Asymptotically flat spacetimes in 3D bigravity

Understand

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.