Domain Walls in Massive Supergravities

TL;DR

This paper demonstrates how to derive various maximally supersymmetric massive supergravities in dimensions up to 8 from eleven-dimensional supergravity through a generalized reduction involving axions with linear coordinate dependence, leading to new domain wall solutions.

Contribution

It introduces a novel generalized reduction method that produces multiple inequivalent massive supergravities and constructs explicit domain wall solutions, including new eleven-dimensional supergravity solutions.

Findings

Multiple inequivalent massive supergravities in D=4 and D=7.

Existence of domain wall solutions preserving half supersymmetry.

New solutions of D=11 supergravity obtained via oxidation.

Abstract

We show how toroidally-compactified eleven-dimensional supergravity can be consistently truncated to yield a variety of maximally-supersymmetric ``massive'' supergravities in spacetime dimensions $D\le 8$. The mass terms arise as a consequence of making a more general ansatz than that in usual Kaluza-Klein dimensional reduction, in which one or more axions are given an additional linear dependence on one of the compactification coordinates. The lower-dimensional theories are nevertheless consistent truncations of eleven-dimensional supergravity. Owing to the fact that the generalised reduction commutes neither with U-duality nor with ordinary dimensional reduction, many different massive theories can result. The simplest examples arise when just a single axion has the additional linear coordinate dependence. We find five inequivalent such theories in D=7, and 71 inequivalent ones in D=4. The massive theories admit no maximally-symmetric vacuum solution, but they do admit $(D-2)$-brane solutions, i.e. domain walls, which preserve half the supersymmetry. We present examples of these solutions, and their oxidations to D=11. Some of the latter are new solutions of D=11 supergravity.