Results 61 to 70 of about 775 (197)
On Kotzig's Perfect Set Problem of Hamiltonian Cycle Decompositions of the Complete Graph
Journal of Combinatorial Designs, Volume 34, Issue 8, Page 388-409, August 2026.ABSTRACT A Hamiltonian cycle decomposition (HCD) of K n is a set of Hamiltonian cycles in which each 1‐path of K n appears exactly once. A Dudeney set of K n is a set of Hamiltonian cycles in which each 2‐path of K n appears exactly once. Kotzig's perfect set of HCDs of K n is a set of HCDs whose union forms a Dudeney set.
Nobuaki Mutoh
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On the Geometry of the Automorphism Group of a Free Group
Bulletin of the London Mathematical Society, 1995 The groups \(\Aut(F_3)\) and \(\text{Out}(F_3)\) satisfy strictly exponential isoperimetric inequalities; in particular, they are not automatic. For \(n\geq 3\), \(\Aut(F_n)\) and \(\text{Out}(F_n)\) do not admit bounded bicombings of sub-exponential length, hence they cannot act properly and cocompactly by isometries of any simply-connected space of ...
Bridson, M, Vogtmann, K
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On Group Ring Automorphisms [PDF]
Algebras and Representation Theory, 2004 Let \(G\) be a finite group and \(R\) be a complete discrete valuation ring of characteristic \(0\). The authors study the group of those automorphisms \(\text{Outcent}(RG)\) of the group ring \(RG\) which fix the center of \(RG\) pointwise. As a main result of the paper the authors show that if \(B\) is a block of the group ring of \(G\) over the \(p\)
Hertweck, Martin, Nebe, Gabriele
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Transforming Solutions for the Oberwolfach Problem into Solutions for the Spouse‐Loving Variant
Journal of Combinatorial Designs, Volume 34, Issue 8, Page 361-377, August 2026.ABSTRACT The Oberwolfach problem OP ( F ), for a 2‐factor F of K n, asks whether there exists a 2‐factorization of K n (if n is odd) or K n − I (if n is even) where each 2‐factor is isomorphic to F. Here, I denotes any 1‐factor of K n. For even n, the problem OP ( F ) may also be denoted OP − ( F ), and has been nicknamed the spouse‐avoiding variant ...
Maruša Lekše, Mateja Šajna
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Automorphism groups of 2-groups
Journal of Algebra, 2006 It is conjectured that \(|G|\mid|\Aut(G)|\) for every nonabelian \(p\)-group \(G\). In this paper the following results are proven. Theorem. For every \(s\in\mathbb{N}\) there exists \(o(r,s)\in\mathbb{N}\) such that \(2^s\mid|G|\mid|\Aut(G)|\) for all \(2\)-groups \(G\) of coclass \(r\) and order at least \(o(r,s)\). -- Corollary.
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A Note on the Automorphism Group of a p-Group [PDF]
Proceedings of the American Mathematical Society, 1968 The relation between the order of a p-group and its automorphism group has been the subject of several papers, see [1], [2], and [4]. The existence of outer-automorphisms of a finite p-group was proved by Gaschiitz [3], but the question of the size of the automorphism group of a p-group still remains.
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On Nielsen equivalence classes of two‐element generators of mapping class groups
Bulletin of the London Mathematical Society, Volume 58, Issue 8, August 2026.Abstract We show that there are infinitely many Nielsen equivalence classes of the mapping class group of a closed oriented surface of genus at least eight.
Susumu Hirose, Naoyuki Monden
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Automorphism Groups of Abelian p-Groups [PDF]
Proceedings of the American Mathematical Society, 1975 Let r be the automorphism group of a nonelementary reduced abelian p-group, p > 5. It is shown that every noncentral norinal subgroup of r contains a noncentral elementary abelian normal p-subgroup of r of rank at least 2. 1. The result. Throughout the following, G is a reduced p-primary abelian group, p > 5, and F is the group of all automorphisms of ...
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Open Mathematics, 2020 A Cayley graph Γ\Gamma on a group G is called a dual Cayley graph on G if the left regular representation of G is a subgroup of the automorphism group of Γ\Gamma (note that the right regular representation of G is always an automorphism group of Γ ...
Pan Jiangmin
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Prime Fano threefolds of genus 12 with a $G_m$-action [PDF]
Épijournal de Géométrie Algébrique, 2018 We give an explicit construction of prime Fano threefolds of genus 12 with a $G_m$-action, describe their isomorphism classes and automorphism groups.
Alexander Kuznetsov, Yuri Prokhorov
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