{ "id": "math/0405590", "version": "v5", "published": "2004-05-31T09:54:57.000Z", "updated": "2007-07-10T16:23:07.000Z", "title": "Twisted conjugacy classes of automorphisms of Baumslag-Solitar groups", "authors": [ "Alexander Fel'shtyn", "Daciberg L. Goncalves" ], "comment": "20 pages, new sections 6 and 7 are added", "categories": [ "math.GR", "math.GT" ], "abstract": "Let $\\phi:G \\to G$ be a group endomorphism where $G$ is a finitely generated group of exponential growth, and denote by $R(\\phi)$ the number of twisted $\\phi$-conjugacy classes. Fel'shtyn and Hill \\cite{fel-hill} conjectured that if $\\phi$ is injective, then $R(\\phi)$ is infinite. This conjecture is true for automorphisms of non-elementary Gromov hyperbolic groups, see \\cite{ll} and \\cite {fel:1}. It was showed in \\cite {gw:2} that the conjecture does not hold in general. Nevertheless in this paper, we show that the conjecture holds for the Baumslag-Solitar groups $B(m,n)$, where either $|m|$ or $|n|$ is greater than 1 and $|m|\\ne |n|$. We also show that in the cases where $|m|=|n|>1$ or $mn=-1$ the conjecture is true for automorphisms. In addition, we derive few results about the coincidence Reidemeister number.", "revisions": [ { "version": "v5", "updated": "2007-07-10T16:23:07.000Z" } ], "analyses": { "subjects": [ "20E45", "37C25", "55M20" ], "keywords": [ "twisted conjugacy classes", "baumslag-solitar groups", "automorphisms", "non-elementary gromov hyperbolic groups", "coincidence reidemeister number" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004math......5590F" } } }