2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/112505We recall how the Gauss-Bonnet theorem can be interpreted as a finite dimen- sional index theorem. We describe the construction given in hep-th/0512293 of a function that can be interpreted as a gravitational effective action on a triangulation. The variation of this function under local rescalings of the edge lengths sharing a vertex is the Euler density, and we use it to illustrate how continuous concepts can have natural discrete analogs.7 pages, 1 figure; Presented at the 26th Winter School GEOMETRY AND PHYSICS at SrniHigh Energy Physics - Theorytext