Notes on the Generalised Second Law of Thermodynamics

TL;DR

This paper discusses the generalized second law of thermodynamics, emphasizing that the total entropy of black holes and matter never decreases, supported by thermodynamic arguments.

Contribution

It offers comments and clarifications on previous proofs of the generalized second law, reinforcing its validity within thermodynamic frameworks.

Findings

Black hole entropy plus matter entropy is non-decreasing.

Supports the law's validity with thermodynamic reasoning.

Clarifies previous proofs and assumptions.

Abstract

Several comments are given to previous proofs of the generalised second law of thermodynamics: black hole entropy plus ordinary matter entropy never decreases for a thermally closed system. Arguments in favour of its truism are given in the spirit of conventional thermodynamics.