2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/77831This paper gives a new proof of a result of Geoghegan and Mihalik which states that whenever a contractible open $n$-manifold $W$ which is not homeomorphic to $\mathbf{R}^n$ is a covering space of an $n$-manifold $M$ and either $n \geq 4$ or $n=3$ and $W$ is irreducible, then the group of covering translations injects into the homeotopy group of $W$.4 pages, LaTeX, amsart styleGeometric Topologytext