Quantum theory of the Lemaitre model for gravitational collapse

TL;DR

This paper explores the quantum behavior of gravitational collapse in a Lemaitre dust model, showing that quantum effects can prevent classical singularities through a bounce, leading to re-expansion.

Contribution

It introduces a quantum treatment of the Lemaitre model, demonstrating singularity avoidance via unitary evolution and a bounce mechanism.

Findings

Quantum collapse results in a bounce at minimal radius.

Classical singularities are avoided in the quantum model.

The dust cloud re-expands after the bounce.

Abstract

We investigate the quantum fate of the classical singularities that occur by gravitational collapse of a dust cloud. For this purpose, we address the quantization of a model first proposed by Georges Lemaitre in 1933. We find that the singularities can generically be avoided. This is a consequence of unitary evolution in the quantum theory, whereby the quantum dust cloud collapses, bounces at a minimal radius and re-expands.