Holographic superfluid ring with a weak link

We explore the generation of topological defects in the course of a dynamical phase transition in a ring with a weak link, i.e., a SSS Josephson junction, from the AdS/CFT correspondence. By setting different parameters of the junction(width, steepness,depth) and the final temperature of the quench, the configurations of the charge density and condensate of the order parameters of the dual field theory are presented. Meanwhile, we observe that in the final equilibrium state, variations in parameters of the junctions only affect the configurations of the charge density and condensate of the order parameters, without altering their values outside the junction. However, variations in the final temperature will directly affect the values of the charge density and condensate of the order parameters outside of the junction. Moreover, in the final equilibrium state, we propose an analytic relation between the gauge-invariant velocity in the two superconducting states in the SSS Josephson junction, which agrees well with the numerical results.

Phase transition of non-linear charged Anti-de Sitter black holes

Understanding the thermodynamic phase transition of black holes can provide a deep insight into the fundamental properties of black hole gravity to establish the theory of quantum gravity.We investigate the condition and latent heat of phase transition for non-linear charged AdS black holes using Maxwell's equal-area law.In addition,we analyze the boundary and curve of the two-phase coexistence area in the expanded phase space.We suggest that the phase transition of the non-linear charged AdS black hole with the fixed temperature(T<T_(c))is related to the electric potential at the horizon,not only to the location of black hole horizon.Recently,the molecular number density was introduced to study the phase transition and microstructure of black holes.On this basis,we discuss the continuous phase transition of a non-linear charged AdS black hole to reveal the potential microstructure of a black hole by introducing the order parameter and using the scalar curvature.

Dynamic property of phase transition for non-linear charged anti-de Sitter black holes

Understanding the thermodynamic phase transition of black holes can provide deep insights into the fundamental properties of black hole gravity and help to establish quantum gravity.In this work,we investigate the phase transition and its dynamics for the charged EPYM AdS black hole.Through reconstructing Maxwell's equal-area law,we find there exists a high-/low-potential black hole(HPBH/LPBL)phase transition,not only the pure large/small black hole phase transition.The Gibbs free energy landscape(G_(L))is treated as a function of the black hole horizon,which is the order parameter of the phase transition due to thermal fluctuation.From the viewpoint of G_(L),the stable HPBH/LPBL states correspond to two wells of G_(L),which have the same depth.The unstable intermediate-potential black hole state corresponds to the local maximum of G_(L).Then we focus on the probability evolution governed by the Fokker-Planck equation.Through solving the Fokker-Planck equation with different reflection/absorption boundary conditions and initial conditions,the dynamics of switching between the coexistent HPBH and LPBL phases is probed within the first passage time.Furthermore,the effect of temperature on the dynamic properties of the phase transition is also investigated.

Phase equilibrium and microstructure of topological AdS black holes in massive gravity

In order to clearly understand the gravitational theory through the thermal properties of the black hole,it is important to further investigate the first-order phase transition of black holes.In this paper,we adopt different conjugate variables(P~V,T~S,C_(1)~c_(1),and C_(2)~c_(2)) and apply Maxwell's equal-area law to study the phase equilibrium of a topological black hole in massive gravity.The condition and latent heat of phase transition are displayed as well as the coexistent curve of P-T.The result shows that the phase transition of this system is the high/low electric potentials one,not only the large/small black holes one.We also analyze the effect of the model's parameters on phase transition.Furthermore we introduce a new order parameter to probe the microstructure of this system.This work will provide the theoretical basis to study the phase structure of topological black holes in massive gravity and to further explore the gravitational theory.

