Non-uniqueness of the shockwave dynamics in effective loop quantum gravity

TL;DR

This paper investigates the non-uniqueness of shockwave dynamics in effective loop quantum gravity, revealing that extensions beyond singularities depend on the chosen mathematical formulation, affecting black hole lifetime predictions.

Contribution

It demonstrates that the extension of spacetime beyond shell-crossing singularities in loop quantum gravity is non-unique and depends on the integral form of the equations of motion.

Findings

Shockwave extensions are not unique.

Black hole lifetime varies with the integral form used.

Features like shell-crossing singularities are sensitive to mathematical choices.

Abstract

Spherically symmetric effective dust collapse inspired by effective loop quantum cosmology predicts a bounce when the stellar energy density becomes planckian, which in turn inevitably leads to shell-crossing singularity formation. An extension of the spacetime beyond such singularities is possible through weak solutions of the equations of motion in integral form, leading to the shockwave model. In this work, we show explicitly that such an extension is not unique, and that relevant features like the black hole life-time strongly depend on the choice of the integral form of the equation of motion.