Stringy Instantons and Quiver Gauge Theories

TL;DR

This paper investigates how Euclidean D3 brane instantons intersecting with space-filling D-branes can generate nonperturbative effects in the 4D superpotential, affecting the vacuum structure in string-derived gauge theories.

Contribution

It provides a detailed analysis of instanton contributions to the superpotential in quiver gauge theories, especially on del Pezzo surfaces, highlighting their impact on vacuum configurations.

Findings

Instantons induce nontrivial operators in the superpotential.

These effects can qualitatively alter the vacuum structure.

Explicit example on a del Pezzo surface demonstrates the phenomena.

Abstract

We explore contributions to the 4D effective superpotential which arise from Euclidean D3 branes (``instantons'') that intersect space-filling D-branes. These effects can perturb the effective field theory on the space-filling branes by nontrivial operators composed of charged matter fields, changing the vacuum structure in a qualitative way in some examples. Our considerations are exemplified throughout by a careful study of a fractional brane configuration on a del Pezzo surface.