Non-perturbative effective interactions from fluxes

Motivated by possible implications on the problem of moduli stabilization and other phenomenological aspects, we study D-brane instanton effects in flux compactifications. We focus on a local model and compute non-perturbative interactions generated by gauge and stringy instantons in a N = 1 quiver theory with gauge group U(N₀) × U(N₁) and matter in the bifundamentals. This model is engineered with fractional D3-branes at a ℂ³/(ℤ₂ × ℤ₂) singularity and its non-perturbative sectors are described by introducing fractional D-instantons. We find a rich variety of instanton-generated interactions, ranging from superpotentials and Beasley-Witten like multi-fermion terms to non-perturbative flux-induced instanton interactions.