{ "id": "0806.3073", "version": "v3", "published": "2008-06-18T19:45:34.000Z", "updated": "2010-09-17T01:33:33.000Z", "title": "Graphs of bounded degree and the $p$-harmonic boundary", "authors": [ "Michael J. Puls" ], "comment": "Give a new proof for theorem 4.7. Change the style of the text in the first two sections", "categories": [ "math.FA", "math.DG" ], "abstract": "Let $p$ be a real number greater than one and let $G$ be a connected graph of bounded degree. In this paper we introduce the $p$-harmonic boundary of $G$. We use this boundary to characterize the graphs $G$ for which the constant functions are the only $p$-harmonic functions on $G$. It is shown that any continuous function on the $p$-harmonic boundary of $G$ can be extended to a function that is $p$-harmonic on $G$. Some properties of this boundary that are preserved under rough-isometries are also given. Now let $\\Gamma$ be a finitely generated group. As an application of our results we characterize the vanishing of the first reduced $\\ell^p$-cohomology of $\\Gamma$ in terms of the cardinality of its $p$-harmonic boundary. We also study the relationship between translation invariant linear functionals on a certain difference space of functions on $\\Gamma$, the $p$-harmonic boundary of $\\Gamma$ with the first reduced $\\ell^p$-cohomology of $\\Gamma$.", "revisions": [ { "version": "v3", "updated": "2010-09-17T01:33:33.000Z" } ], "analyses": { "subjects": [ "60J50", "31C20", "43A15" ], "keywords": [ "harmonic boundary", "bounded degree", "translation invariant linear functionals", "real number greater", "constant functions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008arXiv0806.3073P" } } }