Cosmological future singularities in massive gravity and massive bigravity

TL;DR

This paper investigates various types of future cosmological singularities in massive gravity and bigravity theories, identifying conditions under which these singularities occur or can be avoided.

Contribution

It analyzes the occurrence of finite-time future singularities in massive gravity and bigravity, proposing conditions to remove certain singularities in these models.

Findings

Sudden singularity occurs in dRGT model with open universe.

Bigravity theory exhibits sudden and big brake singularities.

Parameters approaching zero can remove the sudden singularity.

Abstract

We study the future cosmological singularities in the framework of massive gravity and minimal massive bigravity theory. In this regards, we consider the possible classes of finite-time future singularities such as sudden, big rip, big freeze and big brake singularities in the massive universe. In dRGT model with an open expanding universe we obtain the sudden singularity in the future at a finite-time which generally without taking account of any particular realistic equation of state, is not avoidable and except the fluid density, all dynamical physical quantities such as pressure approach to infinity. To complete our study, we search the future cosmological singularities in the context of minimal massive bigravity theory and we find that the cosmology of this theory suffers from the sudden and big brake singularities, in which we can see that the parameters of the model approaches to zero the sudden singularity can be removed.