Matter coupling in 3D "Minimal Massive Gravity"

TL;DR

This paper investigates matter coupling in 3D Minimal Massive Gravity, revealing unique matter source requirements and exploring diverse solutions including cosmological bounces, warped geometries, and black holes.

Contribution

It introduces a consistent matter coupling in MMG and analyzes its implications for various vacuum and cosmological solutions in three dimensions.

Findings

Matter coupling requires a quadratic matter source tensor.

Found smooth bouncing cosmological solutions with matter.

Discovered new vacuum solutions including warped-(A)dS and black holes.

Abstract

The "Minimal Massive Gravity" (MMG) model of massive gravity in three spacetime dimensions (which has the same anti-de Sitter (AdS) bulk properties as "Topologically Massive Gravity" but improved boundary properties) is coupled to matter. Consistency requires a particular matter source tensor, which is quadratic in the stress tensor. The consequences are explored for an ideal fluid in the context of asymptotically de-Sitter (dS) cosmological solutions, which bounce smoothly from contraction to expansion. Various vacuum solutions are also found, including warped-(A)dS, and (for special values of parameters) static black holes and an (A)dS2 x S1 vacuum.