IIB black hole horizons with five-form flux and KT geometry

Understand

We investigate the near horizon geometry of IIB supergravity black holes with non-vanishing 5-form flux preserving at least two supersymmetries.

• We demonstrate that there are three classes of solutions distinguished by the choice of Killing spinors.
• We find that the spatial horizon sections of the class of solutions with an SU(4) invariant pure Killing spinor are hermitian manifolds and admit a hidden Kahler with torsion (KT) geometry compatible with the SU(4) structure.
• Moreover the Bianchi identity of the 5-form, which also implies the field equations, can be expressed in terms of the torsion H as d(\omega\wedge H)=\partial\bar\partial \omega^2=0, where omega is a Hermitian form.