Bimetric gravity doubly coupled to matter: theory and cosmological implications

TL;DR

This paper presents a ghost-free bimetric gravity theory with dual metrics coupled to matter, demonstrating its consistency and potential to explain cosmic acceleration without dark energy.

Contribution

It introduces a consistent, ghost-free bimetric gravity model with matter coupling and explores its cosmological implications, especially in partially massless gravity.

Findings

The theory is shown to be ghost-free and viable.

It can explain cosmic acceleration without dark energy.

Partially massless gravity models fit cosmological data.

Abstract

A ghost-free theory of gravity with two dynamical metrics both coupled to matter is shown to be consistent and viable. Its cosmological implications are studied, and the models, in particular in the context of partially massless gravity, are found to explain the cosmic acceleration without resorting to dark energy.