2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/61686These are the notes from a survey talk given at Arbeitstagung 2001 covering the author's work with Lev Borisov and Sorin Popescu on toric varieties, modular forms, and equations of modular curves.Number TheoryAlgebraic Geometry11F11, 14M25text