A note on bigravity and dark matter

TL;DR

This paper explores how certain bigravity theories can naturally include solutions that describe dark matter and cosmological evolution, connecting them to existing models like Eddington-Born-Infeld gravity.

Contribution

It demonstrates that a class of bigravity theories can encompass dark matter solutions and relate to Eddington-Born-Infeld gravity, with implications for cosmological models.

Findings

Bigravity theories contain solutions describing dark matter.

A specific bigravity model is equivalent to Eddington-Born-Infeld gravity.

Solutions interpolate between matter-dominated and accelerated expansion eras.

Abstract

We show that a class of bi-gravity theories contain solutions describing dark matter. A particular member of this class is also shown to be equivalent to the Eddington-Born-Infeld gravity, recently proposed as a candidate for dark matter. Bigravity theories also have cosmological de Sitter backgrounds and we find solutions interpolating between matter and acceleration eras.