IIB horizons

TL;DR

This paper classifies all supersymmetric near-horizon geometries in type IIB supergravity, revealing their structure as almost Hermitian manifolds and constructing new solutions with combined fluxes.

Contribution

It provides a comprehensive analysis of IIB near-horizon geometries, including special cases with $Spin(7)$ structures and pure Killing spinors, and introduces new solutions with 3-form and 5-form fluxes.

Findings

Generic horizon sections are 8-dimensional almost Hermitian spin${}_c$ manifolds.

Special cases include horizons with $Spin(7)$ structure and pure Killing spinors.

New near-horizon geometries with combined 3-form and 5-form fluxes are constructed.

Abstract

We solve the Killing spinor equations for all near-horizon IIB geometries which preserve at least one supersymmetry. We show that generic horizon sections are 8-dimensional almost Hermitian spin${}_c$ manifolds. Special cases include horizon sections with a $Spin(7)$ structure and those for which the Killing spinor is pure. We also explain how the common sector horizons and the horizons with only 5-form flux are included in our general analysis. We investigate several special cases mainly focusing on the horizons with constant scalars admitting a pure Killing spinor and find that some of these exhibit a generalization of the 2-SCYT condition that arises in the horizons with 5-form fluxes only. We use this to construct new examples of near-horizon geometries with both 3-form and 5-form fluxes.