Dimers, orientifolds and anomalies

We study $4d$ $\mathcal{N}=1$ gauge theories engineered via D-branes at orientifolds of toric singularities, where anomalies are cancelled without the introduction non-compact flavor branes. Using dimer model techniques, we derive geometric criteria for establishing whether a given singularity can admit anomaly-free D-brane configurations purely based on its data and type orientifold projection. Our results therefore extend dictionary between properties singularities physical corresponding theories.