Stationary bubbles and their tunneling channels toward trivial geometry

TL;DR

This paper explores stationary bubble solutions in quantum gravity, demonstrating that tunneling to trivial geometries preserves unitarity and may resolve the black hole information loss paradox.

Contribution

It introduces stable and unstable stationary bubble models and shows how tunneling channels to trivial geometries support unitarity in quantum gravity.

Findings

Tunneling channels exist from stationary bubbles to trivial geometries.

Unitarity is preserved at the wave function level despite apparent information loss.

Classical observers perceive an effective information loss, contrasting with the full quantum description.

Abstract

In the path integral approach, one has to sum over all histories that start from the same initial condition in order to obtain the final condition as a superposition of histories. Applying this into black hole dynamics, we consider stable and unstable stationary bubbles as a reasonable and regular initial condition. We find examples where the bubble can either form a black hole or tunnel toward a trivial geometry, i.e., with no singularity nor event horizon. We investigate the dynamics and tunneling channels of true vacuum bubbles for various tensions. In particular, in line with the idea of superposition of geometries, we build a classically stable stationary thin-shell solution in a Minkowski background where its fate is probabilistically given by non-perturbative effects. Since there exists a tunneling channel toward a trivial geometry in the entire path integral, the entire information is encoded in the wave function. This demonstrates that the unitarity is preserved and there is no loss of information when viewed from the entire wave function of the universe, whereas a semi-classical observer, who can see only a definitive geometry, would find an effective loss of information. This may provide a resolution to the information loss dilemma.