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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

We examine properties of generic automorphisms of the random poset, with the goal of explicitly characterizing them. We associate to each automorphism an auxiliary first-order structure, consisting of the random poset equipped with an…

Logic · Mathematics 2021-01-01 Dakota Thor Ihli

We classify a large class of small groups of finite Morley rank: $N_\circ^\circ$-groups which are the infinite analogues of Thompson's $N$-groups. More precisely, we constrain the $2$-structure of groups of finite Morley rank containing a…

Group Theory · Mathematics 2016-10-05 Adrien Deloro , Eric Jaligot

We prove that the group of automorphisms of the generic meet-tree expansion of an infinite non-unary free Fra\"{\i}ss\'{e} limit over a finite relational language is simple. As a prototypical case, the group of automorphism of the Rado…

Logic · Mathematics 2025-10-01 Itay Kaplan , Binyamin Riahi , Arturo Rodriguez Fanlo

If totally periodic points are dense in a subshift $X$, its automorphism group is residually finite. We show a weak converse: if periodic points are not dense in a subshift $X$, then the automorphism group of $X \times Y$ is not residually…

Dynamical Systems · Mathematics 2026-03-18 Ville Salo

We describe the structure of the algebraic group of automorphisms of all simple finite dimensional Lie superalgebras. Using this and \'etale cohomology considerations, we list all different isomorphism classes of the corresponding twisted…

Rings and Algebras · Mathematics 2007-05-23 Dimitar Grantcharov , Arturo Pianzola

In this paper, we consider the probability that a randomly chosen automorphism of a finite group fixes a randomly chosen element of a subgroup of that group. We obtain several new results as well as generalizations and improvements of some…

Group Theory · Mathematics 2017-06-20 Parama Dutta , Rajat Kanti Nath

A subset of a group is characteristic if it is invariant under every automorphism of the group. We study word length in fundamental groups of closed hyperbolic surfaces with respect to characteristic generating sets consisting of a finite…

Group Theory · Mathematics 2008-04-07 Danny Calegari

We study the automorphism groups of finite-dimensional cyclic Leibniz algebras. In this connection, we consider the relationships between groups, modules over associative rings and Leibniz algebras.

Rings and Algebras · Mathematics 2021-08-21 Leonid A. Kurdachenko , Aleksandr A. Pypka , Igor Ya. Subbotin

It is known that a finite group with an automorphism $\varphi$ of coprime order has a soluble radical of $(|\varphi|,|C_G(\varphi)|)$-bounded Fitting height and index. We extend this classic result as follows. Let $f(x) = a_0 + a_1 \cdot x…

Group Theory · Mathematics 2022-02-22 Wolfgang Alexander Moens

A group G acts infinitely transitively on a set Y if for every positive integer m, its action is m-transitive on Y. Given a real affine algebraic variety Y of dimension greater than or equal to two, we show that, under a mild restriction,…

Algebraic Geometry · Mathematics 2013-05-29 Karine Kuyumzhiyan , Frédéric Mangolte

It is shown that a group defined by forbidding all patterns of size s+1 that do not appear in a given self-similar group of tree automorphisms is the topological closure of a self-similar, countable, regular branch group, branching over its…

Group Theory · Mathematics 2010-12-10 Zoran Sunic

Let $k(G)$ be the number of conjugacy classes of finite groups $G$ and $\pi_e(G)$ be the set of the orders of elements in $G$. Then there exists a non-negative integer $k$ such that $k(G)=|\pi_e(G)|+k$. We call such groups to be $co(k)$…

Group Theory · Mathematics 2007-05-23 Xianglin Du , Wujie Shi

We compute explicitly the automorphism and outer automorphism group of all large-type free-of-infinity Artin groups. Our strategy involves reconstructing the associated Deligne complexes in a purely algebraic manner, i.e. in a way that is…

Group Theory · Mathematics 2024-10-15 Nicolas Vaskou

For a complex surface of general type with a relatively minimal genus 2 fibration, the bounds of the orders of the automorphism group of the fibration, of its abelian subgroups and of its cyclic subgroups are determined as linear functions…

alg-geom · Mathematics 2008-02-03 Zhi-Jie Chen

Let T be a d-regular tree (d > 2) and A=Aut(T), its automorphism group. Let G be a group generated by n independent Haar-random elements of A. We show that almost surely, every nontrivial element of G has finitely many fixed points on T.

Group Theory · Mathematics 2008-10-10 Miklos Abert , Yair Glasner

The maximal symmetry of a quantum system with Heisenberg commutation relations is given by the projective representations of the automorphism group of the Weyl-Heisenberg algebra. The automorphism group is the central extension of the…

Mathematical Physics · Physics 2011-05-09 Stephen G. Low

We look at the automorphisms of Thompson type groups of piecewise linear homeomorphisms of the real line or circle that use slopes that are integral powers of a fixed integer n with n>2. We show that large numbers of "exotic" automorphisms…

Group Theory · Mathematics 2013-09-04 Matthew G. Brin , Fernando Guzman

For every p >= 5, we determine all Z_p-invariant nonsingular quartic surfaces in the three dimensional projective space over an algebraically closed field of characteristic zero. In some cases, we also determine their full projective…

Algebraic Geometry · Mathematics 2019-09-09 Stefano Marcugini , Fernanda Pambianco , Hitoshi Kaneta

An automorphism of a group G is called an IA-automorphism if it induces the identity automorphism on the abelianized group G/G'. Let IA(G) denote the group of all IA-automorphisms of G. We classify all finitely generated nilpotent groups G…

Group Theory · Mathematics 2013-03-21 Deepak Gumber , Hemant Kalra , Sandeep Singh