Covariant LTB collapse in models of loop quantum gravity

TL;DR

This paper investigates gravitational collapse in loop quantum gravity-inspired models, revealing that such collapse leads to singularities rather than bounces, challenging previous expectations of non-singular behavior.

Contribution

It provides a covariant formulation of holonomy modifications in LTB models and analyzes their impact on gravitational collapse outcomes.

Findings

Collapse results in singularities, not bounces.

Holonomy modifications do not prevent singularity formation.

Collapse behavior differs from vacuum space-times with similar modifications.

Abstract

Models of gravitational collapse provide important means to test whether non-classical space-time effects motivated for instance by quantum gravity can be realized in generic ways in physically relevant situations. Here, a detailed analysis of marginally bound Lemaitre-Tolman-Bondi space-times is given in emergent modified gravity, which in particular includes a covariant formulation of holonomy modifications usually considered in models of loop quantum gravity. As a result, generic collapse in this setting is shown to imply a physical singularity that removes the bouncing behavior seen in vacuum space-times with the same type of modifications.