BMS Flux Algebra in Celestial Holography

TL;DR

This paper constructs BMS momentum fluxes in asymptotically flat gravity, relating them to celestial CFT operators and deriving their algebra and transformation properties, advancing celestial holography understanding.

Contribution

It introduces a non-local flux algebra on the celestial sphere and links BMS fluxes to celestial CFT operators, providing new insights into asymptotic symmetries and holography.

Findings

BMS fluxes transform as Virasoro primaries

Supermomentum flux relates to supertranslation operator

Super angular momentum flux links to celestial stress-energy tensor

Abstract

Starting from gravity in asymptotically flat spacetime, the BMS momentum fluxes are constructed. These are non-local expressions of the solution space living on the celestial Riemann surface. They transform in the coadjoint representation of the extended BMS group and correspond to Virasoro primaries under the action of bulk superrotations. The relation between the BMS momentum fluxes and celestial CFT operators is then established: the supermomentum flux is related to the supertranslation operator and the super angular momentum flux is linked to the stress-energy tensor of the celestial CFT. The transformation under the action of asymptotic symmetries and the OPEs of the celestial CFT currents are deduced from the BMS flux algebra.