# On the implications of the Bekenstein bound for black hole evaporation

## TL;DR

This paper explores how the holographic bound influences black hole evaporation, suggesting that geometry and quantum fields are emergent phenomena from a fundamental theory, leading to entanglement and potential information loss.

## Contribution

It introduces a conceptual framework linking holographic principles to black hole evaporation and models entanglement-induced information loss.

## Key findings

- Geometry and quantum fields emerge from fundamental degrees of freedom.
- Entanglement between geometry and fields can cause information loss.
- A toy model demonstrates average information loss during black hole evaporation.

## Abstract

We provide general arguments regarding the connection between low-energy theories (gravity and quantum field theory) and a hypothetical fundamental theory of quantum gravity, under the assumptions of (i) validity of the holographic bound and (ii) preservation of unitary evolution at the level of the fundamental theory. In particular, the appeal to the holographic bound imposed on generic physical systems by the Bekenstein-Hawking entropy implies that both classical geometry and quantum fields propagating on it should be regarded as phenomena emergent from the dynamics of the fundamental theory. The reshuffling of the fundamental degrees of freedom during the unitary evolution then leads to an entanglement between geometry and quantum fields. The consequences of such scenario are considered in the context of black hole evaporation and the related information-loss issue: we provide a simplistic toy model in which an average loss of information is obtained as a consequence of the geometry-field entanglement.