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Related papers: Half-automorphism group of Chein loops

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We introduce the inverse monoid of inner partial automorphisms of a semigroup -- a tool that associates to every semigroup an inverse semigroup. When the semigroup is a group, this inverse semigroup is isomorphic to the group of inner…

We describe the autotopism group Atp(G) of any abelian group G as being a semidirect product of its automorphism group Aut(G) and G^2. We then provide the subgroup structure of Atp(G) when G is a finite cyclic group.

Group Theory · Mathematics 2012-01-30 Lucien Clavier

The goal of this paper is to construct and describe certain arithmetic subgroups of the automorphism group of a partially commutative group. More precisely, given an arbitrary finite graph $\Gamma$ we construct an arithmetic subgroup…

Group Theory · Mathematics 2008-03-17 Andrew J. Duncan , Ilya V. Kazachkov , Vladimir N. Remeslennikov

We introduce a notion of quasimorphism between two arbitrary groups, generalizing the classical notion of Ulam. We then define and study the category of homogeneous quasigroups, whose objects are groups and whose morphisms are equivalence…

Group Theory · Mathematics 2014-03-13 Tobias Hartnick , Pascal Schweitzer

Let G be any finitely generated infinite group. Denote by K(G) the FC-centre of G, i.e., the subgroup of all elements of G whose centralizers are of finite index in G. Let QI(G) denote the group of quasi-isometries of G with respect to word…

Group Theory · Mathematics 2007-05-23 Aniruddha C. Naolekar , Parameswaran Sankaran

For a real semisimple Lie algebra, we consider its automorphism group quotient by its identity component. This is known as the outer automorphism group. In this article, we compute the outer automorphism groups of all real semisimple Lie…

Representation Theory · Mathematics 2022-02-09 Meng-Kiat Chuah , Mingjing Zhang

We prove that every isomorphism of Chevalley groups of type $G_2$ over commutative local rings with 1/2 and 1/3 is standard, i. e., it is a composition of a ring isomorphism and an inner automorphism.

Group Theory · Mathematics 2009-08-10 E. I. Bunina

Let $M^*(q)$ be the unique nonassociative finite simple Moufang loop constructed over $GF(q)$. We prove that $Aut(M^*(2))$ is the Chevalley group $G_2(2)$, by extending multiplicative automorphism of $M^*(2)$ into linear automorphisms of…

Group Theory · Mathematics 2007-05-23 Petr Vojtěchovský

In this paper we prove that every automorphism of a Chevalley group (or its elementary subgroup) with root system of rank >1 over a commutative ring (with 1/2 for the systems A_2, F_4, B_l, C_l; with 1/2 and 1/3 for the system G_2) is…

Group Theory · Mathematics 2023-06-06 Elena Bunina

In 1974 Orin Chein discovered a new family of Moufang loops which are now called Chein loops. Such a loop can be created from any group $W$ together with $\mathbb{Z}_2$ by a variation on a semi-direct product. We study these loops in the…

Group Theory · Mathematics 2011-10-31 Rieuwert J. Blok , Stephen Gagola

In this paper we prove that every automorphism of a Chevalley group with the root system G_2 over a commutative ring R with 1/3, generated by all its invertible elements and the ideal 2R is a composition of ring and inner automorphisms.

Group Theory · Mathematics 2023-07-25 Elena Bunina , Maria Vladykina

A loop whose inner mappings are automorphisms is an \emph{automorphic loop} (or \emph{A-loop}). We characterize commutative (A-)loops with middle nucleus of index 2 and solve the isomorphism problem. Using this characterization and certain…

Group Theory · Mathematics 2011-08-19 Premysl Jedlicka , Michael Kinyon , Petr Vojtechovsky

We describe all automorphisms of a free metabelian anticommutative algebra of rank $n\geq 3$ over a field $K$ that move only one variable while fixing the others. Such automorphisms are called Chein automorphisms in the cases of free…

Rings and Algebras · Mathematics 2025-12-15 Ruslan Nauryzbaev , Ivan Shestakov , Ualbai Umirbaev

Consider a smooth connected algebraic group $G$ acting on a normal projective variety $X$ with an open dense orbit. We show that Aut($X$) is a linear algebraic group if so is $G$; for an arbitrary $G$, the group of components of Aut($X$) is…

Algebraic Geometry · Mathematics 2019-11-21 Michel Brion

A loop is automorphic if all its inner mappings are automorphisms. We construct a large family of automorphic loops as follows. Let $R$ be a commutative ring, $V$ an $R$-module, $E=\mathrm{End}_R(V)$ the ring of $R$-endomorphisms of $V$,…

Group Theory · Mathematics 2017-12-19 Alexandr Grishkov , Marina Rasskazova , Petr Vojtěchovský

We study abelian-by-cyclic Moufang loops. We construct all split $3$-divisible abelian-by-cyclic Moufang loops from so-called Moufang permutations on abelian groups $(X,+)$, which are permutations that deviate from an automorphism of…

Group Theory · Mathematics 2023-01-11 Aleš Drápal , Petr Vojtěchovský

We describe all constructions for loops of Bol-Moufang type analogous to the Chein construction $M(G,*,g_0)$ for Moufang loops.

Group Theory · Mathematics 2007-05-23 Michael K. Kinyon , J. D. Phillips , Petr Vojtěchovský

If G is a group, a pseudocharacter f: G-->R is a function which is "almost" a homomorphism. If G admits a nontrivial pseudocharacter f, we define the space of ends of G relative to f and show that if the space of ends is complicated enough,…

Group Theory · Mathematics 2014-11-11 Jason Fox Manning

We determine the automorphism group for some well known constructions of finite semifields. In particular, we compute the automorphism group of Sandler's semifields and in certain cases the automorphism groups of the Hughes-Kleinfeld and…

Rings and Algebras · Mathematics 2013-05-23 Andrew Steele

We investigate the possible structures imposed on a finite group by its possession of an automorphism sending a large fraction of the group elements to their cubes, the philosophy being that this should force the group to be, in some sense,…

Group Theory · Mathematics 2007-10-24 Peter Hegarty