{ "id": "2005.08089", "version": "v1", "published": "2020-05-16T20:20:36.000Z", "updated": "2020-05-16T20:20:36.000Z", "title": "A Weak Form of Amenability of Topological Semigroups and its Applications in Ergodic and Fixed Point Theories", "authors": [ "Ali Jabbari", "Ali Ebadian", "Madjid Eshaghi Gordji" ], "categories": [ "math.FA" ], "abstract": "In this paper, we introduce a weak form of amenability on topological semigroups that we call $\\varphi$-amenability, where $\\varphi$ is a character on a topological semigroup. Some basic properties of this new notion are obtained and by giving some examples, we show that this definition is weaker than the amenability of semigroups. As a noticeable result, for a topological semigroup $S$, it is shown that if $S$ is $\\varphi$-amenable, then $S$ is amenable. Moreover, $\\varphi$-ergodicity for a topological semigroup $S$ is introduced and it is proved that under some conditions on $S$ and a Banach space $X$, $\\varphi$-amenability and $\\varphi$-ergodicity of any antirepresntation defined by a right action $S$ on $X$, are equivalent. A relation between $\\varphi$-amenability of topological semigroups and existance of a common fixed point is investigated and by this relation, Hahn-Banach property of topological semigroups in the sense of $\\varphi$-amenability defined and studied.", "revisions": [ { "version": "v1", "updated": "2020-05-16T20:20:36.000Z" } ], "analyses": { "subjects": [ "43A07", "22D15", "22A20" ], "keywords": [ "topological semigroup", "fixed point theories", "amenability", "weak form", "applications" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }