9 research outputs found

    The 33-closure of a solvable permutation group is solvable

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    Let mm be a positive integer and let Ω\Omega be a finite set. The mm-closure of GSym(Ω)G\leq\operatorname{Sym}(\Omega) is the largest permutation group on Ω\Omega having the same orbits as GG in its induced action on the Cartesian product Ωm\Omega^m. The 11-closure and 22-closure of a solvable permutation group need not be solvable. We prove that the mm-closure of a solvable permutation group is always solvable for m3m\geq3

    On finite totally 22-closed groups

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    On finite totally 22-closed groups

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    An abstract group GG is called totally 22-closed if H=H(2),ΩH=H^{(2),\Omega } for any set Ω\Omega with GHSym(Ω)G\cong H\le \mathrm{Sym}(\Omega ), where H(2),ΩH^{(2),\Omega } is the largest subgroup of Sym(Ω)\mathrm{Sym}(\Omega ) whose orbits on Ω×Ω\Omega \times \Omega are the same orbits of HH. In this paper, we classify the finite soluble totally 22-closed groups. We also prove that the Fitting subgroup of a totally 22-closed group is a totally 22-closed group. Finally, we prove that a finite insoluble totally 22-closed group GG of minimal order with non-trivial Fitting subgroup has shape ZXZ\cdot X, with Z=Z(G)Z=Z(G) cyclic, and XX is a finite group with a unique minimal normal subgroup, which is nonabelian
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