{ "id": "1004.2126", "version": "v2", "published": "2010-04-13T09:19:50.000Z", "updated": "2011-08-22T11:18:40.000Z", "title": "Actions of Baumslag-Solitar groups on surfaces", "authors": [ "Nancy Guelman", "Isabelle Liousse" ], "comment": "We clarified and improved some results and we added examples", "categories": [ "math.DS", "math.GR" ], "abstract": "Let $BS(1,n) =< a, b \\ | \\ aba^{-1} = b^n >$ be the solvable Baumslag-Solitar group, where $ n\\geq 2$. It is known that BS(1,n) is isomorphic to the group generated by the two affine maps of the real line: $f_0(x) = x + 1$ and $h_0(x) = nx $. This paper deals with the dynamics of actions of BS(1,n) on closed orientable surfaces. We exhibit a smooth BS(1,n) action without finite orbits on $\\TT ^2$, we study the dynamical behavior of it and of its $C^1$-pertubations and we prove that it is not locally rigid. We develop a general dynamical study for faithful topological BS(1,n)-actions on closed surfaces $S$. We prove that such actions $$ admit a minimal set included in $fix(f)$, the set of fixed points of $f$, provided that $fix(f)$ is not empty. When $S= \\TT^2$, we show that there exists a positive integer $N$, such that $fix(f^N)$ is non-empty and contains a minimal set of the action. As a corollary, we get that there are no minimal faithful topological actions of BS(1,n) on $\\TT^2$. When the surface $S$ has genus at least 2, is closed and orientable, and $f$ is isotopic to identity, then $fix(f)$ is non empty and contains a minimal set of the action. Moreover if the action is $C^1$ then $fix(f)$ contains any minimal set.", "revisions": [ { "version": "v2", "updated": "2011-08-22T11:18:40.000Z" } ], "analyses": { "subjects": [ "37Bxx", "37Exx" ], "keywords": [ "minimal set", "real line", "solvable baumslag-solitar group", "minimal faithful topological actions", "paper deals" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1004.2126G" } } }