Results 81 to 90 of about 118,505 (227)
Units in group rings and blocks of Klein four or dihedral defect
Abstract We obtain restrictions on units of even order in the integral group ring ZG$\mathbb {Z}G$ of a finite group G$G$ by studying their actions on the reductions modulo 4 of lattices over the 2‐adic group ring Z2G$\mathbb {Z}_2G$. This improves the “lattice method” which considers reductions modulo primes p$p$, but is of limited use for p=2$p=2 ...
Florian Eisele, Leo Margolis
wiley +1 more source
Remarks on some infinitesimal symmetries of Khovanov–Rozansky homologies in finite characteristic
Abstract We give a new proof of a theorem due to Shumakovitch and Wang on base point independence of Khovanov–Rozansky homology in characteristic p$p$. Some further symmetries of gl(p)$\mathfrak {gl}(p)$‐homology in characteristic p$p$ are also discussed.
You Qi +3 more
wiley +1 more source
Splitting the difference: Computations of the Reynolds operator in classical invariant theory
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 stabilizers in finite permutation groups
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
A categorical interpretation of continuous orbit equivalence for partial dynamical systems
Abstract We define the orbit morphism of partial dynamical systems and prove that an orbit morphism being an isomorphism in the category of partial dynamical systems and orbit morphisms is equivalent to the existence of a continuous orbit equivalence between the given partial dynamical systems that preserves the essential stabilisers. We show that this
Gilles G. de Castro, Eun Ji Kang
wiley +1 more source
Limit trees for free group automorphisms: universality
To 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
Commutativity of automorphisms of subfactors modulo inner automorphisms [PDF]
We introduce a new algebraic invariant χ a ( M , N ) \chi _{a}(M,N) of a subfactor N ⊂ M N \subset M . We show that this is an abelian group and that if the subfactor is strongly amenable, then the group ...
openaire +1 more source
Is every product system concrete?
Abstract Is every product system of Hilbert spaces over a semigroup P$P$ concrete, that is, isomorphic to the product system of an E0$E_0$‐semigroup over P$P$? The answer is no if P$P$ is discrete, cancellative and does not embed in a group. However, we show that the answer is yes for a reasonable class of semigroups.
S. Sundar
wiley +1 more source
On the order of the automorphism group of a finite group [PDF]
W. R. Scott
openalex +2 more sources
Mirror symmetry, Laurent inversion, and the classification of Q$\mathbb {Q}$‐Fano threefolds
Abstract We describe recent progress in a program to understand the classification of three‐dimensional Fano varieties with Q$\mathbb {Q}$‐factorial terminal singularities using mirror symmetry. As part of this we give an improved and more conceptual understanding of Laurent inversion, a technique that sometimes allows one to construct a Fano variety X$
Tom Coates +2 more
wiley +1 more source

