{ "id": "1909.04397", "version": "v1", "published": "2019-09-10T10:42:40.000Z", "updated": "2019-09-10T10:42:40.000Z", "title": "Distal Actions of Automorphisms of Lie Groups $G$ on $\\rm Sub_{G}$", "authors": [ "Riddhi Shah", "Alok Kumar Yadav" ], "categories": [ "math.DS" ], "abstract": "For a locally compact metrizable group $G$, we study the action of $\\rm Aut(G)$ on $\\rm Sub_G$, the set of closed subgroups of $G$ endowed with the Chabauty topology. Given an automorphism $T$ of $G$, we relate the distality of the $T$-action on $\\rm Sub_G$ with that of the $T$-action on $G$ under a certain condition. If $G$ is a connected Lie group, we characterise the distality of the $T$-action on $\\rm Sub_G$ in terms of compactness of the closed group generated by $T$ in $\\rm Aut(G)$ under certain conditions on the center of $G$ or on $T$ as follows: $G$ has no compact central subgroup of positive dimension or $T$ is unipotent or $T$ is contained in the connected component of the identity in $\\rm Aut(G)$. Moreover, we also show that a connected Lie group $G$ acts distally on $\\rm Sub_G$ if and only if $G$ is either compact or it is isomorphic to a direct product of a compact group and a vector group. All the results on the Lie groups mentioned above hold for the action on $\\rm Sub^a_G$, a subset of $\\rm Sub_G$ consisting of closed abelian subgroups of $G$.", "revisions": [ { "version": "v1", "updated": "2019-09-10T10:42:40.000Z" } ], "analyses": { "keywords": [ "distal actions", "automorphism", "connected lie group", "compact central subgroup", "chabauty topology" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }