{ "id": "1805.05160", "version": "v1", "published": "2018-05-14T13:22:20.000Z", "updated": "2018-05-14T13:22:20.000Z", "title": "Twisted conjugacy classes in unitriangular groups", "authors": [ "Timur Nasybullov" ], "categories": [ "math.GR" ], "abstract": "Let $R$ be an integral domain of zero characteristic. In this note we study the Reidemeister spectrum of the group ${\\rm UT}_n(R)$ of unitriangular matrices over $R$. We prove that if $R^+$ is finitely generated and $n>2|R^*|$, then ${\\rm UT}_n(R)$ possesses the $R_{\\infty}$-property, i. e. the Reidemeister spectrum of ${\\rm UT}_n(R)$ contains only $\\infty$, however, if $n\\leq|R^*|$, then the Reidemeister spectrum of ${\\rm UT}_n(R)$ has nonempty intersection with $\\mathbb{N}$. If $R$ is a field, then we prove that the Reidemeister spectrum of ${\\rm UT}_n(R)$ coincides with $\\{1,\\infty\\}$, i. e. in this case ${\\rm UT}_n(R)$ does not possess the $R_{\\infty}$-property.", "revisions": [ { "version": "v1", "updated": "2018-05-14T13:22:20.000Z" } ], "analyses": { "keywords": [ "twisted conjugacy classes", "unitriangular groups", "reidemeister spectrum", "zero characteristic", "nonempty intersection" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }