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We describe the structure of virtually solvable normal subgroups in the automorphism group of a right-angled Artin group ${\rm Aut}(A_\Gamma)$. In particular, we prove that a finite normal subgroup in ${\rm Aut}(A_\Gamma)$ has at most order…

Group Theory · Mathematics 2023-04-18 Philip Möller , Olga Varghese

For a real, non-singular, 2-step nilpotent Lie algebra $\mathfrak{n}$, the group \Aut(\mathfrak{n})/\Aut_0(\mathfrak{n})$, where $\Aut_0(\mathfrak{n})$ is the group of automorphisms which act trivially on the center, is the direct product…

Differential Geometry · Mathematics 2012-06-08 Aroldo Kaplan , Alejandro Tiraboschi

In the paper we prove that every automorphism of any adjoint Chevalley group of types B_2 or G_2 is standard, i.e., it is a composition of the ``inner'' automorphism, ring automorphism and central automorphism.

Group Theory · Mathematics 2007-11-06 E. I. Bunina

Let $A$ be an $n$-dimensional algebra over a field $k$ and $a(A)$ its quantum symmetry semigroup. We prove that the automorphisms group ${\rm Aut}_{\rm Alg} (A)$ of $A$ is isomorphic to the group $U \bigl( G(a (A)^{\rm o} ) \bigl)$ of all…

Rings and Algebras · Mathematics 2022-03-28 G. Militaru

In this paper we classify all finite 2-groups of class 2 for which every automorphism of order 2 leaving the Frattini subgroup elementwise fixed is inner. We prove that every such group G is isomorphic to Q(n; r) = <a, b| a^{2n}= b^{2r}= 1;…

Group Theory · Mathematics 2012-12-05 A. Abdollahi , M. Ahmadi , S. M. Ghoraishi

The Weyl group of the Cuntz algebra O_n, with n finite, is investigated. This is (isomorphic to) the group of polynomial automorphisms of O_n, namely those induced by unitaries that can be written as finite sums of words in the canonical…

Operator Algebras · Mathematics 2013-01-11 Roberto Conti , Jeong Hee Hong , Wojciech Szymanski

For a large class of groups, we exhibit an infinite-dimensional space of homogeneous quasimorphisms that are invariant under the action of the automorphism group. This class includes non-elementary hyperbolic groups, infinitely-ended…

Group Theory · Mathematics 2025-12-02 Francesco Fournier-Facio , Richard D. Wade

Automorphic loops are loops in which all inner mappings are automorphisms. A large class of automorphic loops is obtained as follows: Let $m$ be a positive even integer, $G$ an abelian group, and $\alpha$ an automorphism of $G$ that…

Group Theory · Mathematics 2017-12-19 Mouna Aboras , Petr Vojtěchovský

We show that a separable, nuclear C*-algebra satisfies the UCT if it has a Cartan subalgebra. Furthermore, we prove that the UCT is closed under crossed products by group actions which respect Cartan subalgebras. This observation allows us…

Operator Algebras · Mathematics 2017-06-22 Selçuk Barlak , Xin Li

We characterize the group $\operatorname{Aut}(\mathbb G_2)$ for the symmetrized bidisc $\mathbb G_2:=\{(\lambda_1+\lambda_2,\lambda_1\lambda_2):|\lambda_1|,|\lambda_2|<1\}\sub set\mathbb C^2$.

Complex Variables · Mathematics 2007-05-23 Marek Jarnicki , Peter Pflug

We introduce a quantum automorphism group for hypergraphs, which turns out to generalize the quantum automorphism group of Bichon for classical graphs. Further, we show that our quantum automorphism group acts on hypergraph C*-algebras as…

Operator Algebras · Mathematics 2024-05-21 Nicolas Faroß

Let $P(\mathrm{sl}_2(K))$ be the Poisson enveloping algebra of the Lie algebra $\mathrm{sl}_2(K)$ over an algebraically closed field $K$ of characteristic zero. The quotient algebras $ $ $P(\mathrm{sl}_2(K))/(C_P-\lambda)$, where $C_P$ is…

Rings and Algebras · Mathematics 2021-07-15 Altyngul Naurazbekova , Ualbai Umirbaev

Belov-Kanel and Kontsevich conjectured that the group of automorphisms of the n'th Weyl algebra and the group of polynomial symplectomorphisms of C^2 are canonically isomorphic. We discuss how this conjecture can be approached by means of…

Quantum Algebra · Mathematics 2015-05-19 Erik Backelin

We completely determine the localized automorphisms of the Cuntz algebras $O_n$ corresponding to permutation matrices in $M_n \otimes M_n$ for $n=3$ and $n=4$. This result is obtained through a combination of general combinatorial…

Operator Algebras · Mathematics 2011-04-12 Roberto Conti , Jason Kimberley , Wojciech Szymanski

Given a compact space X and two commuting continuous open surjective maps sigma_1, sigma_2 : X --> X, we construct certain C*-algebras that reflect the dynamics of the N^2-action. When the maps sigma_1, sigma_2 are local homeomorphisms,…

Operator Algebras · Mathematics 2007-05-23 Valentin Deaconu

We describe the groups of automorphisms of two generated free braided associative algebras with involutive diagonal braidings over a field of characteristic $\neq 2$. Depending on the form of the diagonal involutive braiding, five different…

Rings and Algebras · Mathematics 2021-03-12 Riza Mutalip , Altyngul Naurazbekova , Ualbai Umirbaev

The paper is devoted to 2-local automorphisms on $AW^\ast$-algebras. Using the technique of matrix algebras over a unital Banach algebra we prove that any 2-local automorphism on an arbitrary $AW^\ast$-algebra without finite type~I direct…

Operator Algebras · Mathematics 2019-09-16 Shavkat Ayupov , Karimbergen Kudaybergenov , Turabay Kalandarov

The group of automorphisms of the Cuntz algebra $\mathcal{O}_{2}$ is a Polish group with respect to the topology of pointwise convergence in norm. Our main result is that the relations of conjugacy and cocycle conjugacy of automorphisms of…

Operator Algebras · Mathematics 2018-01-08 Eusebio Gardella , Martino Lupini

It is well known that every locally compact abelian group L can be decomposed as L_1 \oplus R^n, where L_1 contains a compact-open subgroup. In this paper, we use this decomposition to study the topological group Aut(L) of automorphisms of…

General Topology · Mathematics 2011-10-11 Iian B. Smythe

In a recent paper it has been established that over an Artinian ring R all two-dimensional polynomial automorphisms having Jacobian determinant one are tame if R is a Q-algebra. This is a generalization of the famous Jung-Van der Kulk…

Commutative Algebra · Mathematics 2012-10-09 Joost Berson