mainly from behaviors of the parameter ψ 2. We mention that properties of transitions in quasi-local gravity are strikingly similar to those in holographic superconductor models. We also obtain an analytical relation ψ 2 ∝ ( μ - μ c )1/2, which also holds for the condensed scalar operator in the holographic insulator/superconductor system in accordance with mean field theories.
Flowing holographic anyonic superfluid
Jokela, Niko; Lifschytz, Gilad; Lippert, Matthew
2014-10-01
We investigate the flow of a strongly coupled anyonic superfluid based on the holographic D3-D7' probe brane model. By analyzing the spectrum of fluctuations, we find the critical superfluid velocity, as a function of the temperature, at which the flow stops being dissipationless when flowing past a barrier. We find that at a larger velocity the flow becomes unstable even in the absence of a barrier.
The dual of the Carroll-Field-Jackiw model
Guimaraes, M.S.; Grigorio, L.; Wotzasek, C.
2006-01-01
In this work we apply different duality techniques, both the dual projection, based on the soldering formalism and the master action, in order to obtain and study the dual description of the Carroll- Field-Jackiw model [1], a theory with a Chern-Simons-like explicitly Lorentz and CPT violating term, including the interaction with external charges. This Maxwell-Chern-Simons-like model may be rewritten in terms of the interacting modes of a massless scalar model and a topologically massive model [2], that are mapped, through duality, into interacting massless Maxwell and massive self-dual modes [3]. It is also shown that these dual modes might be represented into an unified rank-two self-dual model that represents the direct dual of the vector Maxwell-Chern-Simons-like model
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.
Dual models with SL(2, C) symmetry
Brink, L
1972-01-01
Making use of homogeneous space techniques, the authors construct a class of dual models, which is a generalization of the Virasoro- Shapiro type of model. The integrand in the integral representation for the N-point function depends not only on the modulus of the distances between two-dimensional Koba-Nielsen variables, but also on the corresponding phases. This is in fact the most general SL(2, C) invariant amplitude that can be constructed using complex integration variables. The extra phase factors in the integrand provide a possible means of avoiding tachyons both as external particles and as intermediate states in the amplitude. When factorized in a simple- minded fashion the intercepts are fixed to be integers. Although the external particles can be chosen not to be tachyons, such states appear as intermediate states. Within this factorization one can show that there are gauge conditions for the amplitude that can provide a ghostkilling mechanism. (19 refs).
Estes, John; Jensen, Kristan; O’Bannon, Andy; Tsatis, Efstratios; Wrase, Timm
2014-01-01
We study a number of (3+1)- and (2+1)-dimensional defect and boundary conformal field theories holographically dual to supergravity theories. In all cases the defects or boundaries are planar, and the defects are codimension-one. Using holography, we compute the entanglement entropy of a (hemi-)spherical region centered on the defect (boundary). We define defect and boundary entropies from the entanglement entropy by an appropriate background subtraction. For some (3+1)-dimensional theories we find evidence that the defect/boundary entropy changes monotonically under certain renormalization group flows triggered by operators localized at the defect or boundary. This provides evidence that the g-theorem of (1+1)-dimensional field theories generalizes to higher dimensions
Dual Numbers Approach in Multiaxis Machines Error Modeling
Jaroslav Hrdina
2014-01-01
Full Text Available Multiaxis machines error modeling is set in the context of modern differential geometry and linear algebra. We apply special classes of matrices over dual numbers and propose a generalization of such concept by means of general Weil algebras. We show that the classification of the geometric errors follows directly from the algebraic properties of the matrices over dual numbers and thus the calculus over the dual numbers is the proper tool for the methodology of multiaxis machines error modeling.
Topics in dual models and extended solutions
Roth, R.S.
1977-01-01
Two main topics are explored. The first deals with the infinities arising from the one loop planar string diagram of the standard dual model. It is shown that for the number of dimensions d = 25 or 26, these infinities lead to a renormalization of the slope of the Regge trajectories, in addition to a renormalization of the coupling constant. The second topic deals with the propagator for a confined particle (monopole) in a field theory. When summed to all orders, this propagator is altogether free of singularities in the finite momentum plane, and an attempt is made to illustrate this. The Bethe-Salpeter equation is examined and it is shown that ladder diagrams are not sufficient to obtain this result. However, in a nonrelativistic approximation confinement is obtained and all poles disappear
New results in the Dual Parton Model
Van, J.T.T.; Capella, A.
1984-01-01
In this paper, the similarity between the x distribution for particle production and the fragmentation functions are observed in e+e- collisions and in deep inelastic scattering are presented. Based on the observation, the authors develop a complete approach to multiparticle production which incorporates the most important features and concepts learned about high energy collisions. 1. Topological expansion : the dominant diagram at high energy corresponds to the simplest topology. 2. Unitarity : diagrams of various topology contribute to the cross sections in a way that unitary is preserved. 3. Regge behaviour and Duality. 4. Partonic structure of hadrons. These general theoretical ideas, result from many joint experimental and theoretical efforts on the study of soft hadron physics. The dual parton model is able to explain all the experimental features from FNAL to SPS collider energies. It has all the properties of an S-matrix theory and provides a unified description of hadron-hadron, hadron-nucleus and nucleus-nucleus collisions
Gravitation from entanglement in holographic CFTs
Faulkner, Thomas [Institute for Advanced Study,Princeton, NJ 08540 (United States); Guica, Monica [Department of Physics and Astronomy, University of Pennsylvania,209 S. 33rd St., Philadelphia, PA 19104-6396 (United States); Hartman, Thomas [Kavli Institute for Theoretical Physics, University of California,Santa Barbara, CA 93106-4030 (United States); Myers, Robert C. [Perimeter Institute for Theoretical Physics,31 Caroline Street N., Waterloo, Ontario N2L 2Y5 (Canada); Raamsdonk, Mark Van [Department of Physics and Astronomy, University of British Columbia,6224 Agricultural Road, Vancouver, B.C. V6T 1W9 (Canada)
2014-03-11
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=A/(4G{sub 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.
Holographic entanglement entropy and gravitational anomalies
Castro, A.; Detournay, S.; Iqbal, N.; Perlmutter, E.
2014-01-01
We study entanglement entropy in two-dimensional conformal field theories with a gravitational anomaly. In theories with gravity duals, this anomaly is holographically represented by a gravitational Chern-Simons term in the bulk action. We show that the anomaly broadens the Ryu-Takayanagi minimal
The dual model of perfectionism and depression among Chinese ...
The dual model of perfectionism was adopted to explore the influence of adaptive and maladaptive perfectionism on depression in college students. The results support the dual process model of perfectionism in Chinese undergraduates. A sample of 206 Chinese undergraduates completed measures of perfectionism, ...
Holographic non-Gaussianities in general single-field inflation
Isono, Hiroshi [Department of Physics, Faculty of Science,Chulalongkorn University, Bangkok 10330 (Thailand); Noumi, Toshifumi [Department of Physics and Jockey Club Institute for Advanced Study,Hong Kong University of Science and Technology (Hong Kong); Department of Physics,Kobe University, Kobe 657-8501 (Japan); Shiu, Gary [Department of Physics and Jockey Club Institute for Advanced Study,Hong Kong University of Science and Technology (Hong Kong); Department of Physics, University of Wisconsin-Madison,Madison, WI 53706 (United States); Wong, Sam S.C.; Zhou, Siyi [Department of Physics and Jockey Club Institute for Advanced Study,Hong Kong University of Science and Technology (Hong Kong)
2016-12-07
We use holographic techniques to compute inflationary non-Gaussianities for general single-field inflation, including models with a non-trivial sound speed. In this holographic approach, the inflationary dynamics is captured by a relevant deformation of the dual conformal field theory (CFT) in the UV, while the inflationary correlators are computed by conformal perturbation theory. In this paper, we discuss the effects of higher derivative operators, such as (∂{sub μ}ϕ∂{sup μ}ϕ){sup m}, which are known to induce a non-trivial sound speed and source potentially large non-Gaussianities. We compute the full inflationary bispectra from the deformed CFT correlators. We also discuss the squeezed limit of the bispectra from the viewpoint of operator product expansions. As is generic in the holographic description of inflation, our power spectrum is blue tilted in the UV region. We extend our bispectrum computation to the IR region by resumming the conformal perturbations to all orders. We provide a self-consistent setup which reproduces a red tilted power spectrum, as well as all possible bispectrum shapes in the slow-roll regime.
The Complexity of Developmental Predictions from Dual Process Models
Stanovich, Keith E.; West, Richard F.; Toplak, Maggie E.
2011-01-01
Drawing developmental predictions from dual-process theories is more complex than is commonly realized. Overly simplified predictions drawn from such models may lead to premature rejection of the dual process approach as one of many tools for understanding cognitive development. Misleading predictions can be avoided by paying attention to several…
A Dual System Model of Preferences under Risk
Mukherjee, Kanchan
2010-01-01
This article presents a dual system model (DSM) of decision making under risk and uncertainty according to which the value of a gamble is a combination of the values assigned to it independently by the affective and deliberative systems. On the basis of research on dual process theories and empirical research in Hsee and Rottenstreich (2004) and…
Lippert, Matthew
2009-01-01
We investigated the Sakai-Sugimoto model of large N QCD at nonzero temperature and baryon chemical potential and in the presence of background electric and magnetic fields. We studied the holographic representation of baryons and the deconfinement, chiral-symmetry breaking, and nuclear matter phase transitions. In a background electric field, chiral-symmetry breaking corresponds to an insulator-conductor transition. A magnetic field both catalyzes chiral-symmetry breaking and generates, in the confined phase, a pseudo-scalar gradient or, in the deconfined phase, an axial current. The resulting phase diagram is in qualitative agreement with studies of hot, dense QCD.
Charge distribution in an two-chain dual model
Fialkowski, K.; Kotanski, A.
1983-01-01
Charge distributions in the multiple production processes are analysed using the dual chain model. A parametrisation of charge distributions for single dual chains based on the νp and anti vp data is proposed. The rapidity charge distributions are then calculated for pp and anti pp collisions and compared with the previous calculations based on the recursive cascade model of single chains. The results differ at the SPS collider energies and in the energy dependence of the net forward charge supplying the useful tests of the dual chain model. (orig.)
Fourth sound of holographic superfluids
Yarom, Amos
2009-01-01
We compute fourth sound for superfluids dual to a charged scalar and a gauge field in an AdS 4 background. For holographic superfluids with condensates that have a large scaling dimension (greater than approximately two), we find that fourth sound approaches first sound at low temperatures. For condensates that a have a small scaling dimension it exhibits non-conformal behavior at low temperatures which may be tied to the non-conformal behavior of the order parameter of the superfluid. We show that by introducing an appropriate scalar potential, conformal invariance can be enforced at low temperatures.
Holographic complexity and spacetime singularities
Barbón, José L.F. [Instituto de Física Teórica IFT UAM/CSIC,C/ Nicolás Cabrera 13, Campus Universidad Autónoma de Madrid,Madrid 28049 (Spain); Rabinovici, Eliezer [Racah Institute of Physics, The Hebrew University,Jerusalem 91904 (Israel); Laboratoire de Physique Théorique et Hautes Energies, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris Cedex 05 (France)
2016-01-15
We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.
Holographic complexity and spacetime singularities
Barbón, José L.F.; Rabinovici, Eliezer
2016-01-01
We study the evolution of holographic complexity in various AdS/CFT models containing cosmological crunch singularities. We find that a notion of complexity measured by extremal bulk volumes tends to decrease as the singularity is approached in CFT time, suggesting that the corresponding quantum states have simpler entanglement structure at the singularity.
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
The AdS/CFT Correspondence and Holographic QCD
Erlich, J.
2012-01-01
Holographic QCD is an extra-dimensional approach to modeling QCD resonances and their interactions. Holographic models encode information about chiral symmetry breaking, Weinberg sum rules, vector meson dominance, and other phenomenological features of QCD. There are two complementary approaches to holographic model building: a top-down approach which begins with string-theory brane configurations, and a bottom-up approach which is more phenomenological. In this talk I will describe the AdS/CFT correspondence, which motivates Holographic QCD, and the techniques used to build holographic models of QCD and to calculate observables in those models. I will also discuss an intriguing light cone approach to Holographic QCD discovered by Brodsky and De Teramond. (author)
Holographic subregion complexity for singular surfaces
Bakhshaei, Elaheh [Isfahan University of Technology, Department of Physics, Isfahan (Iran, Islamic Republic of); Mollabashi, Ali [Institute for Research in Fundamental Sciences (IPM), School of Physics, Tehran (Iran, Islamic Republic of); Shirzad, Ahmad [Isfahan University of Technology, Department of Physics, Isfahan (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, Tehran (Iran, Islamic Republic of)
2017-10-15
Recently holographic prescriptions were proposed to compute the quantum complexity of a given state in the boundary theory. A specific proposal known as 'holographic subregion complexity' is supposed to calculate the complexity of a reduced density matrix corresponding to a static subregion. We study different families of singular subregions in the dual field theory and find the divergence structure and universal terms of holographic subregion complexity for these singular surfaces. We find that there are new universal terms, logarithmic in the UV cut-off, due to the singularities of a family of surfaces including a kink in (2 + 1) dimensions and cones in even dimensional field theories. We also find examples of new divergent terms such as squared logarithm and negative powers times the logarithm of the UV cut-off parameter. (orig.)
Zhang, Jing-Fei; Zhao, Ming-Ming; Li, Yun-He; Zhang, Xin
2015-01-01
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 ∑ m ν <0.186 eV (95% CL) and N eff =3.75 +0.28 −0.32 in the HDE model from the constraints of these data
Dual processing model of medical decision-making
Djulbegovic, Benjamin; Hozo, Iztok; Beckstead, Jason; Tsalatsanis, Athanasios; Pauker, Stephen G
2012-01-01
Abstract Background Dual processing theory of human cognition postulates that reasoning and decision-making can be described as a function of both an intuitive, experiential, affective system (system I) and/or an analytical, deliberative (system II) processing system. To date no formal descriptive model of medical decision-making based on dual processing theory has been developed. Here we postulate such a model and apply it to a common clinical situation: whether treatment should be administe...
Establishment of animal model of dual liver transplantation in rat.
Ying Zhang
Full Text Available The animal model of the whole-size and reduced-size liver transplantation in both rat and mouse has been successfully established. Because of the difficulties and complexities in microsurgical technology, the animal model of dual liver transplantation was still not established for twelve years since the first human dual liver transplantation has been made a success. There is an essential need to establish this animal model to lay a basic foundation for clinical practice. To study the physiological and histopathological changes of dual liver transplantation, "Y" type vein from the cross part between vena cava and two iliac of donor and "Y' type prosthesis were employed to recanalize portal vein and the bile duct between dual liver grafts and recipient. The dual right upper lobes about 45-50% of the recipient liver volume were taken as donor, one was orthotopically implanted at its original position, the other was rotated 180° sagitally and heterotopically positioned in the left upper quadrant. Microcirculation parameters, liver function, immunohistochemistry and survival were analyzed to evaluate the function of dual liver grafts. No significant difference in the hepatic microcirculatory flow was found between two grafts in the first 90 minutes after reperfusion. Light and electronic microscope showed the liver architecture was maintained without obvious features of cellular destruction and the continuity of the endothelium was preserved. Only 3 heterotopically positioned graft appeared patchy desquamation of endothelial cell, mitochondrial swelling and hepatocytes cytoplasmic vacuolization. Immunohistochemistry revealed there is no difference in hepatocyte activity and the ability of endothelia to contract and relax after reperfusion between dual grafts. Dual grafts made a rapid amelioration of liver function after reperfusion. 7 rats survived more than 7 days with survival rate of 58.3.%. Using "Y" type vein and bile duct prosthesis, we
Anatomy of new SUSY breaking holographic RG flows
Argurio, Riccardo [Physique Théorique et Mathématique andInternational Solvay Institutes, Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Musso, Daniele [International Center of Theoretical Physics (ICTP),Strada Costiera 11, I 34014 Trieste (Italy); Redigolo, Diego [Physique Théorique et Mathématique andInternational Solvay Institutes, Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Sorbonne Universités, UPMC University Paris 06, UMR 7589, LPTHE,F-75005, Paris (France); CNRS, UMR 7589, LPTHE,F-75005, Paris (France)
2015-03-17
We find and thoroughly study new supergravity domain wall solutions which are holographic realizations of supersymmetry breaking strongly coupled gauge theories. We set ourselves in an N=2 gauged supergravity with a minimal content in order to reproduce a dual N=1 effective SCFT which has a U(1){sub R} symmetry, a chiral operator whose components are responsible for triggering the RG flow, and an additional U(1){sub F} symmetry. We present a full three dimensional parameter space of solutions, which generically break supersymmetry. Some known solutions are recovered for specific sets of values of the parameters, with the new solutions interpolating between them. The generic backgrounds being singular, we provide a stability test of their dual theories by showing that there are no tachyonic resonances in the two point correlators. We compute the latter by holographic renormalization. We also carefully analyze the appearance of massless modes, such as the dilaton and the R axion, when the respective symmetries are spontaneously broken, and their lifting when the breaking is explicit. We further comment on the application of such class of backgrounds as archetypes of strongly coupled hidden sectors for gauge mediation of supersymmetry breaking. In particular, we show that it is possible to model in this way all types of hierarchies between the visible sector gaugino and sfermion masses.
Chattopadhyay, Surajit; Pasqua, Antonio; Khurshudyan, Martiros
2014-01-01
Motivated by the work of Yang et al. (Mod. Phys. Lett. A 26:191, 2011), we report on a study of the new holographic dark energy (NHDE) model with energy density given by ρ D = (3φ 2 )/(4ω)(μH 2 + νH) in the framework of chameleon Brans-Dicke cosmology. We have studied the correspondence between the quintessence, the DBI-essence, and the tachyon scalar-field models with the NHDE model in the framework of chameleon Brans-Dicke cosmology. Deriving an expression of the Hubble parameter H and, accordingly, ρ D in the context of chameleon Brans-Dicke chameleon cosmology, we have reconstructed the potentials and dynamics for these scalar-field models. Furthermore, we have examined the stability for the obtained solutions of the crossing of the phantom divide under a quantum correction of massless conformally invariant fields, and we have seen that the quantum correction could be small when the phantom crossing occurs and the obtained solutions of the phantom crossing could be stable under the quantum correction. It has also been noted that the potential increases as the matter. chameleon coupling gets stronger with the evolution of the universe. (orig.)
Chattopadhyay, Surajit [Pailan College of Management and Technology, Kolkata (India); Pasqua, Antonio [University of Trieste, Department of Physics, Trieste (Italy); Khurshudyan, Martiros [Yerevan State University, Department of Theoretical Physics, Yerevan (Armenia); Potsdam-Golm Science Park, Max Planck Institute of Colloids and Interfaces, Potsdam (Germany)
2014-09-15
Motivated by the work of Yang et al. (Mod. Phys. Lett. A 26:191, 2011), we report on a study of the new holographic dark energy (NHDE) model with energy density given by ρ{sub D} = (3φ{sup 2})/(4ω)(μH{sup 2} + νH) in the framework of chameleon Brans-Dicke cosmology. We have studied the correspondence between the quintessence, the DBI-essence, and the tachyon scalar-field models with the NHDE model in the framework of chameleon Brans-Dicke cosmology. Deriving an expression of the Hubble parameter H and, accordingly, ρ{sub D} in the context of chameleon Brans-Dicke chameleon cosmology, we have reconstructed the potentials and dynamics for these scalar-field models. Furthermore, we have examined the stability for the obtained solutions of the crossing of the phantom divide under a quantum correction of massless conformally invariant fields, and we have seen that the quantum correction could be small when the phantom crossing occurs and the obtained solutions of the phantom crossing could be stable under the quantum correction. It has also been noted that the potential increases as the matter. chameleon coupling gets stronger with the evolution of the universe. (orig.)
Cosmological model from the holographic equipartition law with a modified Renyi entropy
Komatsu, Nobuyoshi [Kanazawa University, Department of Mechanical Systems Engineering, Kanazawa, Ishikawa (Japan)
2017-04-15
Cosmological equations were recently derived by Padmanabhan from the expansion of cosmic space due to the difference between the degrees of freedom on the surface and in the bulk in a region of space. In this study, a modified Renyi entropy is applied to Padmanabhan's 'holographic equipartition law', by regarding the Bekenstein-Hawking entropy as a nonextensive Tsallis entropy and using a logarithmic formula of the original Renyi entropy. Consequently, the acceleration equation including an extra driving term (such as a time-varying cosmological term) can be derived in a homogeneous, isotropic, and spatially flat universe. When a specific condition is mathematically satisfied, the extra driving term is found to be constant-like as if it is a cosmological constant. Interestingly, the order of the constant-like term is naturally consistent with the order of the cosmological constant measured by observations, because the specific condition constrains the value of the constant-like term. (orig.)
Superoperators in the dual model with coloured quarks
Manida, S.N.
1978-01-01
The derivation of the dual model with coloured quarks is considered. The model is represented as a superoperator generalization of the Bardakci-Halpern model. It is shown that the three-regeon vertex of the model appears to be more compact and transparent
Generalized exact holographic mapping with wavelets
Lee, Ching Hua
2017-12-01
The idea of renormalization and scale invariance is pervasive across disciplines. It has not only drawn numerous surprising connections between physical systems under the guise of holographic duality, but has also inspired the development of wavelet theory now widely used in signal processing. Synergizing on these two developments, we describe in this paper a generalized exact holographic mapping that maps a generic N -dimensional lattice system to a (N +1 )-dimensional holographic dual, with the emergent dimension representing scale. In previous works, this was achieved via the iterations of the simplest of all unitary mappings, the Haar mapping, which fails to preserve the form of most Hamiltonians. By taking advantage of the full generality of biorthogonal wavelets, our new generalized holographic mapping framework is able to preserve the form of a large class of lattice Hamiltonians. By explicitly separating features that are fundamentally associated with the physical system from those that are basis specific, we also obtain a clearer understanding of how the resultant bulk geometry arises. For instance, the number of nonvanishing moments of the high-pass wavelet filter is revealed to be proportional to the radius of the dual anti-de Sitter space geometry. We conclude by proposing modifications to the mapping for systems with generic Fermi pockets.
[The dual process model of addiction. Towards an integrated model?].
Vandermeeren, R; Hebbrecht, M
2012-01-01
Neurobiology and cognitive psychology have provided us with a dual process model of addiction. According to this model, behavior is considered to be the dynamic result of a combination of automatic and controlling processes. In cases of addiction the balance between these two processes is severely disturbed. Automated processes will continue to produce impulses that ensure the continuance of addictive behavior. Weak, reflective or controlling processes are both the reason for and the result of the inability to forgo addiction. To identify features that are common to current neurocognitive insights into addiction and psychodynamic views on addiction. The picture that emerges from research is not clear. There is some evidence that attentional bias has a causal effect on addiction. There is no evidence that automatic associations have a causal effect, but there is some evidence that automatic action-tendencies do have a causal effect. Current neurocognitive views on the dual process model of addiction can be integrated with an evidence-based approach to addiction and with psychodynamic views on addiction.
New holographic dark energy model with constant bulk viscosity in modified f(R,T) gravity theory
Srivastava, Milan; Singh, C. P.
2018-06-01
The aim of this paper is to study new holographic dark energy (HDE) model in modified f(R,T) gravity theory within the framework of a flat Friedmann-Robertson-Walker model with bulk viscous matter content. It is thought that the negative pressure caused by the bulk viscosity can play the role of dark energy component, and drive the accelerating expansion of the universe. This is the motive of this paper to observe such phenomena with bulk viscosity. In the specific model f(R,T)=R+λ T, where R is the Ricci scalar, T the trace of the energy-momentum tensor and λ is a constant, we find the solution for non-viscous and viscous new HDE models. We analyze new HDE model with constant bulk viscosity, ζ =ζ 0= const. to explain the present accelerated expansion of the universe. We classify all possible scenarios (deceleration, acceleration and their transition) with possible positive and negative ranges of λ over the constraint on ζ 0 to analyze the evolution of the universe. We obtain the solutions of scale factor and deceleration parameter, and discuss the evolution of the universe. We observe the future finite-time singularities of type I and III at a finite time under certain constraints on λ . We also investigate the statefinder and Om diagnostics of the viscous new HDE model to discriminate with other existing dark energy models. In late time the viscous new HDE model approaches to Λ CDM model. We also discuss the thermodynamics and entropy of the model and find that it satisfies the second law of thermodynamics.
Mezey, Paul G.
2017-11-01
Two strongly related theorems on non-degenerate ground state electron densities serve as the basis of "Molecular Informatics". The Hohenberg-Kohn theorem is a statement on global molecular information, ensuring that the complete electron density contains the complete molecular information. However, the Holographic Electron Density Theorem states more: the local information present in each and every positive volume density fragment is already complete: the information in the fragment is equivalent to the complete molecular information. In other words, the complete molecular information provided by the Hohenberg-Kohn Theorem is already provided, in full, by any positive volume, otherwise arbitrarily small electron density fragment. In this contribution some of the consequences of the Holographic Electron Density Theorem are discussed within the framework of the "Nuclear Charge Space" and the Universal Molecule Model. In the Nuclear Charge Space" the nuclear charges are regarded as continuous variables, and in the more general Universal Molecule Model some other quantized parameteres are also allowed to become "de-quantized and then re-quantized, leading to interrelations among real molecules through abstract molecules. Here the specific role of the Holographic Electron Density Theorem is discussed within the above context.
Holographic spin networks from tensor network states
Singh, Sukhwinder; McMahon, Nathan A.; Brennen, Gavin K.
2018-01-01
In the holographic correspondence of quantum gravity, a global on-site symmetry at the boundary generally translates to a local gauge symmetry in the bulk. We describe one way how the global boundary on-site symmetries can be gauged within the formalism of the multiscale renormalization ansatz (MERA), in light of the ongoing discussion between tensor networks and holography. We describe how to "lift" the MERA representation of the ground state of a generic one dimensional (1D) local Hamiltonian, which has a global on-site symmetry, to a dual quantum state of a 2D "bulk" lattice on which the symmetry appears gauged. The 2D bulk state decomposes in terms of spin network states, which label a basis in the gauge-invariant sector of the bulk lattice. This decomposition is instrumental to obtain expectation values of gauge-invariant observables in the bulk, and also reveals that the bulk state is generally entangled between the gauge and the remaining ("gravitational") bulk degrees of freedom that are not fixed by the symmetry. We present numerical results for ground states of several 1D critical spin chains to illustrate that the bulk entanglement potentially depends on the central charge of the underlying conformal field theory. We also discuss the possibility of emergent topological order in the bulk using a simple example, and also of emergent symmetries in the nongauge (gravitational) sector in the bulk. More broadly, our holographic model translates the MERA, a tensor network state, to a superposition of spin network states, as they appear in lattice gauge theories in one higher dimension.
An extended dual search space model of scientific discovery learning
van Joolingen, Wouter; de Jong, Anthonius J.M.
1997-01-01
This article describes a theory of scientific discovery learning which is an extension of Klahr and Dunbar''s model of Scientific Discovery as Dual Search (SDDS) model. We present a model capable of describing and understanding scientific discovery learning in complex domains in terms of the SDDS
On the quark structure of resonance states in dual models
Volkov, D.V.; Zheltukhin, A.A.; Pashnev, A.I.
1975-01-01
It is shown using as an example the Veneziano dual model, that each particular dual model already contains a certain latent quark structure unambiauously determined by internal properties of the dual model. To prove this degeneration of the resonance state spectrum is studied by introducing an additional disturbing interaction into the model being considered. Induced transitions of particles into a vacuum act as such an additional disturbance. This method complements the known factorization method of Fubini, Gordon and Veneziano and turns out to be free from an essential limitation of the latter connected with implicit assumption about the basence of internal additive laws of conservation in the model. By using the method of induced transitions of particles into a vacuum it has been possible to show that the resonance state spectrum is indeed more degenerated than it should be expected from the factorization theorem, and that the supplementary degeneration corresponds to the quark model with an infinite number of quarks of the increasing mass. Structures of some terms of the dual amplitude expansion over the degrees of the constant of the induced transition of particles to vacuum are considered; it is shown that the summation of this expansion may be reduced to a solution of a certain integral equation. On the basis of the integral equation obtained an integral representation ofr dual amplitudes is established. The problems related with degeneration of resonance states and with determination of additive quantum numbers leading to the quark interpretation of the degeneration being considered are discussed
Towards understanding Regge trajectories in holographic QCD
Cata, Oscar
2007-01-01
We reassess a work done by Migdal on the spectrum of low-energy vector mesons in QCD in the light of the anti-de Sitter (AdS)-QCD correspondence. Recently, a tantalizing parallelism was suggested between Migdal's work and a family of holographic duals of QCD. Despite the intriguing similarities, both approaches face a major drawback: the spectrum is in conflict with well-tested Regge scaling. However, it has recently been shown that holographic duals can be modified to accommodate Regge behavior. Therefore, it is interesting to understand whether Regge behavior can also be achieved in Migdal's approach. In this paper we investigate this issue. We find that Migdal's approach, which is based on a modified Pade approximant, is closely related to the issue of quark-hadron duality breakdown in QCD
Constructive use of holographic projections
Schroer, Bert
2008-01-01
Revisiting the old problem of existence of interacting models of QFT with new conceptual ideas and mathematical tools, one arrives at a novel view about the nature of QFT. The recent success of algebraic methods in establishing the existence of factorizing models suggests new directions for a more intrinsic constructive approach beyond Lagrangian quantization. Holographic projection simplifies certain properties of the bulk theory and hence is a promising new tool for these new attempts. (author)
Constructive use of holographic projections
Schroer, Bert [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Institut fuer Theoretische Physik der FU, Berlin (Germany)
2008-07-01
Revisiting the old problem of existence of interacting models of QFT with new conceptual ideas and mathematical tools, one arrives at a novel view about the nature of QFT. The recent success of algebraic methods in establishing the existence of factorizing models suggests new directions for a more intrinsic constructive approach beyond Lagrangian quantization. Holographic projection simplifies certain properties of the bulk theory and hence is a promising new tool for these new attempts. (author)
A dynamic dual process model of risky decision making.
Diederich, Adele; Trueblood, Jennifer S
2018-03-01
Many phenomena in judgment and decision making are often attributed to the interaction of 2 systems of reasoning. Although these so-called dual process theories can explain many types of behavior, they are rarely formalized as mathematical or computational models. Rather, dual process models are typically verbal theories, which are difficult to conclusively evaluate or test. In the cases in which formal (i.e., mathematical) dual process models have been proposed, they have not been quantitatively fit to experimental data and are often silent when it comes to the timing of the 2 systems. In the current article, we present a dynamic dual process model framework of risky decision making that provides an account of the timing and interaction of the 2 systems and can explain both choice and response-time data. We outline several predictions of the model, including how changes in the timing of the 2 systems as well as time pressure can influence behavior. The framework also allows us to explore different assumptions about how preferences are constructed by the 2 systems as well as the dynamic interaction of the 2 systems. In particular, we examine 3 different possible functional forms of the 2 systems and 2 possible ways the systems can interact (simultaneously or serially). We compare these dual process models with 2 single process models using risky decision making data from Guo, Trueblood, and Diederich (2017). Using this data, we find that 1 of the dual process models significantly outperforms the other models in accounting for both choices and response times. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
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. (research papers)
Zhao, Ze; Wang, Shuang
2018-03-01
The main purpose of this work is to distinguish various holographic type dark energy (DE) models, including the ΛHDE, HDE, NADE, and RDE model, by using various diagnostic tools. The first diagnostic tool is the Statefinder hierarchy, in which the evolution of Statefinder hierarchy parmeter S (1) 3( z) and S (1) 4( z) are studied. The second is composite null diagnostic (CND), in which the trajectories of { S (1) 3, ɛ} and { S (1) 4, ɛ} are investigated, where ɛ is the fractional growth parameter. The last is w-w' analysis, where w is the equation of state for DE and the prime denotes derivative with respect to ln a. In the analysis we consider two cases: varying current fractional DE density Ω de0 and varying DE model parameter C. We find that: (1) both the Statefinder hierarchy and the CND have qualitative impact on ΛHDE, but only have quantitative impact on HDE. (2) S (1) 4 can lead to larger differences than S (1) 3, while the CND pair has a stronger ability to distinguish different models than the Statefinder hierarchy. (3) For the case of varying C, the { w,w'} pair has qualitative impact on ΛHDE; for the case of varying Ω de0, the { w, w'} pair only has quantitative impact; these results are different from the cases of HDE, RDE, and NADE, in which the {w,w'} pair only has quantitative impact on these models. In conclusion, compared with HDE, RDE, and NADE, the ΛHDE model can be easily distinguished by using these diagnostic tools.
A holographic model of reminiscence in the poetry of Czesław Miłosz
Agnieszka Rydz
2011-01-01
Full Text Available For a model of nostalgic memory in the poetry of Czesław Miłosz, based on the psychological phenomenon of reminiscence, an allegoric counterpart can be identified in the hologram metaphor (Douwe Draaisma. The question: “Who am I” – reappears in Miłosz’s late lyrical poetry when he ponders over both his biography and the biographies of others. The response is provided, for instance, in the concept of human dialectic biography (of subject and object, formulated by Paul Ricoeur in his philosophical analyses. Human memory remains equally dialectic, placed in the antinomy between memory and oblivion. Still, retrieving a detail which has been remembered evokes all experience along with its rich context. That is the holographic effect, described in literature as the “ghost image”. Also in poetry, the effacing of memory trace does not make a barrier for the restitution of recollection. “The Sun of Memory” beams through the lyric of the author of the collection of poems “This”.
