6D (1,1) Gauged Supergravities from Orientifold Compactifications

TL;DR

This paper classifies orientifold projections in 6D supergravities from string/M-theory compactifications with fluxes and branes, analyzing vacua including Minkowski and (A)dS solutions.

Contribution

It provides a comprehensive classification of orientifold projections leading to 6D supergravities and details the flux-vacua correspondence, including new (A)dS solutions.

Findings

Classified all inequivalent orientifold projections for 6D supergravities.

Identified numerous Minkowski vacua with no-scale structure.

Discovered new (A)dS extrema in the compactification landscape.

Abstract

We study dimensional reductions of M-theory/type II strings down to 6D in the presence of fluxes and spacetime filling branes and orientifold planes of different types. We classify all inequivalent orientifold projections giving rise to $\mathcal{N}=(1,1)$ supergravities in 6D and work out the embedding tensor/fluxes dictionary for each of those. Finally we analyze the set of vacua for the different classes of reductions and find an abundance of "no-scale" type Minkowski vacua, as well as a few novel examples of (A)dS extrema.