Asymptotic symmetries in Carrollian theories of gravity

Understand

Asymptotic symmetries in Carrollian gravitational theories in 3+1 space and time dimensions obtained from "magnetic" and "electric" ultrarelativistic contractions of General Relativity are analyzed.

• In both cases, parity conditions are needed to guarantee a finite symplectic term, in analogy with Einstein gravity.
• For the magnetic contraction, when Regge-Teitelboim parity conditions are imposed, the asymptotic symmetries are described by the Carroll group.
• With Henneaux-Troessaert parity conditions, the asymptotic symmetry algebra corresponds to a BMS-like extension of the Carroll algebra.