Semi-classical stability of supergravity vacua

TL;DR

This paper investigates the semi-classical stability of supergravity vacua by analyzing instantonic decay modes, concluding that physically consistent decay modes are excluded, thus supporting the stability of these vacua.

Contribution

It generalizes previous decay mode constructions to include non-trivial dilaton and tensor fields and proves their incompatibility with supersymmetric vacuum stability.

Findings

Decay modes with incompatible spin structures are excluded.

All physically acceptable decay modes violate the dominant energy condition.

Supersymmetric vacua are semi-classically stable under these conditions.

Abstract

The existence of instantonic decay modes would indicate a semi-classical instability of the vacua of ten and eleven dimensional supergravity theories. Decay modes whose spin structures are incompatible with those of supersymmetric vacua have previously been constructed, and we present generalisations including those involving non trivial dilaton and antisymmetric tensor fields. We then show that the requirement that any instanton describing supersymmetric vacuum decay should admit both a zero momentum hypersurface from which we describe the subsequent Lorentzian evolution and a spin structure at infinity compatible with the putative vacuum excludes all such decay modes, except those with unphysical energy momentum tensors which violate the dominant energy condition.