{ "id": "2101.02981", "version": "v1", "published": "2021-01-08T12:23:49.000Z", "updated": "2021-01-08T12:23:49.000Z", "title": "Contraction groups and the big cell for endomorphisms of Lie groups over local fields", "authors": [ "Helge Glockner" ], "comment": "34 pages, LaTeX; former title: Contraction groups of analytic endomorphisms and dynamics on the big cell", "categories": [ "math.GR" ], "abstract": "Let $G$ be a Lie group over a totally disconnected local field and $\\alpha$ be an analytic endomorphism of $G$. The contraction group of $\\alpha$ ist the set of all $x\\in G$ such that $\\alpha^n(x)\\to e$ as $n\\to\\infty$. Call sequence $(x_{-n})_{n\\geq 0}$ in $G$ an $\\alpha$-regressive trajectory for $x\\in G$ if $\\alpha(x_{-n})=x_{-n+1}$ for all $n\\geq 1$ and $x_0=x$. The anti-contraction group of $\\alpha$ is the set of all $x\\in G$ admitting an $\\alpha$-regressive trajectory $(x_{-n})_{n\\geq 0}$ such that $x_{-n}\\to e$ as $n\\to\\infty$. The Levi subgroup is the set of all $x\\in G$ whose $\\alpha$-orbit is relatively compact, and such that $x$ admits an $\\alpha$-regressive trajectory $(x_{-n})_{n\\geq 0}$ such that $\\{x_{-n}\\colon n\\geq 0\\}$ is relatively compact. The big cell associated to $\\alpha$ is the set $\\Omega$ of all all products $xyz$ with $x$ in the contraction group, $y$ in the Levi subgroup and $z$ in the anti-contraction group. Let $\\pi$ be the mapping from the cartesian product of the contraction group, Levi subgroup and anti-contraction group to $\\Omega$ which maps $(x,y,z)$ to $xyz$. We show: $\\Omega$ is open in $G$ and $\\pi$ is \\'{e}tale for suitable immersed Lie subgroup structures on the three subgroups just mentioned. Moreover, we study group-theoretic properties of contraction groups and anti-contraction groups.", "revisions": [ { "version": "v1", "updated": "2021-01-08T12:23:49.000Z" } ], "analyses": { "subjects": [ "22E20", "22D05", "22E25", "22E35", "32P05", "37B05", "37C05", "37C86", "37D10" ], "keywords": [ "big cell", "lie group", "local field", "anti-contraction group", "immersed lie subgroup structures" ], "note": { "typesetting": "LaTeX", "pages": 34, "language": "en", "license": "arXiv", "status": "editable" } } }