Stringy Instantons and Quiver Gauge Theories

Bogdan Florea, Shamit Kachru, John McGreevy, Natalia Saulina

Published 2006-10-02, updated 2009-05-23Version 3

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.