Sciammarella, C. A.; Sainov, Ventseslav; Simova, Eli
1990-04-01
Theoretical analysis and experimental results on holographic moire contouring (HMC) of difussely reflecting objects are presented. The sensitivity and application constraints of the method are discussed. A high signal-to-noise ratio and contrast of the fringes is achieved through the use of high quality silver halide holographic plates HP-650. A good agreement between theoretical and experimental results is observed.
Cvetič, Mirjam; Papadimitriou, Ioannis
2016-01-01
We construct the holographic dictionary for both running and constant dilaton solutions of the two dimensional Einstein-Maxwell-Dilaton theory that is obtained by a circle reduction from Einstein-Hilbert gravity with negative cosmological constant in three dimensions. This specific model ensures that the dual theory has a well defined ultraviolet completion in terms of a two dimensional conformal field theory, but our results apply qualitatively to a wider class of two dimensional dilaton gravity theories. For each type of solutions we perform holographic renormalization, compute the exact renormalized one-point functions in the presence of arbitrary sources, and derive the asymptotic symmetries and the corresponding conserved charges. In both cases we find that the scalar operator dual to the dilaton plays a crucial role in the description of the dynamics. Its source gives rise to a matter conformal anomaly for the running dilaton solutions, while its expectation value is the only non trivial observable for constant dilaton solutions. The role of this operator has been largely overlooked in the literature. We further show that the only non trivial conserved charges for running dilaton solutions are the mass and the electric charge, while for constant dilaton solutions only the electric charge is non zero. However, by uplifting the solutions to three dimensions we show that constant dilaton solutions can support non trivial extended symmetry algebras, including the one found by Compère, Song and Strominger http://dx.doi.org/10.1007/JHEP05(2013)152, in agreement with the results of Castro and Song http://arxiv.org/abs/1411.1948. Finally, we demonstrate that any solution of this specific dilaton gravity model can be uplifted to a family of asymptotically AdS 2 ×S 2 or conformally AdS 2 ×S 2 solutions of the STU model in four dimensions, including non extremal black holes. The four dimensional solutions obtained by uplifting the running dilaton solutions coincide
AdS{sub 2} holographic dictionary
Cvetič, Mirjam [Department of Physics and Astronomy, University of Pennsylvania,Philadelphia, PA 19104-6396 (United States); Center for Applied Mathematics and Theoretical Physics,University of Maribor, SI2000 Maribor (Slovenia); Papadimitriou, Ioannis [SISSA and INFN - Sezione di Trieste,Via Bonomea 265, 34136 Trieste (Italy)
2016-12-02
We construct the holographic dictionary for both running and constant dilaton solutions of the two dimensional Einstein-Maxwell-Dilaton theory that is obtained by a circle reduction from Einstein-Hilbert gravity with negative cosmological constant in three dimensions. This specific model ensures that the dual theory has a well defined ultraviolet completion in terms of a two dimensional conformal field theory, but our results apply qualitatively to a wider class of two dimensional dilaton gravity theories. For each type of solutions we perform holographic renormalization, compute the exact renormalized one-point functions in the presence of arbitrary sources, and derive the asymptotic symmetries and the corresponding conserved charges. In both cases we find that the scalar operator dual to the dilaton plays a crucial role in the description of the dynamics. Its source gives rise to a matter conformal anomaly for the running dilaton solutions, while its expectation value is the only non trivial observable for constant dilaton solutions. The role of this operator has been largely overlooked in the literature. We further show that the only non trivial conserved charges for running dilaton solutions are the mass and the electric charge, while for constant dilaton solutions only the electric charge is non zero. However, by uplifting the solutions to three dimensions we show that constant dilaton solutions can support non trivial extended symmetry algebras, including the one found by Compère, Song and Strominger http://dx.doi.org/10.1007/JHEP05(2013)152, in agreement with the results of Castro and Song http://arxiv.org/abs/1411.1948. Finally, we demonstrate that any solution of this specific dilaton gravity model can be uplifted to a family of asymptotically AdS{sub 2}×S{sup 2} or conformally AdS{sub 2}×S{sup 2} solutions of the STU model in four dimensions, including non extremal black holes. The four dimensional solutions obtained by uplifting the running dilaton
Polychromatic holographic plasma diagnostics
Zhiglinskij, A.G.; Morozov, A.O.
1992-01-01
Review of holographic interferometry properties is performed and advantages of this method by plasma diagnostics are indicated. Main results obtained by the method of holographic interferometry in studies of various-type plasmas are considered. Special attention is paid to multiwave plasma diagnostics, the necessity of which is related as a rule to multicomponent composition of plasma. The eight laser and gas-discharge sources and holographic schemes, which make it possible to realize plasma polychromatic and holographic interferometry, are considered. The advantages of the method are demonstrated by examples of polychromatic holographic diagnostics of arc discharge and discharge in a hollow cathode. Review of theoretical works determining the applicability area of resonance polychromatic interferometry is carried out
Baryon physics in holographic QCD
Alex Pomarol
2009-03-01
Full Text Available In a simple holographic model for QCD in which the Chern–Simons term is incorporated to take into account the QCD chiral anomaly, we show that baryons arise as stable solitons which are the 5D analogs of 4D skyrmions. Contrary to 4D skyrmions and previously considered holographic scenarios, these solitons have sizes larger than the inverse cut-off of the model, and therefore they are predictable within our effective field theory approach. We perform a numerical determination of several static properties of the nucleons and find a satisfactory agreement with data. We also calculate the amplitudes of “anomalous” processes induced by the Chern–Simons term in the meson sector, such as ω→πγ and ω→3π. A combined fit to baryonic and mesonic observables leads to an agreement with experiments within 16%.
Weak-interacting holographic QCD
Gazit, D.; Yee, H.-U.
2008-06-01
We propose a simple prescription for including low-energy weak-interactions into the frame- work of holographic QCD, based on the standard AdS/CFT dictionary of double-trace deformations. As our proposal enables us to calculate various electro-weak observables involving strongly coupled QCD, it opens a new perspective on phenomenological applications of holographic QCD. We illustrate efficiency and usefulness of our method by performing a few exemplar calculations; neutron beta decay, charged pion weak decay, and meson-nucleon parity non-conserving (PNC) couplings. The idea is general enough to be implemented in both Sakai-Sugimoto as well as Hard/Soft Wall models. (author)
Dual peripheral model up to Serpukhov energies
Schrempp, Barbara
1974-01-01
The high energy behaviour of the s-channel Regge residues is inferred from three plausible requirements. The resulting s-channel helicity amplitudes allow-in a dual sense-the following t-channel interpretation: for -t>or=0.25 GeV/sup 2/ the flip amplitude has the form of a t-channel Regge pole, while the non-flip amplitude looks like a Regge cut. Finally, a quantitative comparison of the predictions with the data available for the set of SU(3) related processes pi N CEX, KN, KN CEX and pi /sup -/p to eta n is performed, covering the energy range 2
A dual model approach to ground water recovery trench design
Clodfelter, C.L.; Crouch, M.S.
1992-01-01
The design of trenches for contaminated ground water recovery must consider several variables. This paper presents a dual-model approach for effectively recovering contaminated ground water migrating toward a trench by advection. The approach involves an analytical model to determine the vertical influence of the trench and a numerical flow model to determine the capture zone within the trench and the surrounding aquifer. The analytical model is utilized by varying trench dimensions and head values to design a trench which meets the remediation criteria. The numerical flow model is utilized to select the type of backfill and location of sumps within the trench. The dual-model approach can be used to design a recovery trench which effectively captures advective migration of contaminants in the vertical and horizontal planes
3D modeling of dual wind-up extensional rheometers
Yu, Kaijia; Román Marín, José Manuel; Rasmussen, Henrik K.
2010-01-01
Fully three-dimensional numerical simulations of a dual wind-up drum rheometer of the Sentmanat Extensional Rheometer (SER; Sentmanat, 2004 [1]) or the Extensional Viscosity Fixture (EVF; Garritano and Berting, 2006 [2]) type have been performed. In the SER and EVF a strip of rectangular shape...... is attached onto two drums, followed by a rotation of both drums in opposite direction. The numerical modeling is based on integral constitutive equations of the K-BKZ type. Generally, to ensure a proper uni-axial extensional deformation in dual wind-up drum rheometers the simulations show that a very small...
The early years of string theory: The dual resonance model
Ramond, P.
1987-10-01
This paper reviews the past quantum mechanical history of the dual resonance model which is an early string theory. The content of this paper is listed as follows: historical review, the Veneziano amplitude, the operator formalism, the ghost story, and the string story
International Family Migration and the Dual-Earner Model
Munk, Martin D.; Nikolka, Till; Poutvaara, Panu
2018-01-01
Gender differences in labor force participation are exceptionally small in Nordic countries. We investigate how couples emigrating from Denmark self-select and sort into different destinations and whether couples pursue the dual-earner model, in which both partners work, when abroad. Female labor...
Scale-invariant inclusive spectra in a dual model
Chikovani, Z.E.; Jenkovsky, L.L.; Martynov, E.S.
1979-01-01
One-particle inclusive distributions at large transverse momentum phisub(tr) are shown to scale, Edσ/d 3 phi approximately phisub(tr)sup(-N)(1-Xsub(tr))sup(1+N/2)lnphisub(tr), in a dual model with Mandelstam analyticity if the Regge trajectories are logarithmic asymptotically
Defect CFTs and holographic multiverse
Fiol, Bartomeu, E-mail: bfiol@ub.edu [Departament de Física Fonamental i Institut de Ciències del Cosmos, Universitat de Barcelona, Martí i Franquès 1, 08193 Barcelona (Spain)
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.
Defect CFTs and holographic multiverse
Fiol, Bartomeu
2010-01-01
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 4 × S 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
Emergent Spacetime and Holographic CFTs
El-Showk, Sheer
2012-01-01
We discuss universal properties of conformal field theories with holographic duals. A central feature of these theories is the existence of a low-lying sector of operators whose correlators factorize. We demonstrate that factorization can only hold in the large central charge limit. Using conformal invariance and factorization we argue that these operators are naturally represented as fields in AdS as this makes the underlying linearity of the system manifest. In this class of CFTs the solution of the conformal bootstrap conditions can be naturally organized in structures which coincide with Witten diagrams in the bulk. The large value of the central charge suggests that the theory must include a large number of new operators not captured by the factorized sector. Consequently we may think of the AdS hologram as an effective representation of a small sector of the CFT, which is embedded inside a much larger Hilbert space corresponding to the black hole microstates.
The holographic Weyl semi-metal
Karl Landsteiner
2016-02-01
Full Text Available We present a holographic model of a Weyl semi-metal. We show the evidences that upon varying a mass parameter the model undergoes a sharp crossover at small temperature from a topologically non-trivial state to a trivial one. The order parameter is the anomalous Hall effect (AHE and we find that it is very strongly suppressed above a critical value of the mass parameter. This can be taken as a hint for an underlying topological quantum phase transition. We give an interpretation of the results in terms of a holographic RG flow and compare to a weakly coupled field theoretical model. Since there are no fermionic quasiparticle excitations in the strongly coupled holographic model the presence of an anomalous Hall effect cannot be bound to notions of topology in momentum spaces.
The holographic Weyl semi-metal
Landsteiner, Karl, E-mail: karl.landsteiner@csic.es; Liu, Yan, E-mail: yan.liu@csic.es
2016-02-10
We present a holographic model of a Weyl semi-metal. We show the evidences that upon varying a mass parameter the model undergoes a sharp crossover at small temperature from a topologically non-trivial state to a trivial one. The order parameter is the anomalous Hall effect (AHE) and we find that it is very strongly suppressed above a critical value of the mass parameter. This can be taken as a hint for an underlying topological quantum phase transition. We give an interpretation of the results in terms of a holographic RG flow and compare to a weakly coupled field theoretical model. Since there are no fermionic quasiparticle excitations in the strongly coupled holographic model the presence of an anomalous Hall effect cannot be bound to notions of topology in momentum spaces.
Functional Dual Adaptive Control with Recursive Gaussian Process Model
Prüher, Jakub; Král, Ladislav
2015-01-01
The paper deals with dual adaptive control problem, where the functional uncertainties in the system description are modelled by a non-parametric Gaussian process regression model. Current approaches to adaptive control based on Gaussian process models are severely limited in their practical applicability, because the model is re-adjusted using all the currently available data, which keeps growing with every time step. We propose the use of recursive Gaussian process regression algorithm for significant reduction in computational requirements, thus bringing the Gaussian process-based adaptive controllers closer to their practical applicability. In this work, we design a bi-criterial dual controller based on recursive Gaussian process model for discrete-time stochastic dynamic systems given in an affine-in-control form. Using Monte Carlo simulations, we show that the proposed controller achieves comparable performance with the full Gaussian process-based controller in terms of control quality while keeping the computational demands bounded. (paper)
Pulse holographic measurement techniques
Kim, Cheol Jung; Baik, Seong Hoon; Hong, Seok Kyung; Kim, Jeong Moog; Kim, Duk Hyun
1992-01-01
With the development of laser, remote inspection techniques using laser have been growing on. The inspection and measurement techniques by pulse holography are well-established technique for precise measurement, and widely used in various fields of industry now. In nuclear industry, this technology is practically used because holographic inspection is remote, noncontact, and precise measurement technique. In relation to remote inspection technology in nuclear industry, state-of-the art of pulse HNDT (Holographic non-destructive testing) and holographic measurement techniques are examined. First of all, the fundamental principles as well as practical problems for applications are briefly described. The fields of pulse holography have been divided into the HNDT, flow visualization and distribution study, and other application techniques. Additionally holographic particle study, bubble chamber holography, and applications to other visualization techniques are described. Lastly, the current status for the researches and applications of pulse holography to nuclear industry which are carried out actively in Europe and USA, is described. (Author)
A dual-trace model for visual sensory memory.
Cappiello, Marcus; Zhang, Weiwei
2016-11-01
Visual sensory memory refers to a transient memory lingering briefly after the stimulus offset. Although previous literature suggests that visual sensory memory is supported by a fine-grained trace for continuous representation and a coarse-grained trace of categorical information, simultaneous separation and assessment of these traces can be difficult without a quantitative model. The present study used a continuous estimation procedure to test a novel mathematical model of the dual-trace hypothesis of visual sensory memory according to which visual sensory memory could be modeled as a mixture of 2 von Mises (2VM) distributions differing in standard deviation. When visual sensory memory and working memory (WM) for colors were distinguished using different experimental manipulations in the first 3 experiments, the 2VM model outperformed Zhang and Luck (2008) standard mixture model (SM) representing a mixture of a single memory trace and random guesses, even though SM outperformed 2VM for WM. Experiment 4 generalized 2VM's advantages of fitting visual sensory memory data over SM from color to orientation. Furthermore, a single trace model and 4 other alternative models were ruled out, suggesting the necessity and sufficiency of dual traces for visual sensory memory. Together these results support the dual-trace model of visual sensory memory and provide a preliminary inquiry into the nature of information loss from visual sensory memory to WM. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Proof of the holographic formula for entanglement entropy
Fursaev, Dmitri V.
2006-01-01
Entanglement entropy for a spatial partition of a quantum system is studied in theories which admit a dual description in terms of the anti-de Sitter (AdS) gravity one dimension higher. A general proof of the holographic formula which relates the entropy to the area of a codimension 2 minimal hypersurface embedded in the bulk AdS space is given. The entanglement entropy is determined by a partition function which is defined as a path integral over Riemannian AdS geometries with non-trivial boundary conditions. The topology of the Riemannian spaces puts restrictions on the choice of the minimal hypersurface for a given boundary conditions. The entanglement entropy is also considered in Randall-Sundrum braneworld models where its asymptotic expansion is derived when the curvature radius of the brane is much larger than the AdS radius. Special attention is paid to the geometrical structure of anomalous terms in the entropy in four dimensions. Modification of the holographic formula by the higher curvature terms in the bulk is briefly discussed
Quenching parameter in a holographic thermal QCD
Patra, Binoy Krishna; Arya, Bhaskar
2017-01-01
We have calculated the quenching parameter, q ˆ in a model-independent way using the gauge-gravity duality. In earlier calculations, the geometry in the gravity side at finite temperature was usually taken as the pure AdS black hole metric for which the dual gauge theory becomes conformally invariant unlike QCD. Therefore we use a metric which incorporates the fundamental quarks by embedding the coincident D7 branes in the Klebanov-Tseytlin background and a finite temperature is switched on by inserting a black hole into the background, known as OKS-BH metric. Further inclusion of an additional UV cap to the metric prepares the dual gauge theory to run similar to thermal QCD. Moreover q ˆ is usually defined in the literature from the Glauber model perturbative QCD evaluation of the Wilson loop, which has no reasons to hold if the coupling is large and is thus against the main idea of gauge-gravity duality. Thus we use an appropriate definition of q ˆ : q ˆ L- = 1 /L2, where L is the separation for which the Wilson loop is equal to some specific value. The above two refinements cause q ˆ to vary with the temperature as T4 always and to depend linearly on the light-cone time L- with an additional (1 /L-) correction term in the short-distance limit whereas in the long-distance limit, q ˆ depends only linearly on L- with no correction term. These observations agree with other holographic calculations directly or indirectly.
Quenching parameter in a holographic thermal QCD
Binoy Krishna Patra
2017-01-01
Full Text Available We have calculated the quenching parameter, qˆ in a model-independent way using the gauge–gravity duality. In earlier calculations, the geometry in the gravity side at finite temperature was usually taken as the pure AdS black hole metric for which the dual gauge theory becomes conformally invariant unlike QCD. Therefore we use a metric which incorporates the fundamental quarks by embedding the coincident D7 branes in the Klebanov–Tseytlin background and a finite temperature is switched on by inserting a black hole into the background, known as OKS-BH metric. Further inclusion of an additional UV cap to the metric prepares the dual gauge theory to run similar to thermal QCD. Moreover qˆ is usually defined in the literature from the Glauber model perturbative QCD evaluation of the Wilson loop, which has no reasons to hold if the coupling is large and is thus against the main idea of gauge–gravity duality. Thus we use an appropriate definition of qˆ: qˆL−=1/L2, where L is the separation for which the Wilson loop is equal to some specific value. The above two refinements cause qˆ to vary with the temperature as T4 always and to depend linearly on the light-cone time L− with an additional (1/L− correction term in the short-distance limit whereas in the long-distance limit, qˆ depends only linearly on L− with no correction term. These observations agree with other holographic calculations directly or indirectly.
Holographic anyonic superfluidity
Jokela, Niko; Lifschytz, Gilad; Lippert, Matthew
2013-10-01
Starting with a holographic construction for a fractional quantum Hall state based on the D3-D7' system, we explore alternative quantization conditions for the bulk gauge fields. This gives a description of a quantum Hall state with various filling fractions. For a particular alternative quantization of the bulk gauge fields, we obtain a holographic anyon fluid in a vanishing background magnetic field. We show that this system is a superfluid, exhibiting the relevant gapless excitation.
Predicting sugar consumption: Application of an integrated dual-process, dual-phase model.
Hagger, Martin S; Trost, Nadine; Keech, Jacob J; Chan, Derwin K C; Hamilton, Kyra
2017-09-01
Excess consumption of added dietary sugars is related to multiple metabolic problems and adverse health conditions. Identifying the modifiable social cognitive and motivational constructs that predict sugar consumption is important to inform behavioral interventions aimed at reducing sugar intake. We tested the efficacy of an integrated dual-process, dual-phase model derived from multiple theories to predict sugar consumption. Using a prospective design, university students (N = 90) completed initial measures of the reflective (autonomous and controlled motivation, intentions, attitudes, subjective norm, perceived behavioral control), impulsive (implicit attitudes), volitional (action and coping planning), and behavioral (past sugar consumption) components of the proposed model. Self-reported sugar consumption was measured two weeks later. A structural equation model revealed that intentions, implicit attitudes, and, indirectly, autonomous motivation to reduce sugar consumption had small, significant effects on sugar consumption. Attitudes, subjective norm, and, indirectly, autonomous motivation to reduce sugar consumption predicted intentions. There were no effects of the planning constructs. Model effects were independent of the effects of past sugar consumption. The model identified the relative contribution of reflective and impulsive components in predicting sugar consumption. Given the prominent role of the impulsive component, interventions that assist individuals in managing cues-to-action and behavioral monitoring are likely to be effective in regulating sugar consumption. Copyright © 2017 Elsevier Ltd. All rights reserved.
Finiteness of PST self-dual models
Del Cima, Oswaldo M.; Piguet, Olivier; Sarandy, Marcelo S.
2000-12-01
The Pasti-Sorokin-Tonin model for describing chiral forms is considered at the quantum level. We study the ultraviolet and infrared behaviour of the model in two, four and six dimensions in the framework of algebraic renormalization. The absence of anomalies, as well as the finiteness, up to non-physical renormalizations, are shown in all dimensions analyzed. (author)
Dual Value Creation and Business Model Design
Turcan, Romeo V.
This ethnographic research explores the process of business model design in the context of an NGO internationalizing to an emerging market. It contributes to the business model literature by investigating how this NGO - targeting multiple key stakeholders - was experimenting (1) with value...
Comparing single- and dual-process models of memory development.
Hayes, Brett K; Dunn, John C; Joubert, Amy; Taylor, Robert
2017-11-01
This experiment examined single-process and dual-process accounts of the development of visual recognition memory. The participants, 6-7-year-olds, 9-10-year-olds and adults, were presented with a list of pictures which they encoded under shallow or deep conditions. They then made recognition and confidence judgments about a list containing old and new items. We replicated the main trends reported by Ghetti and Angelini () in that recognition hit rates increased from 6 to 9 years of age, with larger age changes following deep than shallow encoding. Formal versions of the dual-process high threshold signal detection model and several single-process models (equal variance signal detection, unequal variance signal detection, mixture signal detection) were fit to the developmental data. The unequal variance and mixture signal detection models gave a better account of the data than either of the other models. A state-trace analysis found evidence for only one underlying memory process across the age range tested. These results suggest that single-process memory models based on memory strength are a viable alternative to dual-process models for explaining memory development. © 2016 John Wiley & Sons Ltd.
High effective inverse dynamics modelling for dual-arm robot
Shen, Haoyu; Liu, Yanli; Wu, Hongtao
2018-05-01
To deal with the problem of inverse dynamics modelling for dual arm robot, a recursive inverse dynamics modelling method based on decoupled natural orthogonal complement is presented. In this model, the concepts and methods of Decoupled Natural Orthogonal Complement matrices are used to eliminate the constraint forces in the Newton-Euler kinematic equations, and the screws is used to express the kinematic and dynamics variables. On this basis, the paper has developed a special simulation program with symbol software of Mathematica and conducted a simulation research on the a dual-arm robot. Simulation results show that the proposed method based on decoupled natural orthogonal complement can save an enormous amount of CPU time that was spent in computing compared with the recursive Newton-Euler kinematic equations and the results is correct and reasonable, which can verify the reliability and efficiency of the method.
A dual porosity model of nutrient uptake by root hairs
Zygalakis, K. C.; Kirk, G. J. D.; Jones, D. L.; Wissuwa, M.; Roose, T.
2011-01-01
Summary: • The importance of root hairs in the uptake of sparingly soluble nutrients is understood qualitatively, but not quantitatively, and this limits efforts to breed plants tolerant of nutrient-deficient soils. • Here, we develop a mathematical model of nutrient uptake by root hairs allowing for hair geometry and the details of nutrient transport through soil, including diffusion within and between soil particles. We give illustrative results for phosphate uptake. • Compared with conventional 'single porosity' models, this 'dual porosity' model predicts greater root uptake because more nutrient is available by slow release from within soil particles. Also the effect of soil moisture is less important with the dual porosity model because the effective volume available for diffusion in the soil is larger, and the predicted effects of hair length and density are different. • Consistent with experimental observations, with the dual porosity model, increases in hair length give greater increases in uptake than increases in hair density per unit main root length. The effect of hair density is less in dry soil because the minimum concentration in solution for net influx is reached more rapidly. The effect of hair length is much less sensitive to soil moisture. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.
A dual porosity model of nutrient uptake by root hairs
Zygalakis, K. C.
2011-08-09
Summary: • The importance of root hairs in the uptake of sparingly soluble nutrients is understood qualitatively, but not quantitatively, and this limits efforts to breed plants tolerant of nutrient-deficient soils. • Here, we develop a mathematical model of nutrient uptake by root hairs allowing for hair geometry and the details of nutrient transport through soil, including diffusion within and between soil particles. We give illustrative results for phosphate uptake. • Compared with conventional \\'single porosity\\' models, this \\'dual porosity\\' model predicts greater root uptake because more nutrient is available by slow release from within soil particles. Also the effect of soil moisture is less important with the dual porosity model because the effective volume available for diffusion in the soil is larger, and the predicted effects of hair length and density are different. • Consistent with experimental observations, with the dual porosity model, increases in hair length give greater increases in uptake than increases in hair density per unit main root length. The effect of hair density is less in dry soil because the minimum concentration in solution for net influx is reached more rapidly. The effect of hair length is much less sensitive to soil moisture. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.
Adler zero and the dual multiperipheral model
Balazs, L.A.P.
1978-01-01
We show that the ππ → ππ Adler PCAC (partial conservation of axial-vector current) condition requires a Reggeon intercept α (0) approx. = 0.5 within a broad class of multiperipheral models at the planar and cylinder levels. In the planar approximation this is closely related to the cancellation of the Reggeon-Reggeon cut
Holographic characterization of colloidal particles in turbid media
Cheong, Fook Chiong; Kasimbeg, Priya; Ruffner, David B.; Hlaing, Ei Hnin; Blusewicz, Jaroslaw M.; Philips, Laura A.; Grier, David G.
2017-10-01
Holographic particle characterization uses in-line holographic microscopy and the Lorenz-Mie theory of light scattering to measure the diameter and the refractive index of individual colloidal particles in their native dispersions. This wealth of information has proved invaluable in fields as diverse as soft-matter physics, biopharmaceuticals, wastewater management, and food science but so far has been available only for dispersions in transparent media. Here, we demonstrate that holographic characterization can yield precise and accurate results even when the particles of interest are dispersed in turbid media. By elucidating how multiple light scattering contributes to image formation in holographic microscopy, we establish the range conditions under which holographic characterization can reliably probe turbid samples. We validate the technique with measurements on model colloidal spheres dispersed in commercial nanoparticle slurries.
Model tracking dual stochastic controller design under irregular internal noises
Lee, Jong Bok; Heo, Hoon; Cho, Yun Hyun; Ji, Tae Young
2006-01-01
Although many methods about the control of irregular external noise have been introduced and implemented, it is still necessary to design a controller that will be more effective and efficient methods to exclude for various noises. Accumulation of errors due to model tracking, internal noises (thermal noise, shot noise and l/f noise) that come from elements such as resistor, diode and transistor etc. in the circuit system and numerical errors due to digital process often destabilize the system and reduce the system performance. New stochastic controller is adopted to remove those noises using conventional controller simultaneously. Design method of a model tracking dual controller is proposed to improve the stability of system while removing external and internal noises. In the study, design process of the model tracking dual stochastic controller is introduced that improves system performance and guarantees robustness under irregular internal noises which can be created internally. The model tracking dual stochastic controller utilizing F-P-K stochastic control technique developed earlier is implemented to reveal its performance via simulation
Holographic relaxation of finite size isolated quantum systems
Abajo-Arrastia, Javier; Silva, Emilia da; Lopez, Esperanza; Mas, Javier; Serantes, Alexandre
2014-01-01
We study holographically the out of equilibrium dynamics of a finite size closed quantum system in 2+1 dimensions, modelled by the collapse of a shell of a massless scalar field in AdS_4. In global coordinates there exists a variety of evolutions towards final black hole formation which we relate with different patterns of relaxation in the dual field theory. For large scalar initial data rapid thermalization is achieved as a priori expected. Interesting phenomena appear for small enough amplitudes. Such shells do not generate a black hole by direct collapse, but quite generically, an apparent horizon emerges after enough bounces off the AdS boundary. We relate this bulk evolution with relaxation processes at strong coupling which delay in reaching an ergodic stage. Besides the dynamics of bulk fields, we monitor the entanglement entropy, finding that it oscillates quasi-periodically before final equilibration. The radial position of the travelling shell is brought in correspondence with the evolution of the pattern of entanglement in the dual field theory. We propose, thereafter, that the observed oscillations are the dual counterpart of the quantum revivals studied in the literature. The entanglement entropy is not only able to portrait the streaming of entangled excitations, but it is also a useful probe of interaction effects
Shrinkage Simulation of Holographic Grating Using Diffusion Model in PQ-PMMA Photopolymer
Wei Zepeng
2015-01-01
Full Text Available An extended model based on nonlocal polymerization-driven diffusion model is derived by introducing shrinkage process for describing photopolymerized dynamics in PQ-PMMA photopolymer. The kinetic parameters, polymerization rate and diffusion rate are experimentally determined to provide quantitative simulation. The numerical results show that the fringes at edge of grating are firstly shifted and consequently, it leads to a contrast reduction of holograms. Finally, theoretical results are experimentally checked by temporal evolution of diffraction efficiency, and the shrinkage coefficient 0.5% is approximately achieved under incident intensity 25.3mw/cm2. This work can enhance the applicability of diffusion model and contribute to the reasonable description of the grating formation in the photopolymer.
A dual system model of preferences under risk.
Mukherjee, Kanchan
2010-01-01
This article presents a dual system model (DSM) of decision making under risk and uncertainty according to which the value of a gamble is a combination of the values assigned to it independently by the affective and deliberative systems. On the basis of research on dual process theories and empirical research in Hsee and Rottenstreich (2004) and Rottenstreich and Hsee (2001) among others, the DSM incorporates (a) individual differences in disposition to rational versus emotional decision making, (b) the affective nature of outcomes, and (c) different task construals within its framework. The model has good descriptive validity and accounts for (a) violation of nontransparent stochastic dominance, (b) fourfold pattern of risk attitudes, (c) ambiguity aversion, (d) common consequence effect, (e) common ratio effect, (f) isolation effect, and (g) coalescing and event-splitting effects. The DSM is also used to make several novel predictions of conditions under which specific behavior patterns may or may not occur.
Charm production in the dual topological unitarization model
Batunin, A.V.
1986-01-01
The open and hidden charm hadroproduction has been traced up to the SPS energies in the framework of the dual parton model. The free parameter (the suppression of the charmed sea) comes from the experiments on D-meson hadroproduction. Then the hidden-charm production data are described assuming that the J/ψ-meson production suggests only one cc-bar pair in the string, while the pair ψψ production suggests two cc-bar pairs
An AdS3 dual for minimal model CFTs
Gaberdiel, Matthias R.; Gopakumar, Rajesh
2011-01-01
We propose a duality between the 2d W N minimal models in the large N't Hooft limit, and a family of higher spin theories on AdS 3 . The 2d conformal field theories (CFTs) can be described as Wess-Zumino-Witten coset models, and include, for N=2, the usual Virasoro unitary series. The dual bulk theory contains, in addition to the massless higher spin fields, two complex scalars (of equal mass). The mass is directly related to the 't Hooft coupling constant of the dual CFT. We give convincing evidence that the spectra of the two theories match precisely for all values of the 't Hooft coupling. We also show that the renormalization group flows in the 2d CFT agree exactly with the usual AdS/CFT prediction of the gravity theory. Our proposal is in many ways analogous to the Klebanov-Polyakov conjecture for an AdS 4 dual for the singlet sector of large N vector models.
Holographic Spherically Symmetric Metrics
Petri, Michael
The holographic principle (HP) conjectures, that the maximum number of degrees of freedom of any realistic physical system is proportional to the system's boundary area. The HP has its roots in the study of black holes. It has recently been applied to cosmological solutions. In this article we apply the HP to spherically symmetric static space-times. We find that any regular spherically symmetric object saturating the HP is subject to tight constraints on the (interior) metric, energy-density, temperature and entropy-density. Whenever gravity can be described by a metric theory, gravity is macroscopically scale invariant and the laws of thermodynamics hold locally and globally, the (interior) metric of a regular holographic object is uniquely determined up to a constant factor and the interior matter-state must follow well defined scaling relations. When the metric theory of gravity is general relativity, the interior matter has an overall string equation of state (EOS) and a unique total energy-density. Thus the holographic metric derived in this article can serve as simple interior 4D realization of Mathur's string fuzzball proposal. Some properties of the holographic metric and its possible experimental verification are discussed. The geodesics of the holographic metric describe an isotropically expanding (or contracting) universe with a nearly homogeneous matter-distribution within the local Hubble volume. Due to the overall string EOS the active gravitational mass-density is zero, resulting in a coasting expansion with Ht = 1, which is compatible with the recent GRB-data.
Saha, Pameli; Debnath, Ujjal [Indian Institute of Engineering Science and Technology, Department of Mathematics, Howrah (India)
2016-09-15
Here, we peruse cosmological usage of the most promising candidates of dark energy in the framework of f(T) gravity theory where T represents the torsion scalar teleparallel gravity. We reconstruct the different f(T) modified gravity models in the spatially flat Friedmann-Robertson-Walker universe according to entropy-corrected versions of the holographic and new agegraphic dark energy models in power-law and logarithmic corrections, which describe an accelerated expansion history of the universe. We conclude that the equation of state parameter of the entropy-corrected models can transit from the quintessence state to the phantom regime as indicated by recent observations or can lie entirely in the phantom region. Also, using these models, we investigate the different areas of the stability with the help of the squared speed of sound. (orig.)
