arXiv subjects

Hui-Hua Zhao

Publications and source records attributed to Hui-Hua Zhao.

14 recordsLinked to original sources

arXiv2026

Thermodynamic phase structure and topological charge of Hayward-AdS black holes under phase space constraints

We investigate the thermodynamic behavior of the Hayward-AdS black hole and compare it with its singular counterpart from which it can be constructed through the imposition of an additional constraint. The singular black hole displays a rich phase structure, including reentrant phase transitions reminiscent of those observed in higher-dimensional Kerr-AdS spacetimes. After the constraint is imposed, the resulting Hayward-AdS black hole continues to exhibit Van der Waals-type $P-V$ criticality. However, its Gibbs free energy profile differs qualitatively from that of standard RN-AdS black holes. In addition, we extend the analysis by employing thermodynamic topology to characterize the global structure of the phase space. We find that the topological charge of the singular black hole is $-1$, whereas that of the Hayward-AdS black hole becomes $+1$. This change of topological charge indicates that the constraint not only regularizes the geometry but also induces a qualitative transformation in the thermodynamic configuration space.

hep-th↗

arXiv2025

Thermodynamics of Barrow Einstein-power-Yang-Mills AdS black hole in the restricted phase space

As we know that due to the quantum gravitational effects black hole horizons are ``fractalized'' into a sphereflake by Barrow. Based on this issue, in this work we investigate the phase structure and stability of the Einstein-Power-Yang-Mills AdS black holes with the fractal structure on the black hole horizon in the restricted phase space. Through the thermodynamics first law and the Smarr relation in the restricted phase space, we observe that the mass parameter is understood as the inter energy and the Smarr relation is not a homogeneous function of order one for all quantities due to the fractal structure. And the fractal structure can be regarded as a phase transition probe. When this system with the fixed central charge there exists a novel phenomena: the supercritical phase transition. Furthermore the effects of the fractal parameter and non-linear Yang-Mills parameter on the thermodynamics stability of this system are also investigated.

hep-th↗

arXiv2021

Entropic force between two horizons of dilaton black holes with a power-Maxwell field

In this paper, we consider $(n+1)$-dimensional topological dilaton de Sitter black holes with power-Maxwell field as thermodynamic systems. The thermodynamic quantities corresponding to the black hole horizon and the cosmological horizon respectively are interrelated. So the total entropy of the space-time should be the sum of the entropies of the black hole horizon and the cosmological horizon plus a corrected term which is produced by the association of the two horizons. We analyze the entropic force produced by the corrected term at given temperatures, which is affected by parameters and dimensions of the space-time. It is shown that the change of entropic force with the position ratio of two horizons in some region is similar to that of Lennard-Jones force with the position of particles. If the effect of entropic force is similar to that of Lennard-Jones force, and other forces are absent, the motion of the cosmological horizon relative to the black hole horizon would have an oscillating process. The entropic force between the two horizons is probably one of the participants to drive the evolution of universe.

hep-th↗

arXiv2020

Microstructure and Continuous Phase Transition of the Gauss-Bonnet AdS Black Hole

The phase transition of the Gauss-Bonnet AdS black hole has the similar property with the van der Waals thermodynamic system. However, it is determined by the Gauss-Bonnet coefficient α, not only the horizon radius. Furthermore, the phase transition is not the pure one between a big black hole and a small black hole. With this issue, we introduce a new order parameter to investigate the critical phenomenonand to give the microstructure explanation of the Gauss-Bonnet AdS black hole phase transition. And the critical exponents are also obtained. At the critical pointof the Gauss-Bonnet AdS black hole, we reveal the microstructure of the black hole by investigating the thermodynamic geometry. These results perhaps provide some certain help to deeply explore the black hole microscopic structure and to build the quantum gravity.

hep-th↗

arXiv2018

Maxwell's equal area law for black holes in power Maxwell invariant

In this paper, we consider the phase transition of black hole in power Maxwell invariant by means of Maxwell's equal area law. First, we review and study the analogy of nonlinear charged black hole solutions with the Van der Waals gas-liquid system in the extended phase space, and obtain isothermal $P$-$v$ diagram. Then, using the Maxwell's equal area law we study the phase transition of AdS black hole with different temperatures. Finally, we extend the method to the black hole in the canonical (grand canonical) ensemble in which charge (potential) is fixed at infinity. Interestingly, we find the phase transition occurs in the both ensembles. We also study the effect of the parameters of the black hole on the two-phase coexistence. The results show that the black hole may go through a small-large phase transition similar to those of usual non-gravity thermodynamic systems.

gr-qc↗

arXiv2018

Clapeyron equation and phase equilibrium properties in higher dimensional charged topological dilaton AdS black holes with a nonlinear source

Using Maxwell's equal area law, we discuss the phase transition of higher dimensional charged topological dilaton AdS black holes with a nonlinear source. The coexisting region of the two phases is found and we depict the coexistence region in $P-v$ diagrams. The two-phase equilibrium curves in $P-T$ diagrams are plotted, and we take the first order approximation of volume $v$ in the calculation. To better compare with a general thermodynamic system, the Clapeyron equation is derived for higher dimensional charged topological black hole with a nonlinear source. The latent heat of isothermal phase transition is investigated. We also study the effect of the parameters of the black hole on the region of two-phases coexistence. The results show that the black hole may go through a small-large phase transition similar to those of usual non-gravity thermodynamic systems.

