{ "id": "0711.4670", "version": "v3", "published": "2007-11-29T08:47:57.000Z", "updated": "2008-11-25T12:43:27.000Z", "title": "Automorphism groups of root systems matroids", "authors": [ "Mathieu Dutour Sikiric", "Anna Felikson", "Pavel Tumarkin" ], "comment": "9 pages, 1 table", "categories": [ "math.CO" ], "abstract": "Given a root system $\\mathsf{R}$, the vector system $\\tilde{\\mathsf{R}}$ is obtained by taking a representative $v$ in each antipodal pair $\\{v, -v\\}$. The matroid $M(\\mathsf{R})$ is formed by all independent subsets of $\\tilde{\\mathsf{R}}$. The automorphism group of a matroid is the group of permutations preserving its independent subsets. We prove that the automorphism groups of all irreducible root systems matroids $M(\\mathsf{R})$ are uniquely determined by their independent sets of size 3. As a corollary, we compute these groups explicitly, and thus complete the classification of the automorphism groups of root systems matroids.", "revisions": [ { "version": "v3", "updated": "2008-11-25T12:43:27.000Z" } ], "analyses": { "keywords": [ "automorphism group", "independent subsets", "irreducible root systems matroids", "vector system", "antipodal pair" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007arXiv0711.4670D" } } }