Melting spectral functions of the scalar and vector mesons in a holographic QCD model
Fujita, Mitsutoshi; Kikuchi, Toru; Fukushima, Kenji; Misumi, Tatsuhiro; Murata, Masaki
2010-01-01
We investigate the finite-temperature spectral functions of heavy quarkonia by using the soft-wall anti-de Sitter/QCD model. We discuss the scalar, the pseudoscalar, the vector, and the axial-vector mesons and compare their qualitative features of the melting temperature and growing width. We find that the axial-vector meson melts earlier than the vector meson, while there appears only a slight difference between the scalar and pseudoscalar mesons, which also melt earlier than the vector meson.
Multiparticle production in a two-component dual parton model
Aurenche, P.; Bopp, F.W.; Capella, A.; Kwiecinski, J.; Maire, M.; Ranft, J.; Tran Thanh Van, J.
1992-01-01
The dual parton model (DPM) describes soft and semihard multiparticle production. The version of the DPM presented in this paper includes soft and hard mechanisms as well as diffractive processes. The model is formulated as a Monte Carlo event generator. We calculate in this model, in the energy range of the hadron colliders, rapidity distributions and the rise of the rapidity plateau with the collision energy, transverse-momentum distributions and the rise of average transverse momenta with the collision energy, multiplicity distributions in different pseudorapidity regions, and transverse-energy distributions. For most of these quantities we find a reasonable agreement with experimental data
Holographic quantum error-correcting codes: toy models for the bulk/boundary correspondence
Pastawski, Fernando; Yoshida, Beni [Institute for Quantum Information & Matter and Walter Burke Institute for Theoretical Physics,California Institute of Technology,1200 E. California Blvd., Pasadena CA 91125 (United States); Harlow, Daniel [Princeton Center for Theoretical Science, Princeton University,400 Jadwin Hall, Princeton NJ 08540 (United States); Preskill, John [Institute for Quantum Information & Matter and Walter Burke Institute for Theoretical Physics,California Institute of Technology,1200 E. California Blvd., Pasadena CA 91125 (United States)
2015-06-23
We propose a family of exactly solvable toy models for the AdS/CFT correspondence based on a novel construction of quantum error-correcting codes with a tensor network structure. Our building block is a special type of tensor with maximal entanglement along any bipartition, which gives rise to an isometry from the bulk Hilbert space to the boundary Hilbert space. The entire tensor network is an encoder for a quantum error-correcting code, where the bulk and boundary degrees of freedom may be identified as logical and physical degrees of freedom respectively. These models capture key features of entanglement in the AdS/CFT correspondence; in particular, the Ryu-Takayanagi formula and the negativity of tripartite information are obeyed exactly in many cases. That bulk logical operators can be represented on multiple boundary regions mimics the Rindler-wedge reconstruction of boundary operators from bulk operators, realizing explicitly the quantum error-correcting features of AdS/CFT recently proposed in http://dx.doi.org/10.1007/JHEP04(2015)163.
On the AdS higher spin / O(N) vector model correspondence: degeneracy of the holographic image
Diaz, Danilo E.; Dorn, Harald
2006-01-01
We explore the conjectured duality between the critical O(N) vector model and minimal bosonic massless higher spin (HS) theory in AdS. In the free boundary theory, the conformal partial wave expansion (CPWE) of the four-point function of the scalar singlet bilinear is reorganized to make it explicitly crossing-symmetric and closed in the singlet sector, dual to the bulk HS gauge fields. We are able to analytically establish the factorized form of the fusion coefficients as well as the two-point function coefficient of the HS currents. We insist in directly computing the free correlators from bulk graphs with the unconventional branch. The three-point function of the scalar bilinear turns out to be an 'extremal' one at d = 3. The four-point bulk exchange graph can be precisely related to the CPWs of the boundary dual scalar and its shadow. The flow in the IR by Legendre transforming at leading 1/N, following the pattern of double-trace deformations, and the assumption of degeneracy of the hologram lead to the CPWE of the scalar four-point function at IR. Here we confirm some previous results, obtained from more involved computations of skeleton graphs, as well as extend some of them from d = 3 to generic dimension 2 < d < 4
Interacting holographic dark energy with logarithmic correction
Jamil, Mubasher; Farooq, M. Umar
2010-01-01
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
Gabriel Recchia
2015-01-01
Full Text Available 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.
Interacting-string picture of dual-resonance models
Mandelstam, S.
1985-01-01
Dual-resonance models are an alyzed by means of operators which act within the physical Hilbert space of positive-metric states. The basis of the method is to extend the relativistic-string picture of a previous study to interacting particles. Functional methods are used, but their relation to the operator is evident, and factorization is maintained. An expression is given for the N-point amplitude in terms of physical-particle operators. For the three-point function the Neumann functions which occur in this expression are evaluated, so that we have a formula for the on- and off-energy-shell vertex. The authors assume that the string has no longitudinal degrees of freedom, and their results are Lorentz invariant and dual only if d=26
Holographic Entanglement Entropy
Rangamani, Mukund
2016-01-01
We review the developments in the past decade on holographic entanglement entropy, a subject that has garnered much attention owing to its potential to teach us about the emergence of spacetime in holography. We provide an introduction to the concept of entanglement entropy in quantum field theories, review the holographic proposals for computing the same, providing some justification for where these proposals arise from in the first two parts. The final part addresses recent developments linking entanglement and geometry. We provide an overview of the various arguments and technical developments that teach us how to use field theory entanglement to detect geometry. Our discussion is by design eclectic; we have chosen to focus on developments that appear to us most promising for further insights into the holographic map. This is a preliminary draft of a few chapters of a book which will appear sometime in the near future, to be published by Springer. The book in addition contains a discussion of application o...
Talbot, Michael
1991-01-01
'There is evidence to suggest that our world and everything in it - from snowflakes to maple trees to falling stars and spinning electrons - are only ghostly images, projections from a level of reality literally beyond both space and time.' This is the astonishing idea behind the holographic theory of the universe, pioneered by two eminent thinkers: physicist David Bohm, a former protege of Albert Einstein, and quantum physicist Karl Pribram. The holographic theory of the universe encompasses consciousness and reality as we know them, but can also explain such hitherto unexplained phenomena as telepathy, out-of-body experiences and even miraculous healing. In this remarkable book, Michael Talbot reveals the extraordinary depth and power of the holographic theory of the universe, illustrating how it makes sense of the entire range of experiences within our universe - and in other universes beyond our own.
Photopolymer holographic recording material
Lawrence, J. R.; O'Neill, F. T.; Sheridan, J. T.
Photopolymers are promising materials for use in holography. They have many advantages, such as ease of preparation, and are capable of efficiencies of up to 100%. A disadvantage of these materials is their inability to record high spatial frequency gratings when compared to other materials such as dichromated gelatin and silver halide photographic emulsion. Until recently, the drop off at high spatial frequencies of the material response was not predicted by any of the diffusion based models available. It has recently been proposed that this effect is due to polymer chains growing away from their initiation point and causing a smeared profile to be recorded. This is termed a non-local material response. Simple analytic expressions have been derived using this model and fits to experimental data have allowed values to be estimated for material parameters such as the diffusion coefficient of monomer, the ratio of polymerisation rate to diffusion rate and the distance that the polymer chains spread during holographic recording. The model predicts that the spatial frequency response might be improved by decreasing the mean polymer chain lengths and/or by increasing the mobility of the molecules used in the material. The experimental work carried out to investigate these predictions is reported here. This work involved (a) the changing of the molecular weights of chemical components within the material (dyes and binders) and (b) the addition of a chemical retarder in order to shorten the polymer chains, thereby decreasing the extent of the non-local effect. Although no significant improvement in spatial frequency response was observed the model appears to offer an improved understanding of the operation of the material.
On the time evolution of holographic n-partite information
Alishahiha, Mohsen; Mozaffar, M. Reza Mohammadi; Tanhayi, Mohammad Reza
2015-01-01
We study various scaling behaviors of n-partite information during a process of thermalization for n disjoint system consisting of n parallel strips whose widths are much larger than the separation between them. By making use of the holographic description for entanglement entropy we explore holographic description of the n-partite information by which we show that it has a definite sign: it is positive for even n and negative for odd n. This might thought of as an intrinsic property of a field theory which has gravity dual.
Holographic Ward identities for symmetry breaking in two dimensions
Argurio, Riccardo [Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Giribet, Gaston [Martin Fisher School of Physics, Brandeis University,Waltham, Massachusetts 02453 (United States); Physics Department, University of Buenos Aires FCEN-UBA and IFIBA-CONICET,Ciudad Universitaria, Pabellón I, 1428, Buenos Aires (Argentina); Marzolla, Andrea; Naegels, Daniel [Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Sierra-Garcia, J. Anibal [Department of Particle Physics and IGFAE, University of Santiago de Compostela,E-15782 Santiago de Compostela (Spain)
2017-04-03
We investigate symmetry breaking in two-dimensional field theories which have a holographic gravity dual. Being at large N, the Coleman theorem does not hold and Goldstone bosons are expected. We consider the minimal setup to describe a conserved current and a charged operator, and we perform holographic renormalization in order to find the correct Ward identities describing symmetry breaking. This involves some subtleties related to the different boundary conditions that a vector can have in the three-dimensional bulk. We establish which is the correct prescription that yields, after renormalization, the same Ward identities as in higher dimensions.
Dual coding: a cognitive model for psychoanalytic research.
Bucci, W
1985-01-01
Four theories of mental representation derived from current experimental work in cognitive psychology have been discussed in relation to psychoanalytic theory. These are: verbal mediation theory, in which language determines or mediates thought; perceptual dominance theory, in which imagistic structures are dominant; common code or propositional models, in which all information, perceptual or linguistic, is represented in an abstract, amodal code; and dual coding, in which nonverbal and verbal information are each encoded, in symbolic form, in separate systems specialized for such representation, and connected by a complex system of referential relations. The weight of current empirical evidence supports the dual code theory. However, psychoanalysis has implicitly accepted a mixed model-perceptual dominance theory applying to unconscious representation, and verbal mediation characterizing mature conscious waking thought. The characterization of psychoanalysis, by Schafer, Spence, and others, as a domain in which reality is constructed rather than discovered, reflects the application of this incomplete mixed model. The representations of experience in the patient's mind are seen as without structure of their own, needing to be organized by words, thus vulnerable to distortion or dissolution by the language of the analyst or the patient himself. In these terms, hypothesis testing becomes a meaningless pursuit; the propositions of the theory are no longer falsifiable; the analyst is always more or less "right." This paper suggests that the integrated dual code formulation provides a more coherent theoretical framework for psychoanalysis than the mixed model, with important implications for theory and technique. In terms of dual coding, the problem is not that the nonverbal representations are vulnerable to distortion by words, but that the words that pass back and forth between analyst and patient will not affect the nonverbal schemata at all. Using the dual code
Phases of kinky holographic nuclear matter
Elliot-Ripley, Matthew; Sutcliffe, Paul; Zamaklar, Marija [Department of Mathematical Sciences, Durham University,South Road, Durham (United Kingdom)
2016-10-17
Holographic QCD at finite baryon number density and zero temperature is studied within the five-dimensional Sakai-Sugimoto model. We introduce a new approximation that models a smeared crystal of solitonic baryons by assuming spatial homogeneity to obtain an effective kink theory in the holographic direction. The kink theory correctly reproduces a first order phase transition to lightly bound nuclear matter. As the density is further increased the kink splits into a pair of half-kink constituents, providing a concrete realization of the previously suggested dyonic salt phase, where the bulk soliton splits into constituents at high density. The kink model also captures the phenomenon of baryonic popcorn, in which a first order phase transition generates an additional soliton layer in the holographic direction. We find that this popcorn transition takes place at a density below the dyonic salt phase, making the latter energetically unfavourable. However, the kink model predicts only one pop, rather than the sequence of pops suggested by previous approximations. In the kink model the two layers produced by the single pop form the surface of a soliton bag that increases in size as the baryon chemical potential is increased. The interior of the bag is filled with abelian electric potential and the instanton charge density is localized on the surface of the bag. The soliton bag may provide a holographic description of a quarkyonic phase.
Computer generated holographic microtags
Sweatt, W.C.
1998-01-01
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
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.
3D modeling of dual-gate FinFET.
Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John
2012-11-13
The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 >Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.
Holographic charged Rényi entropies
Belin, Alexandre; Hung, Ling-Yan; Maloney, Alexander; Matsuura, Shunji; Myers, Robert C.; Sierens, Todd
2013-12-01
We construct a new class of entanglement measures by extending the usual definition of Rényi entropy to include a chemical potential. These charged Rényi entropies measure the degree of entanglement in different charge sectors of the theory and are given by Euclidean path integrals with the insertion of a Wilson line encircling the entangling surface. We compute these entropies for a spherical entangling surface in CFT's with holographic duals, where they are related to entropies of charged black holes with hyperbolic horizons. We also compute charged Rényi entropies in free field theories.
Simple recipe for holographic Weyl anomaly
Bugini, F. [Departamento de Física, Facultad de Ciencias Físicas y Matemáticas, Universidad de Concepción,Casilla 160-C, Concepción (Chile); Diaz, D.E. [Departamento de Ciencias Físicas, Facultad de Ciencias Exactas, Universidad Andres Bello,Autopista Concepción-Talcahuano 7100, Talcahuano (Chile)
2017-04-20
We propose a recipe — arguably the simplest — to compute the holographic type-B Weyl anomaly for general higher-derivative gravity in asymptotically AdS spacetimes. In 5 and 7 dimensions we identify a suitable basis of curvature invariants that allows to read off easily, without any further computation, the Weyl anomaly coefficients of the dual CFT. We tabulate the contributions from quadratic, cubic and quartic purely algebraic curvature invariants and also from terms involving derivatives of the curvature. We provide few examples, where the anomaly coefficients have been obtained by other means, to illustrate the effectiveness of our prescription.
Holographic EPR Pairs, Wormholes and Radiation
Chernicoff, Mariano; Güijosa, Alberto; Pedraza, Juan F.
2013-01-01
As evidence for the ER=EPR conjecture, it has recently been observed that the string that is holographically dual to an entangled quark-antiquark pair separating with (asymptotically) uniform acceleration has a wormhole on its worldsheet. We point out that a two-sided horizon and a wormhole actually appear for much more generic quark-antiquark trajectories, which is consistent with the fact that the members of an EPR pair need not be permanently out of causal contact. The feature that determi...
A simple holographic scenario for gapped quenches
Lopez, Esperanza; Bosch, Guillermo Milans del [Instituto de Física Teórica IFT UAM/CSIC, Universidad Autónoma de Madrid,28049 Cantoblanco, Madrid (Spain)
2017-02-24
We construct gravitational backgrounds dual to a family of field theories parameterized by a relevant coupling. They combine a non-trivial scalar field profile with a naked singularity. The naked singularity is necessary to preserve Lorentz invariance along the boundary directions. The singularity is however excised by introducing an infrared cutoff in the geometry. The holographic dictionary associated to the infrared boundary is developed. We implement quenches between two different values of the coupling. This requires considering time dependent boundary conditions for the scalar field both at the AdS boundary and the infrared wall.
Holographic description of large N gauge theory
Lee, Sung-Sik
2011-01-01
Based on the earlier work [S.-S. Lee, Nucl. Rev. B 832 (2010) 567], we derive a holographic dual for the D-dimensional U(N) lattice gauge theory from a first principle construction. The resulting theory is a lattice field theory of closed loops, dubbed as lattice loop field theory which is defined on a (D+1)-dimensional space. The lattice loop field theory is well defined non-perturbatively, and it becomes weakly coupled and local in the large N limit with a large 't Hooft coupling.
Dual processing model of medical decision-making
2012-01-01
Background Dual processing theory of human cognition postulates that reasoning and decision-making can be described as a function of both an intuitive, experiential, affective system (system I) and/or an analytical, deliberative (system II) processing system. To date no formal descriptive model of medical decision-making based on dual processing theory has been developed. Here we postulate such a model and apply it to a common clinical situation: whether treatment should be administered to the patient who may or may not have a disease. Methods We developed a mathematical model in which we linked a recently proposed descriptive psychological model of cognition with the threshold model of medical decision-making and show how this approach can be used to better understand decision-making at the bedside and explain the widespread variation in treatments observed in clinical practice. Results We show that physician’s beliefs about whether to treat at higher (lower) probability levels compared to the prescriptive therapeutic thresholds obtained via system II processing is moderated by system I and the ratio of benefit and harms as evaluated by both system I and II. Under some conditions, the system I decision maker’s threshold may dramatically drop below the expected utility threshold derived by system II. This can explain the overtreatment often seen in the contemporary practice. The opposite can also occur as in the situations where empirical evidence is considered unreliable, or when cognitive processes of decision-makers are biased through recent experience: the threshold will increase relative to the normative threshold value derived via system II using expected utility threshold. This inclination for the higher diagnostic certainty may, in turn, explain undertreatment that is also documented in the current medical practice. Conclusions We have developed the first dual processing model of medical decision-making that has potential to enrich the current medical
Dual processing model of medical decision-making.
Djulbegovic, Benjamin; Hozo, Iztok; Beckstead, Jason; Tsalatsanis, Athanasios; Pauker, Stephen G
2012-09-03
Dual processing theory of human cognition postulates that reasoning and decision-making can be described as a function of both an intuitive, experiential, affective system (system I) and/or an analytical, deliberative (system II) processing system. To date no formal descriptive model of medical decision-making based on dual processing theory has been developed. Here we postulate such a model and apply it to a common clinical situation: whether treatment should be administered to the patient who may or may not have a disease. We developed a mathematical model in which we linked a recently proposed descriptive psychological model of cognition with the threshold model of medical decision-making and show how this approach can be used to better understand decision-making at the bedside and explain the widespread variation in treatments observed in clinical practice. We show that physician's beliefs about whether to treat at higher (lower) probability levels compared to the prescriptive therapeutic thresholds obtained via system II processing is moderated by system I and the ratio of benefit and harms as evaluated by both system I and II. Under some conditions, the system I decision maker's threshold may dramatically drop below the expected utility threshold derived by system II. This can explain the overtreatment often seen in the contemporary practice. The opposite can also occur as in the situations where empirical evidence is considered unreliable, or when cognitive processes of decision-makers are biased through recent experience: the threshold will increase relative to the normative threshold value derived via system II using expected utility threshold. This inclination for the higher diagnostic certainty may, in turn, explain undertreatment that is also documented in the current medical practice. We have developed the first dual processing model of medical decision-making that has potential to enrich the current medical decision-making field, which is still to the
Dual processing model of medical decision-making
Djulbegovic Benjamin
2012-09-01
Full Text Available Abstract Background Dual processing theory of human cognition postulates that reasoning and decision-making can be described as a function of both an intuitive, experiential, affective system (system I and/or an analytical, deliberative (system II processing system. To date no formal descriptive model of medical decision-making based on dual processing theory has been developed. Here we postulate such a model and apply it to a common clinical situation: whether treatment should be administered to the patient who may or may not have a disease. Methods We developed a mathematical model in which we linked a recently proposed descriptive psychological model of cognition with the threshold model of medical decision-making and show how this approach can be used to better understand decision-making at the bedside and explain the widespread variation in treatments observed in clinical practice. Results We show that physician’s beliefs about whether to treat at higher (lower probability levels compared to the prescriptive therapeutic thresholds obtained via system II processing is moderated by system I and the ratio of benefit and harms as evaluated by both system I and II. Under some conditions, the system I decision maker’s threshold may dramatically drop below the expected utility threshold derived by system II. This can explain the overtreatment often seen in the contemporary practice. The opposite can also occur as in the situations where empirical evidence is considered unreliable, or when cognitive processes of decision-makers are biased through recent experience: the threshold will increase relative to the normative threshold value derived via system II using expected utility threshold. This inclination for the higher diagnostic certainty may, in turn, explain undertreatment that is also documented in the current medical practice. Conclusions We have developed the first dual processing model of medical decision-making that has potential to
Waking and scrambling in holographic heating up
Ageev, D. S.; Aref'eva, I. Ya.
2017-10-01
Using holographic methods, we study the heating up process in quantum field theory. As a holographic dual of this process, we use absorption of a thin shell on a black brane. We find the explicit form of the time evolution of the quantum mutual information during heating up from the temperature Ti to the temperature T f in a system of two intervals in two-dimensional space-time. We determine the geometric characteristics of the system under which the time dependence of the mutual information has a bell shape: it is equal to zero at the initial instant, becomes positive at some subsequent instant, further attains its maximum, and again decreases to zero. Such a behavior of the mutual information occurs in the process of photosynthesis. We show that if the distance x between the intervals is less than log 2/2π T i, then the evolution of the holographic mutual information has a bell shape only for intervals whose lengths are bounded from above and below. For sufficiently large x, i.e., for x < log 2/2π T i, the bell-like shape of the time dependence of the quantum mutual information is present only for sufficiently large intervals. Moreover, the zone narrows as T i increases and widens as T f increases.
Holographic complexity and noncommutative gauge theory
Couch, Josiah; Eccles, Stefan; Fischler, Willy; Xiao, Ming-Lei
2018-03-01
We study the holographic complexity of noncommutative field theories. The four-dimensional N=4 noncommutative super Yang-Mills theory with Moyal algebra along two of the spatial directions has a well known holographic dual as a type IIB supergravity theory with a stack of D3 branes and non-trivial NS-NS B fields. We start from this example and find that the late time holographic complexity growth rate, based on the "complexity equals action" conjecture, experiences an enhancement when the non-commutativity is turned on. This enhancement saturates a new limit which is exactly 1/4 larger than the commutative value. We then attempt to give a quantum mechanics explanation of the enhancement. Finite time behavior of the complexity growth rate is also studied. Inspired by the non-trivial result, we move on to more general setup in string theory where we have a stack of D p branes and also turn on the B field. Multiple noncommutative directions are considered in higher p cases.
Emergent Gauge Fields in Holographic Superconductors
Domènech, Oriol; Pomarol, Alex; Salvio, Alberto; Silva, Pedro J
2010-01-01
Holographic superconductors have been studied so far in the absence of dynamical electromagnetic fields, namely in the limit in which they coincide with holographic superfluids. It is possible, however, to introduce dynamical gauge fields if a Neumann-type boundary condition is imposed on the AdS-boundary. In 3+1 dimensions, the dual theory is a 2+1 dimensional CFT whose spectrum contains a massless gauge field, signaling the emergence of a gauge symmetry. We study the impact of a dynamical gauge field in vortex configurations where it is known to significantly affect the energetics and phase transitions. We calculate the critical magnetic fields H_c1 and H_c2, obtaining that holographic superconductors are of Type II (H_c1 < H_c2). We extend the study to 4+1 dimensions where the gauge field does not appear as an emergent phenomena, but can be introduced, by a proper renormalization, as an external dynamical field. We also compare our predictions with those arising from a Ginzburg-Landau theory and identif...
Benini, Francesco; /Princeton U.; Dymarsky, Anatoly; /Stanford U., ITP; Franco, Sebastian; /Santa Barbara, KITP; Kachru, Shamit; Simic, Dusan; /Stanford U., ITP /SLAC; 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.
Holographic optical security systems
Fagan, William F.
1990-06-01
One of the most successful applications of Holography,in recent years,has been its use as an optical security technique.Indeed the general public's awareness of holograms has been greatly enhanced by the incorporation of holographic elements into the VISA and MASTERCHARGE credit cards.Optical techniques related to Holography,are also being used to protect the currencies of several countries against the counterfeiter. The mass production of high quality holographic images is by no means a trivial task as a considerable degree of expertise is required together with an optical laboratory and embossing machinery.This paper will present an overview of the principal holographic and related optical techniques used for security purposes.Worldwide, over thirty companies are involved in the production of security elements utilising holographic and related optical technologies.Counterfeiting of many products is a major criminal activity with severe consequences not only for the manufacturer but for the public in general as defective automobile parts,aircraft components,and pharmaceutical products, to cite only a few of the more prominent examples,have at one time or another been illegally copied.
Magnetic Catalysis of Chiral Symmetry Breaking: A Holographic Prospective
Filev, V.; Rashkov, R.; Rashkov, R.
2010-01-01
We review a recent investigation of the effect of magnetic catalysis of mass generation in holographic Yang-Mills theories. We aim at a self-contained and pedagogical form of the review. We provide a brief field theory background and review the basics of holographic flavordynamics. The main part of the paper investigates the influence of external magnetic field to holographic gauge theories dual to the D3/D5- and D3/D7-brane intersections. Among the observed phenomena are the spontaneous breaking of a global internal symmetry, Zeeman splitting of the energy levels, and the existence of pseudo, Goldstone modes. An analytic derivation of the Gell-Mann-Oaks-Renner relation for the D3/D7 set up is reviewed. In the D3/D5 case, the pseudo-Goldstone modes satisfy nonrelativistic dispersion relation. The studies reviewed confirm the universal nature of the magnetic catalysis of mass generation.
A defect in holographic interpretations of tensor networks
Czech, Bartłomiej [Institute for Advanced Study,Princeton, NJ 08540 (United States); Nguyen, Phuc H.; Swaminathan, Sivaramakrishnan [Theory Group, Department of Physics and Texas Cosmology Center,The University of Texas at Austin,Austin, TX 78712 (United States)
2017-03-16
We initiate the study of how tensor networks reproduce properties of static holographic space-times, which are not locally pure anti-de Sitter. We consider geometries that are holographically dual to ground states of defect, interface and boundary CFTs and compare them to the structure of the requisite MERA networks predicted by the theory of minimal updates. When the CFT is deformed, certain tensors require updating. On the other hand, even identical tensors can contribute differently to estimates of entanglement entropies. We interpret these facts holographically by associating tensor updates to turning on non-normalizable modes in the bulk. In passing, we also clarify and complement existing arguments in support of the theory of minimal updates, propose a novel ansatz called rayed MERA that applies to a class of generalized interface CFTs, and analyze the kinematic spaces of the thin wall and AdS{sub 3}-Janus geometries.
Covariant generalized holographic dark energy and accelerating universe
Nojiri, Shin'ichi; Odintsov, S. D.
2017-08-01
We propose the generalized holographic dark energy model where the infrared cutoff is identified with the combination of the FRW universe parameters: the Hubble rate, particle and future horizons, cosmological constant, the universe lifetime (if finite) and their derivatives. It is demonstrated that with the corresponding choice of the cutoff one can map such holographic dark energy to modified gravity or gravity with a general fluid. Explicitly, F( R) gravity and the general perfect fluid are worked out in detail and the corresponding infrared cutoff is found. Using this correspondence, we get realistic inflation or viable dark energy or a unified inflationary-dark energy universe in terms of covariant holographic dark energy.
Covariant introduction of quark spin into the dual resonance model
Iroshnikov, G.S.
1979-01-01
A very simple method of insertion of a quark spin into the dual resonance model of hadron interaction is proposed. The method is suitable for amplitudes with an arbitrary number of particles. The amplitude of interaction of real particles is presented as a product of contribution of oscillatory excitations in the (q anti q) system and of a spin factor. The latter is equal to the trace of the product of the external particle wave functions constructed from structural quarks and satisfying the relativistic Bargman-Wigner equations. Two examples of calculating the meson interaction amplitudes are presented
Nonscaling parametrization of hadronic spectra and dual parton model
Gaponenko, O.N.
2001-01-01
Using the popular Wdowczyk-Wolfendale parametrization (WW-parametrization) as an example one studies restrictions imposed by a dual parton model for different nonscaling parametrizations of the pulsed hadron spectra in soft hadron-hadron and hadron-nuclear interactions. One derived a new parametrization free from basic drawback of the WW-formulae. In the central range the determined parametrization show agreement with the Wdowczyk-Wolfendale formula, but in contrast to the last-named one it does not result in contradiction with the experiment due to fast reduction of inelastic factor reduction with energy increase [ru
Conical Refraction: new observations and a dual cone model.
Sokolovskii, G S; Carnegie, D J; Kalkandjiev, T K; Rafailov, E U
2013-05-06
We propose a paraxial dual-cone model of conical refraction involving the interference of two cones of light behind the exit face of the crystal. The supporting experiment is based on beam selecting elements breaking down the conically refracted beam into two separate hollow cones which are symmetrical with one another. The shape of these cones of light is a product of a 'competition' between the divergence caused by the conical refraction and the convergence due to the focusing by the lens. The developed mathematical description of the conical refraction demonstrates an excellent agreement with experiment.
Dual degree partnership in nursing: an innovative undergraduate educational model.
Bastable, Susan B; Markowitz, Marianne
2012-10-01
We report the success of a unique articulation Dual Degree Partnership in Nursing (DDPN) model. The process used to establish and implement this approach is described. Unlike typical 2+2 agreements between associate degree (AD) and bachelor degree (BS) nursing education programs, the DDPN is designed with a 1+2+1 sequence. Intended to attract high school students, this model provides the opportunity to earn two degrees (AD and BS) while experiencing a 4-year campus living and learning environment. This configuration was accomplished without compromising the integrity of either of the established programs. After collecting data over the past 6 years, this model demonstrates popularity with the traditional-aged student, as well as success from an academic perspective. Statistics on retention, graduation, and NCLEX® pass rates indicate the feasibility and success of the model. Based on the findings, the potential for replication is promising for other colleges interested in a similar collaboration. Copyright 2012, SLACK Incorporated.
Mathematical Modeling of Dual Intake Transparent Transpired Solar Collector
Thomas Semenou
2015-01-01
Full Text Available Nowadays, in several types of commercial or institutional buildings, a significant rise of transpired solar collectors used to preheat the fresh air of the building can be observed. Nevertheless, when the air mass flow rate is low, the collector efficiency collapses and a large amount of energy remains unused. This paper presents a simple yet effective mathematical model of a transparent transpired solar collector (TTC with dual intake in order to remove stagnation problems in the plenum and ensure a better thermal efficiency and more heat recovery. A thermal model and a pressure loss model were developed. Then, the combined model was validated with experimental data from the Solar Rating and Certification Corporation (SRCC. The results show that the collector efficiency can be up to 70% and even 80% regardless of operating conditions. The temperature gain is able to reach 20°K when the solar irradiation is high.
Modifications to holographic entanglement entropy in warped CFT
Song, Wei; Wen, Qiang; Xu, Jianfei [Yau Mathematical Sciences Center, Tsinghua University,Beijing 100084 (China)
2017-02-13
In https://www.doi.org/10.1103/PhysRevLett.117.011602 it was observed that asymptotic boundary conditions play an important role in the study of holographic entanglement beyond AdS/CFT. In particular, the Ryu-Takayanagi proposal must be modified for warped AdS{sub 3} (WAdS{sub 3}) with Dirichlet boundary conditions. In this paper, we consider AdS{sub 3} and WAdS{sub 3} with Dirichlet-Neumann boundary conditions. The conjectured holographic duals are warped conformal field theories (WCFTs), featuring a Virasoro-Kac-Moody algebra. We provide a holographic calculation of the entanglement entropy and Rényi entropy using AdS{sub 3}/WCFT and WAdS{sub 3}/WCFT dualities. Our bulk results are consistent with the WCFT results derived by Castro-Hofman-Iqbal using the Rindler method. Comparing with https://www.doi.org/10.1103/PhysRevLett.117.011602, we explicitly show that the holographic entanglement entropy is indeed affected by boundary conditions. Both results differ from the Ryu-Takayanagi proposal, indicating new relations between spacetime geometry and quantum entanglement for holographic dualities beyond AdS/CFT.
Improved dual sided doped memristor: modelling and applications
Anup Shrivastava
2014-05-01
Full Text Available Memristor as a novel and emerging electronic device having vast range of applications suffer from poor frequency response and saturation length. In this paper, the authors present a novel and an innovative device structure for the memristor with two active layers and its non-linear ionic drift model for an improved frequency response and saturation length. The authors investigated and compared the I–V characteristics for the proposed model with the conventional memristors and found better results in each case (different window functions for the proposed dual sided doped memristor. For circuit level simulation, they developed a SPICE model of the proposed memristor and designed some logic gates based on hybrid complementary metal oxide semiconductor memristive logic (memristor ratioed logic. The proposed memristor yields improved results in terms of noise margin, delay time and dynamic hazards than that of the conventional memristors (single active layer memristors.
HOMES - Holographic Optical Method for Exoplanet Spectroscopy
National Aeronautics and Space Administration — HOMES (Holographic Optical Method for Exoplanet Spectroscopy) is a space telescope that employs a double dispersion architecture, using a holographic optical element...
From Planck Data to Planck Era: Observational Tests of Holographic Cosmology.
Afshordi, Niayesh; Corianò, Claudio; Delle Rose, Luigi; Gould, Elizabeth; Skenderis, Kostas
2017-01-27
We test a class of holographic models for the very early Universe against cosmological observations and find that they are competitive to the standard cold dark matter model with a cosmological constant (ΛCDM) of cosmology. These models are based on three-dimensional perturbative superrenormalizable quantum field theory (QFT), and, while they predict a different power spectrum from the standard power law used in ΛCDM, they still provide an excellent fit to the data (within their regime of validity). By comparing the Bayesian evidence for the models, we find that ΛCDM does a better job globally, while the holographic models provide a (marginally) better fit to the data without very low multipoles (i.e., l≲30), where the QFT becomes nonperturbative. Observations can be used to exclude some QFT models, while we also find models satisfying all phenomenological constraints: The data rule out the dual theory being a Yang-Mills theory coupled to fermions only but allow for a Yang-Mills theory coupled to nonminimal scalars with quartic interactions. Lattice simulations of 3D QFTs can provide nonperturbative predictions for large-angle statistics of the cosmic microwave background and potentially explain its apparent anomalies.