gr-qc↗

arXiv2017

Thermodynamics and critical behaviors of topological dS black holes with nonlinear source

We discuss black hole solutions of Einstein gravity in presence of nonlinear electrodynamics in dS spacetime. Considering prescribed entropy, thermodynamic volume of dS spacetime, We investigate properties of the effective thermodynamic quantities under influence of nonlinearity parameter $α$. They show a similar phase transition and criticality properties with that of black holes in AdS spacetime. And the nonlinearity parameter $α$ combined with electric charge is found to have effects on the phase structure. By the Ehrenfest equations we prove the critical phase transition is a second order equilibrium transition.

hep-th↗

arXiv2016

Phase Transition and Clapeyon Equation of Black Hole in Higher Dimensional AdS Spacetime

By Maxwell equal area law we study the phase transition in higher dimensional Anti-de Sitter (AdS) Reissner-Nordström (RN) black hole and Kerr black hole in this paper. The coexisting region of the two phases involved in the phase transition is found and the coexisting curves are shown in $P-T$ figures. We also analytically investigate the parameters which affect the coexisting curves. To better compare with ordinary thermodynamic systems, the Clapeyon equation is derived for higher dimensional AdS black holes. This paper can help to deepen the understanding of the phase transition and phase structure of AdS black holes.

hep-th↗

arXiv2015

Two-phase equilibrium properties in charged topological dilaton AdS black holes

In this paper we discuss phase transition of the charged topological dilaton AdS black holes by Maxwell equal area law. The two phases involved in the phase transition could be coexist and we depict the coexistence region in $P-v$ diagrams. The two-phase equilibrium curves in $P-T$ diagrams are plotted, the Clapeyron equation for the black hole is derived, and the latent heat of isothermal phase transition is investigated. We also analyze of the parameters of the black hole that have an effect on the two phases coexistence. The results show that the black hole may go through a small-large phase transition similar to those of usual non-gravity thermodynamic systems.

gr-qc↗

arXiv2014

Phase transition of the higher dimensional charged Gauss-Bonnet black hole in de Sitter spacetime

We study the phase transition of charged Gauss-Bonnet-de Sitter (GB-dS) black hole. For black holes in de Sitter spacetime, there is not only black hole horizon, but also the cosmological horizon. The thermodynamic quantities on the both horizons satisfy the first law of the black hole thermodynamics, respectively; moreover, there are additional connections between them. Using the effective temperature approach, we obtained the effective thermodynamic quantities of charged GB-dS black hole. According to Ehrenfest classification, we calculate some response functions and plot their figures, from which one can see that the spacetime undergoes a second-order phase transition at the critical point. It is shown that the critical values of effective temperature and pressure decrease with the increase of the value of GB parameter $α$.

gr-qc↗

arXiv2014

Thermodynamics of phase transition in higher dimensional Reissner-Nordström-de Sitter black hole

It is well known that there are black hole and the cosmological horizons for the Reissner-Nordström-de Sitter spacetime. Although the thermodynamic quantities on the horizons are not irrelevant, they satisfy the laws of black hole thermodynamics respectively. In this paper by considering the relations between the two horizons we give the effective thermodynamic quantities in $(n+2)$-dimensional Reissner-Nordström-de Sitter spacetime. The thermodynamic properties of these effective quantities are analyzed, moreover, the critical temperature, critical pressure and critical volume are obtained. We carry out an analytical check of Ehrenfest equations and prove that both Ehrenfest equations are satisfied. So the spacetime undergoes a second order phase transition at the critical point. This result is consistent with the nature of liquid--gas phase transition at the critical point, hence deepening the understanding of the analogy of charged dS spacetime and liquid--gas systems.

gr-qc↗

arXiv2013

Existence condition and phase transition of Reissner-Nordström-de Sitter black hole

After introducing the connection between the black hole horizon and the cosmological horizon, we discuss the thermodynamic properties of Reissner-Nordstrom-de Sitter (RN-dS) spacetime. We present the condition under which RN-dS black hole can exist. Employing Ehrenfest' classification we conclude that the phase transition of RN-dS black hole is the second-order one. The position of the phase transition point is irrelevant to the electric charge of the system. It only depends on the ratio of the black hole horizon and the cosmological horizon.

hep-th↗

arXiv2013

On the critical phenomena and thermodynamics of charged topological dilaton AdS black holes

In this paper, we study the phase structure and equilibrium state space geometry of charged topological dilaton black holes in $(n+1)$-dimensional anti-de Sitter spacetime. By considering the pairs of parameters $(P\sim V)$ and $(Q\sim U)$ as variables, we analyze the phase structure and critical phenomena of black holes and discuss the relation between the two kinds of critical phenomena. We find that the phase structures and critical phenomena drastically depend on the cosmological constant $l$ (or the static electric charge $Q$ of the black holes), dimensionality $n$ and dilaton field $Φ$.

gr-qc↗

arXiv2013

Quantized space-time and its influences on some physical problems

Based on the idea of quantized space-time of Snyder, we derive new generalized uncertainty principle and new modified density of states. Accordingly we discuss the influences of the modified density of states on some physical quantities and laws. In addition we analyzed the exact solution of the harmonic oscillator in Snyder's quantized space-time.

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