An Uneventful Horizon in Two Dimensions

TL;DR

This paper examines the presence of firewalls in a two-dimensional gravity model, demonstrating their absence and analyzing the entanglement structure of Hawking radiation.

Contribution

It shows that in the CGHS model, firewalls are absent and the horizon remains smooth, challenging assumptions of black hole complementarity.

Findings

Firewalls are absent in the CGHS model.

Hawking radiation is entangled with a long-lived remnant.

The model does not satisfy all postulates of black hole complementarity.

Abstract

We investigate the possibility of firewalls in the Einstein-dilaton gravity model of CGHS. We use the results of the numerical simulation carried out by Ashtekar et al. to demonstrate that firewalls are absent and the horizon is drama free. We show that the lack of a firewall is consistent because the model does not satisfy one of the postulates of black hole complementarity. In particular, we show that the Hawking radiation is not pure, and is completely entangled with a long-lived remnant beyond the last ray.