Holographic EPR pairs, wormholes and radiation
Chernicoff, Mariano; Güijosa, Alberto; Pedraza, Juan F.
2013-10-01
As evidence for the ER = EPR conjecture, it has recently been observed that the string that is holographically dual to an entangled quark-antiquark pair separating with (asymptotically) uniform acceleration has a wormhole on its worldsheet. We point out that a two-sided horizon and a wormhole actually appear for much more generic quark-antiquark trajectories, which is consistent with the fact that the members of an EPR pair need not be permanently out of causal contact. The feature that determines whether the causal structure of the string worldsheet is trivial or not turns out to be the emission of gluonic radiation by the dual quark and antiquark. In the strongly-coupled gauge theory, it is only when radiation is emitted that one obtains an unambiguous separation of the pair into entangled subsystems, and this is what is reflected on the gravity side by the existence of the worldsheet horizon.
Supersymmetric null-like holographic cosmologies
Lin Fengli; Wen Wenyu
2006-01-01
We construct a new class of 1/4-BPS time dependent domain-wall solutions with null-like metric and dilaton in type II supergravities, which admit a null-like big bang singularity. Based on the domain-wall/QFT correspondence, these solutions are dual to 1/4-supersymmetric quantum field theories living on a boundary cosmological background with time dependent coupling constant and UV cutoff. In particular we evaluate the holographic c function for the 2-dimensional dual field theory living on the corresponding null-like cosmology. We find that this c function runs in accordance with the c-theorem as the boundary universe evolves, this means that the number of degrees of freedom is divergent at big bang and suggests the possible resolution of big bang singularity
Holographic renormalization group and cosmology in theories with quasilocalized gravity
Csaki, Csaba; Erlich, Joshua; Hollowood, Timothy J.; Terning, John
2001-01-01
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
Real-time holographic endoscopy
Smigielski, Paul; Albe, Felix; Dischli, Bernard
1992-08-01
Some new experiments concerning holographic endoscopy are presented. The quantitative measurements of deformations of objects are obtained by the double-exposure and double- reference beam method, using either a cw-laser or a pulsed laser. Qualitative experiments using an argon laser with time-average holographic endoscopy are also presented. A video film on real-time endoscopic holographic interferometry was recorded with the help of a frequency-doubled YAG-laser working at 25 Hz for the first time.
Holographic probes of collapsing black holes
Hubeny, Veronika E.; Maxfield, Henry
2014-01-01
We continue the programme of exploring the means of holographically decoding the geometry of spacetime inside a black hole using the gauge/gravity correspondence. To this end, we study the behaviour of certain extremal surfaces (focusing on those relevant for equal-time correlators and entanglement entropy in the dual CFT) in a dynamically evolving asymptotically AdS spacetime, specifically examining how deep such probes reach. To highlight the novel effects of putting the system far out of equilibrium and at finite volume, we consider spherically symmetric Vaidya-AdS, describing black hole formation by gravitational collapse of a null shell, which provides a convenient toy model of a quantum quench in the field theory. Extremal surfaces anchored on the boundary exhibit rather rich behaviour, whose features depend on dimension of both the spacetime and the surface, as well as on the anchoring region. The main common feature is that they reach inside the horizon even in the post-collapse part of the geometry. In 3-dimensional spacetime, we find that for sub-AdS-sized black holes, the entire spacetime is accessible by the restricted class of geodesics whereas in larger black holes a small region near the imploding shell cannot be reached by any boundary-anchored geodesic. In higher dimensions, the deepest reach is attained by geodesics which (despite being asymmetric) connect equal time and antipodal boundary points soon after the collapse; these can attain spacetime regions of arbitrarily high curvature and simultaneously have smallest length. Higher-dimensional surfaces can penetrate the horizon while anchored on the boundary at arbitrarily late times, but are bounded away from the singularity. We also study the details of length or area growth during thermalization. While the area of extremal surfaces increases monotonically, geodesic length is neither monotonic nor continuous
Linearity of holographic entanglement entropy
Almheiri, Ahmed [Stanford Institute for Theoretical Physics, Department of Physics,Stanford University, Stanford, CA 94305 (United States); Dong, Xi [School of Natural Sciences, Institute for Advanced Study,Princeton, NJ 08540 (United States); Swingle, Brian [Stanford Institute for Theoretical Physics, Department of Physics,Stanford University, Stanford, CA 94305 (United States)
2017-02-14
We consider the question of whether the leading contribution to the entanglement entropy in holographic CFTs is truly given by the expectation value of a linear operator as is suggested by the Ryu-Takayanagi formula. We investigate this property by computing the entanglement entropy, via the replica trick, in states dual to superpositions of macroscopically distinct geometries and find it consistent with evaluating the expectation value of the area operator within such states. However, we find that this fails once the number of semi-classical states in the superposition grows exponentially in the central charge of the CFT. Moreover, in certain such scenarios we find that the choice of surface on which to evaluate the area operator depends on the density matrix of the entire CFT. This nonlinearity is enforced in the bulk via the homology prescription of Ryu-Takayanagi. We thus conclude that the homology constraint is not a linear property in the CFT. We also discuss the existence of ‘entropy operators’ in general systems with a large number of degrees of freedom.
Deriving covariant holographic entanglement
Dong, Xi [School of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540 (United States); Lewkowycz, Aitor [Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Rangamani, Mukund [Center for Quantum Mathematics and Physics (QMAP), Department of Physics, University of California, Davis, CA 95616 (United States)
2016-11-07
We provide a gravitational argument in favour of the covariant holographic entanglement entropy proposal. In general time-dependent states, the proposal asserts that the entanglement entropy of a region in the boundary field theory is given by a quarter of the area of a bulk extremal surface in Planck units. The main element of our discussion is an implementation of an appropriate Schwinger-Keldysh contour to obtain the reduced density matrix (and its powers) of a given region, as is relevant for the replica construction. We map this contour into the bulk gravitational theory, and argue that the saddle point solutions of these replica geometries lead to a consistent prescription for computing the field theory Rényi entropies. In the limiting case where the replica index is taken to unity, a local analysis suffices to show that these saddles lead to the extremal surfaces of interest. We also comment on various properties of holographic entanglement that follow from this construction.
Holographic Optical Data Storage
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
Andersen, G.
2000-01-01
Full text: We have constructed a Raman lidar system that incorporates a holographic optical element. By resolving just 3 nitrogen lines in the Resonance Raman spectroscopy (RRS) spectrum, temperature fits as good as 1% at altitudes of 20km can be made in 30 minutes. Due to the narrowband selectivity of the HOE, the lidar provides measurements over a continuous 24hr period. By adding a 4th channel to capture the Rayleigh backscattered light, temperature profiles can be extended to 80km
A dual resonance model for high energy electroweak reactions
Picard, Jean-Francois
1995-01-01
The aim of this work is to propose an original model for the weak interaction at high energy (about 1 TeV) that is inspired from resonance dual models established for hadron physics. The first chapter details the basis and assumptions of the standard model. The second chapter deals with various scenarios that go beyond the standard model and that involve a strong interaction and a perturbative approach to assess coupling. The third chapter is dedicated to the main teachings of hadron physics concerning resonances, the model of Regge poles and the concept of duality. We present our new model in the fourth chapter, we build a scenario in which standard fermions and the 3 massive gauge bosons would have a sub-structure alike that of hadrons. In order to give non-null values to the width of resonances we use the K matrix method, we describe this method in the last chapter and we apply it for the computation of the width of the Z 0 boson. Our model predicts a large spectra of states particularly with the 143-up-lets of ff-bar states. The K matrix method has allowed us to compute amplitudes for helicity, then to collapse them in amplitudes invariant with SU(2) and to project these amplitudes in partial waves of helicity. For most resonances partial widths are very low compared to their mass
A holographic perspective on phonons and pseudo-phonons
Amoretti, Andrea [Institute of Theoretical Physics and Astrophysics, University of Würzburg,97074 Würzburg (Germany); Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Areán, Daniel [Max-Planck-Institut für Physik (Werner-Heisenberg-Institut),Föhringer Ring 6, D-80805, Munich (Germany); Argurio, Riccardo [Physique Théorique et Mathématique and International Solvay Institutes,Université Libre de Bruxelles,C.P. 231, 1050 Brussels (Belgium); Musso, Daniele [Departamento de Física de Partículas, Universidade de Santiago de Compostelaand Instituto Galego de Física de Altas Enerxías (IGFAE),E-15782, Santiago de Compostela (Spain); Zayas, Leopoldo A. Pando [Michigan Center for Theoretical Physics, Department of Physics, University of Michigan,Ann Arbor, MI 48109 (United States)
2017-05-10
We analyze the concomitant spontaneous breaking of translation and conformal symmetries by introducing in a CFT a complex scalar operator that acquires a spatially dependent expectation value. The model, inspired by the holographic Q-lattice, provides a privileged setup to study the emergence of phonons from a spontaneous translational symmetry breaking in a conformal field theory and offers valuable hints for the treatment of phonons in QFT at large. We first analyze the Ward identity structure by means of standard QFT techniques, considering both spontaneous and explicit symmetry breaking. Next, by implementing holographic renormalization, we show that the same set of Ward identities holds in the holographic Q-lattice. Eventually, relying on the holographic and QFT results, we study the correlators realizing the symmetry breaking pattern and how they encode information about the low-energy spectrum.
Holographic fluctuations and the principle of minimal complexity
Chemissany, Wissam [Institut für Theoretische Physik, Leibniz Universität Hannover,Appelstr. 2, 30167 Hannover (Germany); Department of Mechanical Engineering, MIT,Cambridge MA 02139 (United States); Osborne, Tobias J. [Institut für Theoretische Physik, Leibniz Universität Hannover,Appelstr. 2, 30167 Hannover (Germany)
2016-12-14
We discuss, from a quantum information perspective, recent proposals of Maldacena, Ryu, Takayanagi, van Raamsdonk, Swingle, and Susskind that spacetime is an emergent property of the quantum entanglement of an associated boundary quantum system. We review the idea that the informational principle of minimal complexity determines a dual holographic bulk spacetime from a minimal quantum circuit U preparing a given boundary state from a trivial reference state. We describe how this idea may be extended to determine the relationship between the fluctuations of the bulk holographic geometry and the fluctuations of the boundary low-energy subspace. In this way we obtain, for every quantum system, an Einstein-like equation of motion for what might be interpreted as a bulk gravity theory dual to the boundary system.
Dual deep modeling: multi-level modeling with dual potencies and its formalization in F-Logic.
Neumayr, Bernd; Schuetz, Christoph G; Jeusfeld, Manfred A; Schrefl, Michael
2018-01-01
An enterprise database contains a global, integrated, and consistent representation of a company's data. Multi-level modeling facilitates the definition and maintenance of such an integrated conceptual data model in a dynamic environment of changing data requirements of diverse applications. Multi-level models transcend the traditional separation of class and object with clabjects as the central modeling primitive, which allows for a more flexible and natural representation of many real-world use cases. In deep instantiation, the number of instantiation levels of a clabject or property is indicated by a single potency. Dual deep modeling (DDM) differentiates between source potency and target potency of a property or association and supports the flexible instantiation and refinement of the property by statements connecting clabjects at different modeling levels. DDM comes with multiple generalization of clabjects, subsetting/specialization of properties, and multi-level cardinality constraints. Examples are presented using a UML-style notation for DDM together with UML class and object diagrams for the representation of two-level user views derived from the multi-level model. Syntax and semantics of DDM are formalized and implemented in F-Logic, supporting the modeler with integrity checks and rich query facilities.
Unitary truncations and critical gravity : a toy model
Bergshoeff, Eric A.; de Haan, Sjoerd; Merbis, Wout; Porrati, Massimo; Rosseel, Jan
We investigate a higher-derivative scalar field model in a fixed d+1 dimensional AdS background as a toy model for a gravitational dual to a higher-rank logarithmic CFT. The holographic two-point correlation functions on the boundary agree with higher-rank LCFT correlation functions. For odd rank,
The Hubble IR cutoff in holographic ellipsoidal cosmologies
Cataldo, Mauricio [Universidad del Bio-Bio, Departamento de Fisica, Facultad de Ciencias, Concepcion (Chile); Cruz, Norman [Grupo de Cosmologia y Gravitacion-UBB, Concepcion (Chile)
2018-01-15
It is well known that for spatially flat FRW cosmologies, the holographic dark energy disfavors the Hubble parameter as a candidate for the IR cutoff. For overcoming this problem, we explore the use of this cutoff in holographic ellipsoidal cosmological models, and derive the general ellipsoidal metric induced by a such holographic energy density. Despite the drawbacks that this cutoff presents in homogeneous and isotropic universes, based on this general metric, we developed a suitable ellipsoidal holographic cosmological model, filled with a dark matter and a dark energy components. At late time stages, the cosmic evolution is dominated by a holographic anisotropic dark energy with barotropic equations of state. The cosmologies expand in all directions in accelerated manner. Since the ellipsoidal cosmologies given here are not asymptotically FRW, the deviation from homogeneity and isotropy of the universe on large cosmological scales remains constant during all cosmic evolution. This feature allows the studied holographic ellipsoidal cosmologies to be ruled by an equation of state ω = p/ρ, whose range belongs to quintessence or even phantom matter. (orig.)
Holographic entanglement entropy in 2D holographic superconductor via AdS3/CFT2
Davood Momeni
2015-07-01
Full Text Available The aim of the present letter is to find the holographic entanglement entropy (HEE in 2D holographic superconductors (HSC. Indeed, it is possible to compute the exact form of this entropy due to an advantage of approximate solutions inside normal and superconducting phases with backreactions. By making the UV and IR limits applied to the integrals, an approximate expression for HEE is obtained. In case the software cannot calculate minimal surface integrals analytically, it offers the possibility to proceed with a numerical evaluation of the corresponding terms. We'll understand how the area formula incorporates the structure of the domain wall approximation. We see that HEE changes linearly with belt angle. It's due to the extensivity of this type of entropy and the emergent of an entropic force. We find that the wider belt angle corresponds to a larger holographic surface. Another remarkable observation is that no “confinement/deconfinement” phase transition point exists in our 2D dual field theory. Furthermore, we observe that the slope of the HEE with respect to the temperature dSdT decreases, thanks to the emergence extra degree of freedom(s in low temperature system. A first order phase transition is detected near the critical point.
Uncertainty in dual permeability model parameters for structured soils
Arora, B.; Mohanty, B. P.; McGuire, J. T.
2012-01-01
Successful application of dual permeability models (DPM) to predict contaminant transport is contingent upon measured or inversely estimated soil hydraulic and solute transport parameters. The difficulty in unique identification of parameters for the additional macropore- and matrix-macropore interface regions, and knowledge about requisite experimental data for DPM has not been resolved to date. Therefore, this study quantifies uncertainty in dual permeability model parameters of experimental soil columns with different macropore distributions (single macropore, and low- and high-density multiple macropores). Uncertainty evaluation is conducted using adaptive Markov chain Monte Carlo (AMCMC) and conventional Metropolis-Hastings (MH) algorithms while assuming 10 out of 17 parameters to be uncertain or random. Results indicate that AMCMC resolves parameter correlations and exhibits fast convergence for all DPM parameters while MH displays large posterior correlations for various parameters. This study demonstrates that the choice of parameter sampling algorithms is paramount in obtaining unique DPM parameters when information on covariance structure is lacking, or else additional information on parameter correlations must be supplied to resolve the problem of equifinality of DPM parameters. This study also highlights the placement and significance of matrix-macropore interface in flow experiments of soil columns with different macropore densities. Histograms for certain soil hydraulic parameters display tri-modal characteristics implying that macropores are drained first followed by the interface region and then by pores of the matrix domain in drainage experiments. Results indicate that hydraulic properties and behavior of the matrix-macropore interface is not only a function of saturated hydraulic conductivity of the macroporematrix interface (Ksa) and macropore tortuosity (lf) but also of other parameters of the matrix and macropore domains.
Extended charge banking model of dual path shocks for implantable cardioverter defibrillators.
Dosdall, Derek J; Sweeney, James D
2008-08-01
Single path defibrillation shock methods have been improved through the use of the Charge Banking Model of defibrillation, which predicts the response of the heart to shocks as a simple resistor-capacitor (RC) circuit. While dual path defibrillation configurations have significantly reduced defibrillation thresholds, improvements to dual path defibrillation techniques have been limited to experimental observations without a practical model to aid in improving dual path defibrillation techniques. The Charge Banking Model has been extended into a new Extended Charge Banking Model of defibrillation that represents small sections of the heart as separate RC circuits, uses a weighting factor based on published defibrillation shock field gradient measures, and implements a critical mass criteria to predict the relative efficacy of single and dual path defibrillation shocks. The new model reproduced the results from several published experimental protocols that demonstrated the relative efficacy of dual path defibrillation shocks. The model predicts that time between phases or pulses of dual path defibrillation shock configurations should be minimized to maximize shock efficacy. Through this approach the Extended Charge Banking Model predictions may be used to improve dual path and multi-pulse defibrillation techniques, which have been shown experimentally to lower defibrillation thresholds substantially. The new model may be a useful tool to help in further improving dual path and multiple pulse defibrillation techniques by predicting optimal pulse durations and shock timing parameters.
Cultural differences of a dual-motivation model on health risk behaviour
Ohtomo, S.; Hirose, Y.; Midden, C.J.H.
2011-01-01
This study investigated the cultural differences of a dual-motivation model of unhealthy risk behaviour in the Netherlands and Japan. Our model assumes dual motivations involved in unhealthy eating behaviour, a behavioural willingness that leads behaviour unintentionally or subconsciously and a
The Linked Dual Representation model of vocal perception and production
Sean eHutchins
2013-11-01
Full Text Available The voice is one of the most important media for communication, yet there is a wide range of abilities in both the perception and production of the voice. In this article, we review this range of abilities, focusing on pitch accuracy as a particularly informative case, and look at the factors underlying these abilities. Several classes of models have been posited describing the relationship between vocal perception and production, and we review the evidence for and against each class of model. We look at how the voice is different from other musical instruments and review evidence about both the association and the dissociation between vocal perception and production abilities. Finally, we introduce the Linked Dual Representation model, a new approach which can account for the broad patterns in prior findings, including trends in the data which might seem to be countervailing. We discuss how this model interacts with higher-order cognition and examine its predictions about several aspects of vocal perception and production.
Dyon Condensation and Dual Superconductivity in Abelian Higgs Model of QCD
B. S. Rajput
2010-01-01
Full Text Available Constructing the effective action for dyonic field in Abelian projection of QCD, it has been demonstrated that any charge (electrical or magnetic of dyon screens its own direct potential to which it minimally couples and antiscreens the dual potential leading to dual superconductivity in accordance with generalized Meissner effect. Taking the Abelian projection of QCD, an Abelian Higgs model, incorporating dual superconductivity and confinement, has been constructed and its representation has been obtained in terms of average of Wilson loop.
A holographic bound for D3-brane
Momeni, Davood; Myrzakul, Aizhan; Myrzakulov, Ratbay [Eurasian National University, Eurasian International Center for Theoretical Physics, Astana (Kazakhstan); Eurasian National University, Department of General Theoretical Physics, Astana (Kazakhstan); Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Bahamonde, Sebastian [University College London, Department of Mathematics, London (United Kingdom)
2017-06-15
In this paper, we will regularize the holographic entanglement entropy, holographic complexity and fidelity susceptibility for a configuration of D3-branes. We will also study the regularization of the holographic complexity from the action for a configuration of D3-branes. It will be demonstrated that for a spherical shell of D3-branes the regularized holographic complexity is always greater than or equal to the regularized fidelity susceptibility. Furthermore, we will also demonstrate that the regularized holographic complexity is related to the regularized holographic entanglement entropy for this system. Thus, we will obtain a holographic bound involving regularized holographic complexity, regularized holographic entanglement entropy and regularized fidelity susceptibility of a configuration of D3-brane. We will also discuss a bound for regularized holographic complexity from action, for a D3-brane configuration. (orig.)
Relativistic strings and dual models of strong interactions
Marinov, M.S.
1977-01-01
The theory of strong interactions,based on the model depicting a hardon as a one-dimentional elastic relativistic system(''string'') is considered. The relationship between this model and the concepts of quarks and partons is discussed. Presented are the principal results relating to the Veneziano dual theory, which may be considered as the consequence of the string model, and to its modifications. The classical string theory is described in detail. Attention is focused on questions of importance to the construction of the quantum theory - the Hamilton mechanisms and conformal symmetry. Quantization is described, and it is shown that it is not contradictory only in the 26-dimentional space and with a special requirement imposed on the spectrum of states. The theory of a string with a distributed spin is considered. The spin is introduced with the aid of the Grassman algebra formalism. In this case quantization is possible only in the 10-dimentional space. The strings interact by their ruptures and gluings. A method for calculating the interaction amplitudes is indicated
Interacting holographic dark energy with logarithmic correction
Jamil, Mubasher; Farooq, M. Umar
2010-01-01
The holographic dark energy (HDE) is considered to be the most promising candidate of dark energy. Its definition is originally 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. Using this new definition, we investigate the model of interacting dark energy and derive its effective equation of s...
Holographic processing of track chamber data
Bykovsky, Y A; Larkin, A I; Markilov, A A; Starikov, S N [Moskovskij Fiziko-Tekhnicheskij Inst. (USSR)
1975-12-01
The holographic pattern recognition method was applied for processing of track chamber photographs. Experiments on detection of such events as a definitely directed track, an angle formed by two tracks, a three-pronged star, a definitely curved track were performed by using models. It is proposed to recognize these events in a filmshot by the shape of correlation signals. The experiment to recognize the event in a real bubble chamber filmshot was realized; requirements to the processing films were determined.
Laser adaptive holographic hydrophone
Romashko, R V; Kulchin, Yu N; Bezruk, M N; Ermolaev, S A [Institute of Automation and Control Processes, Far Eastern Branch of the Russian Academy of Sciences, Vladivostok (Russian Federation)
2016-03-31
A new type of a laser hydrophone based on dynamic holograms, formed in a photorefractive crystal, is proposed and studied. It is shown that the use of dynamic holograms makes it unnecessary to use complex optical schemes and systems for electronic stabilisation of the interferometer operating point. This essentially simplifies the scheme of the laser hydrophone preserving its high sensitivity, which offers the possibility to use it under a strong variation of the environment parameters. The laser adaptive holographic hydrophone implemented at present possesses the sensitivity at a level of 3.3 mV Pa{sup -1} in the frequency range from 1 to 30 kHz. (laser hydrophones)
Cornelia Denz
2000-05-01
Full Text Available Volume holography represents a promising alternative to existing storage technologies. Its parallel data storage leads to high capacities combined with short access times and high transfer rates. The design and realization of a compact volume holographic storage demonstrator is presented. The technique of phase-coded multiplexing implemented to superimpose many data pages in a single location enables to store up to 480 holograms per storage location without any moving parts. Results of analog and digital data storage are shown and real time optical image processing is demonstrated.
War and peace: morphemes and full forms in a noninteractive activation parallel dual-route model.
Baayen, H; Schreuder, R
This article introduces a computational tool for modeling the process of morphological segmentation in visual and auditory word recognition in the framework of a parallel dual-route model. Copyright 1999 Academic Press.
Electromagnetic holographic sensitivity field of two-phase flow in horizontal wells
Zhang, Kuo; Wu, Xi-Ling; Yan, Jing-Fu; Cai, Jia-Tie
2017-03-01
Electromagnetic holographic data are characterized by two modes, suggesting that image reconstruction requires a dual-mode sensitivity field as well. We analyze an electromagnetic holographic field based on tomography theory and Radon inverse transform to derive the expression of the electromagnetic holographic sensitivity field (EMHSF). Then, we apply the EMHSF calculated by using finite-element methods to flow simulations and holographic imaging. The results suggest that the EMHSF based on the partial derivative of radius of the complex electric potential φ is closely linked to the Radon inverse transform and encompasses the sensitivities of the amplitude and phase data. The flow images obtained with inversion using EMHSF better agree with the actual flow patterns. The EMHSF overcomes the limitations of traditional single-mode sensitivity fields.
Towards Dense Nuclear Matter in A Modified Sakai-Sugimoto Model
Rho Mannque
2012-02-01
Full Text Available As a part of the attempt to address dense baryonic matter, we first review holographic approaches to QCD. The big advantage of the holographic approaches is that they render strongly coupled 4D gauge theories as duals of certain weakly coupled string/supergravity that are well understood. Its relevance to real QCD is one of the central problems in hadron/nuclear physics as well as in the context of applied string theory. None of the models based on these holographic approaches presently available can adequately describe the system we are interested in, namely dense baryonic matter. Nevertheless, some aspects of the holographic approach are found to describe certain processes both in vacuum and in medium. In this talk we only present the structure of a model that appears to be closest to QCD, and has the potential to address the problem.
Properties of multilayer nonuniform holographic structures
Pen, E F; Rodionov, Mikhail Yu
2010-01-01
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)
A Test of Two Alternative Cognitive Processing Models: Learning Styles and Dual Coding
Cuevas, Joshua; Dawson, Bryan L.
2018-01-01
This study tested two cognitive models, learning styles and dual coding, which make contradictory predictions about how learners process and retain visual and auditory information. Learning styles-based instructional practices are common in educational environments despite a questionable research base, while the use of dual coding is less…
Holographic free energy and thermodynamic geometry
Ghorai, Debabrata; Gangopadhyay, Sunandan
2016-12-01
We obtain the free energy and thermodynamic geometry of holographic superconductors in 2+1 dimensions. The gravitational theory in the bulk dual to this 2+1-dimensional strongly coupled theory lives in the 3+1 dimensions and is that of a charged AdS black hole together with a massive charged scalar field. The matching method is applied to obtain the nature of the fields near the horizon using which the holographic free energy is computed through the gauge/gravity duality. The critical temperature is obtained for a set of values of the matching point of the near horizon and the boundary behaviour of the fields in the probe limit approximation which neglects the back reaction of the matter fields on the background spacetime geometry. The thermodynamic geometry is then computed from the free energy of the boundary theory. From the divergence of the thermodynamic scalar curvature, the critical temperature is obtained once again. We then compare this result for the critical temperature with that obtained from the matching method.
Holographic free energy and thermodynamic geometry
Ghorai, Debabrata; Gangopadhyay, Sunandan
2016-01-01
We obtain the free energy and thermodynamic geometry of holographic superconductors in 2 + 1 dimensions. The gravitational theory in the bulk dual to this 2 + 1-dimensional strongly coupled theory lives in the 3 + 1 dimensions and is that of a charged AdS black hole together with a massive charged scalar field. The matching method is applied to obtain the nature of the fields near the horizon using which the holographic free energy is computed through the gauge/gravity duality. The critical temperature is obtained for a set of values of the matching point of the near horizon and the boundary behaviour of the fields in the probe limit approximation which neglects the back reaction of the matter fields on the background spacetime geometry. The thermodynamic geometry is then computed from the free energy of the boundary theory. From the divergence of the thermodynamic scalar curvature, the critical temperature is obtained once again. We then compare this result for the critical temperature with that obtained from the matching method. (orig.)
Holographic free energy and thermodynamic geometry
Ghorai, Debabrata [S.N. Bose National Centre for Basic Sciences, Kolkata (India); Gangopadhyay, Sunandan [Indian Institute of Science Education and Research, Kolkata, Nadia (India); West Bengal State University, Department of Physics, Barasat (India); Inter University Centre for Astronomy and Astrophysics, Pune (India)
2016-12-15
We obtain the free energy and thermodynamic geometry of holographic superconductors in 2 + 1 dimensions. The gravitational theory in the bulk dual to this 2 + 1-dimensional strongly coupled theory lives in the 3 + 1 dimensions and is that of a charged AdS black hole together with a massive charged scalar field. The matching method is applied to obtain the nature of the fields near the horizon using which the holographic free energy is computed through the gauge/gravity duality. The critical temperature is obtained for a set of values of the matching point of the near horizon and the boundary behaviour of the fields in the probe limit approximation which neglects the back reaction of the matter fields on the background spacetime geometry. The thermodynamic geometry is then computed from the free energy of the boundary theory. From the divergence of the thermodynamic scalar curvature, the critical temperature is obtained once again. We then compare this result for the critical temperature with that obtained from the matching method. (orig.)
Holographic gauge mediation via strongly coupled messengers
McGuirk, Paul; Shiu, Gary; Sumitomo, Yoske
2010-01-01
We consider a relative of semidirect gauge mediation where the hidden sector exists at large 't Hooft coupling. Such scenarios can be difficult to describe using perturbative field theory methods but may fall into the class of holographic gauge mediation scenarios, meaning that they are amenable to the techniques of gauge/gravity duality. We use a recently found gravity solution to examine one such case, where the hidden sector is a cascading gauge theory resulting in a confinement scale not much smaller than the messenger mass. In the original construction of holographic gauge mediation, as in other examples of semidirect gauge mediation at strong coupling, the primary contributions to visible sector soft terms come from weakly coupled messenger mesons. In contrast to these examples, we describe the dual of a gauge theory where there are significant contributions from scales in which the strongly coupled messenger quarks are the effective degrees of freedom. In this regime, the visible sector gaugino mass can be calculated entirely from holography.
The traveltime holographic principle
Huang, Y.; Schuster, Gerard T.
2014-01-01
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.
The traveltime holographic principle
Huang, Y.
2014-11-06
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.
The traveltime holographic principle
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.
Modeling of Perpendicularly Driven Dual-Frequency Capacitively Coupled Plasma
Wang Hongyu; Sun Peng; Zhao Shuangyun; Li Yang; Jiang Wei
2016-01-01
We analyzed perpendicularly configured dual-frequency (DF) capacitively coupled plasmas (CCP). In this configuration, two pairs of electrodes are arranged oppositely, and the discharging is perpendicularly driven by two radio frequency (RF) sources. Particle-in-cell/Monte Carlo (PIC/MC) simulation showed that the configuration had some advantages as this configuration eliminated some dual frequency coupling effects. Some variation and potential application of the discharging configuration is discussed briefly. (paper)
The dual-gate lumen model of renal monoamine transport
Marty Hinz
2010-07-01
Full Text Available Marty Hinz1, Alvin Stein2, Thomas Uncini31Clinical Research, NeuroResearch Clinics, Inc. Cape Coral, Florida, USA; 2Stein Orthopedic Associates, Plantation, Florida, USA; 3DBS Labs, Duluth, Minnesota, USAAbstract: The three-phase response of urinary serotonin and dopamine in subjects simultaneously taking amino acid precursors of serotonin and dopamine has been defined.1,2 No model exists regarding the renal etiology of the three-phase response. This writing outlines a model explaining the origin of the three-phase response of urinary serotonin and dopamine. A “dual-gate lumen transporter model” for the basolateral monoamine transporters of the kidneys is proposed as being the etiology of the three-phase urinary serotonin and dopamine responses.Purpose: The purpose of this writing is to document the internal renal function model that has evolved in research during large-scale assay with phase interpretation of urinary serotonin and dopamine.Patients and methods: In excess of 75,000 urinary monoamine assays from more than 7,500 patients were analyzed. The serotonin and the dopamine phase were determined for specimens submitted in the competitive inhibition state. The phase determination findings were then correlated with peer-reviewed literature.Results: The correlation between the three-phase response of urinary serotonin and dopamine with internal renal processes of the bilateral monoamine transporter and the apical monoamine transporter of the proximal convoluted renal tubule cells is defined.Conclusion: The phase of urinary serotonin and dopamine is dependent on the status of the serotonin gate, dopamine gate, and lumen of the basolateral monoamine transporter while in the competitive inhibition state.Keywords: serotonin, dopamine, basolateral, apical, kidney, proximal
The CP-odd sector and $θ$ dynamics in holographic QCD
Arean, Daniel; Iatrakis, Ioannis; Jarvinen, Matti; Kiritsis, Elias
2017-01-01
The holographic model of V-QCD is used to analyze the physics of QCD in the Veneziano large-N limit. An unprecedented analysis of the CP-odd physics is performed going beyond the level of effective field theories. The structure of holographic saddle-points at finite $\\theta$ is determined, as well
Holographic entanglement entropy of surface defects
Gentle, Simon A.; Gutperle, Michael; Marasinou, Chrysostomos [Department of Physics and Astronomy, University of California,Los Angeles, CA 90095 (United States)
2016-04-12
We calculate the holographic entanglement entropy in type IIB supergravity solutions that are dual to half-BPS disorder-type surface defects in N=4 supersymmetric Yang-Mills theory. The entanglement entropy is calculated for a ball-shaped region bisected by a surface defect. Using the bubbling supergravity solutions we also compute the expectation value of the defect operator. Combining our result with the previously-calculated one-point function of the stress tensor in the presence of the defect, we adapt the calculation of Lewkowycz and Maldacena http://dx.doi.org/10.1007/JHEP05(2014)025 to obtain a second expression for the entanglement entropy. Our two expressions agree up to an additional term, whose possible origin and significance is discussed.
