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Let $\varphi:V\times V\to W$ be a bilinear map of finite vector spaces $V$ and $W$ over a finite field $\mathbb{F}_q$. We present asymptotic bounds on the number of isomorphism classes of bilinear maps under the natural action of…

Combinatorics · Mathematics 2025-03-11 Markus Bläser , Yinan Li , Youming Qiao , Alexander Rogovskyy

We give a cohomological criterion for existence of outer automorphisms of a semisimple algebraic group over an arbitrary field. This criterion is then applied to the special case of groups of type D_2n over a global field, which completes…

Group Theory · Mathematics 2015-03-12 Skip Garibaldi

Let A be a simple unital AT algebra of real rank zero and Inn(A) the group of inner automorphisms of A. In the previous paper we have shown that the natural map of the group of approximately inner automorphisms into Ext(K_1(A),K_0(A)) oplus…

Operator Algebras · Mathematics 2007-05-23 A. Kishimoto , A. Kumjian

We show that the octonions are a twisting of the group algebra of Z_2 x Z_2 x Z_2 in the quasitensor category of representations of a quasi-Hopf algebra associated to a group 3-cocycle. We consider general quasi-associative algebras of this…

Quantum Algebra · Mathematics 2007-05-23 H. Albuquerque , S. Majid

This paper exploits adjacencies between the orbits of an ordered set P and a consequence of the classification of finite simple groups to, in many cases, exponentially bound the number of automorphisms. Results clearly identify the…

Combinatorics · Mathematics 2023-09-12 Bernd S. W. Schröder

We study distinguished subalgebras and automorphisms of boundary quotients arising from algebraic dynamical systems $(G,P,\theta)$. Our work includes a complete solution to the problem of extending Bogolubov automorphisms from the Cuntz…

Operator Algebras · Mathematics 2020-10-13 Valeriano Aiello , Roberto Conti , Stefano Rossi , Nicolai Stammeier

Double coverings of the orthogonal groups of the real and complex spaces are considered. The relation between discrete transformations of these spaces and fundamental automorphisms of Clifford algebras is established, where an isomorphism…

Mathematical Physics · Physics 2007-05-23 Vadim V. Varlamov

Let R a be countable ergodic equivalence relation of type II_1 on a standard probability space (X,m). The group Out(R) of outer automorphisms of R consists of all invertible Borel measure preserving maps of the space which map R-classes to…

Dynamical Systems · Mathematics 2007-05-23 Alex Furman

Automorphisms of order $2$ are studied in order to understand generalized symmetric spaces. The groups of type $E_6$ we consider here can be realized as both the group of linear maps that leave a certain determinant invariant, and also as…

Group Theory · Mathematics 2016-01-05 John Hutchens

A monomial algebra B is defined as a quotient of a polynomial ring by a monomial ideal, which is an ideal generated by a finite set of monomials. In this paper, we determine the automorphism group of a monomial algebra B, under the…

Algebraic Geometry · Mathematics 2026-04-28 Roberto Díaz , Alvaro Liendo , Gonzalo Manzano-Flores , Andriy Regeta

In our previous paper math/0502157 we classified a large class of finite-dimensional pointed Hopf algebras up to isomorphism. However the following problem was left open for Hopf algebras of of type $A,D$ or $E_6$, that is whose Cartan…

Quantum Algebra · Mathematics 2007-05-23 Nicol/'as Andruskiewitsch , Hans-Jürgen Schneider

We give a bijection between the tilting complexes in the bounded homotopy category of the Auslander algebra of the truncated polynomial ring and ZxB where B is the Artin braid goup of type A with n-1 generators. The tilting complexes have…

Rings and Algebras · Mathematics 2019-07-12 Julia Sauter

We describe the automorphism groups of elliptic Poisson algebras on polynomial algebras in three variables and give an explicit set of generators and defining relations for this group.

Rings and Algebras · Mathematics 2020-01-03 Leonid Makar-Limanov , Umut Turusbekova , Ualbai Umirbaev

The Cayley-Dickson loop Q_n is the multiplicative closure of basic elements of the algebra constructed by n applications of the Cayley-Dickson doubling process (the first few examples of such algebras are real numbers, complex numbers,…

Group Theory · Mathematics 2012-04-24 Jenya Kirshtein

We investigate the general structure of the automorphism group and the Lie algebra of derivations of a finitely generated vertex operator algebra. The automorphism group is isomorphic to an algebraic group. Under natural assumptions, the…

Quantum Algebra · Mathematics 2007-05-23 C. Dong , R. L. Griess

The principal observation of the present paper is that an inner isotopy (i.e. a principal isotopy defined by an algebra endomorphism) is a very helpful instrument in constructing and studying interesting classes of nonassociative algebras.…

Rings and Algebras · Mathematics 2024-09-11 Vladimir G. Tkachev

We describe the outer automorphism group of a one-ended fundamental group of a graph of groups, when edge groups are cyclic, and vertex groups are torsion-free with cyclic centralizers. We show that in this case the outer automorphism group…

Group Theory · Mathematics 2025-07-23 Dario Ascari , Montserrat Casals-Ruiz , Ilya Kazachkov

The Drinfeld upper half-planes play the role of symmetric spaces in the $p$-adic analytic world. We find the automorphism group of a product of such spaces, where each may be defined over a different field. We deduce a rigidity theorem for…

Number Theory · Mathematics 2017-03-02 Gil Alon

For convex domains with $C^{1,\epsilon}$ boundary we give a precise description of the automorphism group: if an orbit of the automorphism group accumulates on at least two different closed complex faces of the boundary, then the…

Complex Variables · Mathematics 2021-02-03 Andrew Zimmer

We prove a variety results on tensor product factorizations of finite dimensional Hopf algebras (more generally Hopf algebras satisfying chain conditions in suitable braided categories). The results are analogs of well-known results on…

Rings and Algebras · Mathematics 2016-02-24 Marc Keilberg , Peter Schauenburg