{ "id": "2308.12237", "version": "v1", "published": "2023-08-23T16:24:53.000Z", "updated": "2023-08-23T16:24:53.000Z", "title": "Extension properties of orbit spaces of proper actions revisited", "authors": [ "Sergey Antonyan" ], "categories": [ "math.GN" ], "abstract": "Let $G$ be a locally compact Hausdorff group. We study orbit spaces of equivariant absolute neighborhood extensors ($G$-${\\rm ANE}$'s) in the class of all proper $G$-spaces that are metrizable by a $G$-invariant metric. We prove that if a proper $G$-space $X$ is a $G$-${\\rm ANE}$ and all $G $-orbits in $X$ are metrizable, then the $G$-orbit space $X/G$ is an {\\rm ANE}. If $G$ is a Lie group and $H$ is a closed normal subgroup of $G$, then the $H$-orbit space $X/H$ is a $G/H$-{\\rm ANE}.", "revisions": [ { "version": "v1", "updated": "2023-08-23T16:24:53.000Z" } ], "analyses": { "subjects": [ "54C55", "54C20", "54H15", "57S20" ], "keywords": [ "proper actions", "extension properties", "equivariant absolute neighborhood extensors", "locally compact hausdorff group", "study orbit spaces" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }