https://jhap.du.ac.ir/ Journal of Holography Applications in Physics en daily 1 Mon, 13 Jul 2026 00:00:00 +0330 Mon, 13 Jul 2026 00:00:00 +0330 https://jhap.du.ac.ir/article_2114.html I'll begin  with some well-deserved acknowledgements: I am grateful to Daniel Harlow for discussions of time-reversal holonomies. I have also benefited from a long ongoing correspondence with Edward Witten, but frankly in both cases I can't tell whether they agree with me or not. I have often been accused of imprecision, especially toward the later parts of a paper, where I expect that my readers have ``caught on." That does eventually happen-the readers catching on and I thank them-but I'm now almost 86 and I can't wait. So I've  tried to maintain a level of conceptual if not mathematical rigor throughout. Mathematical rigor(mortis) can sometimes be the enemy of conceptual clarity. I thank my friend Richard Feynman for  reminding me of that lesson. Finally I thank the chatbot who gave me the definition of scaffold in section 1.3. It was better than anything I was able to do. Symmetries of a  Holographic  theory; whether continuous or discrete, local or global,  are gauge symmetries of the bulk. This includes discrete space-time symmetries such as C and P.  But time-reversal is sufficiently different from other symmetries  that we may question the standard wisdom and ask whether symmetries involving T should be gauged in the bulk. Harlow and Numasawa [1] say yes; time-reversal is a gauge symmetry. Witten [2]  says no: time reversal is different and does not manifest as a gauge symmetry of the bulk. My view is-yes-but with a  twist: Time-reversal is indeed a gauge symmetry; but it is hidden by  spontaneous symmetry  breaking. In this paper I will review the case for spontaneous symmetry  breaking of time-reversal and explain the ``smoking gun"-a closed curve and a holonomy  which flips forward-going clocks to backward going clocks, and vice versa. https://jhap.du.ac.ir/article_2151.html The equation for the function F(T) within the teleparallel gravity with torsion field T which provides the exponential scale factor is obtained and the function F(T) was computed. It is shown that the deceleration parameter $q_0\approx -0.535$, according to the Planck data at the current epoch, can not be realized for cosmology based on the exponential scale factor. In the framework of entropic cosmology, the associated entropy was found. https://jhap.du.ac.ir/article_2133.html We construct a static spherically symmetric black hole (BH) solution in Kalb-Ramond (KR) gravity that simultaneously hosts a Hayward magnetic-monopole regular core, a Letelier cloud of strings (CoS), and an anti-de Sitter (AdS) asymptote with the cosmological constant identified as thermodynamic pressure. The lapse function $f(r)=(1-\alpha_{s})/(1-\ell)-2Mr^{2}/[(1-\ell)(r^{3}+g^{3})]+8\pi P r^{2}/[3(1-\ell)]$ carries four independent parameters with transparent physical roles: the KR Lorentz-violation (LV) parameter $\ell$ rescales the asymptotic potential, the Hayward length $g$ removes the central singularity, the CoS deficit $\alpha_{s}$ deforms the solid angle, and $P=-\Lambda/8\pi$ sets the AdS curvature. Symbolic verification confirms regularity of every curvature invariant at $r=0$, with $f(r)$ admitting a finite limit and reducing to the Ditta {\it et al.} (JHEAP 2025) solution as $g\to 0$, $\alpha_{s}\to 0$. We work out the horizon structure, photon sphere $r_{\rm ph}$ and shadow radius $r_{\rm sh}$, weak-deflection lensing via the Gauss-Bonnet theorem (GBT), innermost stable circular orbits (ISCO), Hawking temperature, Bekenstein-Hawking entropy, heat capacity, Gibbs free energy, $P$-$V$ criticality, Joule-Thomson (JT) inversion, and the eikonal quasinormal-mode (QNM) spectrum. The Van der Waals (VdW) critical point exists across the whole window of $g$ tested above $g\to 0$, with the universal ratio $\rho_{c}\equiv P_{c}v_{c}/T_{c}$ depending on $\ell$ alone through the factorisation $\rho_{c}=(1-\ell)\,\rho_{c}^{\rm Hay\text{-}AdS}$ with $\rho_{c}^{\rm Hay\text{-}AdS}=0.39303$, so that the reference $(\alpha_{s},\ell)=(0.05,0.10)$ configuration gives $\rho_{c}=0.354$, $5.6\%$ below the standard $3/8$ value of the charged-AdS class. The Wei-Liu-Mann thermodynamic-topology classification places the solution in the $W=+1$ topological class, the same as Reissner-Nordstr\"om-AdS (RN-AdS): three BH branches appear below $\tau_{c}$ with windings $\{+1,-1,+1\}$, merge at $\tau_{c}$, and reduce to one $W=+1$ branch above $\tau_{c}$. The numerical analysis shows that $\alpha_{s}$ and $\ell$ act on photon and scalar-wave barriers in opposite directions. The combined dependence makes the four parameters separately identifiable in principle from a joint shadow-ringdown measurement at Event Horizon Telescope (EHT) angular resolution and LIGO/Virgo ringdown sensitivity. https://jhap.du.ac.ir/article_2136.html Digital holography has emerged as a powerful label-free imaging modality for quantitative