Remnants in two-dimensional quantum gravity

TL;DR

This paper investigates two-dimensional quantum black holes sourced by trace anomaly, demonstrating a proportionality between black hole size and internal states, and revealing the existence of a minimal remnant size.

Contribution

It proves that 2D quantum black holes have a size proportional to their internal states and identifies a minimal remnant size, suggesting weak coupling in higher dimensions.

Findings

Black hole size proportional to the number of internal states

Existence of a minimal black hole remnant size

Remnant size larger than Planck length implying weak coupling

Abstract

In this work we consider a two-dimensional quantum black hole sourced by the trace anomaly of a conformal field theory. By using holography, we are able to prove that the black hole size is always proportional to the number of states inside the black hole, a result that might be interpreted as a two dimensional version of the Bekenstein entropy law. Finally, we also show that such a black hole has a minimal size (a remnant). Extrapolating this result for higher dimensions, we show that this would imply that the remnant has a size way larger than the Planck length and is, therefore, always weakly coupled.