Holographic entanglement entropy of surface defects
Gentle, Simon A.; Gutperle, Michael; Marasinou, Chrysostomos
2016-01-01
We calculate the holographic entanglement entropy in type IIB supergravity solutions that are dual to half-BPS disorder-type surface defects in N=4 supersymmetric Yang-Mills theory. The entanglement entropy is calculated for a ball-shaped region bisected by a surface defect. Using the bubbling supergravity solutions we also compute the expectation value of the defect operator. Combining our result with the previously-calculated one-point function of the stress tensor in the presence of the defect, we adapt the calculation of Lewkowycz and Maldacena http://dx.doi.org/10.1007/JHEP05(2014)025 to obtain a second expression for the entanglement entropy. Our two expressions agree up to an additional term, whose possible origin and significance is discussed.
Quantum corrections to holographic mutual information
Agón, Cesar A.; Faulkner, Thomas
2016-01-01
We compute the leading contribution to the mutual information (MI) of two disjoint spheres in the large distance regime for arbitrary conformal field theories (CFT) in any dimension. This is achieved by refining the operator product expansion method introduced by Cardy http://dx.doi.org/10.1088/1751-8113/46/28/285402. For CFTs with holographic duals the leading contribution to the MI at long distances comes from bulk quantum corrections to the Ryu-Takayanagi area formula. According to the FLM proposal http://dx.doi.org/10.1007/JHEP11(2013)074 this equals the bulk MI between the two disjoint regions spanned by the boundary spheres and their corresponding minimal area surfaces. We compute this quantum correction and provide in this way a non-trivial check of the FLM proposal.
Understanding the holographic principle via RG flow
Mukhopadhyay, Ayan
2016-01-01
This is a review of some recent works which demonstrate how the classical equations of gravity in AdS themselves hold the key to understanding their holographic origin in the form of a strongly coupled large $N$ QFT whose algebra of local operators can be generated by a few (single-trace) elements. I discuss how this can be realised by reformulating Einstein's equations in AdS in the form of a non-perturbative RG flow that further leads to a new approach towards constructing strongly interacting QFTs. In particular, the RG flow can self-determine the UV data that are otherwise obtained by solving classical gravity equations and demanding that the solutions do not have naked singularities. For a concrete demonstration, I focus on the hydrodynamic limit in which case this RG flow connects the AdS/CFT correspondence with the membrane paradigm, and also reproduces the known values of the dual QFT transport coefficients.
Quantum corrections to holographic mutual information
Agón, Cesar A. [Martin Fisher School of Physics, Brandeis University,Waltham, MA 02453 (United States); Faulkner, Thomas [University of Illinois, Urbana-Champaign,Urbana, IL 61801-3080 (United States)
2016-08-22
We compute the leading contribution to the mutual information (MI) of two disjoint spheres in the large distance regime for arbitrary conformal field theories (CFT) in any dimension. This is achieved by refining the operator product expansion method introduced by Cardy http://dx.doi.org/10.1088/1751-8113/46/28/285402. For CFTs with holographic duals the leading contribution to the MI at long distances comes from bulk quantum corrections to the Ryu-Takayanagi area formula. According to the FLM proposal http://dx.doi.org/10.1007/JHEP11(2013)074 this equals the bulk MI between the two disjoint regions spanned by the boundary spheres and their corresponding minimal area surfaces. We compute this quantum correction and provide in this way a non-trivial check of the FLM proposal.
Holographic bulk reconstruction with α' corrections
Roy, Shubho R.; Sarkar, Debajyoti
2017-10-01
We outline a holographic recipe to reconstruct α' corrections to anti-de Sitter (AdS) (quantum) gravity from an underlying CFT in the strictly planar limit (N →∞ ). Assuming that the boundary CFT can be solved in principle to all orders of the 't Hooft coupling λ , for scalar primary operators, the λ-1 expansion of the conformal dimensions can be mapped to higher curvature corrections of the dual bulk scalar field action. Furthermore, for the metric perturbations in the bulk, the AdS /CFT operator-field isomorphism forces these corrections to be of the Lovelock type. We demonstrate this by reconstructing the coefficient of the leading Lovelock correction, also known as the Gauss-Bonnet term in a bulk AdS gravity action using the expression of stress-tensor two-point function up to subleading order in λ-1.
Constraints on holographic dark energy from type Ia supernova observations
Zhang Xin; Wu Fengquan
2005-01-01
In this paper, we use the type Ia supernovae data to constrain the holographic dark energy model proposed by Li. We also apply a cosmic age test to this analysis. We consider in this paper a spatially flat Friedmann-Robertson-Walker universe with a matter component and a holographic dark energy component. The fit result shows that the case c m 0 =0.28, and h=0.65, which lead to the present equation of state of dark energy w 0 =-1.03 and the deceleration/acceleration transition redshift z T =0.63. Finally, an expected supernova/acceleration probe simulation using ΛCDM as a fiducial model is performed on this model, and the result shows that the holographic dark energy model takes on c<1 (c=0.92) even though the dark energy is indeed a cosmological constant
Slow Steps towards Dual Earner/Dual Carer Family Model: Why Do Fathers Not Take Parental Leave
Marre Karu
2011-06-01
Full Text Available The article looks at the transition of Estonian society towards dual earner/dual carer family model and focuses on fathers’ decision regarding taking their parental leave. Based on theory of planned behaviour by Ajzen, data from 20 qualitative interviews with fathers of small children are analysed to explore the beliefs fathers have when it comes to parental leave. The analysis distinguishes between two images of ‘good parenting’ that play a role in the fathers’ intention to take parental leave. First, there is an image of an outcome-oriented ‘project manager’ aﬀected by failure anxiety, and second, there is a much more relaxed image of a ‘good parent’ as a ‘companion’ who values everyday contact and a close relationship with the child(ren.
Magnonic holographic imaging of magnetic microstructures
Gutierrez, D.; Chiang, H.; Bhowmick, T.; Volodchenkov, A.D.; Ranjbar, M.; Liu, G.; Jiang, C.; Warren, C. [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States); Khivintsev, Y.; Filimonov, Y. [Kotelnikov Institute of Radioengineering and Electronics of Russian Academy of Sciences, Saratov Branch, Saratov 410019 (Russian Federation); Saratov State University, Saratov 410012 (Russian Federation); Garay, J.; Lake, R.; Balandin, A.A. [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States); Khitun, A., E-mail: akhitun@engr.ucr.edu [Department of Electrical and Computer Engineering, University of California - Riverside, Riverside, CA 92521 (United States)
2017-04-15
We propose and demonstrate a technique for magnetic microstructure imaging via their interaction with propagating spin waves. In this approach, the object of interest is placed on top of a magnetic testbed made of material with low spin wave damping. There are micro-antennas incorporated in the testbed. Two of these antennas are used for spin wave excitation while another one is used for the detecting of inductive voltage produced by the interfering spin waves. The measurements are repeated for different phase differences between the spin wave generating antennas which is equivalent to changing the angle of illumination. The collected data appear as a 3D plot – the holographic image of the object. We present experimental data showing magnonic holographic images of a low-coercivity Si/Co sample, a high-coercivity sample made of SrFe{sub 12}O{sub 19} and a diamagnetic copper sample. We also present images of the three samples consisting of a different amount of SrFe{sub 12}O{sub 19} powder. The imaging was accomplished on a Y{sub 3}Fe{sub 2}(FeO{sub 4}){sub 3} testbed at room temperature. The obtained data reveal the unique magnonic signatures of the objects. Experimental data is complemented by the results of numerical modeling, which qualitatively explain the characteristic features of the images. Potentially, magnonic holographic imaging may complement existing techniques and be utilized for non-destructive in-situ magnetic object characterization. The fundamental physical limits of this approach are also discussed. - Highlights: • A technique for magnetic microstructure imaging via their interaction with propagating spin waves is proposed. • In this technique, magnetic structures appear as 3D objects. • Several holographic images of magnetic microstructures are presented.
A holographic waveguide based eye tracker
Liu, Changgeng; Pazzucconi, Beatrice; Liu, Juan; Liu, Lei; Yao, Xincheng
2018-02-01
We demonstrated the feasibility of using holographic waveguide for eye tracking. A custom-built holographic waveguide, a 20 mm x 60 mm x 3 mm flat glass substrate with integrated in- and out-couplers, was used for the prototype development. The in- and out-couplers, photopolymer films with holographic fringes, induced total internal reflection in the glass substrate. Diffractive optical elements were integrated into the in-coupler to serve as an optical collimator. The waveguide captured images of the anterior segment of the eye right in front of it and guided the images to a processing unit distant from the eye. The vector connecting the pupil center (PC) and the corneal reflex (CR) of the eye was used to compute eye position in the socket. An eye model, made of a high quality prosthetic eye, was used prototype validation. The benchtop prototype demonstrated a linear relationship between the angular eye position and the PC/CR vector over a range of 60 horizontal degrees and 30 vertical degrees at a resolution of 0.64-0.69 degrees/pixel by simple pixel count. The uncertainties of the measurements at different angular positions were within 1.2 pixels, which indicated that the prototype exhibited a high level of repeatability. These results confirmed that the holographic waveguide technology could be a feasible platform for developing a wearable eye tracker. Further development can lead to a compact, see-through eye tracker, which allows continuous monitoring of eye movement during real life tasks, and thus benefits diagnosis of oculomotor disorders.
Holographic sensors for diagnostics of solution components
Kraiskii, A V; Suitanov, T T; Postnikov, V A; Khamidulin, A V
2010-01-01
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 -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)
Magnonic holographic imaging of magnetic microstructures
Gutierrez, D.; Chiang, H.; Bhowmick, T.; Volodchenkov, A. D.; Ranjbar, M.; Liu, G.; Jiang, C.; Warren, C.; Khivintsev, Y.; Filimonov, Y.; Garay, J.; Lake, R.; Balandin, A. A.; Khitun, A.
2017-04-01
We propose and demonstrate a technique for magnetic microstructure imaging via their interaction with propagating spin waves. In this approach, the object of interest is placed on top of a magnetic testbed made of material with low spin wave damping. There are micro-antennas incorporated in the testbed. Two of these antennas are used for spin wave excitation while another one is used for the detecting of inductive voltage produced by the interfering spin waves. The measurements are repeated for different phase differences between the spin wave generating antennas which is equivalent to changing the angle of illumination. The collected data appear as a 3D plot - the holographic image of the object. We present experimental data showing magnonic holographic images of a low-coercivity Si/Co sample, a high-coercivity sample made of SrFe12O19 and a diamagnetic copper sample. We also present images of the three samples consisting of a different amount of SrFe12O19 powder. The imaging was accomplished on a Y3Fe2(FeO4)3 testbed at room temperature. The obtained data reveal the unique magnonic signatures of the objects. Experimental data is complemented by the results of numerical modeling, which qualitatively explain the characteristic features of the images. Potentially, magnonic holographic imaging may complement existing techniques and be utilized for non-destructive in-situ magnetic object characterization. The fundamental physical limits of this approach are also discussed.
Computer assisted holographic moire contouring
Sciammarella, Cesar A.
2000-01-01
Theoretical analyses and experimental results on holographic moire contouring on diffusely reflecting objects are presented. The sensitivity and limitations of the method are discussed. Particular emphasis is put on computer-assisted data retrieval, processing, and recording.
Model-based crosstalk compensation in simultaneous dual isotope SPECT
Frey, E.C.; Tsui, B.M.W.; Du, A.Y.; Song, X.Y.
2002-01-01
Simultaneous dual isotope imaging has the potential of allowing imaging of two different physiological processes at the same time. Two examples are Tc-99m stress and Tl-201 rest myocardial perfusion imaging and Tc-99m perfusion and I-123 neuroreceptor brain imaging. However, for both of these cases crosstalk is a significant problem that results in degradation of the simultaneously acquired images. For the Tc-99m and Tl-201 case, the crosstalk includes downscatter and the generation of Pb x-rays detected in the Tl-201 energy window. For the Tc-99m/I-123 case, the crosstalk includes overlap of the two photopeaks, downscatter, especially of the 159 keV photons into the Tc-99m energy window, and contamination of the images of both isotopes by low abundance, high-energy I-123 photons. We have developed methods to accurately model the crosstalk in both cases. For the Tc-99m/Tl-201 case, the crosstalk model uses a previously described method for modeling scatter, effective source scatter estimation (ESSE). The scatter estimates are combined with a parameterization of the Pb x-ray response of the collimator to estimate the crosstalk. For the I-123/Tc-99m case we combine ESSE with a MC simulated collimator scatter and penetration responses to model the contamination due to the high-energy photons from I-123. In both cases the crosstalk models have been incorporated into an iterative reconstruction procedure that allows simultaneous reconstruction of the activity distributions from two isotopes including crosstalk compensation We have evaluated these methods both by Monte Carlo simulation studies and using physical phantom experiments. We find that the methods perform well and produce images with a quality and contrast approaching that of separately acquired images. However, the compensated simultaneously acquired images do have an increase in image noise. To reduce the noise we have applied ideal observer methodology to determine optimal energy windows and relative
Holographic cutoff on inflationary universes
Santos, Fabio M. de N.; Cunha, Bruno Carneiro da
2011-01-01
Full text: Cosmological Inflation has been widely accepted as the standard explanation of the onset of Big-Bang Cosmology. However, many critiques have been made about the lack of an account of quantum gravity degrees of freedom in cosmology. There is no definite consensus in the literature if we should consider the influence of pre-Plackian modes, for example, in inflationary models. We propose here a general approach to take quantum gravity into account by imposing a holographic cutoff on the number of states of cosmological theories. We apply the method to inflationary scalar field models coupled to a generic potential V (φ). This thermodynamic cutoff allow us to assess the relative volume of phase space which inflates for the particular model where V (φ) = m 2 φ 2 /2. The density of states of the model is defined by taking the coincidence limit of the Hadamard Green function G (1) and we use the point-splitting method to regulate the expression. Our conclusion is that inflation has probability very close to one. (author)
Khoury, Justin; Parikh, Maulik
2009-01-01
Mach's principle is the proposition that inertial frames are determined by matter. We put forth and implement a precise correspondence between matter and geometry that realizes Mach's principle. Einstein's equations are not modified and no selection principle is applied to their solutions; Mach's principle is realized wholly within Einstein's general theory of relativity. The key insight is the observation that, in addition to bulk matter, one can also add boundary matter. Given a space-time, and thus the inertial frames, we can read off both boundary and bulk stress tensors, thereby relating matter and geometry. We consider some global conditions that are necessary for the space-time to be reconstructible, in principle, from bulk and boundary matter. Our framework is similar to that of the black hole membrane paradigm and, in asymptotically anti-de Sitter space-times, is consistent with holographic duality.
Holographic Chiral Magnetic Spiral
Kim, Keun-Young; Sahoo, Bindusar; Yee, Ho-Ung
2010-06-01
We study the ground state of baryonic/axial matter at zero temperature chiral-symmetry broken phase under a large magnetic field, in the framework of holographic QCD by Sakai-Sugimoto. Our study is motivated by a recent proposal of chiral magnetic spiral phase that has been argued to be favored against previously studied phase of homogeneous distribution of axial/baryonic currents in terms of meson super-currents dictated by triangle anomalies in QCD. Our results provide an existence proof of chiral magnetic spiral in strong coupling regime via holography, at least for large axial chemical potentials, whereas we don't find the phenomenon in the case of purely baryonic chemical potential. (author)
Dual permeability FEM models for distributed fiber optic sensors development
Aguilar-López, Juan Pablo; Bogaard, Thom
2017-04-01
Fiber optic cables are commonly known for being robust and reliable mediums for transferring information at the speed of light in glass. Billions of kilometers of cable have been installed around the world for internet connection and real time information sharing. Yet, fiber optic cable is not only a mean for information transfer but also a way to sense and measure physical properties of the medium in which is installed. For dike monitoring, it has been used in the past for detecting inner core and foundation temperature changes which allow to estimate water infiltration during high water events. The DOMINO research project, aims to develop a fiber optic based dike monitoring system which allows to directly sense and measure any pore pressure change inside the dike structure. For this purpose, questions like which location, how many sensors, which measuring frequency and which accuracy are required for the sensor development. All these questions may be initially answered with a finite element model which allows to estimate the effects of pore pressure change in different locations along the cross section while having a time dependent estimation of a stability factor. The sensor aims to monitor two main failure mechanisms at the same time; The piping erosion failure mechanism and the macro-stability failure mechanism. Both mechanisms are going to be modeled and assessed in detail with a finite element based dual permeability Darcy-Richards numerical solution. In that manner, it is possible to assess different sensing configurations with different loading scenarios (e.g. High water levels, rainfall events and initial soil moisture and permeability conditions). The results obtained for the different configurations are later evaluated based on an entropy based performance evaluation. The added value of this kind of modelling approach for the sensor development is that it allows to simultaneously model the piping erosion and macro-stability failure mechanisms in a time
Compact Holographic Data Storage
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.
Nontopological bare solutions in the relativistic self-dual Maxwell-Chern-Simons-Higgs model
Han, Jongmin; Jang, Jaeduk
2005-01-01
In this paper we prove the existence of the radially symmetric nontopological bare solutions in the relativistic self-dual Maxwell-Chern-Simons-Higgs model. We also verify the Chern-Simons limit for those solutions
Model predictive control for a dual active bridge inverter with a floating bridge
Chowdhury, Shajjad; Wheeler, Patrick W.; Gerada, C.; Patel, Chintan
2016-01-01
This paper presents a Model Predictive Control technique applied to a dual active bridge inverter where one of the bridges is floating. The proposed floating bridge topology eliminates the need for isolation transformer in a dual inverter system and therefore reduces the size, weight and losses in the system. To achieve multilevel output voltage waveforms the floating inverter DC link capacitor is charged to the half of the main DC link voltage. A finite-set Model Predictive Control technique...
E. Majchrzak
2008-12-01
Full Text Available The dual reciprocity boundary element method is applied for numerical modelling of solidification process. This variant of the BEM is connected with the transformation of the domain integral to the boundary integrals. In the paper the details of the dual reciprocity boundary element method are presented and the usefulness of this approach to solidification process modelling is demonstrated. In the final part of the paper the examples of computations are shown.
Quark-parton model from dual topological unitarization
Cohen-Tannoudji, G.; El Hassouni, A.; Kalinowski, J.; Peschanski, R.
1979-01-01
Topology, which occurs in the topological expansion of quantum chromodynamics (QCD) and in the dual topological unitarization (DTU) schemes, allows us to establish a quantitative correspondence between QCD and the dual S-matrix approaches. This topological correspondence, proposed by Veneziano and made more explicit in a recent paper for current-induced reactions, provides a clarifying and unifying quark-parton interpretation of soft inclusive processes. Precise predictions for inclusive cross sections in hadron-hadron collisions, structure functions of hadrons, and quark fragmentation functions including absolute normalizations are shown to agree with data. On a more theoretical ground the proposed scheme suggests a new approach to the confinement problem
Pricing Model for Dual Sales Channel with Promotion Effect Consideration
Chuiri Zhou
2016-01-01
We focus on the pricing strategy of a dual sales channel member when his/her online retailer faces an upcoming overloaded express delivery service due to the sales peak of online shopping, especially referring to the occurring affairs in China. We characterize the pricing problem of the dual selling channel system as a two-period game. When the price discount is only provided by the online seller, we find that the prices of the traditional channel and the online channel in the two periods are...
Illustrated study of the semi-holographic non-perturbative framework
Banerjee, Souvik; Gaddam, Nava; Mukhopadhyay, Ayan
2017-01-01
Semi-holography has been proposed as an effective nonperturbative framework which can combine perturbative and nonperturbative effects consistently for theories like QCD. It is postulated that the strongly coupled nonperturbative sector has a holographic dual in the form of a classical gravity
Modeling and Control of a Dual-Input Isolated Full-Bridge Boost Converter
Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.
2012-01-01
In this paper, a steady-state model, a large-signal (LS) model and an ac small-signal (SS) model for a recently proposed dual-input transformer-isolated boost converter are derived respectively by the switching flow-graph (SFG) nonlinear modeling technique. Based upon the converter’s model...
Applied string theory, hot and cold. A holographic view on quark-gluon plasma and superfluids
Samberg, Andreas Wilhelm
2015-12-21
This thesis deals with applications of gauge/gravity duality to strong-coupling phenomena in the quark-gluon plasma and far-from-equilibrium superfluids. In a first part we search for model-independent (universal) behavior in various non-Abelian gauge-theory plasmas at finite temperature and chemical potential. We employ the holographic duals of strongly coupled N=4 supersymmetric Yang-Mills theory and three one-parameter families of non-conformal deformations thereof, two of which solve the equations of motion of a five-dimensional Einstein-Maxwell-scalar action. We study the free energy and associated thermodynamic quantities of heavy quarks and bound quark-anti-quark (Q anti Q) pairs as well as the Q anti Q binding energy and the running coupling. We find qualitative agreement with available lattice QCD data. Moreover, we show that several observables exhibit universal behavior for all values of the chemical potential. In a second part we investigate the real-time dynamics of a bosonic superfluid in two spatial dimensions after initial quenches that take the system to far-from-equilibrium states characterized by many topological vortex defects in association with quantum turbulence. To this end we numerically solve the full equations of motion of the holographically dual Abelian Higgs model on four-dimensional anti-de Sitter space. We observe a universal non-equilibrium late-time regime characterized by power-law behavior in a two-point correlation function and in characteristic length scales, which we interpret as a non-thermal fixed point.
Applied string theory, hot and cold. A holographic view on quark-gluon plasma and superfluids
Samberg, Andreas Wilhelm
2015-01-01
This thesis deals with applications of gauge/gravity duality to strong-coupling phenomena in the quark-gluon plasma and far-from-equilibrium superfluids. In a first part we search for model-independent (universal) behavior in various non-Abelian gauge-theory plasmas at finite temperature and chemical potential. We employ the holographic duals of strongly coupled N=4 supersymmetric Yang-Mills theory and three one-parameter families of non-conformal deformations thereof, two of which solve the equations of motion of a five-dimensional Einstein-Maxwell-scalar action. We study the free energy and associated thermodynamic quantities of heavy quarks and bound quark-anti-quark (Q anti Q) pairs as well as the Q anti Q binding energy and the running coupling. We find qualitative agreement with available lattice QCD data. Moreover, we show that several observables exhibit universal behavior for all values of the chemical potential. In a second part we investigate the real-time dynamics of a bosonic superfluid in two spatial dimensions after initial quenches that take the system to far-from-equilibrium states characterized by many topological vortex defects in association with quantum turbulence. To this end we numerically solve the full equations of motion of the holographically dual Abelian Higgs model on four-dimensional anti-de Sitter space. We observe a universal non-equilibrium late-time regime characterized by power-law behavior in a two-point correlation function and in characteristic length scales, which we interpret as a non-thermal fixed point.
A fuzzy-stochastic power system planning model: Reflection of dual objectives and dual uncertainties
Zhang, X.Y.; Huang, G.H.; Zhu, H.; Li, Y.P.
2017-01-01
In this study, a fuzzy stochastic dynamic fractional programming (FSDFP) method is proposed for supporting sustainable management of electric power system (EPS) under dual uncertainties. As an improvement upon the mixed-integer linear fractional programming, FSDFP can not only tackle multi-objective issues effectively without setting weights, but also can deal with uncertain parameters which have both stochastic and fuzzy characteristics. Thus, the developed method can help provide valuable information for supporting capacity-expansion planning and in-depth policy analysis of EPS management problems. For demonstrating these advantages, FSDFP has been applied to a case study of a typical regional EPS planning, where the decision makers have to deal with conflicts between economic development that maximizes the system profit and environmental protection that minimizes the carbon dioxide emissions. The obtained results can be analyzed to generate several decision alternatives, and can then help decision makers make suitable decisions under different input scenarios. Furthermore, comparisons of the solution from FSDFP method with that from fuzzy stochastic dynamic linear programming, linear fractional programming and dynamic stochastic fractional programming methods are undertaken. The contrastive analysis reveals that FSDFP is a more effective approach that can better characterize the complexities and uncertainties of real EPS management problems. - Highlights: • A fuzzy stochastic dynamic fractional programming (FSDFP) method is proposed. • FSDFP can address multiple conflicting objectives without setting weights. • FSDFP can reflect dual uncertainties with both stochastic and fuzzy characteristics. • Some reasonable solutions for a case of power system sustainable planning are generated. • Comparisons of the solutions from FSDFP with other optimization methods are undertaken.
Holographic dark energy with cosmological constant
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.
Holographic dark energy with cosmological constant
Hu, Yazhou; Li, Nan; Zhang, Zhenhui [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, 100190 (China); Li, Miao, E-mail: asiahu@itp.ac.cn, E-mail: mli@itp.ac.cn, E-mail: linan@itp.ac.cn, E-mail: zhangzhh@mail.ustc.edu.cn [School of Astronomy and Space Science, Sun Yat-Sen University, Guangzhou 510275 (China)
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 Ω{sub hde} 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 χ{sup 2}{sub min}=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<Ω{sub Λ0}<0.68 and correspondingly 0.04<Ω{sub hde0}<0.79, implying at present there is considerable degeneracy between the holographic dark energy and cosmological constant components in the ΛHDE model.
Holographic dark energy with cosmological constant
Hu, Yazhou; Li, Nan; Zhang, Zhenhui; Li, Miao
2015-01-01
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 Ω hde 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 χ 2 min =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<Ω Λ0 <0.68 and correspondingly 0.04<Ω hde0 <0.79, implying at present there is considerable degeneracy between the holographic dark energy and cosmological constant components in the ΛHDE model
Katsioloudis, Petros J.; Jones, Mildred V.
2018-01-01
A number of studies indicate that the use of holographic displays can influence spatial visualization ability; however, research provides inconsistent results. Considering this, a quasi-experimental study was conducted to identify the existence of statistically significant effects on sectional view drawing ability due to the impacts of holographic…
Direct Evidence for a Dual Process Model of Deductive Inference
Markovits, Henry; Brunet, Marie-Laurence; Thompson, Valerie; Brisson, Janie
2013-01-01
In 2 experiments, we tested a strong version of a dual process theory of conditional inference (cf. Verschueren et al., 2005a, 2005b) that assumes that most reasoners have 2 strategies available, the choice of which is determined by situational variables, cognitive capacity, and metacognitive control. The statistical strategy evaluates inferences…
AC conductivity for a holographic Weyl semimetal
Grignani, Gianluca; Marini, Andrea; Peña-Benitez, Francisco; Speziali, Stefano [Dipartimento di Fisica e Geologia, Università di Perugia,I.N.F.N. Sezione di Perugia,Via Pascoli, I-06123 Perugia (Italy)
2017-03-23
We study the AC electrical conductivity at zero temperature in a holographic model for a Weyl semimetal. At small frequencies we observe a linear dependence in the frequency. The model shows a quantum phase transition between a topological semimetal (Weyl semimetal phase) with a non vanishing anomalous Hall conductivity and a trivial semimetal. The AC conductivity has an intermediate scaling due to the presence of a quantum critical region in the phase diagram of the system. The phase diagram is reconstructed using the scaling properties of the conductivity. We compare with the experimental data of https://www.doi.org/10.1103/PhysRevB.93.121110 obtaining qualitative agreement.
Fluctuations and instabilities of a holographic metal
Jokela, Niko; Järvinen, Matti; Lippert, Matthew
2013-02-01
We analyze the quasinormal modes of the D2-D8' model of 2+1-dimensional, strongly-coupled, charged fermions in a background magnetic field and at non-zero density. The model is known to include a quantum Hall phase with integer filling fraction. As expected, we find a hydrodynamical diffusion mode at small momentum and the nonzero-temperature holographic zero sound, which becomes massive above a critical magnetic field. We confirm the previously-known thermodynamic instability. In addition, we discover an instability at low temperature, large mass, and in a charge density and magnetic field range near the quantum Hall phase to an inhomogeneous striped phase.
Holographic QCD beyond the leading order
Kim, Youngman; Ko, P.; Wu, Xiao-Hong
2008-01-01
We consider a holographic QCD model for light mesons beyond the leading order in the context of 5-dim gauged linear sigma model on the interval in the AdS 5 space. We include two dimension-6 operators in addition to the canonical bulk kinetic terms, and study chiral dynamics of π, ρ, a 1 and some of their KK modes. As novel features of dim-6 operators, we get non-vanishing Br(a 1 → πγ), the electromagnetic form factor and the charge radius of a charged pion, which improve the leading order results significantly and agree well with the experimental results.
Connection between Einstein equations, nonlinear sigma models, and self-dual Yang-Mills theory
Sanchez, N.; Whiting, B.
1986-01-01
The authors analyze the connection between nonlinear sigma models self-dual Yang-Mills theory, and general relativity (self-dual and non-self-dual, with and without killing vectors), both at the level of the equations and at the level of the different type of solutions (solitons and calorons) of these theories. They give a manifestly gauge invariant formulation of the self-dual gravitational field analogous to that given by Yang for the self-dual Yang-Mills field. This formulation connects in a direct and explicit way the self-dual Yang-Mills and the general relativity equations. They give the ''R gauge'' parametrization of the self-dual gravitational field (which corresponds to modified Yang's-type and Ernst equations) and analyze the correspondence between their different types of solutions. No assumption about the existence of symmetries in the space-time is needed. For the general case (non-self-dual), they show that the Einstein equations contain an O nonlinear sigma model. This connection with the sigma model holds irrespective of the presence of symmetries in the space-time. They found a new class of solutions of Einstein equations depending on holomorphic and antiholomorphic functions and we relate some subclasses of these solutions to solutions of simpler nonlinear field equations that are well known in other branches of physics, like sigma models, SineGordon, and Liouville equations. They include gravitational plane wave solutions. They analyze the response of different accelerated quantum detector models, compare them to the case when the detectors are linterial in an ordinary Planckian gas at a given temperature, and discuss the anisotropy of the detected response for Rindler observers
Physically based model for extracting dual permeability parameters using non-Newtonian fluids
Abou Najm, M. R.; Basset, C.; Stewart, R. D.; Hauswirth, S.
2017-12-01
Dual permeability models are effective for the assessment of flow and transport in structured soils with two dominant structures. The major challenge to those models remains in the ability to determine appropriate and unique parameters through affordable, simple, and non-destructive methods. This study investigates the use of water and a non-Newtonian fluid in saturated flow experiments to derive physically-based parameters required for improved flow predictions using dual permeability models. We assess the ability of these two fluids to accurately estimate the representative pore sizes in dual-domain soils, by determining the effective pore sizes of macropores and micropores. We developed two sub-models that solve for the effective macropore size assuming either cylindrical (e.g., biological pores) or planar (e.g., shrinkage cracks and fissures) pore geometries, with the micropores assumed to be represented by a single effective radius. Furthermore, the model solves for the percent contribution to flow (wi) corresponding to the representative macro and micro pores. A user-friendly solver was developed to numerically solve the system of equations, given that relevant non-Newtonian viscosity models lack forms conducive to analytical integration. The proposed dual-permeability model is a unique attempt to derive physically based parameters capable of measuring dual hydraulic conductivities, and therefore may be useful in reducing parameter uncertainty and improving hydrologic model predictions.
Covariant generalized holographic dark energy and accelerating universe
Nojiri, Shin' ichi [Nagoya University, Department of Physics, Nagoya (Japan); Nagoya University, Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya (Japan); Odintsov, S.D. [ICREA, Barcelona (Spain); Institute of Space Sciences (IEEC-CSIC), Barcelona (Spain); National Research Tomsk State University, Tomsk (Russian Federation); Tomsk State Pedagogical University, Tomsk (Russian Federation)
2017-08-15
We propose the generalized holographic dark energy model where the infrared cutoff is identified with the combination of the FRW universe parameters: the Hubble rate, particle and future horizons, cosmological constant, the universe lifetime (if finite) and their derivatives. It is demonstrated that with the corresponding choice of the cutoff one can map such holographic dark energy to modified gravity or gravity with a general fluid. Explicitly, F(R) gravity and the general perfect fluid are worked out in detail and the corresponding infrared cutoff is found. Using this correspondence, we get realistic inflation or viable dark energy or a unified inflationary-dark energy universe in terms of covariant holographic dark energy. (orig.)
Covariant generalized holographic dark energy and accelerating universe
Nojiri, Shin'ichi; Odintsov, S.D.
2017-01-01
We propose the generalized holographic dark energy model where the infrared cutoff is identified with the combination of the FRW universe parameters: the Hubble rate, particle and future horizons, cosmological constant, the universe lifetime (if finite) and their derivatives. It is demonstrated that with the corresponding choice of the cutoff one can map such holographic dark energy to modified gravity or gravity with a general fluid. Explicitly, F(R) gravity and the general perfect fluid are worked out in detail and the corresponding infrared cutoff is found. Using this correspondence, we get realistic inflation or viable dark energy or a unified inflationary-dark energy universe in terms of covariant holographic dark energy. (orig.)
Higher-curvature corrections to holographic entanglement with momentum dissipation
Tanhayi, M.R. [Islamic Azad University Central Tehran Branch (IAUCTB), Department of Physics, Faculty of Basic Science, Tehran (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Physics, Tehran (Iran, Islamic Republic of); Vazirian, R. [Islamic Azad University Central Tehran Branch (IAUCTB), Department of Physics, Faculty of Basic Science, Tehran (Iran, Islamic Republic of)
2018-02-15
We study the effects of Gauss-Bonnet corrections on some nonlocal probes (entanglement entropy, n-partite information and Wilson loop) in the holographic model with momentum relaxation. Higher-curvature terms as well as scalar fields make in fact nontrivial corrections to the coefficient of the universal term in entanglement entropy. We use holographic methods to study such corrections. Moreover, holographic calculation indicates that mutual and tripartite information undergo a transition beyond which they identically change their values. We find that the behavior of the transition curves depends on the sign of the Gauss-Bonnet coupling λ. The transition for λ > 0 takes place in larger separation of subsystems than that of λ < 0. Finally, we examine the behavior of modified part of the force between external point-like objects as a function of Gauss-Bonnet coupling and its sign. (orig.)