New holographic Weyl superconductors in Lifshitz gravity

We build holographic p-wave conductor(insulator)/superconductor models via the numerical method with a new form of Weyl coupling in five-dimensional Lifshitz gravity,and then investigate how the Weyl coupling parameterγand the Lifshitz scaling parameter z affect the superconductor models.In the conductor/superconductor model,an increase in the Weyl correction(Lifshitz scaling)enhances(inhibits)the superconductor phase transition.Meanwhile,both the Weyl correction(when the Lifshitz parameter is large enough and fixed)and the Lifshitz scaling suppress the growth of the real part of the conductivity.The Weyl correction used here(CB^(2))shows weaker effects on the critical value than the previous Weyl correction(CF^(2)).In the insulator/superconductor model,larger vaules of the Weyl parameter hinder the formation of condensate.However,in increase in the Lifshitz scaling enhances the appearance of condensate.In addition,the calculation suggests that a competitive relation may exist between the Weyl correction and the Lifshitz scaling.

Shadow thermodynamics of non-linear charged Anti-de Sitter black holes

It is well known that when vacuum polarization emerges in quantum electrodynamics,the non-linear interaction between electromagnetic fields should be considered.Moreover,the corresponding field of non-linear electrodynamics can have important effects on black hole physics.In this work,we focus on the relationship between an observable quantity,that is,the shadow radius,and the first-order phase transition of non-linear charged AdS black holes in the framework of Einstein-power-Yang-Mills gravity.The results show that,under a certain condition,there exists a first-order phase transition from the viewpoint of both the shadow radius and horizon radius,which depend on temperature(or pressure).From the viewpoint of the shadow radius,the phase transition temperature is higher than that from the viewpoint of the horizon radius under the same condition.This may be due to the non-linear Yang Mills charge and the gravitational effect.This indicates that the shadow radius can be regarded as a probe to reveal the thermodynamic phase transition information of black holes.The thermal profiles of coexistent large and small black hole phases when the system is undergoing the phase transition are presented for two different values of the non-linear Yang Mills charge parameter:γ=1,1.5.Furthermore,the effects of the non-linear Yang Mills charge parameter on the shadow radius and thermal profile are investigated.

Continuous phase transition of the de Sitter spacetime with charged black holes and cloud of strings and quintessence

Recently,some meaningful results have been obtained by studying the phase transition,critical exponents,and other thermodynamical properties of different black holes.Especially for the Anti-de Sitter(AdS)black holes,their thermodynamical properties nearby the critical point have attracted considerable attention.However,there exists little work on the thermodynamic properties of the de Sitter(dS)spacetime with black holes.In this paper,based on the effective thermodynamical quantities and the method of the Maxwell's equal-area law,we explore the phase equilibrium for the de Sitter spacetime with the charged black holes and the cloud of string and quintessence(i.e.,C-dSSQ spacetime).The boundaries of the two-phase coexistence region in both P_(eff)−T_(eff)and T_(eff)−S diagrams are obtained.The coexistent curve and the latent heat of phase transition for this system are also investigated.Furthermore,we analyze the effect of parameters(the state parameterωand the ratio of two horizon radii x=r+/r_(c))on the two-phase coexistence region boundary.The results indicate that the phase transition in C-dSSQ spacetime is analogous to that in a van der Waals fluid(vdw)system,which is determined by the electrical potential at the horizon.These results are helpful for understanding the basic properties of black holes and are also of great value for the establishment of quantum gravity.

Entropy of higher-dimensional charged Gauss–Bonnet black hole in de Sitter space

The fundamental equation of the thermodynamic system gives the relation between the internal energy, entropy and volume of two adjacent equilibrium states. Taking a higher-dimensional charged Gauss–Bonnet black hole in de Sitter space as a thermodynamic system, the state parameters have to meet the fundamental equation of thermodynamics. We introduce the effective thermodynamic quantities to describe the black hole in de Sitter space. Considering that in the lukewarm case the temperature of the black hole horizon is equal to that of the cosmological horizon, we conjecture that the effective temperature has the same value. In this way, we can obtain the entropy formula of spacetime by solving the differential equation. We find that the total entropy contains an extra term besides the sum of the entropies of the two horizons. The corrected term of the entropy is a function of the ratio of the black hole horizon radius to the cosmological horizon radius, and is independent of the charge of the spacetime.