Curvature Singularities from Gravitational Contraction in f(R) Gravity

TL;DR

This paper investigates how gravitational contraction in certain f(R) gravity models can lead to curvature singularities, analyzing the conditions and timescales for their development in a contracting dust cloud.

Contribution

It explores the emergence of curvature singularities during gravitational contraction within viable f(R) gravity models, highlighting the conditions and timescales involved.

Findings

Curvature singularities can form during contraction in f(R) gravity.

The timescales for singularity development depend on initial density and mass.

Modified gravity models may lead to different singularity behaviors compared to General Relativity.

Abstract

The discovery of the accelerated expansion of the Universe has had a vast resonance on a number of physical disciplines. In recent years several viable modified gravity models have been proposed, which naturally lead to a late-time de Sitter stage while basically reducing to General Relativity in the early Universe. We consider a contracting cloud of pressureless dust, having arbitrary mass and initial density, and discuss some aspects of these modified gravity models. We show how the increasing energy/mass density may lead to a curvature singularity and discuss the typical timescales for its development.