A generic unitary black-hole evaporation model based on first principles

TL;DR

This paper proposes a macroscopic model of black hole evaporation based on horizon area quanta, introducing a hidden sector to account for unknown final states, and connects the model's features to soft hair phenomena.

Contribution

It introduces a novel effective horizon quantum model incorporating a hidden sector and links microscopic state features to soft hair concepts.

Findings

Model captures black hole evaporation with a hidden sector.

Identifies a zero-frequency pole structure related to excess entropy.

Suggests soft hairs may participate in evaporation processes.

Abstract

Based on the discretized horizon picture, we introduce a macroscopic effective model of the horizon area quanta that encapsulates the features necessary for black holes to evaporate consistently. The price to pay is the introduction of a "hidden sector" that represents our lack of knowledge about the final destination of the black hole entropy. We focus on the peculiar form of the interaction between this hidden sector and the black hole enforced by the self-consistency. Despite the expressive power of the model, we arrive at several qualitative statements. Furthermore, we identify these statements as features inside the microscopic density of states of the horizon quanta, with the dimension of the configuration space being associated with the area per quanta in Planck unit, a UV cutoff proportional to the amount of excess entropy relative to Bekenstein's law at the end of evaporation, and a zero-frequency-pole-like structure corresponding to, similarly, the amount of excess entropy at IR limit. We then relate this nearly-zero-frequency structure to the soft hairs proposed by Strominger et al., and argue that we should consider deviating away from the zero frequency limit for soft hairs to participate in the black hole evaporation.