Physics

Charge (physics)

Pure mathematics

Action (physics)

Mathematics

Mathematical physics

Algebra over a field

Phase space

Mathematical analysis

Philosophy

Null (SQL)

Poisson bracket

Programming language

Geometry

Extension (predicate logic)

Space (punctuation)

Computer science

Linguistics

Lie algebra

Quantum mechanics

Homogeneous space

Infinity

Database

Physical review. D/Physical review. D.

It has been argued that the symmetries of gravity at null infinity should include a Diff$(S^2)$ factor associated to diffeomorphisms on the celestial sphere. However, the standard phase space of gravity does not support the action of such transformations. Building on earlier work by Laddha and one of the authors, we present an extension of the phase space of gravity at null infinity on which Diff$(S^2)$ acts canonically. The Poisson brackets of supertranslation and Diff$(S^2)$ charges reproduce the generalized BMS algebra introduced in arXiv:1408.2228 .

Generalized BMS charge algebra