Particle absorption by black holes and the generalized second law of thermodynamics

TL;DR

This paper explores the entropy change during particle absorption by black holes, proposing a thermodynamic model that links quantum reflection phenomena with entropy considerations, suggesting a fundamental connection between thermodynamics and quantum mechanics.

Contribution

It introduces a thermodynamic formulation for black hole particle absorption probabilities that incorporates entropy changes, bridging quantum reflection and thermodynamic principles.

Findings

Absorption probability relates to entropy change and quantum reflection.

Suppression of absorption when entropy decreases, but not forbidden.

Quantum behaviors emerge naturally from thermodynamic considerations.

Abstract

The change in entropy, /DeltaS, associated with the quasi-static absorption of a particle of energy u by a Schwarzschild black hole (ScBH) is approximately (u/T)-s, where T is the Hawking temperature of the black hole and s is the entropy of the particle. Motivated by the statistical interpretation of entropy, it is proposed here that absorption should be suppressed, but not forbidden, when /DeltaS<0, which requires the absorption cross-section to be sensitive to /DeltaS. A purely thermodynamic formulation of the probability for absorption is obtained from the standard relationship between microstates and entropy. If /DeltaS>>1 and s<<u/T then the probability for the particle not to be absorbed is approximately exp[-u/T], which is identical to the probability for quantum mechanical reflection by the horizon of a ScBH. The manifestation of quantum behaviors in the new probability function may intimate a fundamental physical unity between thermodynamics and quantum mechanics.