Cosmological perturbation and matter power spectrum in bimetric massive gravity

TL;DR

This paper analyzes linear cosmological perturbations in bimetric massive gravity, showing suppression of matter perturbations and constraining deviations from the cosmological constant using large-scale structure data.

Contribution

It provides the first detailed analysis of matter perturbations and stability constraints in a minimal bimetric massive gravity model.

Findings

Matter density perturbations are suppressed in the model.

Deviations from the cosmological constant are constrained to be less than 1%.

The model faces stability and ghost issues that limit its viability.

Abstract

We discuss the linear perturbation equations with the synchronous gauge in a minimal scenario of the bimetric massive gravity theory. We find that the matter density perturbation and matter power spectrum are suppressed. We also examine the ghost and stability problems and show that the allowed deviation of this gravitational theory from the cosmological constant is constrained to be smaller than $\mathcal{O}(10^{-2})$ by the large scale structure observational data.