BMN vacua, superstars and non-abelian T-duality

Abstract

Acting with non-Abelian T-duality on the S3 inside the AdS5 subspace of AdS5 × S5 with N units of flux, we generate a new half-BPS solution with SU(2|4) symmetry that belongs to the Lin-Lunin-Maldacena class of geometries. The analysis of the asymptotics, quantised charges and probe branes in this geometry suggests an interpretation as the gravity dual to the Berenstein-Maldacena-Nastase Plane Wave Matrix Model, in a particular vacuum associated to a partition of N, in which the multiplicity of each SU(2) irreducible representation is equal to its dimension. This vacuum is interpreted in M-theory in terms of giant gravitons backreacting in the maximally supersymmetric pp-wave geometry. Consistently with this, we show that the non-Abelian T-dual solution exactly agrees with the Penrose limit of the superstar solution in AdS7 × S4. This suggests an interesting global completion of the non-Abelian T-dual solution in terms of an M5-brane geometry.