A Quantum Weyl Conjecture

TL;DR

This paper investigates the quantum properties of colliding plane-wave space-times, proposing a conjecture that the Coulomb part of the Weyl tensor determines their quantum traversability, with implications for understanding singularities.

Contribution

It introduces the quantum Weyl conjecture linking Weyl tensor components to quantum probe behavior in space-times with singularities.

Findings

Khan-Penrose singularity cannot be quantumly probed, similar to Schwarzschild.

Ferrari-Ibáñez singularity can be traversed by quantum fields.

Proposes a backreaction scenario based on the conjecture.

Abstract

We perform a quantum probing of colliding plane-wave space-times. In particular, we consider the Khan-Penrose and the Ferrari-Ib\'a\~nez solutions, which admit a strong and a weak singularity after the two waves collide. While we find that, like Schwarzschild, for the Khan-Penrose solution the singularity cannot be probed by quantum field theory, the Ferrari-Ib\'a\~nez singularity can be traversed. Our results culminate in a quantum Weyl conjecture: The significant geometric property to classify space-times with respect to quantum probes is given by the Coulomb part of the Weyl tensor. We then use this conjecture to sketch a possible backreaction scenario for plane waves.