Aspects of the BMS/CFT correspondence

TL;DR

This paper explores the symmetries and classical solutions in the AdS3/CFT2 and asymptotically flat spacetimes, highlighting a novel symmetry algebra involving supertranslations and local conformal transformations in 4D.

Contribution

It introduces a new perspective on the symmetry algebra of asymptotically flat spacetimes at null infinity, incorporating local conformal transformations instead of Lorentz algebra.

Findings

Derived the realization of the symmetry algebra on solution space

Analyzed the behavior of Bondi's news tensor under conformal transformations

Explored the implications for mass and angular momentum aspects

Abstract

After a review of symmetries and classical solutions involved in the AdS3/CFT2 correspondence, we apply a similar analysis to asymptotically flat spacetimes at null infinity in 3 and 4 dimensions. In the spirit of two dimensional conformal field theory, the symmetry algebra of asymptotically flat spacetimes at null infinity in 4 dimensions is taken to be the semi-direct sum of supertranslations with infinitesimal local conformal transformations and not, as usually done, with the Lorentz algebra. As a first application, we derive how the symmetry algebra is realized on solution space. In particular, we work out the behavior of Bondi's news tensor, mass and angular momentum aspects under local conformal transformations.