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. © 2011 Optical Society of America
Holographic Fermions in Anisotropic Einstein-Maxwell-Dilaton-Axion Theory
Kuang, Xiao-Mei; Fang, Li-Qing
2015-01-01
We investigate the properties of the holographic Fermionic system dual to an anisotropic charged black brane bulk in Einstein-Maxwell-Dilaton-Axion gravity theory. We consider the minimal coupling between the Dirac field and the gauge field in the bulk gravity theory and mainly explore the dispersion relation exponents of the Green functions of the dual Fermionic operators in the dual field theory. We find that along both the anisotropic and the isotropic directions the Fermi momentum will be effected by the anisotropy of the bulk theory. However, the anisotropy has influence on the dispersion relation which is almost linear for massless Fermions with charge q=2. The universal properties that the mass and the charge of the Fermi possibly correspond to nonlinear dispersion relation are also investigated
Probabilistic Modeling of Seismic Risk Based Design for a Dual System Structure
Sidi, Indra Djati
2017-01-01
The dual system structure concept has gained popularity in the construction of high-rise buildings over the last decades. Meanwhile, earthquake engineering design provisions for buildings have moved from the uniform hazard concept to the uniform risk concept upon recognizing the uncertainties involved in the earthquake resistance of concrete structures. In this study, a probabilistic model for the evaluation of such risk is proposed for a dual system structure consisting of shear walls or cor...
Modeling and simulation of a dual-junction CIGS solar cell using Silvaco ATLAS
Fotis, Konstantinos
2012-01-01
Approved for public release; distribution is unlimited. The potential of designing a dual-junction Copper Indium Gallium Selenide (CIGS) photovoltaic cell is investigated in this thesis. Research into implementing a dual-junction solar cell, using a CIGS bottom cell and different thin-film designs as a top cell, was conducted in order to increase the current record efficiency of 20.3% for a single CIGS cell. This was accomplished through modeling and simulation using Silvaco ATLASTM, an ad...
Estimating dual deposit insurance premium rates and forecasting non-performing loans: Two new models
Yoshino, Naoyuki; Taghizadeh-Hesary, Farhad; Nili, Farhad
2015-01-01
Risky banks that endanger the stability of the financial system should pay higher deposit insurance premiums than healthy banks and other financial institutions that have shown good financial performance. It is necessary, therefore, to have at least a dual fair premium rate system. In this paper, we develop a model for calculating dual fair premium rates. Our definition of a fair premium rate in this paper is a rate that could cover the operational expenditures of the deposit insuring organiz...
The dual-electrode DC arc furnace-modelling brush arc conditions
Reynolds, Q.G.
2012-01-01
The dual-electrode DC arc furnace, an alternative design using an anode and cathode electrode instead of a hearth anode, was studied at small scale using computational modelling methods. Particular attention was paid to the effect of two key design variables, the arc length and the electrode separation, on the furnace behaviour. It was found that reducing the arc length to brush arc conditions was a valid means of overcoming several of the limitations of the dual-electrode design, namely high...
Theta dependence in holographic QCD
Bartolini, Lorenzo [Dipartimento di Fisica “E. Fermi' , Università di Pisa and INFN, Sezione di Pisa,Largo B. Pontecorvo 3, I-56127 Pisa (Italy); Bigazzi, Francesco [INFN, Sezione di Firenze,Via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Bolognesi, Stefano [Dipartimento di Fisica “E. Fermi' , Università di Pisa and INFN, Sezione di Pisa,Largo B. Pontecorvo 3, I-56127 Pisa (Italy); Cotrone, Aldo L. [INFN, Sezione di Firenze,Via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze,Via G. Sansone 1, I-50019 Sesto Fiorentino (Firenze) (Italy); Manenti, Andrea [Institute of Physics, EPFL,Rte de la Sorge, BSP 728, CH-1015 Lausanne (Switzerland)
2017-02-07
We study the effects of the CP-breaking topological θ-term in the large N{sub c} QCD model by Witten, Sakai and Sugimoto with N{sub f} degenerate light flavors. We first compute the ground state energy density, the topological susceptibility and the masses of the lowest lying mesons, finding agreement with expectations from the QCD chiral effective action. Then, focusing on the N{sub f}=2 case, we consider the baryonic sector and determine, to leading order in the small θ regime, the related holographic instantonic soliton solutions. We find that while the baryon spectrum does not receive O(θ) corrections, this is not the case for observables like the electromagnetic form factor of the nucleons. In particular, it exhibits a dipole term, which turns out to be vector-meson dominated. The resulting neutron electric dipole moment, which is exactly the opposite as that of the proton, is of the same order of magnitude of previous estimates in the literature. Finally, we compute the CP-violating pion-nucleon coupling constant ḡ{sub πNN}, finding that it is zero to leading order in the large N{sub c} limit.
Holographic superconductor in the analytic hairy black hole
Myung, Yun Soo; Park, Chanyong
2011-01-01
We study the charged black hole of hyperbolic horizon with scalar hair (charged Martinez-Troncoso-Zanelli: CMTZ black hole) as a model of analytic hairy black hole for holographic superconductor. For this purpose, we investigate the second order phase transition between CMTZ and hyperbolic Reissner-Nordstroem-AdS (HRNAdS) black holes. However, this transition unlikely occurs. As an analytic treatment for holographic superconductor, we develop superconductor in the bulk and superfluidity on the boundary using the CMTZ black hole below the critical temperature. The presence of charge destroys the condensates around the zero temperature, which is in accord with the thermodynamic analysis of the CMTZ black hole.
Models of color confinement based on dual superconductors
Ripka, Georges; Hosek, Jiri
2003-01-01
Recently, the relatively old speculation that the physical QCD vacuum might be a kind of dual superconductor, in which color-magnetic monopoles have condensed, seems to have received some 'experimental' confirmation in lattice calculations. The lattice calculations do not dictate, however, the form of the effective low-energy theory. And indeed, a rather wide panoply of possible effective theories has been proposed. The purpose of this talk is to review them in order to contrast their properties
Modeling of dual cylinder wind-up extensional rheometers
Yu, Kaijia; Marin, Jose; Jensen, Mette
measurements are useful for polymer characterization. The Sentmanat extensional Rheometer[1] is an new testing platform for the study of polymers and elastomers in extensional flow. This technique employs a dual wind-up drum technique to perform an uni-axial extensional deformation during experiments......). *The title of this submission has been modified to remove the name of a commercial product or company to bring the title into compliance with SOR policy....
Thermalization in a holographic confining gauge theory
Ishii, Takaaki; Kiritsis, Elias; Rosen, Christopher
2015-01-01
Time dependent perturbations of states in the holographic dual of a 3+1 dimensional confining theory are considered. The perturbations are induced by varying the coupling to the theory’s most relevant operator. The dual gravitational theory belongs to a class of Einstein-dilaton theories which exhibit a mass gap at zero temperature and a first order deconfining phase transition at finite temperature. The perturbation is realized in various thermal bulk solutions by specifying time dependent boundary conditions on the scalar, and we solve the fully backreacted Einstein-dilaton equations of motion subject to these boundary conditions. We compute the characteristic time scale of many thermalization processes, noting that in every case we examine, this time scale is determined by the imaginary part of the lowest lying quasi-normal mode of the final state black brane. We quantify the dependence of this final state on parameters of the quench, and construct a dynamical phase diagram. Further support for a universal scaling regime in the abrupt quench limit is provided.
Thermalization in a holographic confining gauge theory
Ishii, Takaaki; Kiritsis, Elias; Rosen, Christopher
2015-08-01
Time dependent perturbations of states in the holographic dual of a 3+1 dimensional confining theory are considered. The perturbations are induced by varying the coupling to the theory's most relevant operator. The dual gravitational theory belongs to a class of Einstein-dilaton theories which exhibit a mass gap at zero temperature and a first order deconfining phase transition at finite temperature. The perturbation is realized in various thermal bulk solutions by specifying time dependent boundary conditions on the scalar, and we solve the fully backreacted Einstein-dilaton equations of motion subject to these boundary conditions. We compute the characteristic time scale of many thermalization processes, noting that in every case we examine, this time scale is determined by the imaginary part of the lowest lying quasi-normal mode of the final state black brane. We quantify the dependence of this final state on parameters of the quench, and construct a dynamical phase diagram. Further support for a universal scaling regime in the abrupt quench limit is provided.
Nonvolatile Rad-Hard Holographic Memory
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.
Gauge invariance and holographic renormalization
Keun-Young Kim
2015-10-01
Full Text Available We study the gauge invariance of physical observables in holographic theories under the local diffeomorphism. We find that gauge invariance is intimately related to the holographic renormalization: the local counter terms defined in the boundary cancel most of gauge dependences of the on-shell action as well as the divergences. There is a mismatch in the degrees of freedom between the bulk theory and the boundary one. We resolve this problem by noticing that there is a residual gauge symmetry (RGS. By extending the RGS such that it satisfies infalling boundary condition at the horizon, we can understand the problem in the context of general holographic embedding of a global symmetry at the boundary into the local gauge symmetry in the bulk.
A Dual-Process Model of the Alcohol-Behavior Link for Social Drinking
Moss, Antony C.; Albery, Ian P.
2009-01-01
A dual-process model of the alcohol-behavior link is presented, synthesizing 2 of the major social-cognitive approaches: expectancy and myopia theories. Substantial evidence has accrued to support both of these models, and recent neurocognitive models of the effects of alcohol on thought and behavior have provided evidence to support both as well.…
Logical Reasoning versus Information Processing in the Dual-Strategy Model of Reasoning
Markovits, Henry; Brisson, Janie; de Chantal, Pier-Luc
2017-01-01
One of the major debates concerning the nature of inferential reasoning is between counterexample-based strategies such as mental model theory and statistical strategies underlying probabilistic models. The dual-strategy model, proposed by Verschueren, Schaeken, & d'Ydewalle (2005a, 2005b), which suggests that people might have access to both…
Magnetic properties of confined holographic QCD
Bergman, Oren; Lifschytz, Gilad; Lippert, Matthew
2013-12-01
We investigate the Sakai-Sugimoto model at nonzero baryon chemical potential in a background magnetic field in the confined phase where chiral symmetry is broken. The D8-brane Chern-Simons term holographically encodes the axial anomaly and generates a gradient of the η' meson, which carries a non-vanishing baryon charge. Above a critical value of the chemical potential, there is a second-order phase transition to a mixed phase which includes also ordinary baryonic matter. However, at fixed baryon charge density, the matter is purely η'-gradient above a critical magnetic field.
Phase-measuring laser holographic interferometer for use in high speed flows
Yanta, William J.; Spring, W. Charles, III; Gross, Kimberly Uhrich; McArthur, J. Craig
Phase-measurement techniques have been applied to a dual-plate laser holographic interferometer (LHI). This interferometer has been used to determine the flowfield densities in a variety of two-dimensional and axisymmetric flows. In particular, LHI has been applied in three different experiments: flowfield measurements inside a two-dimensional scramjet inlet, flow over a blunt cone, and flow over an indented nose shape. Comparisons of experimentally determined densities with computational results indicate that, when phase-measurement techniques are used in conjunction with state-of-the-art image-processing instrumentation, holographic interferometry can be a diagnostic tool with high resolution, high accuracy, and rapid data retrieval.
Holographic inspection of nuclear plant
Gordon, A.L.; Armour, I.A.; Glanville, R.; Malcolm, G.J.; Wright, D.G.
1988-01-01
The high resolution, enormous depth of field and high tolerance to radiation of holography mean that it has great potential as an inspection tool in the nuclear industry. In addition, the ability of double-pulse holography to yield detailed information on vibration over the whole field of both large and small structures provides measurements that often cannot be obtained in any other way. This paper reviews the development of equipment for the holographic inspection of nuclear fuel elements; a portable holocamera for use inside reactors; and the application of holographic techniques for vibration measurements in a nuclear power station. (author)
Information retrieval from holographic interferograms: Fundamentals and problems
Vest, Charles M.
1987-01-01
Holographic interferograms can contain large amounts of information about flow and temperature fields. Their information content can be very high because they can be viewed from many different directions. This multidirectionality, and fringe localization add to the information contained in the fringe pattern if diffuse illumination is used. Additional information, and increased accuracy can be obtained through the use of dual reference wave holography to add reference fringes or to effect discrete phase shift or hetrodyne interferometry. Automated analysis of fringes is possible if interferograms are of simple structure and good quality. However, in practice a large number of practical problems can arise, so that a difficult image processing task results.
Holographic entanglement entropy for gravitational anomaly in four dimensions
Ali, Tibra [Perimeter Institute for Theoretical Physics, 31 Caroline Street N., Waterloo, ON N2L 2Y5 (Canada); Haque, S. Shajidul [Laboratory for Quantum Gravity & Strings, Department of Mathematics & Applied Mathematics,University of Cape Town, Mathematics Building, Rondebosch, Cape Town, 7700 (South Africa); Murugan, Jeff [Laboratory for Quantum Gravity & Strings, Department of Mathematics & Applied Mathematics,University of Cape Town, Mathematics Building, Rondebosch, Cape Town, 7700 (South Africa); School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr., Princeton, NJ 08540 (United States)
2017-03-15
We compute the holographic entanglement entropy for the anomaly polynomial TrR{sup 2} in 3+1 dimensions. Using the perturbative method developed for computing entanglement entropy for quantum field theories, we also compute the parity odd contribution to the entanglement entropy of the dual field theory that comes from a background gravitational Chern-Simons term. We find that, in leading order in the perturbation of the background geometry, the two contributions match except for a logarithmic divergent term on the field theory side. We interpret this extra contribution as encoding our ignorance of the source which creates the perturbation of the geometry.
Holographic interaction effects on transport in Dirac semimetals
Jacobs, V.P.J.; Vandoren, S.; Stoof, H.T.C.
2014-01-01
Strongly interacting Dirac semimetals are investigated using a holographic model especially geared to compute the single-particle correlation function for this case, including both interaction effects and non-zero temperature. We calculate the (homogeneous) optical conductivity at zero chemical
Massive pions, anomalies and baryons in holographic QCD
Domenech, O. [Departament de Fisica and IFAE, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Panico, G., E-mail: panico@phys.ethz.c [Institute for Theoretical Physics, ETH Zurich, 8093 Zurich (Switzerland); Wulzer, A. [Institut de Theorie des Phenomenes Physiques, EPFL, CH-1015 Lausanne (Switzerland)
2011-03-01
We consider a holographic model of QCD, obtained by a very simple modification of the original construction, which describes at the same time the pion mass, the QCD anomalies and the baryons as topological solitons. We study in detail its phenomenological implications in both the mesonic and baryonic sectors and compare with the observations.
A Dual Coding Theoretical Model of Decoding in Reading: Subsuming the LaBerge and Samuels Model
Sadoski, Mark; McTigue, Erin M.; Paivio, Allan
2012-01-01
In this article we present a detailed Dual Coding Theory (DCT) model of decoding. The DCT model reinterprets and subsumes The LaBerge and Samuels (1974) model of the reading process which has served well to account for decoding behaviors and the processes that underlie them. However, the LaBerge and Samuels model has had little to say about…
Pricing Model for Dual Sales Channel with Promotion Effect Consideration
Chuiri Zhou
2016-01-01
Full Text Available We focus on the pricing strategy of a dual sales channel member when his/her online retailer faces an upcoming overloaded express delivery service due to the sales peak of online shopping, especially referring to the occurring affairs in China. We characterize the pricing problem of the dual selling channel system as a two-period game. When the price discount is only provided by the online seller, we find that the prices of the traditional channel and the online channel in the two periods are higher while the overloaded degree of express delivery is lower and the overloaded delivery services can decrease the profits of both channels. When the price discounts are provided by both traditional and online sellers, we find that the derived Nash price equilibrium of both channels includes five possible combinations of prices. Both traditional and online sellers will choose their price strategies, respectively, according to their cost advantages which are affected by the overloaded degree of express delivery.
Glöckner, A.; Witteman, C.L.M.
2010-01-01
Intuitive-automatic processes are crucial for making judgements and decisions. The fascinating complexity of these processes has attracted many decision researchers, prompting them to start investigating intuition empirically and to develop numerous models. Dual-process models assume a clear
The Dual-Factor Model of Mental Health: Further Study of the Determinants of Group Differences
Lyons, Michael D.; Huebner, E. Scott; Hills, Kimberly J.; Shinkareva, Svetlana V.
2012-01-01
Consistent with a positive psychology framework, this study examined the contributions of personality, environmental, and perceived social support variables in classifying adolescents using Greenspoon and Saklofske's Dual-Factor model of mental health. This model incorporates information about positive subjective well-being (SWB), along with…
The dual pathway model of overeating. Replication and extension with actual food consumption
Ouwens, M.A.; Strien, T. van; Leeuwe, J.F.J. van; Staak, C.P.F. van der
2009-01-01
van Strien et al. [van Strien, T., Engels, R. C. M. E., van Leeuwe, J., Snoek, H. M. (2005). The Stice model of overeating: tests in clinical and non-clinical samples. Appetite, 45, 205–213] extended the negative affect pathway of Stice's dual pathway model of overeating Stice [Stice, E. (1994).
The dual pathway model of overeating. Replication and extension with actual food consumption
Ouwens, Machteld A; van Strien, T; Leeuwe, J.F.J.; van der Staak, C P F
van Strien et al. [van Strien, T., Engels, R. C. M. E., van Leeuwe, J., Snoek, H. M. (2005). The Stice model of overeating: tests in clinical and non-clinical samples. Appetite, 45, 205-213] extended the negative affect pathway of Stice's dual pathway model of overeating Stice [Stice, E. (1994).
Dual-Extrusion 3D Printing of Anatomical Models for Education
Smith, Michelle L.; Jones, James F. X.
2018-01-01
Two material 3D printing is becoming increasingly popular, inexpensive and accessible. In this paper, freely available printable files and dual extrusion fused deposition modelling were combined to create a number of functional anatomical models. To represent muscle and bone FilaFlex[superscript 3D] flexible filament and polylactic acid (PLA)…
A Dual-Stage Two-Phase Model of Selective Attention
Hubner, Ronald; Steinhauser, Marco; Lehle, Carola
2010-01-01
The dual-stage two-phase (DSTP) model is introduced as a formal and general model of selective attention that includes both an early and a late stage of stimulus selection. Whereas at the early stage information is selected by perceptual filters whose selectivity is relatively limited, at the late stage stimuli are selected more efficiently on a…
Forward-backward correlations in pp interactions in a dual model
Fialkowsky, K.; Kotanski, A.; Uniwersytet Jagiellonski, Krakow
1982-01-01
Forward-backward correlations in lepton and hadron induced processes are compared according to the dual model. It is indicated that the effect of the chain energy spread in hadron processes is important. After including this effect the model is shown to explain the forward-backward correlations in pp data assuming no dynamical correlations within a single chain. (orig.)
Novaro, Marc
The high-speed holographic camera is a disgnostic instrument using holography as an information storing support. It allows us to take 10 holograms, of an object, with exposures times of 1,5ns, separated in time by 1 or 2ns. In order to get these results easily, no mobile part is used in the set-up [fr
Music holographic physiotherapy by laser
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.
Conformal symmetry and holographic cosmology
Bzowski, A.W.
2013-01-01
This thesis presents a novel approach to cosmology using gauge/gravity duality. Analysis of the implications of conformal invariance in field theories leads to quantitative cosmological predictions which are in agreement with current data. Furthermore, holographic cosmology extends the theory of
Sharma, S; Turner, M M
2013-01-01
Dual-frequency capacitive discharges are widespread in the semiconductor industry and are used, for example, in etching of semiconductor materials to manufacture microchips. In low-pressure dual radio-frequency capacitive discharges, stochastic heating is an important phenomenon. Recent theoretical work on this problem using several different approaches has produced results that are broadly in agreement insofar as scaling with the discharge parameters is concerned, but there remains some disagreement in detail concerning the absolute size of the effect for the case of dual-frequency capacitive discharges. In this work, we investigate the dependence of stochastic heating on various discharge parameters with the help of particle-in-cell (PIC) simulation. The dual-frequency analytical models are in fair agreement with PIC results for values of the low-frequency current density amplitude J lf (or dimensionless control parameter H lf ∼ 5) typical of many modern experiments. However, for higher values of J lf (or higher H lf ), new physical phenomena (like field reversal, reflection of ions, etc) appear and the simulation results deviate from existing dual-frequency analytical models. On the other hand, for lower J lf (or lower H lf ) again the simulation results deviate from analytical models. So this research work produces a relatively extensive set of simulation data that may be used to validate theories over a wide range of parameters. (paper)
Shape Dependence of Holographic Rényi Entropy in Conformal Field Theories
Dong, Xi
2016-06-01
We develop a framework for studying the well-known universal term in the Rényi entropy for an arbitrary entangling region in four-dimensional conformal field theories that are holographically dual to gravitational theories. The shape dependence of the Rényi entropy Sn is described by two coefficients: fb(n ) for traceless extrinsic curvature deformations and fc(n ) for Weyl tensor deformations. We provide the first calculation of the coefficient fb(n ) in interacting theories by relating it to the stress tensor one-point function in a deformed hyperboloid background. The latter is then determined by a straightforward holographic calculation. Our results show that a previous conjecture fb(n )=fc(n ), motivated by surprising evidence from a variety of free field theories and studies of conical defects, fails holographically.
New Higgs transitions between dual N=2 string models
Berglund, P.; Katz, S.; Klemm, A.; Mayr, P.
1997-01-01
We describe a new kind of transition between topologically distinct N=2 type II Calabi-Yau vacua through points with enhanced non-abelian gauge symmetries together with fundamental charged matter hyper multiplets. We connect the appearance of matter to the local geometry of the singularity and discuss the relation between the instanton numbers of the Calabi-Yau manifolds taking part in the transition. In a dual heterotic string theory on K3 x T 2 the process corresponds to Higgsing a semi-classical gauge group or equivalently to a variation of the gauge bundle. In special cases the situation reduces to simple conifold transitions in the Coulomb phase of the non-abelian gauge symmetries. (orig.)
Commensurability effects in holographic homogeneous lattices
Andrade, Tomas; Krikun, Alexander
2016-01-01
An interesting application of the gauge/gravity duality to condensed matter physics is the description of a lattice via breaking translational invariance on the gravity side. By making use of global symmetries, it is possible to do so without scarifying homogeneity of the pertinent bulk solutions, which we thus term as “homogeneous holographic lattices.' Due to their technical simplicity, these configurations have received a great deal of attention in the last few years and have been shown to correctly describe momentum relaxation and hence (finite) DC conductivities. However, it is not clear whether they are able to capture other lattice effects which are of interest in condensed matter. In this paper we investigate this question focusing our attention on the phenomenon of commensurability, which arises when the lattice scale is tuned to be equal to (an integer multiple of) another momentum scale in the system. We do so by studying the formation of spatially modulated phases in various models of homogeneous holographic lattices. Our results indicate that the onset of the instability is controlled by the near horizon geometry, which for insulating solutions does carry information about the lattice. However, we observe no sharp connection between the characteristic momentum of the broken phase and the lattice pitch, which calls into question the applicability of these models to the physics of commensurability.
Holographic photon production in heavy ion collisions
Iatrakis, Ioannis; Kiritsis, Elias; Shen, Chun; Yang, Di-Lun
2017-01-01
The thermal-photon emission from strongly coupled gauge theories at finite temperature is calculated using holographic models for QCD in the Veneziano limit (V-QCD). The emission rates are then embedded in hydrodynamic simulations combined with prompt photons from hard scattering and the thermal photons from hadron gas to analyze the spectra and anisotropic flow of direct photons at RHIC and LHC. The results from different sources responsible for the thermal photons in QGP including the weakly coupled QGP (wQGP) from perturbative calculations, strongly coupled N=4 super Yang-Mills (SYM) plasma (as a benchmark for reference), and Gubser’s phenomenological holographic model are then compared. It is found that the direct-photon spectra are enhanced in the strongly coupled scenario compared with the ones in the wQGP, especially at high momenta. Moreover, both the elliptic flow and triangular flow of direct photons are amplified at high momenta for V-QCD and the SYM plasma. The results are further compared with experimental observations.
Ricci-Gauss-Bonnet holographic dark energy
Saridakis, Emmanuel N.
2018-03-01
We present a model of holographic dark energy in which the infrared cutoff is determined by both the Ricci and the Gauss-Bonnet invariants. Such a construction has the significant advantage that the infrared cutoff, and consequently the holographic dark energy density, does not depend on the future or the past evolution of the universe, but only on its current features, and moreover it is determined by invariants, whose role is fundamental in gravitational theories. We extract analytical solutions for the behavior of the dark energy density and equation-of-state parameters as functions of the redshift. These reveal the usual thermal history of the universe, with the sequence of radiation, matter and dark energy epochs, resulting in the future to a complete dark energy domination. The corresponding dark energy equation-of-state parameter can lie in the quintessence or phantom regime, or experience the phantom-divide crossing during the cosmological evolution, and its asymptotic value can be quintessencelike, phantomlike, or be exactly equal to the cosmological-constant value. Finally, we extract the constraints on the model parameters that arise from big bang nucleosynthesis.
Holographic photon production in heavy ion collisions
Iatrakis, Ioannis [Institute for Theoretical Physics and Center for Extreme Matter and Emergent Phenomena,Utrecht University,Leuvenlaan 4, 3584 CE Utrecht (Netherlands); Kiritsis, Elias [Crete Center for Theoretical Physics, Institute of Theoretical and Computational Physics,Department of Physics, University of Crete,71003 Heraklion (Greece); Crete Center for Quantum Complexity and Nanotechnology,Department of Physics, University of Crete,71003 Heraklion (Greece); APC, Univ Paris Diderot, Sorbonne Paris Cité, APC, UMR 7164 CNRS,F-75205 Paris (France); Shen, Chun [Department of Physics, McGill University,3600 University Street, Montreal, QC, H3A 2T8 (Canada); Yang, Di-Lun [Theoretical Research Division, Nishina Center, RIKEN, Wako,Saitama 351-0198 (Japan)
2017-04-07
The thermal-photon emission from strongly coupled gauge theories at finite temperature is calculated using holographic models for QCD in the Veneziano limit (V-QCD). The emission rates are then embedded in hydrodynamic simulations combined with prompt photons from hard scattering and the thermal photons from hadron gas to analyze the spectra and anisotropic flow of direct photons at RHIC and LHC. The results from different sources responsible for the thermal photons in QGP including the weakly coupled QGP (wQGP) from perturbative calculations, strongly coupled N=4 super Yang-Mills (SYM) plasma (as a benchmark for reference), and Gubser’s phenomenological holographic model are then compared. It is found that the direct-photon spectra are enhanced in the strongly coupled scenario compared with the ones in the wQGP, especially at high momenta. Moreover, both the elliptic flow and triangular flow of direct photons are amplified at high momenta for V-QCD and the SYM plasma. The results are further compared with experimental observations.
Holographic dark energy in Brans-Dicke cosmology with chameleon scalar field
Setare, M.R.; Jamil, Mubasher
2010-01-01
We study a cosmological implication of holographic dark energy in the Brans-Dicke gravity. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in non-flat (closed) universe enclosed by the event horizon measured from the sphere of horizon named L. Our analysis shows that one can obtain the phantom crossing scenario if the model parameter α (of order unity) is tuned accordingly. Moreover, this behavior is achieved by treating the Brans-Dicke scalar field as a Chameleon scalar field and taking a non-minimal coupling of the scalar field with matter. Hence one can generate phantom-like equation of state from a holographic dark energy model in non-flat universe in the Brans-Dicke cosmology framework.
Holographic dark energy in Brans-Dicke cosmology with chameleon scalar field
Setare, M.R., E-mail: rezakord@ipm.i [Department of Science of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Jamil, Mubasher, E-mail: mjamil@camp.edu.p [Center for Advanced Mathematics and Physics, National University of Sciences and Technology, Rawalpindi 46000 (Pakistan)
2010-06-07
We study a cosmological implication of holographic dark energy in the Brans-Dicke gravity. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in non-flat (closed) universe enclosed by the event horizon measured from the sphere of horizon named L. Our analysis shows that one can obtain the phantom crossing scenario if the model parameter {alpha} (of order unity) is tuned accordingly. Moreover, this behavior is achieved by treating the Brans-Dicke scalar field as a Chameleon scalar field and taking a non-minimal coupling of the scalar field with matter. Hence one can generate phantom-like equation of state from a holographic dark energy model in non-flat universe in the Brans-Dicke cosmology framework.
Pawel Boguslawski
2016-02-01
Full Text Available There is an increasing need for building models that permit interior navigation, e.g., for escape route analysis. This paper presents a non-manifold Computer-Aided Design (CAD data structure, the dual half-edge based on the Poincaré duality that expresses both the geometric representations of individual rooms and their topological relationships. Volumes and faces are expressed as vertices and edges respectively in the dual space, permitting a model just based on the storage of primal and dual vertices and edges. Attributes may be attached to all of these entities permitting, for example, shortest path queries between specified rooms, or to the exterior. Storage costs are shown to be comparable to other non-manifold models, and construction with local Euler-type operators is demonstrated with two large university buildings. This is intended to enhance current developments in 3D Geographic Information Systems for interior and exterior city modelling.
Cubrovic, Mihailo; Liu Yan; Schalm, Koenraad; Sun Yawen; Zaanen, Jan
2011-01-01
We argue that the electron star and the anti-de Sitter (AdS) Dirac hair solution are two limits of the free charged Fermi gas in AdS. Spectral functions of holographic duals to probe fermions in the background of electron stars have a free parameter that quantifies the number of constituent fermions that make up the charge and energy density characterizing the electron star solution. The strict electron star limit takes this number to be infinite. The Dirac hair solution is the limit where this number is unity. This is evident in the behavior of the distribution of holographically dual Fermi surfaces. As we decrease the number of constituents in a fixed electron star background the number of Fermi surfaces also decreases. An improved holographic Fermi ground state should be a configuration that shares the qualitative properties of both limits.
The holographic dictionary for Beta functions of multi-trace coupling constants
Aharony, Ofer [Department of Particle Physics and Astrophysics,Weizmann Institute of Science, Rehovot 7610001 (Israel); Gur-Ari, Guy [Department of Particle Physics and Astrophysics,Weizmann Institute of Science, Rehovot 7610001 (Israel); Stanford Institute for Theoretical Physics, Stanford University, Stanford, California 94305 (United States); Klinghoffer, Nizan [Department of Particle Physics and Astrophysics,Weizmann Institute of Science, Rehovot 7610001 (Israel)
2015-05-06
Field theories with weakly coupled holographic duals, such as large N gauge theories, have a natural separation of their operators into ‘single-trace operators’ (dual to single-particle states) and ‘multi-trace operators’ (dual to multi-particle states). There are examples of large N gauge theories where the beta functions of single-trace coupling constants all vanish, but marginal multi-trace coupling constants have non-vanishing beta functions that spoil conformal invariance (even when all multi-trace coupling constants vanish). The holographic dual of such theories should be a classical solution in anti-de Sitter space, in which the boundary conditions that correspond to the multi-trace coupling constants depend on the cutoff scale, in a way that spoils conformal invariance. We argue that this is realized through specific bulk coupling constants that lead to a running of the multi-trace coupling constants. This fills a missing entry in the holographic dictionary.
Homodyne detection of holographic memory systems
Urness, Adam C.; Wilson, William L.; Ayres, Mark R.
2014-09-01
We present a homodyne detection system implemented for a page-wise holographic memory architecture. Homodyne detection by holographic memory systems enables phase quadrature multiplexing (doubling address space), and lower exposure times (increasing read transfer rates). It also enables phase modulation, which improves signal-to-noise ratio (SNR) to further increase data capacity. We believe this is the first experimental demonstration of homodyne detection for a page-wise holographic memory system suitable for a commercial design.
Bounding the space of holographic CFTs with chaos
Perlmutter, Eric [Department of Physics, Princeton University,Jadwin Hall, Princeton, NJ 08544 (United States)
2016-10-13
Thermal states of quantum systems with many degrees of freedom are subject to a bound on the rate of onset of chaos, including a bound on the Lyapunov exponent, λ{sub L}≤2π/β. We harness this bound to constrain the space of putative holographic CFTs and their would-be dual theories of AdS gravity. First, by studying out-of-time-order four-point functions, we discuss how λ{sub L}=2π/β in ordinary two-dimensional holographic CFTs is related to properties of the OPE at strong coupling. We then rule out the existence of unitary, sparse two-dimensional CFTs with large central charge and a set of higher spin currents of bounded spin; this implies the inconsistency of weakly coupled AdS{sub 3} higher spin gravities without infinite towers of gauge fields, such as the SL(N) theories. This fits naturally with the structure of higher-dimensional gravity, where finite towers of higher spin fields lead to acausality. On the other hand, unitary CFTs with classical W{sub ∞}[λ] symmetry, dual to 3D Vasiliev or hs[λ] higher spin gravities, do not violate the chaos bound, instead exhibiting no chaos: λ{sub L}=0. Independently, we show that such theories violate unitarity for |λ|>2. These results encourage a tensionless string theory interpretation of the 3D Vasiliev theory.
Exchange mechanisms for single photo- and electroproduction using the dual fermion model
Becker, L.; Weigt, G.
