2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/67387We consider the cohomology of local systems on the moduli space of curves of genus 2 and the moduli space of abelian surfaces. We give an explicit formula for the Eisenstein cohomology and a conjectural formula for the endoscopic contribution. We show how counting curves over finite fields provides us with detailed information about Siegel modular forms.7 pagesAlgebraic GeometryNumber Theory11F46; 11G18; 14G35; 14H10Sur la cohomologie des systèmes locaux sur les espaces des modules des courbes de genre 2 et des surfaces abéliennestext