2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/60079The closed 3-manifolds of constant positive curvature were classified long ago by Seifert and Threlfall. Using well-known information about the orthogonal group O(4), we calculate their full isometry groups Isom(M), determine which elliptic 3-manifolds admit Seifert fiberings that are invariant under all isometries, and verify that the inclusion of Isom(M) to Diff(M) is a bijection on path components.Geometric TopologyDifferential Geometry57M50; 57M60; 58D99text