Entropy relations and bounds of regular and singular black holes with nonlinear electrodynamics sources

Abstract

In this paper, we study entropy relations and bounds of regular and singular black holes with nonlinear electrodynamics sources. We focus on the regular and singular Bardeen and Hayward black holes in asymptotically flat and AdS spacetimes. For black holes with vanishing effective mass M eff , it is found that the entropy product is always mass-independent in asymptotically flat spacetime, while the entropy sum takes the mass-independent universality in asymptotically AdS spacetime. For the cases with nonzero effective mass M eff in asymptotically flat and AdS spacetimes, entropy relations are both some functions of mass and charge, hence are always mass-dependent. Besides, the non-linear electrodynamics always affects the entropy bounds of horizons.

Regular black hole powered by a self-gravitating magnetic monopole

“…The corresponding thermodynamical quantities such as temperature, total energy, and entropy, in a black hole system are the ADM (Arnowitt, Deser, and Misner) mass, the surface gravity, and the area of the black hole. There have been several works on the thermal stability and thermodynamics of the black holes in the context of gravity coupled with nonlinear electrodynamics [38][39][40][41][42][43][44][45][46][47][48]. A black hole is called thermally stable if its temperature and its heat capacity are simultaneously positive.…”