Eur. Phys. J. Plus (2021) 136: 1223
https://doi.org/10.1140/epjp/s13360-021-02236-8

Regular Article

Thermodynamic geometry of static and rotating regular black holes in conformal massive gravity

¹ Faculty of Technology and Mining, Yasouj University, 75761-59836, Choram, Iran
² Department of Physics, University of Guilan, 41335-1914, Rasht, Iran
³ Center for Space Research, North-West University, 2745, Mahikeng, South Africa
⁴ School of Astronomy, Institute for Research in Fundamental Sciences (IPM), P. O. Box 19395-5531, Tehran, Iran

^d h.sh.ahmadi@gmail.com, h.sheikhahmadi@ipm.ir

Received: 30 October 2021
Accepted: 28 November 2021
Published online: 8 December 2021

Abstract

A version of massive gravity, namely conformal massive gravity, is employed to study the behaviour of thermodynamic geometry for both the static and the rotating regular black holes. Whereas in thermodynamic geometry singularity can be interpreted as the second phase transition, seeing such phenomena as heat capacity behaviour for both cases is investigated in detail. In addition, other thermodynamic quantities like the entropy and the temperature are analyzed as well. Another important property of the black holes is the so-called stability, in which utilising the first phase transition of the heat capacity is detailed, for both cases, say the static and the spinning black holes. It is also interestingly figured out that the behaviour of temperature of the uncharged black holes in the presence of hair parameter, , can mimic the charged ones. The effects of scalar charge, Q, and hair parameters with both positive and negative signs and how it affects key parameters in the study of black holes are investigated as well. To investigate the properties of the black holes, both regular thermodynamics and thermodynamic geometry approaches are considered. Then, one can observe that aiming to realise the physics of the black holes, many complicated phenomena can be analyzed dramatically easier by considering the latter approach.