New Boundary Conditions for AdS3

TL;DR

The paper introduces new chiral boundary conditions for quantum gravity in AdS3, revealing a novel asymptotic symmetry group and connections to warped AdS3, with implications for black hole physics and string theory.

Contribution

It presents a new set of boundary conditions in AdS3 gravity that lead to a unique asymptotic symmetry algebra involving a U(1) Kac-Moody-Virasoro structure.

Findings

Asymptotic symmetry group is a single right-moving U(1) Kac-Moody-Virasoro algebra.

Kac-Moody zero mode relates to mass and spin of BTZ black holes.

Level of the algebra varies between vacuum and black hole sectors, indicating ergosphere formation.

Abstract

New chiral boundary conditions are found for quantum gravity with matter on AdS3. The associated asymptotic symmetry group is generated by a single right-moving U(1) Kac-Moody-Virasoro algebra with c_R = 3l/2G. The Kac-Moody zero mode generates global left-moving translations and equals, for a BTZ black hole, the sum of the total mass and spin. The level is positive about the global vacuum and negative in the black hole sector, corresponding to ergosphere formation. Realizations arising in Chern-Simons gravity and string theory are analyzed. The new boundary conditions are shown to naturally arise for warped AdS3 in the limit that the warp parameter is taken to zero.