Stringy instanton effects in N=2 gauge theories

TL;DR

This paper investigates how stringy instantons induce non-perturbative effects in N=2 SU(2) gauge theories, computing corrections to the prepotential up to instanton number five using localization techniques.

Contribution

It provides explicit calculations of non-perturbative corrections from stringy instantons in N=2 gauge theories, extending understanding of their effects beyond field theory.

Findings

Non-perturbative terms match expected structures for all instanton numbers.

Explicit localization computations up to instanton number five.

Series of non-perturbative corrections to the prepotential.

Abstract

We study the non-perturbative effects induced by stringy instantons on N=2 SU}(N) gauge theories in four dimensions, realized on fractional D3 branes in a C^3/Z_3 orientifold. The stringy instantons, corresponding to D(-1) branes that occupy a node of the orientifold quiver diagram where no D3 brane is present, have the right content of zero-modes to produce non-perturbative terms in the four-dimensional effective action. In the SU(2) theory these terms have the same structure for all instanton numbers and yield a series of non-perturbative corrections to the prepotential. We explicitly compute these corrections up to instanton number k=5 using localization methods.