1976-01-01
Single pion real and virtual photoproduction data are compared with phenomenological dual fermion amplitudes, which were previously applied to quasi-two body vector and tensor meson production. The similar structures of the photon and the corresponding vector meson data (in the s-channel helicity system) such as spikes and dips, usually described by Regge pole/Regge cut interferences, are reproduced by the dual Born amplitudes. Predictions of the model for the differential cross sections, in particular their parts for natural and unnatural spin-parity t-channel exchanges as well as their mass dependence, and photon and target asymmetries are in reasonable agreement with the experimental data. (author)
Rural-urban migration: policy simulations in a dual economy model of Bangladesh.
Ahmed, S
1986-03-01
The process of rural-urban migration in Bangladesh is analyzed using a dual economy model. The focus is on the period 1976-1985. The main purpose of the paper is to examine alternative policies designed to reduce the level of such migration without adversely affecting the country's economy.
Description of inelastic nucleus-nucleus interactions at medium energy using dual parton model
Polanski, A.; Shmakov, S.Yu.; Uzhinskij, V.V.
1989-01-01
It is shown that the dual parton model taking into account the processes of diffraction dissociation to the low mass states and finite energy corrections to the asymptotic Abramovski-Gribov-Kancheli cutting rules allows satisfactory description of existing experimental data on hadron-nucleus and nucleus-nucleus interactions at medium energy. (orig.)
Saab, Rim; Tausch, Nicole; Spears, Russell; Cheung, Wing-Yee
We examined predictors of collective action among bystander group members in solidarity with a disadvantaged group by extending the dual pathway model of collective action, which proposes one efficacy-based and one emotion-based path to collective action (Van Zomeren, Spears, Fischer, & Leach,
Sibley, Chris G.; Overall, Nickola C.
2011-01-01
We tested a dual process motivational model of ambivalent sexism and gender differences in intimate partner preferences. Meta-analysis of 32 samples (16 with men, 16 with women; N = 5,459) indicated that Benevolent Sexism (BS) in women was associated with greater preferences for high-resource partners (r = 0.24), whereas Hostile Sexism (HS) in men…
Personality and creativity : The dual pathway to creativity model and a research agenda
Baas, Matthijs; Roskes, Marieke; Sligte, Daniel; Nijstad, Bernard A.; De Dreu, Carsten K W
2013-01-01
To better understand the relation between personality traits and creativity, we invoke the Dual-Pathway to Creativity model (DPCM) that identifies two pathways to creative outcomes: (1) flexible processing of information (cognitive flexibility) and (2) persistent probing, and systematically and
Hewes, Dean E.
2009-01-01
The purpose of the author's contribution to this colloquy was to spark conversation on the theoretical nature of communication processes and the evidentiary requirements for testing their relationship to group outcomes. Co-discussants have raised important issues concerning the philosophical basis of the socioegocentric model (SM) and dual-level…
van Zomeren, Martijn; Leach, Colin Wayne; Spears, Russell
To explain the psychology behind individuals' motivation to participate in collective action against collective disadvantage (e.g., protest marches), the authors introduce a dynamic dual pathway model of approach coping that integrates many common explanations of collective action (i.e., group
On a relation between massive Yang-Mills theories and dual string models
Mickelsson, J.
1983-01-01
The relations between mass terms in Yang-Mills theories, projective representations of the group of gauge transformations, boundary conditions on vector potentials and Schwinger terms in local charge algebra commutation relations are discussed. The commutation relations (with Schwinger terms) are similar to the current algebra commutation relations of the SU(N) extended dual string model. (orig.)
The dual pathway to creativity model: creative ideation as a function of flexibility and persistence
Nijstad, B.A.; de Dreu, C.K.W.; Rietzschel, E.F.; Baas, M.
2010-01-01
The dual pathway to creativity model argues that creativity—the generation of original and appropriate ideas—is a function of cognitive flexibility and cognitive persistence, and that dispositional or situational variables may influence creativity either through their effects on flexibility, on
Nijstad, B.A.; De Dreu, C.K.W.; Rietzschel, E.F.; Baas, M.
2010-01-01
The dual pathway to creativity model argues that creativity-the generation of original and appropriate ideas-is a function of cognitive flexibility and cognitive persistence, and that dispositional or situational variables may influence creativity either through their effects on flexibility, on
Holographic study of the QCD matter under external conditions
Katanaeva Alisa
2017-01-01
We use methods of the bottom-up AdS/QCD approach to bring out the phase structure of several holographic models in which transition to a deconfined phase is related to a (first order Hawking-Page phase transition. The impact of phenomenological model parameters on the critical temperature and chemical potential is studied in detail. Comparison of the model predictions with results of experimental investigations, lattice QCD simulations and other methods is also done.
Raso , L.; Malaterre , P.O.; Bader , J.C.
2017-01-01
International audience; This article presents an innovative streamflow process model for use in reservoir operational rule design in stochastic dual dynamic programming (SDDP). Model features, which can be applied independently, are (1) a multiplicative process model for the forward phase and its linearized version for the backward phase; and (2) a nonuniform time-step length that is inversely proportional to seasonal variability. The advantages are (1) guaranteeing positive streamflow values...
Holographic duality: Stealing dimensions from metals
Zaanen, Jan
2013-10-01
Although electrically charged black holes seem remote from superconductors and strange metals in the laboratory, they might be intimately related by the holographic dualities discovered in string theory.
Holographic Two-Photon Induced Photopolymerization
Federal Laboratory Consortium — Holographic two-photon-induced photopolymerization (HTPIP) offers distinct advantages over conventional one-photon-induced photopolymerization and current techniques...
Dual lattice representations for O(N and CP(N−1 models with a chemical potential
Falk Bruckmann
2015-10-01
Full Text Available We derive dual representations for O(N and CP(N−1 models on the lattice. In terms of the dual variables the partition sums have only real and positive contributions also at finite chemical potential. Thus the complex action problem of the conventional formulation is overcome and using the dual variables Monte Carlo simulations are possible at arbitrary chemical potential.
Lorentzian condition in holographic cosmology
Hertog, Thomas; Monten, Ruben; Vreys, Yannick
2017-01-01
We derive a sufficient set of conditions on the Euclidean boundary theory in dS/CFT for it to predict classical, Lorentzian bulk evolution at large spatial volumes. Our derivation makes use of a canonical transformation to express the bulk wave function at large volume in terms of the sources of the dual partition function. This enables a sharper formulation of dS/CFT. The conditions under which the boundary theory predicts classical bulk evolution are stronger than the criteria usually employed in quantum cosmology. We illustrate this in a homogeneous isotropic minisuperspace model of gravity coupled to a scalar field in which we identify the ensemble of classical histories explicitly.
Phase-field modeling of corrosion kinetics under dual-oxidants
Wen, You-Hai; Chen, Long-Qing; Hawk, Jeffrey A.
2012-04-01
A phase-field model is proposed to simulate corrosion kinetics under a dual-oxidant atmosphere. It will be demonstrated that the model can be applied to simulate corrosion kinetics under oxidation, sulfidation and simultaneous oxidation/sulfidation processes. Phase-dependent diffusivities are incorporated in a natural manner and allow more realistic modeling as the diffusivities usually differ by many orders of magnitude in different phases. Simple free energy models are then used for testing the model while calibrated free energy models can be implemented for quantitative modeling.
Perceiving pain in others: validation of a dual processing model.
McCrystal, Kalie N; Craig, Kenneth D; Versloot, Judith; Fashler, Samantha R; Jones, Daniel N
2011-05-01
Accurate perception of another person's painful distress would appear to be accomplished through sensitivity to both automatic (unintentional, reflexive) and controlled (intentional, purposive) behavioural expression. We examined whether observers would construe diverse behavioural cues as falling within these domains, consistent with cognitive neuroscience findings describing activation of both automatic and controlled neuroregulatory processes. Using online survey methodology, 308 research participants rated behavioural cues as "goal directed vs. non-goal directed," "conscious vs. unconscious," "uncontrolled vs. controlled," "fast vs. slow," "intentional (deliberate) vs. unintentional," "stimulus driven (obligatory) vs. self driven," and "requiring contemplation vs. not requiring contemplation." The behavioural cues were the 39 items provided by the PROMIS pain behaviour bank, constructed to be representative of the diverse possibilities for pain expression. Inter-item correlations among rating scales provided evidence of sufficient internal consistency justifying a single score on an automatic/controlled dimension (excluding the inconsistent fast vs. slow scale). An initial exploratory factor analysis on 151 participant data sets yielded factors consistent with "controlled" and "automatic" actions, as well as behaviours characterized as "ambiguous." A confirmatory factor analysis using the remaining 151 data sets replicated EFA findings, supporting theoretical predictions that observers would distinguish immediate, reflexive, and spontaneous reactions (primarily facial expression and paralinguistic features of speech) from purposeful and controlled expression (verbal behaviour, instrumental behaviour requiring ongoing, integrated responses). There are implicit dispositions to organize cues signaling pain in others into the well-defined categories predicted by dual process theory. Copyright © 2011 International Association for the Study of Pain. Published by
Noh, Seong Jin; Tachikawa, Yasuto; Shiiba, Michiharu; Kim, Sunmin
Applications of data assimilation techniques have been widely used to improve upon the predictability of hydrologic modeling. Among various data assimilation techniques, sequential Monte Carlo (SMC) filters, known as "particle filters" provide the capability to handle non-linear and non-Gaussian state-space models. This paper proposes a dual state-parameter updating scheme (DUS) based on SMC methods to estimate both state and parameter variables of a hydrologic model. We introduce a kernel smoothing method for the robust estimation of uncertain model parameters in the DUS. The applicability of the dual updating scheme is illustrated using the implementation of the storage function model on a middle-sized Japanese catchment. We also compare performance results of DUS combined with various SMC methods, such as SIR, ASIR and RPF.
Vertically-Integrated Dual-Continuum Models for CO2 Injection in Fractured Aquifers
Tao, Y.; Guo, B.; Bandilla, K.; Celia, M. A.
2017-12-01
Injection of CO2 into a saline aquifer leads to a two-phase flow system, with supercritical CO2 and brine being the two fluid phases. Various modeling approaches, including fully three-dimensional (3D) models and vertical-equilibrium (VE) models, have been used to study the system. Almost all of that work has focused on unfractured formations. 3D models solve the governing equations in three dimensions and are applicable to generic geological formations. VE models assume rapid and complete buoyant segregation of the two fluid phases, resulting in vertical pressure equilibrium and allowing integration of the governing equations in the vertical dimension. This reduction in dimensionality makes VE models computationally more efficient, but the associated assumptions restrict the applicability of VE model to formations with moderate to high permeability. In this presentation, we extend the VE and 3D models for CO2 injection in fractured aquifers. This is done in the context of dual-continuum modeling, where the fractured formation is modeled as an overlap of two continuous domains, one representing the fractures and the other representing the rock matrix. Both domains are treated as porous media continua and can be modeled by either a VE or a 3D formulation. The transfer of fluid mass between rock matrix and fractures is represented by a mass transfer function connecting the two domains. We have developed a computational model that combines the VE and 3D models, where we use the VE model in the fractures, which typically have high permeability, and the 3D model in the less permeable rock matrix. A new mass transfer function is derived, which couples the VE and 3D models. The coupled VE-3D model can simulate CO2 injection and migration in fractured aquifers. Results from this model compare well with a full-3D model in which both the fractures and rock matrix are modeled with 3D models, with the hybrid VE-3D model having significantly reduced computational cost. In
The effect of inclusion of inlets in dual drainage modelling
Chang, Tsang-Jung; Wang, Chia-Ho; Chen, Albert S.; Djordjević, Slobodan
2018-04-01
In coupled sewer and surface flood modelling approaches, the flow process in gullies is often ignored although the overland flow is drained to sewer network via inlets and gullies. Therefore, the flow entering inlets is transferred to the sewer network immediately, which may lead to a different flood estimation than the reality. In this paper, we compared two modelling approach with and without considering the flow processes in gullies in the coupled sewer and surface modelling. Three historical flood events were adopted for model calibration and validation. The results showed that the inclusion of flow process in gullies can further improve the accuracy of urban flood modelling.
Holographic interferometry in construction analysis
Hartikainen, T.
1995-12-31
In this work techniques for visualizing phase and opaque objects by ruby laser interferometry are introduced. A leakage flow as a phase object is studied by holographic interferometry and the intensity distribution of the interferograms presenting the leakage flow are computer-simulated. A qualitative and quantitative analysis of the leakage flow is made. The analysis is based on the experimental and theoretical results presented in this work. The holographic setup and the double pass method for visualizing leakage flow are explained. A vibrating iron plate is the opaque object. Transient impact waves are generated by a pistol bullet on the iron plate and visualized by holographic interferometry. An apparatus with the capability of detecting and calculating the delays necessary for laser triggering is introduced. A time series of interferograms presenting elastic wave formation in an iron plate is shown. A computer-simulation of the intensity distributions of these interferograms is made. An analysis based on the computer-simulation and the experimental data of the transient elastic wave is carried out and the results are presented. (author)
Modified holographic dark energy in DGP brane world
Liu, Dao-Jun; Wang, Hua; Yang, Bin
2010-01-01
In this Letter, the cosmological dynamics of a modified holographic dark energy which is derived from the UV/IR duality by considering the black hole mass in higher dimensions as UV cutoff, is investigated in Dvali-Gabadadze-Porrati (DGP) brane world model. We choose Hubble horizon and future event horizon as IR cutoff respectively. And the two branches of the DGP model are both taken into account. When Hubble horizon is considered as IR cutoff, the modified holographic dark energy (HDE) behaves like an effect dark energy that modification of gravity in pure DGP brane world model acts and it can drive the expansion of the universe speed up at late time in ε=-1 branch which in pure DGP model cannot undergo an accelerating phase. When future event horizon acts as IR cutoff, the equation of state parameter of the modified HDE can cross the phantom divide.
An integrated treatment model for dual diagnosis of psychosis and addiction.
Minkoff, K
1989-10-01
A model that integrates the treatment of patients with a dual diagnosis of psychosis and addiction has been developed on a general hospital psychiatric unit. The model emphasizes the parallels between the standard biopsychosocial illness-and-rehabilitation model for treatment of serious psychiatric disorders and the 12-step disease-and-recovery model of Alcoholics Anonymous for treatment of addiction. Dual-diagnosis patients are viewed as having two primary, chronic, biologic mental illnesses, each requiring specific treatment to stabilize acute symptoms and engage the patient in a recovery process. An integrated treatment program is described, as are the steps taken to alleviate psychiatric clinicians' concerns about patient involvement in AA and addiction clinicians' discomfort with patients' use of medication.
Karami, K., E-mail: kkarami@uok.ac.ir [Department of Physics, University of Kurdistan, Pasdaran St., Sanandaj (Iran, Islamic Republic of)
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.
Dual Education: The Win-Win Model of Collaboration between Universities and Industry
Monika Pogatsnik
2018-05-01
Full Text Available The purpose of this paper is to describe the new experiences of the dual training model in engineering education in Hungary. This new model has been introduced recently in the higher education and has become a focus of interest. This is a fa-vorable program for the students to experience the real industry environment pri-or to graduation and it is a good tool to motivate them to study harder. The dual education students study in the institutional academic period together with the regular full-time students at their higher education institute, and parallel to their academic education they participate in the practical training. It gives the students an opportunity to join a specific training program at an enterprise. Being involved in specific "operational" practical tasks and project-oriented work enhances inde-pendent work, learning soft skills and experiencing the culture of work. Our ob-jectives are to analyze the benefits of the dual training for all three parties: the stu-dent, the company and university. The study confirms earlier results from prior studies which show, for example, that students who choose the dual option achieve better program outcomes.
Multiple Model Adaptive Control Using Dual Youla-Kucera Factorisation
Bendtsen, Jan Dimon; Trangbæk, Klaus
2012-01-01
We propose a multi-model adaptive control scheme for uncertain linear plants based on the concept of model unfalsification. The approach relies on examining the ability of a pre-computed set of plant-controller candidates and choosing the one that is best able to reproduce observed in- and output...
Self-dual form of Ruijsenaars–Schneider models and ILW equation with discrete Laplacian
A. Zabrodin
2018-02-01
Full Text Available We discuss a self-dual form or the Bäcklund transformations for the continuous (in time variable glN Ruijsenaars–Schneider model. It is based on the first order equations in N+M complex variables which include N positions of particles and M dual variables. The latter satisfy equations of motion of the glM Ruijsenaars–Schneider model. In the elliptic case it holds M=N while for the rational and trigonometric models M is not necessarily equal to N. Our consideration is similar to the previously obtained results for the Calogero–Moser models which are recovered in the non-relativistic limit. We also show that the self-dual description of the Ruijsenaars–Schneider models can be derived from complexified intermediate long wave equation with discrete Laplacian by means of the simple pole ansatz likewise the Calogero–Moser models arise from ordinary intermediate long wave and Benjamin–Ono equations.
Karimova, A. E.; Amanova, A. S.; Sadykova, A. M.; Kuzembaev, N. E.; Makisheva, A. T.; Kurmangazina, G. Zh.; Sakenov, Janat
2016-01-01
The article explores the significant problem of developing a theoretical model of professional competence development in dual-specialty students (on the example of the "History, Religious studies" specialty). In order to validate the specifics of the professional competence development in dual-specialty students (on the example of the…
Toward a holographic theory for general spacetimes
Nomura, Yasunori; Salzetta, Nico; Sanches, Fabio; Weinberg, Sean J.
2017-04-01
We study a holographic theory of general spacetimes that does not rely on the existence of asymptotic regions. This theory is to be formulated in a holographic space. When a semiclassical description is applicable, the holographic space is assumed to be a holographic screen: a codimension-1 surface that is capable of encoding states of the gravitational spacetime. Our analysis is guided by conjectured relationships between gravitational spacetime and quantum entanglement in the holographic description. To understand basic features of this picture, we catalog predictions for the holographic entanglement structure of cosmological spacetimes. We find that qualitative features of holographic entanglement entropies for such spacetimes differ from those in AdS/CFT but that the former reduce to the latter in the appropriate limit. The Hilbert space of the theory is analyzed, and two plausible structures are found: a direct-sum and "spacetime-equals-entanglement" structure. The former preserves a naive relationship between linear operators and observable quantities, while the latter respects a more direct connection between holographic entanglement and spacetime. We also discuss the issue of selecting a state in quantum gravity, in particular how the state of the multiverse may be selected in the landscape.
Self-dual configurations in Abelian Higgs models with k-generalized gauge field dynamics
Casana, R.; Cavalcante, A. [Departamento de Física, Universidade Federal do Maranhão,65080-805, São Luís, Maranhão (Brazil); Hora, E. da [Departamento de Física, Universidade Federal do Maranhão,65080-805, São Luís, Maranhão (Brazil); Coordenadoria Interdisciplinar de Ciência e Tecnologia, Universidade Federal do Maranhão,65080-805, São Luís, Maranhão (Brazil)
2016-12-14
We have shown the existence of self-dual solutions in new Maxwell-Higgs scenarios where the gauge field possesses a k-generalized dynamic, i.e., the kinetic term of gauge field is a highly nonlinear function of F{sub μν}F{sup μν}. We have implemented our proposal by means of a k-generalized model displaying the spontaneous symmetry breaking phenomenon. We implement consistently the Bogomol’nyi-Prasad-Sommerfield formalism providing highly nonlinear self-dual equations whose solutions are electrically neutral possessing total energy proportional to the magnetic flux. Among the infinite set of possible configurations, we have found families of k-generalized models whose self-dual equations have a form mathematically similar to the ones arising in the Maxwell-Higgs or Chern-Simons-Higgs models. Furthermore, we have verified that our proposal also supports infinite twinlike models with |ϕ|{sup 4}-potential or |ϕ|{sup 6}-potential. With the aim to show explicitly that the BPS equations are able to provide well-behaved configurations, we have considered a test model in order to study axially symmetric vortices. By depending of the self-dual potential, we have shown that the k-generalized model is able to produce solutions that for long distances have a exponential decay (as Abrikosov-Nielsen-Olesen vortices) or have a power-law decay (characterizing delocalized vortices). In all cases, we observe that the generalization modifies the vortex core size, the magnetic field amplitude and the bosonic masses but the total energy remains proportional to the quantized magnetic flux.
Holographic complexity for time-dependent backgrounds
Momeni, Davood, E-mail: davoodmomeni78@gmail.com [Eurasian International Center for Theoretical Physics and Department of General Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan); Faizal, Mir, E-mail: mirfaizalmir@googlemail.com [Irving K. Barber School of Arts and Sciences, University of British Columbia, Okanagan, 3333 University Way, Kelowna, British Columbia V1V 1V7 (Canada); Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta, T1K 3M4 (Canada); Bahamonde, Sebastian, E-mail: sebastian.beltran.14@ucl.ac.uk [Department of Mathematics, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Myrzakulov, Ratbay [Eurasian International Center for Theoretical Physics and Department of General Theoretical Physics, Eurasian National University, Astana 010008 (Kazakhstan)
2016-11-10
In this paper, we will analyze the holographic complexity for time-dependent asymptotically AdS geometries. We will first use a covariant zero mean curvature slicing of the time-dependent bulk geometries, and then use this co-dimension one spacelike slice of the bulk spacetime to define a co-dimension two minimal surface. The time-dependent holographic complexity will be defined using the volume enclosed by this minimal surface. This time-dependent holographic complexity will reduce to the usual holographic complexity for static geometries. We will analyze the time-dependence as a perturbation of the asymptotically AdS geometries. Thus, we will obtain time-dependent asymptotically AdS geometries, and we will calculate the holographic complexity for such time-dependent geometries.
Multiverse Space-Antispace Dual Calabi-Yau `Exciplex-Zitterbewegung' Particle Creation
Amoroso, Richard L.
Modeling the `creation/emergence' of matter from spacetime is as old as modern cosmology itself and not without controversy within each model such as Static, Steady-state, Big Bang or Multiverse Continuous-State. In this paper we present only a brief primitive introduction to a new form of `Exciplex-Zitterbewegung' dual space-antispace vacuum Particle Creation applicable especially to Big Bang alternatives which are well-known but ignored; Hubble discovered `Redshift' not a Doppler expansion of the universe which remains the currently popular interpretation. Holographic Anthropic Multiverse cosmology provides viable alternatives to all seemingly sacrosanct pillars of the Big Bang. A model for Multiverse Space-Antispace Dual Calabi-Yau `Exciplex-Zitterbewegung' particle creation has only become possible by incorporating the additional degrees of freedom provided by the capacity complex dimensional extended Yang-Mills Kaluza-Klein correspondence provides.
Current constraints on interacting holographic dark energy
Wu Qiang; Gong Yungui; Wang Anzhong; Alcaniz, J.S.
2008-01-01
Although there is mounting observational evidence that the cosmic expansion is undergoing a late-time acceleration, the physical mechanism behind such a phenomenon is yet unknown. In this Letter, we investigate a holographic dark energy (HDE) model with interaction between the components of the dark sector in the light of current cosmological observations. We use both the new gold sample of 182 type Ia supernovae (SNe Ia) and the 192 SNe Ia ESSENCE data, the baryon acoustic oscillation measurement from the Sloan Digital Sky Survey and the shift parameter from the three-year Wilkinson Microwave Anisotropy Probe data. In agreement with previous results, we show that these observations suggest a very weak coupling or even a noninteracting HDE. The phantom crossing behavior in the context of these scenarios is also briefly discussed
One dimensional modeling of a diesel-CNG dual fuel engine
Azman, Putera Adam; Fawzi, Mas; Ismail, Muammar Mukhsin; Osman, Shahrul Azmir
2017-04-01
Some of the previous studies have shown that the use of compressed natural gas (CNG) in diesel engines potentially produce engine performance improvement and exhaust gas emission reduction, especially nitrogen oxides, unburned hydrocarbons, and carbon dioxide. On the other hand, there are other researchers who claimed that the use of CNG increases exhaust gas emissions, particularly nitrogen oxides. In this study, a one-dimensional model of a diesel-CNG dual fuel engine was made based on a 4-cylinder 2.5L common rail direct injection diesel engine. The software used is GT-Power, and it was used to analyze the engine performance and exhaust gas emissions of several diesel-CNG dual fuel blend ratios, i.e. 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50. The effect of 100%, 75%, 50% engine loads on the exhaust gas emissions were also studied. The result shows that all diesel-CNG fuel blends produces higher brake torque and brake power at engine speed of 2000-3000 rpm compared with 100% diesel. The 50:50 diesel-CNG blend produces the highest brake torque and brake power, but also has the highest brake specific fuel consumption. As a higher percentage of CNG added to the dual fuel blend, unburned hydrocarbons and carbon monoxide emission increased while carbon dioxide emission decreased. The nitrogen oxides emission concentration is generally unaffected by any change of the dual fuel ratio.
Dual states estimation of a subsurface flow-transport coupled model using ensemble Kalman filtering
El Gharamti, Mohamad
2013-10-01
Modeling the spread of subsurface contaminants requires coupling a groundwater flow model with a contaminant transport model. Such coupling may provide accurate estimates of future subsurface hydrologic states if essential flow and contaminant data are assimilated in the model. Assuming perfect flow, an ensemble Kalman filter (EnKF) can be used for direct data assimilation into the transport model. This is, however, a crude assumption as flow models can be subject to many sources of uncertainty. If the flow is not accurately simulated, contaminant predictions will likely be inaccurate even after successive Kalman updates of the contaminant model with the data. The problem is better handled when both flow and contaminant states are concurrently estimated using the traditional joint state augmentation approach. In this paper, we introduce a dual estimation strategy for data assimilation into a one-way coupled system by treating the flow and the contaminant models separately while intertwining a pair of distinct EnKFs, one for each model. The presented strategy only deals with the estimation of state variables but it can also be used for state and parameter estimation problems. This EnKF-based dual state-state estimation procedure presents a number of novel features: (i) it allows for simultaneous estimation of both flow and contaminant states in parallel; (ii) it provides a time consistent sequential updating scheme between the two models (first flow, then transport); (iii) it simplifies the implementation of the filtering system; and (iv) it yields more stable and accurate solutions than does the standard joint approach. We conducted synthetic numerical experiments based on various time stepping and observation strategies to evaluate the dual EnKF approach and compare its performance with the joint state augmentation approach. Experimental results show that on average, the dual strategy could reduce the estimation error of the coupled states by 15% compared with the
Resolution enhancement of holographic printer using a hogel overlapping method.
Hong, Keehoon; Park, Soon-gi; Yeom, Jiwoon; Kim, Jonghyun; Chen, Ni; Pyun, Kyungsuk; Choi, Chilsung; Kim, Sunil; An, Jungkwuen; Lee, Hong-Seok; Chung, U-in; Lee, Byoungho
2013-06-17
We propose a hogel overlapping method for the holographic printer to enhance the lateral resolution of holographic stereograms. The hogel size is directly related to the lateral resolution of the holographic stereogram. Our analysis by computer simulation shows that there is a limit to decreasing the hogel size while printing holographic stereograms. Instead of reducing the size of hogel, the lateral resolution of holographic stereograms can be enhanced by printing overlapped hogels, which makes it possible to take advantage of multiplexing property of the volume hologram. We built a holographic printer, and recorded two holographic stereograms using the conventional and proposed overlapping methods. The images and movies of the holographic stereograms experimentally captured were compared between the conventional and proposed methods. The experimental results confirm that the proposed hogel overlapping method improves the lateral resolution of holographic stereograms compared to the conventional holographic printing method.
Holographic RG flows from Quasi-Topological Gravity
Camara da Silva, U.; Sotkov, G.M.
2013-01-01
We investigate the holographic Renormalization Group (RG) flows and the critical phenomena that take place in the QFT's dual to the d-dimensional cubic Quasi-Topological Gravity coupled to scalar matter. The knowledge of the corresponding flat Domain Walls (DW's) solutions allows us to derive the explicit form of the QFT's β-functions, as well as of the trace anomalies a(l) and c(l), in terms of the matter superpotential. As a consequence we are able to determine the complete set of CFT data characterizing the universality classes of the UV and IR critical points and to follow the particular RG evolution of this data. We further analyse the dependence of the critical properties of such dual QFT's on the values of the Lovelock couplings and on the shape of the superpotential. For odd values of d, the explicit form of the “a and c-central charges” as functions of the running coupling constant, enable us to establish the conditions under which the a and c-Theorems for their decreasing are valid. The restrictions imposed on the massless holographic RG flows by the requirements of the positivity of the energy fluxes are derived. The particular case of quartic Higgs-like superpotential is studied in detail. It provides an example of unitary dual QFT's having few c≠a-critical points representing second or infinite order phase transitions. Depending on the range of the values of the coupling constant they exhibit massive and massless phases, described by a chain of distinct DW's solutions sharing common boundaries
Assessment of CO2 Storage Potential in Naturally Fractured Reservoirs With Dual-Porosity Models
March, Rafael; Doster, Florian; Geiger, Sebastian
2018-03-01
Naturally Fractured Reservoirs (NFR's) have received little attention as potential CO2 storage sites. Two main facts deter from storage projects in fractured reservoirs: (1) CO2 tends to be nonwetting in target formations and capillary forces will keep CO2 in the fractures, which typically have low pore volume; and (2) the high conductivity of the fractures may lead to increased spatial spreading of the CO2 plume. Numerical simulations are a powerful tool to understand the physics behind brine-CO2 flow in NFR's. Dual-porosity models are typically used to simulate multiphase flow in fractured formations. However, existing dual-porosity models are based on crude approximations of the matrix-fracture fluid transfer processes and often fail to capture the dynamics of fluid exchange accurately. Therefore, more accurate transfer functions are needed in order to evaluate the CO2 transfer to the matrix. This work presents an assessment of CO2 storage potential in NFR's using dual-porosity models. We investigate the impact of a system of fractures on storage in a saline aquifer, by analyzing the time scales of brine drainage by CO2 in the matrix blocks and the maximum CO2 that can be stored in the rock matrix. A new model to estimate drainage time scales is developed and used in a transfer function for dual-porosity simulations. We then analyze how injection rates should be limited in order to avoid early spill of CO2 (lost control of the plume) on a conceptual anticline model. Numerical simulations on the anticline show that naturally fractured reservoirs may be used to store CO2.
Photoproduction within the two-component Dual Parton Model: amplitudes and cross sections
Engel, R.; Siegen Univ.
1995-01-01
In the framework of the Dual Parton Model an approximation scheme to describe high energy photoproduction processes is presented. Based on the distinction between direct, resolved soft, and resolved hard interaction processes we construct effective impact parameter amplitudes. In order to treat low mass diffraction within the eikonal formalism in a consistent way a phenomenological ansatz is proposed. The free parameters of the model are determined by fits to high energy hadro- and photoproduction cross sections. We calculate the partial photoproduction cross sections and discuss predictions of the model at HERA energies. Using hadro- and photoproduction data together, the uncertainties of the model predictions are strongly reduced. (orig.)
Cross sections and multiparticle production at supercollider energies in the dual parton model
Ranft, J.
1993-01-01
The dual parton model (DPM) describes soft and semihard multiparticle production and treats diffractive processes for the first time in a consistent way. The model is formulated in the form of a Monte-Carlo event generator, DTUJET for hadron-hadron collisions at collider energies. The uncertainties in the model predictions in the TeV energy range due to the unknown parton structure functions at x≤0.02 is explored. The behaviour of the model studied in the forward fragmentation region, which is especially relevant for the interaction of Cosmic Rays
Lifshitz effects on holographic p-wave superfluid
Ya-Bo Wu
2015-02-01
Full Text Available In the probe limit, we numerically build a holographic p-wave superfluid model in the four-dimensional Lifshitz black hole coupled to a Maxwell-complex vector field. We observe the rich phase structure and find that the Lifshitz dynamical exponent z contributes evidently to the effective mass of the matter field and dimension of the gravitational background. Concretely, we obtain that the Cave of Winds appeared only in the five-dimensional anti-de Sitter (AdS spacetime, and the increasing z hinders not only the condensate but also the appearance of the first-order phase transition. Furthermore, our results agree with the Ginzburg–Landau results near the critical temperature. In addition, the previous AdS superfluid model is generalized to the Lifshitz spacetime. Keywords: Gauge/gravity duality, Holographic superconductor, Lifshitz black hole, Maxwell-complex vector field
Magnetic phenomena in holographic superconductivity with Lifshitz scaling
Aldo Dector
2015-09-01
Full Text Available We investigate the effects of Lifshitz dynamical critical exponent z on a family of minimal D=4+1 holographic superconducting models, with a particular focus on magnetic phenomena. We see that it is possible to have a consistent Ginzburg–Landau approach to holographic superconductivity in a Lifshitz background. By following this phenomenological approach we are able to compute a wide array of physical quantities. We also calculate the Ginzburg–Landau parameter for different condensates, and conclude that in systems with higher dynamical critical exponent, vortex formation is more strongly unfavored energetically and exhibits a stronger Type I behavior. Finally, following the perturbative approach proposed by Maeda, Natsuume and Okamura, we calculate the critical magnetic field of our models for different values of z.
