On singularity-resolution in mimetic gravity

TL;DR

This paper investigates a modified mimetic gravity model that avoids singularities through a delicate branch-changing mechanism in a multi-valued function, with implications for its connection to loop quantum cosmology.

Contribution

It reveals the critical role of branch changing in the non-singular bounce and explores its implications for the link to loop quantum cosmology.

Findings

Singularity-free bounce depends on subtle branch changing in the multi-valued function f

The model's non-singular behavior is sensitive to the rapid vanishing of f for small arguments

Implications for the connection between mimetic gravity and loop quantum cosmology

Abstract

Recently, it was shown that modified mimetic gravity, with a $f(\square\phi)$ term, results in a singularity-free model of gravity, for both cosmological and black hole spacetimes [1, 2]. In this work, we analyze this model further and show that, since the function $f$ was tuned to vanish rapidly for small values of the argument, the non-singular bounce relies heavily on a subtle branch changing mechanism for the multi-valued function $f$. Furthermore, this mechanism has interesting implications for the proposed link between this model and loop quantum cosmology.