Generalized second law and entropy bound for a Reissner- Nordstr\"om black hole

Abstract

It has been conjectured that black hole interacting with its surroundings will obey the Generalized Second Law ($GSL$) of thermodynamics. Conservation of $GSL$ is due to the fully thermal nature of Hawking radiation and an upper bound on entropy. We study these aspects for a Reissner-Nordstr$\ddot{\textbf{o}}$m ($RN$)black hole and conjecture that $GSL$ may be conserved if the equation of state of radiation near the horizon is modified. An upper bound on $S/E$, similar to the Bekenstein form evolves in the calculation.