Bidirectional holographic codes and sub-AdS locality
Yang, Zhao; Hayden, Patrick; Qi, Xiao-Liang [Stanford Institute for Theoretical Physics,Physics Department, Stanford University, CA 94304-4060 (United States)
2016-01-28
Tensor networks implementing quantum error correcting codes have recently been used to construct toy models of holographic duality explicitly realizing some of the more puzzling features of the AdS/CFT correspondence. These models reproduce the Ryu-Takayanagi entropy formula for boundary intervals, and allow bulk operators to be mapped to the boundary in a redundant fashion. These exactly solvable, explicit models have provided valuable insight but nonetheless suffer from many deficiencies, some of which we attempt to address in this article. We propose a new class of tensor network models that subsume the earlier advances and, in addition, incorporate additional features of holographic duality, including: (1) a holographic interpretation of all boundary states, not just those in a “code” subspace, (2) a set of bulk states playing the role of “classical geometries” which reproduce the Ryu-Takayanagi formula for boundary intervals, (3) a bulk gauge symmetry analogous to diffeomorphism invariance in gravitational theories, (4) emergent bulk locality for sufficiently sparse excitations, and (5) the ability to describe geometry at sub-AdS resolutions or even flat space.
A Dual Hesitant Fuzzy Multigranulation Rough Set over Two-Universe Model for Medical Diagnoses
Zhang, Chao; Li, Deyu; Yan, Yan
2015-01-01
In medical science, disease diagnosis is one of the difficult tasks for medical experts who are confronted with challenges in dealing with a lot of uncertain medical information. And different medical experts might express their own thought about the medical knowledge base which slightly differs from other medical experts. Thus, to solve the problems of uncertain data analysis and group decision making in disease diagnoses, we propose a new rough set model called dual hesitant fuzzy multigranulation rough set over two universes by combining the dual hesitant fuzzy set and multigranulation rough set theories. In the framework of our study, both the definition and some basic properties of the proposed model are presented. Finally, we give a general approach which is applied to a decision making problem in disease diagnoses, and the effectiveness of the approach is demonstrated by a numerical example. PMID:26858772
Dual process interaction model of HIV-risk behaviors among drug offenders.
Ames, Susan L; Grenard, Jerry L; Stacy, Alan W
2013-03-01
This study evaluated dual process interaction models of HIV-risk behavior among drug offenders. A dual process approach suggests that decisions to engage in appetitive behaviors result from a dynamic interplay between a relatively automatic associative system and an executive control system. One synergistic type of interplay suggests that executive functions may dampen or block effects of spontaneously activated associations. Consistent with this model, latent variable interaction analyses revealed that drug offenders scoring higher in affective decision making were relatively protected from predictive effects of spontaneous sex associations promoting risky sex. Among drug offenders with lower levels of affective decision making ability, spontaneous sexually-related associations more strongly predicted risky sex (lack of condom use and greater number of sex partners). These findings help elucidate associative and control process effects on appetitive behaviors and are important for explaining why some individuals engage in risky sex, while others are relatively protected.
Mothers Coping With Bereavement in the 2008 China Earthquake: A Dual Process Model Analysis.
Chen, Lin; Fu, Fang; Sha, Wei; Chan, Cecilia L W; Chow, Amy Y M
2017-01-01
The purpose of this study is to explore the grief experiences of mothers after they lost their children in the 2008 China earthquake. Informed by the Dual Process Model, this study conducted in-depth interviews to explore how six bereaved mothers coped with such grief over a 2-year period. Right after the earthquake, these mothers suffered from intensive grief. They primarily coped with loss-oriented stressors. As time passed, these mothers began to focus on restoration-oriented stressors to face changes in life. This coping trajectory was a dynamic and integral process, which bereaved mothers oscillated between loss- and restoration-oriented stressors. This study offers insight in extending the existing empirical evidence of the Dual Process Model.
Simulation and experimental validation of the dynamical model of a dual-rotor vibrotactor
Miklós, Á.; Szabó, Z.
2015-01-01
In this work, a novel design for small vibrotactors called the Dual Excenter is presented, which makes it possible to produce vibrations with independently adjustable frequency and amplitude. This feature has been realized using two coaxially aligned eccentric rotors, which are driven by DC motors independently. The prototype of the device has been built, where mechanical components are integrated on a frame with two optical sensors for the measurement of angular velocity and phase angle. The system is equipped with a digital controller. Simulations confirm the results of analytical investigations and they allow us to model the sampling method of the signals of the angular velocity and the phase angle between the rotors. Furthermore, we model the discrete behavior of the controller, which is a PI controller for the angular velocities and a PID controller for the phase angle. Finally, simulation results are compared to experimental ones, which show that the Dual Excenter concept is feasible.
Yu Qingjuan; Lu Youjun; Mohayaee, Roya; Colin, Jacques
2011-01-01
Dual active galactic nuclei (AGNs) are natural byproducts of hierarchical mergers of galaxies in the ΛCDM cosmogony. Recent observations have shown that only a small fraction (∼0.1%-2.5%) of AGNs at redshift z ∼< 0.3 are dual with kpc-scale separations, which is rather low compared to the high merger rate of galaxies. Here we construct a phenomenological model to estimate the number density of dual AGNs and its evolution according to the observationally estimated major merger rates of galaxies and various scaling relations on the properties of galaxies and their central massive black holes. We show that our model reproduces the observed frequency and separation distribution of dual AGNs provided that significant nuclear activities are triggered only in gas-rich progenitor galaxies with central massive black holes and only when the nuclei of these galaxies are roughly within the half-light radii of their companion galaxies. Under these constraints, the observed low dual AGN frequency is consistent with the relatively high merger rate of galaxies and supports the hypothesis that major mergers lead to AGN/QSO activities. We also predict that the number of kpc-scale dual AGNs decreases with increasing redshift and only about 0.02%-0.06% of AGNs are dual AGNs with double-peaked narrow line features at redshifts of z ∼ 0.5-1.2. Future observations of high-redshift dual AGNs would provide a solid test for this prediction.
Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope.
Chang, Cheng-Yang; Chen, Tsung-Lin
2017-10-31
Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT) material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the "open loop sensitivity" of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.
Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope
Cheng-Yang Chang
2017-10-01
Full Text Available Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the “open loop sensitivity” of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.
Nielsen, Mikkel Cornelius; Johansen, Tor Arne; Blanke, Mogens
2018-01-01
This paper considers the problem of rendezvous and docking with visual constraints in the context of underwater robots with camera-based navigation. The objective is the convergence of the vehicles to a common point while maintaining visual contact. The proposed solution includes the design of a ...... of a distributed model predictive controller based on dual decomposition, which allows for optimization in a decentralized fashion. The proposed distributed controller enables rendezvous and docking between vehicles while maintaining visual contact....
Pozníková, Gabriela; Fischer, Milan; Pohanková, Eva; Trnka, Miroslav
2014-01-01
Roč. 62, č. 5 (2014), s. 1079-1086 ISSN 1211-8516 R&D Projects: GA MŠk LH12037; GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : evapotranspiration * dual crop coefficient model * Bowen ratio/energy balance method * transpiration * soil evaporation * spring barley Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7)
On the algebraic structure of self-dual gauge fields and sigma models
Bais, F.A.; Sasaki, R.
1983-01-01
An extensive and detailed analysis of self-dual gauge fields, in particular with axial symmetry, is presented, culminating in a purely algebraic procedure to generate solutions. The method which is particularly suited for the construction of multimonopole solutions for a theory with arbitrary G, is also applicable to a wide class of non-linear sigma models. The relevant symmetries as well as the associated linear problems which underly the exact solubility of the problem, are constructed and discussed in detail. (orig.)
Reliable Dual Tensor Model Estimation in Single and Crossing Fibers Based on Jeffreys Prior
Yang, Jianfei; Poot, Dirk H. J.; Caan, Matthan W. A.; Su, Tanja; Majoie, Charles B. L. M.; van Vliet, Lucas J.; Vos, Frans M.
2016-01-01
Purpose This paper presents and studies a framework for reliable modeling of diffusion MRI using a data-acquisition adaptive prior. Methods Automated relevance determination estimates the mean of the posterior distribution of a rank-2 dual tensor model exploiting Jeffreys prior (JARD). This data-acquisition prior is based on the Fisher information matrix and enables the assessment whether two tensors are mandatory to describe the data. The method is compared to Maximum Likelihood Estimation (MLE) of the dual tensor model and to FSL’s ball-and-stick approach. Results Monte Carlo experiments demonstrated that JARD’s volume fractions correlated well with the ground truth for single and crossing fiber configurations. In single fiber configurations JARD automatically reduced the volume fraction of one compartment to (almost) zero. The variance in fractional anisotropy (FA) of the main tensor component was thereby reduced compared to MLE. JARD and MLE gave a comparable outcome in data simulating crossing fibers. On brain data, JARD yielded a smaller spread in FA along the corpus callosum compared to MLE. Tract-based spatial statistics demonstrated a higher sensitivity in detecting age-related white matter atrophy using JARD compared to both MLE and the ball-and-stick approach. Conclusions The proposed framework offers accurate and precise estimation of diffusion properties in single and dual fiber regions. PMID:27760166
Holographic conductivity of holographic superconductors with higher-order corrections
Sheykhi, Ahmad [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Ghazanfari, Afsoon; Dehyadegari, Amin [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of)
2018-02-15
We analytically and numerically disclose the effects of the higher-order correction terms in the gravity and in the gauge field on the properties of s-wave holographic superconductors. On the gravity side, we consider the higher curvature Gauss-Bonnet corrections and on the gauge field side, we add a quadratic correction term to the Maxwell Lagrangian. We show that, for this system, one can still obtain an analytical relation between the critical temperature and the charge density. We also calculate the critical exponent and the condensation value both analytically and numerically. We use a variational method, based on the Sturm-Liouville eigenvalue problem for our analytical study, as well as a numerical shooting method in order to compare with our analytical results. For a fixed value of the Gauss-Bonnet parameter, we observe that the critical temperature decreases with increasing the nonlinearity of the gauge field. This implies that the nonlinear correction term to the Maxwell electrodynamics makes the condensation harder. We also study the holographic conductivity of the system and disclose the effects of the Gauss-Bonnet and nonlinear parameters α and b on the superconducting gap. We observe that, for various values of α and b, the real part of the conductivity is proportional to the frequency per temperature, ω/T, as the frequency is large enough. Besides, the conductivity has a minimum in the imaginary part which is shifted toward greater frequency with decreasing temperature. (orig.)
Modeling the dual pacemaker system of the tau mutant hamster.
Oda, G A; Menaker, M; Friesen, W O
2000-06-01
Circadian pacemakers in many animals are compound. In rodents, a two-oscillator model of the pacemaker composed of an evening (E) and a morning (M) oscillator has been proposed based on the phenomenon of "splitting" and bimodal activity peaks. The authors describe computer simulations of the pacemaker in tau mutant hamsters viewed as a system of mutually coupled E and M oscillators. These mutant animals exhibit normal type 1 PRCs when released into DD but make a transition to a type 0 PRC when held for many weeks in DD. The two-oscillator model describes particularly well some recent behavioral experiments on these hamsters. The authors sought to determine the relationships between oscillator amplitude, period, PRC, and activity duration through computer simulations. Two complementary approaches proved useful for analyzing weakly coupled oscillator systems. The authors adopted a "distinct oscillators" view when considering the component E and M oscillators and a "system" view when considering the system as a whole. For strongly coupled systems, only the system view is appropriate. The simulations lead the authors to two primary conjectures: (1) the total amplitude of the pacemaker system in tau mutant hamsters is less than in the wild-type animals, and (2) the coupling between the unit E and M oscillators is weakened during continuous exposure of hamsters to DD. As coupling strength decreases, activity duration (alpha) increases due to a greater phase difference between E and M. At the same time, the total amplitude of the system decreases, causing an increase in observable PRC amplitudes. Reduced coupling also increases the relative autonomy of the unit oscillators. The relatively autonomous phase shifts of E and M oscillators can account for both immediate compression and expansion of activity bands in tau mutant and wild-type hamsters subjected to light pulses.
Synfograms: a new generation of holographic applications
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.
Modelling and analysis of the transformer current resonance in dual active bridge converters
Qin, Zian; Shen, Zhan; Blaabjerg, Frede
2017-01-01
Due to the parasitic capacitances of the transformer and inductor in Dual Active Bridge (DAB) converters, resonance happens in the transformer currents. This high frequency resonant current flowing into the full bridges will worsen their soft-switching performance and thereby reduce its efficiency....... In order to study the generation mechanism of this current resonance, the impedance of the transformer and inductor with parasitic components is modelled in this digest. Then, based on the impedance model, an approach is proposed to mitigate the current resonance. Finally, both the impedance model...
Modelling of the dual frequency capacitive sheath in the intermediate pressure range
Boyle, P C; Robiche, J; Turner, M M
2004-01-01
The nonlinearity of the plasma sheath in dual frequency capacitively coupled reactors is investigated for frequencies well above the ion plasma frequency. This work focuses on the behaviour of the voltage and the sheath width with respect to the driving current source and the collisionality regime. For typical plasma processing applications, the gas pressure ranges from a few milliTorrs to hundreds of milliTorrs, and the ion dynamics span different collisional regimes. To describe these different ion dynamics, we have used a collisionless model and a variable mobility model. The sheath widths and the voltages obtained from these two models have then been compared
Motivation and justification: a dual-process model of culture in action.
Vaisey, Stephen
2009-05-01
This article presents a new model of culture in action. Although most sociologists who study culture emphasize its role in post hoc sense making, sociologists of religion and social psychologists tend to focus on the role beliefs play in motivation. The dual-process model integrates justificatory and motivational approaches by distinguishing between "discursive" and "practical" modes of culture and cognition. The author uses panel data from the National Study of Youth and Religion to illustrate the model's usefulness. Consistent with its predictions, he finds that though respondents cannot articulate clear principles of moral judgment, their choice from a list of moral-cultural scripts strongly predicts later behavior.
Dual-process models of health-related behaviour and cognition: a review of theory.
Houlihan, S
2018-03-01
The aim of this review was to synthesise a spectrum of theories incorporating dual-process models of health-related behaviour. Review of theory, adapted loosely from Cochrane-style systematic review methodology. Inclusion criteria were specified to identify all relevant dual-process models that explain decision-making in the context of decisions made about human health. Data analysis took the form of iterative template analysis (adapted from the conceptual synthesis framework used in other reviews of theory), and in this way theories were synthesised on the basis of shared theoretical constructs and causal pathways. Analysis and synthesis proceeded in turn, instead of moving uni-directionally from analysis of individual theories to synthesis of multiple theories. Namely, the reviewer considered and reconsidered individual theories and theoretical components in generating the narrative synthesis' main findings. Drawing on systematic review methodology, 11 electronic databases were searched for relevant dual-process theories. After de-duplication, 12,198 records remained. Screening of title and abstract led to the exclusion of 12,036 records, after which 162 full-text records were assessed. Of those, 21 records were included in the review. Moving back and forth between analysis of individual theories and the synthesis of theories grouped on the basis of theme or focus yielded additional insights into the orientation of a theory to an individual. Theories could be grouped in part on their treatment of an individual as an irrational actor, as social actor, as actor in a physical environment or as a self-regulated actor. Synthesising identified theories into a general dual-process model of health-related behaviour indicated that such behaviour is the result of both propositional and unconscious reasoning driven by an individual's response to internal cues (such as heuristics, attitude and affect), physical cues (social and physical environmental stimuli) as well as
Religion, fertility and genes: a dual inheritance model
Rowthorn, Robert
2011-01-01
Religious people nowadays have more children on average than their secular counterparts. This paper uses a simple model to explore the evolutionary implications of this difference. It assumes that fertility is determined entirely by culture, whereas subjective predisposition towards religion is influenced by genetic endowment. People who carry a certain ‘religiosity’ gene are more likely than average to become or remain religious. The paper considers the effect of religious defections and exogamy on the religious and genetic composition of society. Defections reduce the ultimate share of the population with religious allegiance and slow down the spread of the religiosity gene. However, provided the fertility differential persists, and people with a religious allegiance mate mainly with people like themselves, the religiosity gene will eventually predominate despite a high rate of defection. This is an example of ‘cultural hitch-hiking’, whereby a gene spreads because it is able to hitch a ride with a high-fitness cultural practice. The theoretical arguments are supported by numerical simulations. PMID:21227968
Religion, fertility and genes: a dual inheritance model.
Rowthorn, Robert
2011-08-22
Religious people nowadays have more children on average than their secular counterparts. This paper uses a simple model to explore the evolutionary implications of this difference. It assumes that fertility is determined entirely by culture, whereas subjective predisposition towards religion is influenced by genetic endowment. People who carry a certain 'religiosity' gene are more likely than average to become or remain religious. The paper considers the effect of religious defections and exogamy on the religious and genetic composition of society. Defections reduce the ultimate share of the population with religious allegiance and slow down the spread of the religiosity gene. However, provided the fertility differential persists, and people with a religious allegiance mate mainly with people like themselves, the religiosity gene will eventually predominate despite a high rate of defection. This is an example of 'cultural hitch-hiking', whereby a gene spreads because it is able to hitch a ride with a high-fitness cultural practice. The theoretical arguments are supported by numerical simulations.
Kay-Michael Voit
2013-01-01
Full Text Available Holographic spectroscopy is highlighted as a powerful tool for the analysis of photosensitive materials with pronounced alterations of the complex permittivity over a broad range in the visible spectrum, due to the advances made both in the fields of advanced holographic media and highly tunable lasers systems. To analytically discuss consequences for in- and off-Bragg reconstruction, we revised Kogelnik’s coupled wave theory strictly on the basis of complex permittivities. We extended it to comply with modern experimental parameters such as out-of-phase mixed holograms and highly modulated gratings. A spatially modulated, wavelength-dependent permittivity that superimposes a spatially homogeneous wavelength-dependent ground state spectrum is taken into account for signal wave reconstruction with bulky elementary mixed gratings as an example. The dispersion characteristics of the respective diffraction efficiency is modelled for color-center-absorption and absorption of strongly localized carriers. As an example for the theoretical possibilities of our newly derived set of equations, we present a quantitative analysis of the Borrmann effect connected to out-of-phase gratings, providing easier and more intuitive methods for the derivation of their grating parameters.
Moving through a multiplex holographic scene
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'.
Read-only high accuracy volume holographic optical correlator
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.
C P -odd sector and θ dynamics in holographic QCD
Areán, Daniel; Iatrakis, Ioannis; Järvinen, Matti; Kiritsis, Elias
2017-07-01
The holographic model of V-QCD is used to analyze the physics of QCD in the Veneziano large-N limit. An unprecedented analysis of the C P -odd physics is performed going beyond the level of effective field theories. The structure of holographic saddle points at finite θ is determined, as well as its interplay with chiral symmetry breaking. Many observables (vacuum energy and higher-order susceptibilities, singlet and nonsinglet masses and mixings) are computed as functions of θ and the quark mass m . Wherever applicable the results are compared to those of chiral Lagrangians, finding agreement. In particular, we recover the Witten-Veneziano formula in the small x →0 limit, we compute the θ dependence of the pion mass, and we derive the hyperscaling relation for the topological susceptibility in the conformal window in terms of the quark mass.
Holographic metal-insulator transition in higher derivative gravity
Ling, Yi, E-mail: lingy@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai, 200444 (China); Liu, Peng, E-mail: liup51@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wu, Jian-Pin, E-mail: jianpinwu@mail.bnu.edu.cn [Institute of Gravitation and Cosmology, Department of Physics, School of Mathematics and Physics, Bohai University, Jinzhou 121013 (China); Shanghai Key Laboratory of High Temperature Superconductors, Shanghai, 200444 (China); Zhou, Zhenhua, E-mail: zhouzh@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)
2017-03-10
We introduce a Weyl term into the Einstein–Maxwell-Axion theory in four dimensional spacetime. Up to the first order of the Weyl coupling parameter γ, we construct charged black brane solutions without translational invariance in a perturbative manner. Among all the holographic frameworks involving higher derivative gravity, we are the first to obtain metal-insulator transitions (MIT) when varying the system parameters at zero temperature. Furthermore, we study the holographic entanglement entropy (HEE) of strip geometry in this model and find that the second order derivative of HEE with respect to the axion parameter exhibits maximization behavior near quantum critical points (QCPs) of MIT. It testifies the conjecture in that HEE itself or its derivatives can be used to diagnose quantum phase transition (QPT).
Photon structure functions at small x in holographic QCD
Watanabe, Akira; Li, Hsiang-nan
2015-01-01
We investigate the photon structure functions at small Bjorken variable x in the framework of the holographic QCD, assuming dominance of the Pomeron exchange. The quasi-real photon structure functions are expressed as convolution of the Brower–Polchinski–Strassler–Tan (BPST) Pomeron kernel and the known wave functions of the U(1) vector field in the five-dimensional AdS space, in which the involved parameters in the BPST kernel have been fixed in previous studies of the nucleon structure functions. The predicted photon structure functions, as confronted with data, provide a clean test of the BPST kernel. The agreement between theoretical predictions and data is demonstrated, which supports applications of holographic QCD to hadronic processes in the nonperturbative region. Our results are also consistent with those derived from the parton distribution functions of the photon proposed by Glück, Reya, and Schienbein, implying realization of the vector meson dominance in the present model setup.
Modelling and simulation of a thermally induced optical transparency in a dual micro-ring resonator.
Lydiate, Joseph
2017-07-01
This paper introduces the simulation and modelling of a novel dual micro-ring resonator. The geometric configuration of the resonators, and the implementation of a simulated broadband excitation source, results in the realization of optical transparencies in the combined through port output spectrum. The 130 nm silicon on insulator rib fabrication process is adopted for the simulation of the dual-ring configuration. Two titanium nitride heaters are positioned over the coupling regions of the resonators, which can be operated independently, to control the spectral position of the optical transparency. A third heater, centrally located above the dual resonator rings, can be used to red shift the entire spectrum to a required reference resonant wavelength. The free spectral range with no heater currents applied is 4.29 nm. For a simulated heater current of 7 mA (55.7 mW heater power) applied to one of the through coupling heaters, the optical transparency exhibits a red shift of 1.79 nm from the reference resonant wavelength. The ring-to-ring separation of approximately 900 nm means that it can be assumed that there is a zero ring-to-ring coupling field in this model. This novel arrangement has potential applications as a gas mass airflow sensor or a gas species identification sensor.
Holographic Protection of Chronology in Universes of the Godel Type
Boyda, Edward; Ganguli, Surya; Horava, Petr; Varadarajan, Uday
2002-12-07
We analyze the structure of supersymmetric Godel-like cosmological solutions of string theory. Just as the original four-dimensional Godel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on"phenomenological" aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Godel universes. We find that holography can serve as a chronology protection agency: The closed timelike curves are either hidden behind the holographic screen, or broken by it into causal pieces. In fact, holography in Godel universes has many features in common with de Sitter space, suggesting that Godel universes could represent a supersymmetric laboratory for addressing the conceptual puzzles of de Sitter holography. Then we initiate the investigation of"microscopic" aspects of holography of Godel universes in string theory. We show that Godel universes are T-dual to pp-waves, and use this fact to generate new Godel-like solutions of string and M-theory by T-dualizing known supersymmetric pp-wave solutions.
Holographic protection of chronology in universes of the Goedel type
Boyda, Edward K.; Ganguli, Surya; Horava, Petr; Varadarajan, Uday
2003-01-01
We analyze the structure of supersymmetric Goedel-like cosmological solutions of string theory. Just as the original four-dimensional Goedel universe, these solutions represent rotating, topologically trivial cosmologies with a homogeneous metric and closed timelike curves. First we focus on the 'phenomenological' aspects of holography, and identify the preferred holographic screens associated with inertial comoving observers in Goedel universes. We find that holography can serve as a chronology protection agency: The closed timelike curves are either hidden behind the holographic screen, or broken by it into causal pieces. In fact, holography in Goedel universes has many features in common with de Sitter space, suggesting that Goedel universes could represent a supersymmetric laboratory for addressing the conceptual puzzles of de Sitter holography. Then we initiate the investigation of 'microscopic' aspects of holography of Goedel universes in string theory. We show that Goedel universes are T dual to pp waves, and use this fact to generate new Goedel-like solutions of string and M theory by T dualizing known supersymmetric pp-wave solutions
Brink, L; Scherk, J
1973-01-01
Study of the non-planar orientable single dual loop diagrams in 26 space-time dimensions has revealed an infinite positive-definite spectrum of 'pomeron' intermediate states which couple to reggeons via a bilinear pomeron-reggeon vertex operator. General algebraic techniques are developed to derive the behaviour of this vertex with respect to the Visasoro gauge operators. A reflection and transmission behaviour is found, reminiscent of the behaviour of a wave incident at the interface between two different media (in this case reggeonic and pomeronic). These gauge properties are such as to guarantee the desired 'good properties', namely completeness of the transverse reggeon states when coupled between physical reggeon states on one side, and on the other side, either physical pomeron states or else physical reggeon states created via an intermediate pomeron. This is yet another example of the amazing and gratifying self-consistency of the dual model with respect to duality, transversality and unitarity. (13 r...
Holographic stress-energy tensor near the Cauchy horizon inside a rotating black hole
Ishibashi, Akihiro; Maeda, Kengo; Mefford, Eric
2017-07-01
We investigate a stress-energy tensor for a conformal field theory (CFT) at strong coupling inside a small five-dimensional rotating Myers-Perry black hole with equal angular momenta by using the holographic method. As a gravitational dual, we perturbatively construct a black droplet solution by applying the "derivative expansion" method, generalizing the work of Haddad [Classical Quantum Gravity 29, 245001 (2012), 10.1088/0264-9381/29/24/245001] and analytically compute the holographic stress-energy tensor for our solution. We find that the stress-energy tensor is finite at both the future and past outer (event) horizons and that the energy density is negative just outside the event horizons due to the Hawking effect. Furthermore, we apply the holographic method to the question of quantum instability of the Cauchy horizon since, by construction, our black droplet solution also admits a Cauchy horizon inside. We analytically show that the null-null component of the holographic stress-energy tensor negatively diverges at the Cauchy horizon, suggesting that a singularity appears there, in favor of strong cosmic censorship.
Lifshitz scaling effects on holographic superconductors
Lu, Jun-Wang; Wu, Ya-Bo; Qian, Peng; Zhao, Yue-Yue; Zhang, Xue; Zhang, Nan
2014-01-01
Via numerical and analytical methods, the effects of the Lifshitz dynamical exponent z on the holographic superconductor models are studied in some detail, including s-wave and p-wave models. Working in the probe limit, we calculate the condensation and conductivity in both Lifshitz black hole and soliton backgrounds with a general z. For both the s-wave and p-wave models in the black hole backgrounds, as z increases, the phase transition becomes difficult and the conductivity is suppressed. For the Lifshitz soliton background, when z increases, the critical chemical potential increases in both the s-wave model (with a fixed mass of the scalar field) and p-wave model. For the p-wave model in both the Lifshitz black hole and soliton backgrounds, the anisotropy between the AC conductivity in different spatial directions is suppressed when z increases. In all cases, we find that the critical exponent of the condensation is always 1/2, independent of z and spacetime dimension. The analytical results from the Sturm–Liouville variational method uphold the numerical calculations. The implications of these results are discussed
Richardson, George B; Hardesty, Patrick
2012-01-01
Researchers have recently applied evolutionary life history theory to the understanding of behaviors often conceived of as prosocial or antisocial. In addition, researchers have applied cognitive science to the understanding of substance use and used dual process models, where explicit cognitive processes are modeled as relatively distinct from implicit cognitive processes, to explain and predict substance use behaviors. In this paper we synthesized these two theoretical perspectives to produce an adaptive and cognitive framework for explaining substance use. We contend that this framework provides new insights into the nature of substance use that may be valuable for both clinicians and researchers.
George B. Richardson
2012-10-01
Full Text Available Researchers have recently applied evolutionary life history theory to the understanding of behaviors often conceived of as prosocial or antisocial. In addition, researchers have applied cognitive science to the understanding of substance use and used dual process models, where explicit cognitive processes are modeled as relatively distinct from implicit cognitive processes, to explain and predict substance use behaviors. In this paper we synthesized these two theoretical perspectives to produce an adaptive and cognitive framework for explaining substance use. We contend that this framework provides new insights into the nature of substance use that may be valuable for both clinicians and researchers.
The Dual Rounding Model: Forging Therapeutic Alliances in Oncology and Palliative Care.
Baxley, Carey E
2016-04-01
Inpatients with solid tumors at Duke University Hospital in Durham, NC, are cared for in a dynamic integrated care model that incorporates medical oncology and palliative care. This has profound implications for patients, their loved ones, medical and surgical staff, and oncology nurses. As a nurse with less than three years of experience, my participation in a setting that uses the Dual Rounding Model has accelerated my professional and personal development. During a typical shift, I am an oncology nurse, a palliative care nurse, and a hospice nurse. .
Establishment and analysis of coupled dynamic model for dual-mass silicon micro-gyroscope
Wang, Zhanghui; Qiu, Anping; Shi, Qin; Zhang, Taoyuan
2017-12-01
This paper presents a coupled dynamic model for a dual-mass silicon micro-gyroscope (DMSG). It can quantitatively analyze the influence of left-right stiffness difference on the natural frequencies, modal matrix and modal coupling coefficient of the DMSG. The analytic results are verified by using the finite element method (FEM) simulation. The model shows that with the left-right stiffness difference of 1%, the modal coupling coefficient is 12% in the driving direction and 31% in the sensing direction. It also shows that in order to achieve good separation, the stiffness of base beam should be small enough in both the driving and sensing direction.
Holographic RG flows on curved manifolds and quantum phase transitions
Ghosh, J. K.; Kiritsis, E.; Nitti, F.; Witkowski, L. T.
2018-05-01
Holographic RG flows dual to QFTs on maximally symmetric curved manifolds (dS d , AdS d , and S d ) are considered in the framework of Einstein-dilaton gravity in d + 1 dimensions. A general dilaton potential is used and the flows are driven by a scalar relevant operator. The general properties of such flows are analyzed and the UV and IR asymptotics computed. New RG flows can appear at finite curvature which do not have a zero curvature counterpart. The so-called `bouncing' flows, where the β-function has a branch cut at which it changes sign, are found to persist at finite curvature. Novel quantum first-order phase transitions are found, triggered by a variation in the d-dimensional curvature in theories allowing multiple ground states.
Holographic description of AdS2 black holes
Castro, Alejandra; Larsen, Finn; Grumiller, Daniel; McNees, Robert
2008-01-01
We develop the holographic renormalization of AdS 2 gravity systematically. We find that a bulk Maxwell term necessitates a boundary mass term for the gauge field and verify that this unusual term is invariant under gauge transformations that preserve the boundary conditions. We determine the energy-momentum tensor and the central charge, recovering recent results by Hartman and Strominger. We show that our expressions are consistent with dimensional reduction of the AdS 3 energy-momentum tensor and the Brown-Henneaux central charge. As an application of our results we interpret the entropy of AdS 2 black holes as the ground state entropy of a dual CFT.
On holographic entanglement entropy with second order excitations
He, Song; Sun, Jia-Rui; Zhang, Hai-Qing
2018-03-01
We study the low-energy corrections to the holographic entanglement entropy (HEE) in the boundary CFT by perturbing the bulk geometry up to second order excitations. Focusing on the case that the boundary subsystem is a strip, we show that the area of the bulk minimal surface can be expanded in terms of the conserved charges, such as mass, angular momentum and electric charge of the AdS black brane. We also calculate the variation of the energy in the subsystem and verify the validity of the first law-like relation of thermodynamics at second order. Moreover, the HEE is naturally bounded at second order perturbations if the cosmic censorship conjecture for the dual black hole still holds.
On holographic entanglement entropy with second order excitations
Song He
2018-03-01
Full Text Available We study the low-energy corrections to the holographic entanglement entropy (HEE in the boundary CFT by perturbing the bulk geometry up to second order excitations. Focusing on the case that the boundary subsystem is a strip, we show that the area of the bulk minimal surface can be expanded in terms of the conserved charges, such as mass, angular momentum and electric charge of the AdS black brane. We also calculate the variation of the energy in the subsystem and verify the validity of the first law-like relation of thermodynamics at second order. Moreover, the HEE is naturally bounded at second order perturbations if the cosmic censorship conjecture for the dual black hole still holds.
Niemann, Hans Henrik
2003-01-01
A different aspect of using the parameterisation of all systems stabilised by a given controller, i.e. the dual Youla parameterisation, is considered. The relation between system change and the dual Youla parameter is derived in explicit form. A number of standard uncertain model descriptions...... are considered and the relation with the dual Youla parameter given. Some applications of the dual Youla parameterisation are considered in connection with the design of controllers and model/performance validation....
Qualification of MHD effects in dual-coolant DEMO blanket and approaches to their modelling
Mas de les Valls, E.; Batet, L.; Medina, V. de; Fradera, J.; Sedano, L.A.
2011-01-01
Design refinements of vertical insulated banana-shaped liquid metal channels are being considered as a progress of conceptual design of dual-coolant liquid metal blankets (DEMO specifications). Among them: (a) optimised channel geometry and (b) improvements on flow channel inserts. Progress of channel conceptual design is conducted in parallel with underlying physics of MHD models in diverse aspects: (1) MHD models, (2) MHD turbulence, (3) LM buoyancy effects, (4) three-dimensional flows, and (5) LM/FCI/wall electrical and thermal coupling; in order to progress on common liquid metal flow characterisation, pressure drop and three-dimensional flows. The analyses are assumed as extension of those previous carried out for the DCLL blankets for new design refinements. At the present stage of the conceptual design progress, a preliminary thermofluid MHD study is of crucial interest for further design improvements and future detailed modelling. The paper overviews the ongoing modelling studies, making model refinements explicit, and anticipates some modelling results.