Do subleading corrections to Bekenstein-Hawking entropy hold the key to quantum gravity?

TL;DR

This paper explores how subleading corrections to Bekenstein-Hawking entropy, derived from quantum entanglement, can provide insights into the microscopic degrees of freedom in quantum gravity, emphasizing the importance of disentangling these contributions.

Contribution

It demonstrates that the degrees of freedom responsible for Bekenstein-Hawking entropy differ from those causing subleading corrections, highlighting the significance of these corrections in understanding quantum gravity.

Findings

Subleading corrections follow a power-law form.

Different degrees of freedom underlie entropy and its corrections.

Corrections relate to the horizon's kinematic properties.

Abstract

Black-holes are considered to be theoretical laboratories for testing models of quantum gravity. It is usually believed that any candidate for quantum gravity must explain the microscopic origin of the Bekenstein-Hawking ($S_{_{\rm BH}}$) entropy. In this letter, we argue (i) the requirement for a candidate approach to go beyond $S_{_{\rm BH}}$ and provide generic subleading corrections, and (ii) the importance to {\it disentangle} and identify the degrees of freedom leading to $S_{_{\rm BH}}$ and its subleading corrections. Using the approach of entanglement of modes across the horizon, we show that the microscopic degrees of freedom that lead to $S_{_{\rm BH}}$ and subleading corrections are different. We further show, using microcanonical and canonical ensemble approaches, that the quantum entanglement predicts generic power-law corrections to $S_{_{\rm BH}}$ and that the corrections can be identified with the kinematical properties of the event-horizon.