2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/98554We construct a formal connection on the Aomoto complex of an arrangement of hyperplanes, and use it to study the Gauss-Manin connection for the moduli space of the arrangement in the cohomology of a complex rank one local system. We prove that the eigenvalues of the Gauss-Manin connection are integral linear combinations of the weights which define the local system.LaTeX, 15 pages. v2: minor changes. v3: 16 pages, to appear in Compositio MathAlgebraic GeometryCombinatorics32S22, 14D05, 52C35, 55N25text