2017/09/30 by Z. Dayyani, A. Sheykhi, M. H. Dehghani +1 · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Black hole (networking) #Canonical ensemble #Cosmology and Gravitation Theories #Coupling constant #Critical exponent #Dilaton #Gibbs free energy #Nonlinear system #Phase transition #Quantum Electrodynamics and Casimir Effect #gr-qc #hep-th
paper · pdf · doi:10.1140/epjc/s10052-018-5623-5
published as Eur. Phys. J. C (2018) 78:152
openalex created_date 2017/10/06 · openalex publication_date 2018/02/01 · arxiv created 2018/03/11 · arxiv updated 2018/03/13 · openalex updated_date 2026/08/05
In this paper, we take into account the dilaton black hole solutions of Einstein gravity in the presence of logarithmic and exponential forms of nonlinear electrodynamics. First of all, we consider the cosmological constant and nonlinear parameter as thermodynamic quantities which can vary. We obtain thermodynamic quantities of the system such as pressure, temperature and Gibbs free energy in an extended phase space. We complete the analogy of the nonlinear dilaton black holes with the Van der Waals liquid–gas system. We work in the canonical ensemble and hence we treat the charge of the black hole as an external fixed parameter. Moreover, we calculate the critical values of temperature, volume and pressure and show that they depend on the dilaton coupling constant as well as on the nonlinear parameter. We also investigate the critical exponents and find that they are universal and independent of the dilaton and nonlinear parameters, which is an expected result. Finally, we explore the phase transition of nonlinear dilaton black holes by studying the Gibbs free energy of the system. We find that in the case of T>Tc , we have no phase transition. When T=Tc , the system admits a second-order phase transition, while for T=Tf<Tc the system experiences a first-order transition. Interestingly, for Tf<T<Tc we observe a zeroth-order phase transition in the presence of a dilaton field. This novel zeroth-order phase transition occurs due to a finite jump in the Gibbs free energy which is generated by the dilaton–electromagnetic coupling constant, α , for a certain range of pressure.