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Related papers: Automorphisms fixing a variable of K<x,y,z>

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We study automorphisms of the free associative algebra K<x,y,z> over a field K which fix the variable z. We describe the structure of the group of z-tame automorphisms and derive algorithms which recognize z-tame automorphisms and z-tame…

Rings and Algebras · Mathematics 2007-05-23 Vesselin Drensky , Jie-Tai Yu

Recently Umirbaev has proved the long-standing Anick conjecture, that is, there exist wild automorphisms of the free associative algebra K<x,y,z> over a field K of characteristic 0. In particular, the well-known Anick automorphism is wild.…

Rings and Algebras · Mathematics 2022-07-06 Vesselin Drensky , Jie-Tai Yu

We study z-automorphisms of the polynomial algebra K[x,y,z] and the free associative algebra K<x,y,z> over a field K, i.e., automorphisms which fix the variable z. We survey some recent results on such automorphisms and on the corresponding…

Rings and Algebras · Mathematics 2007-05-23 Vesselin Drensky , Jie-Tai Yu

We prove that the well-known Anick automorphism of the free associative algebra F<x,y,z> over an arbitrary field F of characteristic 0 is wild.

Rings and Algebras · Mathematics 2020-01-03 Ualbai Umirbaev

It is proved that the tame automorphism group of a differential polynomial algebra $k\{x,y\}$ over a field $k$ of characteristic $0$ in two variables $x,y$ with $m$ commuting derivations $\delta_1, \ldots, \delta_m$ is a free product with…

Rings and Algebras · Mathematics 2020-01-03 Bibinur Duisengalieva , Altyngul Naurazbekova , Ualbai Umirbaev

It is proved that every z-automorphism (z-coordinate, respectively) of the free associative algebra F<x,y,z> over an arbitrary field F is stably tame.

Rings and Algebras · Mathematics 2017-12-05 Alexei Belov , Jie-Tai Yu

In this paper we prove that over algebraically closed field $K$ of positive characteristic $\neq 2$ every automorphism of the group of origin-preserving automorphisms of the polynomial algebra $K[x_1,\ldots, x_n]$ ($n>3$) which fixes every…

Algebraic Geometry · Mathematics 2021-03-25 Alexei Belov-Kanel , Andrey Elishev , Jie-Tai Yu

Let K<x,y> be the free associative algebra of rank 2 over an algebraically closed constructive field of any characteristic. We present an algorithm which decides whether or not two elements in K<x,y> are equivalent under an automorphism of…

Rings and Algebras · Mathematics 2007-05-23 Vesselin Drensky , Jie-Tai Yu

Let $K[x,y]$ be the polynomial algebra in two variables over an algebraically closed field $K$. We generalize to the case of any characteristic the result of Furter that over a field of characteristic zero the set of automorphisms $(f,g)$…

Algebraic Geometry · Mathematics 2008-07-07 Vesselin Drensky , Jie-Tai Yu

We construct an Anick type wild automorphism $\delta$ in a 3-generated free Poisson algebra which induces a tame automorphism in a 3-generated polynomial algebra. We also show that $\delta$ is stably tame. Dedicated to the memory of…

Rings and Algebras · Mathematics 2024-07-09 Ivan Shestakov , Zerui Zhang

The automorphisms of free groups with boundaries form a family of groups A_{n,k} closely related to mapping class groups, with the standard automorphisms of free groups as A_{n,0} and (essentially) the symmetric automorphisms of free groups…

Geometric Topology · Mathematics 2014-10-01 Craig A. Jensen , Nathalie Wahl

We study automorphic Lie algebras using a family of evaluation maps parametrised by the representations of the associative algebra of functions. This provides a descending chain of ideals for the automorphic Lie algebra which is used to…

Representation Theory · Mathematics 2024-04-16 Drew Duffield , Vincent Knibbeler , Sara Lombardo

We prove that every derivation and every locally nilpotent derivation of the subalgebra $K[x^n, x^{n-1}y,\ldots,xy^{n-1}, y^n]$, where $n\geq 2$, of the polynomial algebra $K[x,y]$ in two variables over a field $K$ of characteristic zero is…

Commutative Algebra · Mathematics 2022-10-25 Bakhyt Aitzhanova , Ualbai Umirbaev

We prove that the group of tame automorphisms of a free Lie algebra (as well as of a free anticommutative algebra) rank 3 over an arbitrary integral domain has the structure of an amalgamated free product. We construct an example of a wild…

Rings and Algebras · Mathematics 2020-01-03 Alibek Alimbaev , Ruslan Nauryzbaev , Ualbai Umirbaev

We show that if a field k contains sufficiently many elements(for instance, if k is infinite), and K is an algebraically closed field containing k, then every linear algebraic k-group over K is k-isomorphic to Aut(A\otimes_kK), where A is a…

Rings and Algebras · Mathematics 2007-05-23 Nikolai L. Gordeev , Vladimir L. Popov

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

In 2004 Shestakov and Umirbaev proved that the Nagata automorphism of the polynomial algebra in three variables is wild. We fix a Z-grading on this algebra and consider graded-wild automorphisms, i.e. such automorphisms that can not be…

Algebraic Geometry · Mathematics 2021-04-09 Anton Trushin

Given a variety of universal algebras. A method is suggested for describing automorphisms of a category of free algebras of this variety. Applying this general method all automorphisms of such categories are found in two cases: 1) for the…

Rings and Algebras · Mathematics 2007-05-23 Boris Plotkin , Grigori Zhitomirski

We describe the automorphism group of the endomorphism semigroup $\End(K[x_1,...,x_n])$ of ring $K[x_1,...,x_n]$ of polynomials over an {\it arbitrary} field $K$. A similar result is obtained for automorphism group of the category of…

Rings and Algebras · Mathematics 2017-12-05 A. Belov-Kanel , R. Lipyanski

We prove the existence of wild automorphisms on an affine quadric threefold. The method we use is an adaptation of the one used by Shestakov and Umirbaev to prove the existence of wild automorphisms on the affine three dimensional space.

Algebraic Geometry · Mathematics 2018-05-16 Stéphane Lamy , Stéphane Vénéreau
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