scholarly journals Phase transition, critical behavior, and critical exponents of Myers-Perry black holes

2013 ◽  
Vol 88 (2) ◽  
Author(s):  
Mohammad Bagher Jahani Poshteh ◽  
Behrouz Mirza ◽  
Zeinab Sherkatghanad
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Critical Behavior ◽  
Critical Exponents

scholarly journals P–V criticality and geometrical thermodynamics of black holes with Born–Infeld type nonlinear electrodynamics

2016 ◽  
Vol 25 (01) ◽  
pp. 1650010 ◽  
Author(s):  
S. H. Hendi ◽  
S. Panahiyan ◽  
B. Eslam Panah
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Heat Capacity ◽  
Phase Space ◽  
Critical Behavior ◽  
Nonlinear Electrodynamics ◽  
Extended Phase Space ◽  
Maxwell Theory ◽  
Extended Phase ◽  
Transition Points

In this paper, we take into account the black-hole solutions of Einstein gravity in the presence of logarithmic and exponential forms of nonlinear electrodynamics. At first, we consider the cosmological constant as a dynamical pressure to study the phase transitions and analogy of the black holes with the Van der Waals liquid–gas system in the extended phase space. We make a comparison between linear and nonlinear electrodynamics and show that the lowest critical temperature belongs to Maxwell theory. Also, we make some arguments regarding how power of nonlinearity brings the system to Schwarzschild-like and Reissner–Nordström-like limitations. Next, we study the critical behavior of the system in the context of heat capacity. We show that critical behavior of system is similar to the one in phase diagrams of extended phase space. We also extend the study of phase transition points through geometrical thermodynamics (GTs). We introduce two new thermodynamical metrics for extended phase space and show that divergencies of thermodynamical Ricci scalar (TRS) of the new metrics coincide with phase transition points of the system. Then, we introduce a new method for obtaining critical pressure and horizon radius by considering denominator of the heat capacity.

CRITICAL BEHAVIOR IN THE MODEL OF RANDOM SURFACES WITH DYNAMICAL HOLES EMBEDDED IN −2- AND 1-DIMENSIONAL SPACES

1991 ◽  
Vol 06 (01) ◽  
pp. 79-87 ◽  
Author(s):  
D.V. BOULATOV
Keyword(s):  
Phase Transition ◽  
Critical Behavior ◽  
Critical Exponents ◽  
Random Surfaces ◽  
Scalar Particles ◽  
Exactly Solvable ◽  
The Mean

The model of discretized random surfaces with dynamical holes recently proposed by V.A. Kazakov for D=0 is considered for nontrivial embeddings, the cases D=−2 and 1 being exactly solvable. The model has two new parameters: the fugacity for the number of the holes ξ and a mass of scalar particles moving along their borders m. At m=mc the mean length of the borders and the mean number of the holes undergo the phase transition — related to an explosion of the holes — becoming singular at ξ=0. The singularity still exists for m<mc where the phase of “completely torn” surfaces takes place. The correspondent critical exponents are calculated.

scholarly journals THERMODYNAMIC GEOMETRY AND CRITICAL BEHAVIOR OF BLACK HOLES

2007 ◽  
Vol 22 (01) ◽  
pp. 11-27 ◽  
Author(s):  
JIANYONG SHEN ◽  
RONG-GEN CAI ◽  
BIN WANG ◽  
RU-KENG SU
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Black Hole ◽  
Critical Behavior ◽  
Hessian Matrix ◽  
Black Hole Entropy ◽  
De Sitter ◽  
Ads Black Holes ◽  
Gas System ◽  
The One

Based on the observations that there exists an analogy between the Reissner–Nordström–Anti-de Sitter (RN–AdS) black holes and the van der Waals–Maxwell liquid-gas system, in which a correspondence of variables is (ϕ,q) ↔ (V,P), we study the Ruppeiner geometry, defined as Hessian matrix of black hole entropy with respect to the internal energy (not the mass) of black hole and electric potential (angular velocity), for the RN, Kerr and RN–AdS black holes. It is found that the geometry is curved and the scalar curvature goes to negative infinity at the Davies' phase transition point for the RN and Kerr black holes. Our result for the RN–AdS black holes is also in good agreement with the one about phase transition and its critical behavior in the literature.

