2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/221216It is a classical fact that the elliptic modular functions satisfies an algebraic differential equation of order 3, and none of lower order. We show how this generalizes to Siegel modular functions of arbitrary degree. The key idea is that the partial differential equations they satisfy are governed by Gauss--Manin connections, whose monodromy groups are well-known. Modular theta functions provide a concrete interpretation of our result, and we study their differential properties in detail in the case of degree 2.21 pages, AmSTeX, uses picture.sty for 1 LaTeX picture; submitted for publicationNumber TheoryAlgebraic Geometry11J89, 11F46 (Primary), 11F27, 14G35 (Secondary)text