2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/68006If $Q$ is a group acting as a group of automorphisms of another group $G$ (with finite orbits), denote by $C_*(G)^Q$ the subcomplex of $Q$-invariant chains in the bar complex $C_*(G)$. In this paper, we study the homology of the complex $C_*(G)^Q$ and compute several examples.18 pagesAlgebraic TopologyGroup Theory20J05; 55N91text