scholarly journals Structure, Magnetocaloric Effect and Critical Behavior of the Fe60Co12Gd4Mo3B21 Amorphous Ribbons

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 34
Author(s):  
Agnieszka Łukiewska ◽  
Piotr Gębara
Keyword(s):  
Phase Transition ◽  
Magnetic Properties ◽  
Critical Behavior ◽  
Critical Exponents ◽  
Amorphous Structure ◽  
X Ray ◽  
Amorphous Ribbons ◽  
Spectroscopy Studies ◽  
Arrott Plots ◽  
Second Order Phase Transition

The aim of the paper was to study the structure, magnetic properties and critical behavior of the Fe60Co12Gd4Mo3B21 alloy. The X-ray diffractometry and the Mössbauer spectroscopy studies confirmed amorphous structure. The analysis of temperature evolution of the exponent n (ΔSM = C·(Bmax)n) and the Arrott plots showed the second order phase transition in investigated material. The analysis of critical behavior was carried out in order to reveal the critical exponents and precise TC value. The ascertained critical exponents were used to determine the theoretical value of the exponent n, which corresponded well with experimental results.

scholarly journals Phase Transitions, Geometrothermodynamics, and Critical Exponents of Black Holes with Conformal Anomaly

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jie-Xiong Mo ◽  
Wen-Biao Liu
Keyword(s):  
Phase Transition ◽  
Black Holes ◽  
Phase Transitions ◽  
Scalar Curvature ◽  
Critical Exponents ◽  
Phase Structure ◽  
Scaling Laws ◽  
Canonical Ensemble ◽  
Conformal Anomaly ◽  
Transition Points

We investigate the phase transitions of black holes with conformal anomaly in canonical ensemble. Some interesting and novel phase transition phenomena have been discovered. It is shown that there are striking differences in both Hawking temperature and phase structure between black holes with conformal anomaly and those without it. Moreover, we probe in detail the dependence of phase transitions on the choice of parameters. The results show that black holes with conformal anomaly have much richer phase structure than those without it. There would be two, only one, or no phase transition points depending on the parameters. The corresponding parameter regions are derived both numerically and graphically. Geometrothermodynamics are built up to examine the phase structure we have discovered. It is shown that Legendre invariant thermodynamic scalar curvature diverges exactly where the specific heat diverges. Furthermore, critical behaviors are investigated by calculating the relevant critical exponents. And we prove that these critical exponents satisfy the thermodynamic scaling laws.

scholarly journals Determination of Phase Transition and Critical Behavior of the As-Cast GdGeSi-(X) Type Alloys (Where X = Ni, Nd and Pr)

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 185
Author(s):  
Piotr Gębara ◽  
Mariusz Hasiak
Keyword(s):  
Phase Transition ◽  
Order Phase Transition ◽  
Critical Behavior ◽  
Critical Exponents ◽  
Second Order ◽  
Experimental Result ◽  
First Order Phase Transition ◽  
First Order Phase ◽  
Second Order Phase Transition

The aim of the paper is to present a study of the magnetocaloric effect and the nature of phase transition in the Gd80Ge15Si5 (S1), Gd75Ge15Si5Ni5 (S2), Gd75Ge15Si5Pr5 (S3) and Gd75Ge15Si5Nd5 (S4) alloys. The magnetic entropy changes determined for studied samples, under external magnetic field ~3T, were 11.91, 12.11, 5.08 and 4.71 J/(kg K) for S1, S2, S3 and S4, respectively. The values of refrigerant capacity (under ~3T) were 164, 140, 160 and 140 J/kg for S1, S2, S3 and S4, respectively. The first order phase transition was detected for samples S1 and S2, while specimens S3 and S4 manifested the second order phase transition at the Curie point (TC). The analysis of temperature evolution of the exponent n (ΔSM = C·(Bmax)n) showed the validity of this method in detecting either the first or the second order phase transition and the structural transition. The analysis of critical behavior was carried out for samples S3 and S4. The critical exponents and precise TC values were calculated. The ascertained critical exponents were used to determine the theoretical value of the exponent n, which corresponded well with experimental result.

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