Adding new hair to the 3-charge black ring

TL;DR

This paper constructs new 1/8-BPS supergravity solutions with a non-trivial B-field, extending black ring geometries and revealing novel features like extra dipole charges, with implications for microstate counting in string theory.

Contribution

It introduces a class of 1/8-BPS solutions with a non-zero B-field, connecting them to M-theory and 5D supergravity, and identifies explicit black ring examples with new charge properties.

Findings

New solutions with non-trivial NS-NS B-field in supergravity

Black rings with an extra dipole charge

Near-horizon geometry matches AdS_3 x S^3, linking to D1-D5 CFT

Abstract

Motivated by the string theory analysis of arXiv:1108.6331, we construct a class of 1/8-BPS solutions of type IIB supergravity compactified on S^1 x T^4. In this duality frame our ansatz allows for a non-trivial NS-NS B-field which has been usually set to zero in previous studies of 1/8-BPS geometries. We provide a M-theory description of these new geometries and show that they can be interpreted as the lift of solutions of the N=2 5D supergravity with three vector multiplets and whose scalar manifold is the symmetric space SO(1,1) x (SO(1,2)/SO(2)). Finally we show that the non-minimal 5D black rings provide an explicit example of solutions falling in this ansatz. In particular we point out the existence of a black ring that has an extra dipole charge with respect to the solutions of the STU-model. In the near-horizon limit, this ring has an AdS_3 x S^3 geometry with the same radius as the one of the 3-charge black hole and thus its microstates should belong to the usual D1-D5 CFT.