Asymptotically flat spacetimes in 3D bigravity

TL;DR

This paper demonstrates that certain 3D bigravity theories admit asymptotically flat solutions with BMS symmetry and explores their potential as regular black holes.

Contribution

It identifies asymptotically flat solutions in 3D bigravity and analyzes their symmetry structure and possible black hole interpretation.

Findings

Asymptotically flat solutions exist in 3D bigravity.

The solutions preserve BMS symmetry at null infinity.

The algebra of canonical generators has a central extension.

Abstract

We report that a class of three-dimensional bimetric theories contain asymptotically flat solutions. These spacetimes can be cast in a set of asymptotic conditions at null infinity which are preserved under the infinite dimensional BMS group. Moreover, the algebra of the canonical generators exhibits a central extension. The possibility that these solutions describe regular black holes is also discussed.