Bouncing cosmologies in massive gravity on de Sitter

TL;DR

This paper explores bouncing cosmological solutions within massive gravity on de Sitter space, revealing that bounces can occur under conditions that typically prevent them in general relativity, due to additional effective fluid terms.

Contribution

It demonstrates the existence of bouncing solutions in massive gravity with a de Sitter reference metric, analyzing their stability and phase space behavior.

Findings

Bouncing solutions occur when matter satisfies the strong energy condition.

Additional terms in the Friedmann equations act as an effective fluid enabling bounces.

Phase space analysis reveals stable fixed points corresponding to bouncing cosmologies.

Abstract

In the framework of massive gravity with a de Sitter reference metric, we study homogeneous and isotropic solutions with positive spatial curvature. Remarkably, we find that bounces can occur when cosmological matter satisfies the strong energy condition, in contrast to what happens in classical general relativity. This is due to the presence in the Friedmann equations of additional terms, which depend on the scale factor and its derivatives and can be interpreted as an effective fluid. We present a detailed study of the system using a phase space analysis. After having identified the fixed points of the system and investigated their stability properties, we discuss the cosmological evolution in the global physical phase space. We find that bouncing solutions