String Theory and ALE Instantons

TL;DR

This paper explores supersymmetric self-dual backgrounds in heterotic and type I string theories, revealing two classes: flat metrics with axionic instantons and ALE gravitational instantons with gauge instantons, expanding understanding of string theory solutions.

Contribution

It identifies and analyzes two distinct classes of supersymmetric self-dual backgrounds in low-energy string effective theories, including ALE instantons coupled with gauge fields.

Findings

Two classes of supersymmetric self-dual backgrounds identified.

ALE gravitational instantons coupled with gauge instantons analyzed.

Extension of known solutions to include ALE backgrounds.

Abstract

We show that the classical equations of motion of the low-energy effective field theory describing the massless modes of the heterotic (or type I) string admit two classes of supersymmetric self--dual backgrounds. The first class, which was already considered in the literature, consists of solutions with a (conformally) flat metric coupled to axionic instantons. The second includes Asymptotically Locally Euclidean (ALE) gravitational instantonic backgrounds coupled to gauge instantons through the so--called ``standard embedding''. Talk given by F.Fucito at the XI SIGRAV meeting, Trieste, September 27-30, 1994