On the Stringy Hartle-Hawking State

TL;DR

This paper investigates how non-perturbative string effects modify the Hartle-Hawking state of an eternal black hole, suggesting potential implications for the firewall paradox in string theory.

Contribution

It demonstrates that stringy non-perturbative effects make the Hartle-Hawking state singular at the horizon, challenging previous assumptions about black hole horizons in string theory.

Findings

Non-perturbative $5'$ effects induce singularities at the black hole horizon.

The Hartle-Hawking state is not smooth due to stringy corrections.

Implications for the firewall paradox in string theory are discussed.

Abstract

We argue that non-perturbative $\alpha'$ stringy effects render the Hartle-Hawking state associated with the $SL(2)/U(1)$ eternal black hole singular at the horizon. We discuss implications of this observation on firewalls in string theory.