{ "id": "1209.0954", "version": "v1", "published": "2012-09-05T12:53:05.000Z", "updated": "2012-09-05T12:53:05.000Z", "title": "Collineation group as a subgroup of the symmetric group", "authors": [ "Fedor Bogomolov", "Marat Rovinsky" ], "comment": "9 pages", "categories": [ "math.GR", "math.CO" ], "abstract": "Let $\\Psi$ be the projectivization (i.e., the set of one-dimensional vector subspaces) of a vector space of dimension $\\ge 3$ over a field. Let $H$ be a closed (in the pointwise convergence topology) subgroup of the permutation group $\\mathfrak{S}_{\\Psi}$ of the set $\\Psi$. Suppose that $H$ contains the projective group and an arbitrary self-bijection of $\\Psi$ transforming a triple of collinear points to a non-collinear triple. It is well-known from \\cite{KantorMcDonough} that if $\\Psi$ is finite then $H$ contains the alternating subgroup $\\mathfrak{A}_{\\Psi}$ of $\\mathfrak{S}_{\\Psi}$. We show in Theorem \\ref{density} below that $H=\\mathfrak{S}_{\\Psi}$, if $\\Psi$ is infinite.", "revisions": [ { "version": "v1", "updated": "2012-09-05T12:53:05.000Z" } ], "analyses": { "keywords": [ "symmetric group", "collineation group", "one-dimensional vector subspaces", "collinear points", "vector space" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1209.0954B" } } }