Results 71 to 80 of about 12,736,939 (290)
Splitting the difference: Computations of the Reynolds operator in classical invariant theory
Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.Abstract If G$G$ is a linearly reductive group acting rationally on a polynomial ring S$S$, then the inclusion SG↪S$S^{G} \hookrightarrow S$ possesses a unique G$G$‐equivariant splitting, called the Reynolds operator. We describe algorithms for computing the Reynolds operator for the classical actions as in Weyl's book.
Aryaman Maithani
wiley +1 more source
On a Dimension Formula for Twisted Spherical Conjugacy Classes in Semisimple Algebraic Groups [PDF]
, 2010 Let $G$ be a connected semisimple algebraic group over an algebraically closed field of characteristic zero, and let $\th$ be an automorphism of $G$. We give a characterization of $\th$-twisted spherical conjugacy classes in $G$ by a formula for their ...
Lu, Jiang-Hua
core
On the characterization of Danielewski surfaces by their automorphism group
, 2019 In this note we show that if the automorphism group of a normal affine surface $S$ is isomorphic to the automorphism group of a Danielewski surface, then $S$ is isomorphic to a Danielewski surface.Comment: 5 pages.
Liendo, Alvaro +2 more
core +1 more source
On stabilizers in finite permutation groups
Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.Abstract Let G$G$ be a permutation group on the finite set Ω$\Omega$. We prove various results about partitions of Ω$\Omega$ whose stabilizers have good properties. In particular, in every solvable permutation group there is a set‐stabilizer whose orbits have length at most 6, which is best possible and answers two questions of Babai.
Luca Sabatini
wiley +1 more source
Double automorphisms of graded Lie algebras
, 2012 We introduce the concept of a double automorphism of an A-graded Lie algebra L. Roughly, this is an automorphism of L which also induces an automorphism of the group A. It is clear that the set of all double automorphisms of L forms a subgroup in Aut(L).
Acciarri, Cristina, Shumyatsky, Pavel
core +1 more source
On Group Ring Automorphisms [PDF]
Algebras and Representation Theory, 2004 Let \(G\) be a finite group and \(R\) be a complete discrete valuation ring of characteristic \(0\). The authors study the group of those automorphisms \(\text{Outcent}(RG)\) of the group ring \(RG\) which fix the center of \(RG\) pointwise. As a main result of the paper the authors show that if \(B\) is a block of the group ring of \(G\) over the \(p\)
Hertweck, Martin, Nebe, Gabriele
openaire +1 more source
On contact 3‐manifolds that admit a nonfree toric action
Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.Abstract We classify all contact structures on 3‐manifolds that admit a nonfree toric action, up to contactomorphism, and present them through explicit topological descriptions. Our classification is based on Lerman's classification of toric contact 3‐manifolds up to equivariant contactomorphism [Lerman, J. Symplectic Geom. 1 (2003), 785–828].
Aleksandra Marinković, Laura Starkston
wiley +1 more source
Limit trees for free group automorphisms: universality
Forum of Mathematics, SigmaTo any free group automorphism, we associate a universal (cone of) limit tree(s) with three defining properties: first, the tree has a minimal isometric action of the free group with trivial arc stabilizers; second, there is a unique expanding dilation ...
Jean Pierre Mutanguha
doaj +1 more source
The automorphism group of a variety with torus action of complexity one [PDF]
, 2012 We consider a normal complete rational variety with a torus action of complexity one. In the main results, we determine the roots of the automorphism group and give an explicit description of the root system of its semisimple part.
I. Arzhantsev +3 more
semanticscholar +1 more source
Module structure of Weyl algebras
Journal of the London Mathematical Society, Volume 113, Issue 1, January 2026.Abstract The seminal paper (Stafford, J. Lond. Math. Soc. (2) 18 (1978), no. 3, 429–442) was a major step forward in our understanding of Weyl algebras. Beginning with Serre's Theorem on free summands of projective modules and Bass' Stable Range Theorem in commutative algebra, we attempt to trace the origins of this work and explain how it led to ...
Gwyn Bellamy
wiley +1 more source