Firewalls in the non-perturbative bulk Hilbert space of JT gravity

TL;DR

This paper investigates the non-perturbative structure of JT gravity's bulk Hilbert space, revealing that firewall and smooth geometries' probabilities saturate at late times, challenging traditional perturbative approaches.

Contribution

It introduces a non-perturbative bulk inner product in JT gravity, demonstrating probability saturation for firewall and smooth geometries at late times.

Findings

Probabilities approach constant values at late times.

Non-perturbative effects lead to saturation of tunneling probabilities.

Challenges perturbative predictions of unbounded probability growth.

Abstract

It has been shown that a very old black hole can tunnel into a white hole through the emission of a large baby universe. This process can be modeled by a genus-one geometry corresponding to a single baby universe emission, with a tunneling probability proportional to \( t^{2} e^{-2S(E)} \), where \( t \) denotes the black hole age and \( S(E) \) its entropy at energy \( E \). The growth of this probability at late times raises the question of its behavior near \( t \sim e^{S} \). A natural possibility is that the full genus expansion, together with its non-perturbative completion, leads to saturation of the tunneling probability. Motivated by this idea, the present analysis employs a non-perturbative bulk inner product in place of the perturbative one and shows that, at late times, the probabilities of realizing firewall geometries and smooth geometries approach constant values.