{ "id": "0911.0445", "version": "v1", "published": "2009-11-02T21:41:42.000Z", "updated": "2009-11-02T21:41:42.000Z", "title": "Groups that together with any transformation generate regular semigroups or idempotent generated semigroups", "authors": [ "Joao Araujo", "J. D. Mitchell", "Csaba Schneider" ], "categories": [ "math.GR" ], "abstract": "Let $a$ be a non-invertible transformation of a finite set and let $G$ be a group of permutations on that same set. Then $\\genset{G, a}\\setminus G$ is a subsemigroup, consisting of all non-invertible transformations, in the semigroup generated by $G$ and $a$. Likewise, the conjugates $a^g=g^{-1}ag$ of $a$ by elements $g\\in G$ generate a semigroup denoted $\\genset{a^g | g\\in G}$. We classify the finite permutation groups $G$ on a finite set $X$ such that the semigroups $\\genset{G,a}$, $\\genset{G, a}\\setminus G$, and $\\genset{a^g | g\\in G}$ are regular for all transformations of $X$. We also classify the permutation groups $G$ on a finite set $X$ such that the semigroups $\\genset{G, a}\\setminus G$ and $\\genset{a^g | g\\in G}$ are generated by their idempotents for all non-invertible transformations of $X$.", "revisions": [ { "version": "v1", "updated": "2009-11-02T21:41:42.000Z" } ], "analyses": { "subjects": [ "20M20", "20M17", "20B30", "20B35", "20B15", "20B40" ], "keywords": [ "transformation generate regular semigroups", "idempotent generated semigroups", "finite set", "non-invertible transformation", "finite permutation groups" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0911.0445A" } } }