Dynamical Origin of the Entropy of a Black Hole

TL;DR

This paper proposes a new dynamical and invariant statistical mechanical definition of black hole entropy, showing that it mainly arises from thermally excited modes near the horizon, aligning well with traditional values.

Contribution

It introduces a novel invariant definition of black hole entropy based on dynamical degrees of freedom and thermal modes near the horizon.

Findings

Entropy is primarily due to thermally excited 'invisible' modes near the horizon.

The proposed entropy calculation matches the standard entropy value.

Modes inside the horizon are identified as dynamical degrees of freedom.

Abstract

Modes of physical fields which are located inside a horizon and which cannot be observed by a distant observer are identified with dynamical degrees of freedom of a black hole. A new invariant statistical mechanical definition of a black-hole's entropy is proposed. It is shown that the main contribution to the entropy is given by thermally excited `invisible' modes propagating in the close vicinity of the horizon. A calculation based on the proposed definition yields a value of the entropy which is in good agreement with the usually adopted value.