interrogation of microscale flow phenomena in microfluidic and biomedical systems; however, conventional reconstruction methods remain limited by ill-posed inverse formulations, noise sensitivity, twin-image artifacts, and substantial computational cost. Recent advances in artificial neural networks (ANNs) have transformed this landscape through data-driven, physics-informed, and hybrid reconstruction strategies that improve phase retrieval, denoising, particle tracking, and velocity estimation while enabling near real-time diagnostics. Following a PRISMA-guided critical synthesis, this review systematically examines the evolution of ANN-assisted digital holography, spanning optical foundations, conventional computational reconstruction, deep learning frameworks, and emerging physics-constrained models. Existing approaches are organized into physics-based, data-driven, and hybrid paradigms, and critically bench marked in terms of reconstruction fidelity, computational efficiency, automation readiness, and diagnostic applicability. Particular emphasis is placed on applications in flow cytometry, microcirculation analysis, label-free disease detection, and intelligent lab-on-a-chip diagnostics. The review further identifies persistent challenges involving model generalization, annotated data scarcity, explainability, and multiphysics integration, while highlighting emerging opportunities in physics-informed learning, autonomous holographic diagnostics, and digital twin-enabled flow monitoring. By consolidating current advances and outlining a strategic research roadmap, this work establishes a unified framework for next-generation intelligent quantitative flow diagnostics through the convergence of digital holography and artificial intelligence. https://jhap.du.ac.ir/article_2118.html Holography asserts that the dynamics of a gravitational system may be determined by degrees of freedom associated with a lower-dimensional structure, rather than by independent volumetric variables. While this principle is well established in boundary-based constructions, its realization in cosmology has remained elusive due to the absence of fixed asymptotic boundaries. In this work, we present an explicit realization of holography in cosmology arising directly from the hyperbolic structure of general relativity. We show that the nonlinear evolution of the Einstein equations coupled to a scalar field generically produces a global control structure identified with the cosmological apparent horizon. By applying the Unified First Law of Thermodynamics ($-dE = T\,dS$) to this horizon, we obtain a geometric closure for the net exchange flux $Q$ under the explicit assumption that the only energy exchange between the bulk and the auxiliary (unresolved) sector is mediated through the apparent-horizon screen, constraining the bulk energy density to scale as $\rho \propto L^{-2}$ and thereby imposing a Bekenstein-Hawking area law ($S \propto A$) on the bulk entropy. We demonstrate that bulk cosmological observables -- including the expansion history and late-time acceleration -- are functionals of this codimension-one structure rather than independent volumetric degrees of freedom. The construction constitutes a concrete, equation-level realization of holography in cosmology, achieved via dynamical dimensional reduction of the phase space. https://jhap.du.ac.ir/article_2147.html We examine holographic and Barrow holographic dark energy (HDE and BHDE) models in the framework of $f(Q,B)$ gravity with $f(Q,B)=\alpha Q^{n}+\beta B^{m}$. The cosmic evolution is analyzed using the Hubble function $H(z)=H_{0}\sqrt{\Omega_{m0}(1+z)^{3}+(1-\Omega_{m0})\left[1+\varepsilon\ln(1+z)\right]}$, constrained through a joint analysis of CC46, DESI DR2 BAO and Pantheon+ datasets. The best-fit parameters are $H_{0}= 67.5868^{+1.2115}_{-1.2320}~\mathrm{km\,s^{-1}\,Mpc^{-1}}$, $\Omega_{m0}=0.2654^{+0.0182}_{-0.0170}$ and $\varepsilon= 0.0230^{+0.2614}_{-0.2496}$, consistent with Planck 2018 and mildly alleviating the Hubble tension. For the HDE model, $\omega_{0}\simeq -0.885$ (Hubble cutoff) and $\omega_{0}\simeq -0.742$ (Granda--Oliveros cutoff), while for BHDE, $\omega_{0}\simeq -0.648$, indicating quintessence-like behavior. The NEC and DEC hold, whereas the SEC is violated, supporting cosmic acceleration. The transition redshift is $z_{\mathrm{tr}}\simeq 0.74$, the present value $q_{0} = -0.574$ and the Universe’s age is $t_{0}=13.24~\mathrm{Gyr}$. Compared to HDE, the BHDE model exhibits a smoother and more stable late-time evolution, showing that Barrow entropy corrections enhance the dynamical nature of dark energy in $f(Q,B)$ gravity. https://jhap.du.ac.ir/article_2107.html We investigate the thermodynamic properties of four-dimensional cylindrically symmetric black strings embedded in an Anti-de Sitter (AdS) spacetime. By incorporating the Generalized Uncertainty Principle (GUP), we introduce minimal length corrections to the thermodynamic framework, thereby capturing