2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/131954We present two approaches to the study of the cohomology of moduli spaces of curves. Together, they allow us to compute the rational cohomology of the moduli space \Mbar_4 of stable complex curves of genus 4, with its Hodge structure.28 pages. Changes mainly of notational and expository nature. The published paper is available at http://www.springerlink.comAlgebraic Geometry14H10text