Effective Quantum Gravitational Collapse in a Polymer Framework

TL;DR

This paper investigates how polymer quantization inspired by loop quantum gravity modifies gravitational collapse, preventing singularities and suggesting new astrophysical objects like white holes or other exotic entities.

Contribution

It introduces a novel approach to gravitational collapse analysis using area-based variables within a polymer quantization framework, revealing singularity avoidance and new object formations.

Findings

Singularity formation is avoided due to quantum effects.

Collapse can lead to white holes or new astrophysical objects.

Constraints on the area gap parameter are established.

Abstract

We study how the presence of an area gap, different than zero, affects the gravitational collapse of a dust ball. The implementation of such discreteness is achieved through the framework of polymer quantization, a scheme inspired by loop quantum gravity (LQG). We study the collapse using variables which represent the area, in order to impose the non-zero area gap condition. The collapse is analyzed for both the flat and spherical Oppenheimer-Snyder models. In both scenarios the formation of the singularity is avoided, due to the inversion of the velocity at finite values of the sphere surface. This happens due to the presence of a negative pressure, with origins at a quantum level. When the inversion happens inside the black hole event horizon, we achieve a geometry transition to a white hole. When the inversion happens outside the event horizon, we find a new possible astrophysical object. A characterization of such hypothetical object is done. Some constraints on the value for the area gap are also imposed in order to maintain the link with our already established physical theories.