Sixteen-fermion and related terms in M-theory on T**2

TL;DR

This paper investigates specific one-loop processes in eleven-dimensional supergravity compactified on T2, revealing exact non-perturbative terms in type II string theory effective actions, especially involving sixteen fermions and supersymmetry relations.

Contribution

It explicitly relates one-loop supergravity processes to non-perturbative terms in type II string theories, highlighting supersymmetry constraints on these interactions.

Findings

Derived exact non-perturbative terms in effective actions

Connected supergravity loop processes to string theory interactions

Identified supersymmetry relations among various terms

Abstract

Certain one-loop processes in eleven-dimensional supergravity compactified on T**2 determine exact, non-perturbative, terms in the effective action of type II string theories compactified on a circle. One example is the modular invariant U(1)-violating interaction of sixteen complex spin-1/2 fermions of ten-dimensional type IIB theory. This term, together with the (curvature)**4 term, and many other terms of the same dimension are all explicitly related by supersymmetry.