Instantons on Quivers and Orientifolds
Francesco Fucito, Jose F. Morales, Rubik Poghossian
TL;DR
This work develops a Nekrasov-style localization framework for computing the prepotential of gauge theories descended from N=4 SYM via quiver projections and mass deformations, covering product gauge groups with bifundamental matter and extending to orientifold setups with SO/Sp groups. It formulates the D(-1)/D3 system in BRST language, derives the moduli space tangent space under orbifold and orientifold projections, and obtains the centered instanton partition function by summing over fixed points labeled by Young diagrams. The resulting quiver prepotentials are explicitly constructed for two-node cases and generalized to Z_p orbifolds, with matter contributions shown to enter off-diagonally and to reproduce Seiberg-Witten curves in the absence of gravitational corrections. The orientifold analysis further yields SO/Sp prepotentials, including fractional instantons in Sp theories, and demonstrates consistency with known SW structures while providing a streamlined determinant expression for the fixed-point contribution.
Abstract
We compute the prepotential for gauge theories descending from ${\cal N}=4$ SYM via quiver projections and mass deformations. This accounts for gauge theories with product gauge groups and bifundamental matter. The case of massive orientifold gauge theories with gauge group SO/Sp is also described. In the case with no gravitational corrections the results are shown to be in agreement with Seiberg-Witten analysis and previous results in the literature.
