Interior metric and ray-tracing map in the firework black-to-white hole transition

TL;DR

This paper introduces an improved metric for the black-to-white hole transition via quantum tunnelling, providing a complete description of the process and an explicit ray-tracing map.

Contribution

It presents a refined metric that models the entire black-to-white hole transition and explicitly computes the associated ray-tracing map, advancing understanding of quantum gravitational effects.

Findings

The metric describes the full transition process.

The Einstein equations are solved except on a small transition surface.

An explicit ray-tracing map from past to future infinity is derived.

Abstract

The possibility that a black hole could tunnel into a white hole has recently received attention. Here we present a metric that improves the 'firework' metric: it describes the entire process and solves the Einstein equations everywhere except on a small transition surface that corresponds to the quantum tunnelling. We compute the corresponding ray-tracing map from past infinity to future infinity explicitly.