quantum gravity effects in the near-horizon regime. We demonstrate that these GUP-induced modifications lead to logarithmic corrections in the entropy-area relation, particularly for small horizon radii, while preserving thermodynamic consistency with the first law of thermodynamics. Through a detailed analysis of the Helmholtz and Gibbs free energies, we observe that the equation of state is significantly deformed by quantum corrections, driving instabilities in black strings with sufficiently small horizon radii. The study of specific heat capacity further confirms a phase transition from stable to unstable configurations, highlighting the role of the minimal length scale on the thermal stability of black string systems. https://jhap.du.ac.ir/article_2122.html In this work, based on an analogy with holographic confining geometries and using complexified fields, we build a holographic toy model of third order photonic exceptional points (EPs) of ternary coupled microrings with gain and loss, which makes an open, non-Hermitian quantum system. In our model, we discuss the Ferrell-Glover-Tinkham sum rule for various combinations of gain and loss systems, and numerically find the behavior of spectra which matches with the experiments. We also discuss the inhomogeneous case of a holographic lattice for three-site photonic EPs. Additionally, we numerically find the behavior of phase rigidity and the Petermann factor around EPs versus various parameters of the model. We also discuss the connections between recent developments in complexified, time-dependent entanglement entropy and EPs, and then, we connect EPs and the $\theta$-vacuum of QCD through topological structures, partition functions, and winding numbers, and find a second-order EP in a perturbed $\theta$-vacuum model. Finally, we examined a controlled non-Hermitian deformation of $\theta$-vacuum toy model, by using the Lindblad formalism and Liouvillian eigenvalues. https://jhap.du.ac.ir/article_2124.html We propose that the Big Bang can be understood as a cosmic-scale entanglement transition occurring in a pre-geometric quantum state. Motivated by the black hole information paradox and the AMPS argument, we interpret the pre-Bang phase as an over-constrained entanglement structure producing a monogamy tension, rather than a fundamental violation of quantum mechanics. The resulting cosmic firewall is not a localized destructive barrier, but a global reorganization of quantum correlations that preserves fine-grained unitarity while allowing the emergence of semiclassical spacetime. We model the pre-Bang substrate as a quantum graph whose highly connected phase encodes dense pre-geometric correlations. Within a semiclassical approximation, the replica trick applied to the gravitational path integral leads to an entanglement--cosmology scaling relation linking variations of entanglement entropy to variations of the effective cosmological constant through the normalized spacetime volume of the emergent background. This scaling is consistent with the known dependence of de Sitter entropy on the cosmological constant. The framework provides a unitary information-theoretic mechanism for spacetime emergence, connects the thermodynamic arrow of time to post-transition entanglement growth, and extends the firewall paradigm from black hole horizons to cosmological initial conditions. It also suggests possible observational windows in primordial non-Gaussianities, stochastic gravitational-wave backgrounds, and ultra-slow variations of effective couplings. https://jhap.du.ac.ir/article_2115.html We argue, in the context of AdS/CFT correspondence, that the structure of the geometry dual to two entangled CFTs is a time non-orientable spacetime. Further, we elevate this argument to any entangled quantum system. Accordingly, we should expect entangled quantum systems (particles in a subsidiary) not to experience the flow of time. As a result, the lifetimes of the entangled particles should be considerably longer than those of their unentangled counterparts.   https://jhap.du.ac.ir/article_2153.html In this work, we investigate the cosmological dynamics of the $f(Q,T) = \alpha Q + \beta T$ gravity model by considering a time-dependent scale factor as $a(t) = (\sinh(\alpha t))^{1/n}$. The corresponding field equations are solved to obtain the cosmological parameters in terms of redshift. The model parameters are constrained employing observational datasets consisting of Hubble, DESI BAO, and Union3 supernova data using the Markov Chain Monte Carlo (MCMC) method. The physical behavior of the derived model is examined by analysis of the deceleration parameter,pressure, energy density, equation of state parameter, and the \(Om(z)\) diagnostic, while the physical credibility of the model is investigated using the energy conditions. Collectively, the model provides a consistent description of the accelerated expansion of the Universe at late-times and remains compatible based on observational data.