English
Related papers

Related papers: Transfinite product reduction in fundamental group…

200 papers

Let $G$ be an irreducible imprimitive subgroup of $\operatorname{GL}_n(\mathbb{F})$, where $\mathbb{F}$ is a field. Any system of imprimitivity for $G$ can be refined to a nonrefinable system of imprimitivity, and we consider the question…

Group Theory · Mathematics 2021-09-07 Mikko Korhonen , Cai Heng Li

We extend the theory of fast Fourier transforms on finite groups to finite inverse semigroups. We use a general method for constructing the irreducible representations of a finite inverse semigroup to reduce the problem of computing its…

Group Theory · Mathematics 2011-08-02 Martin Malandro

We describe a general technique for embedding certain amalgamated products into direct products. This technique provides us with a way of constructing a host of finitely presented subgroups of automatic groups which are not even…

Group Theory · Mathematics 2008-02-03 Gilbert Baumslag , Martin Bridson , Charles Miller , Hamish Short

In recent years there has been significant progress in the study of products of subsets of finite groups and of finite simple groups in particular. In this paper we consider which families of finite simple groups $G$ have the property that…

Group Theory · Mathematics 2020-07-17 Michael Larsen , Aner Shalev , Pham Huu Tiep

In this note we prove that the set of all uniformly continuous units on a product system over a C* algebra B can be endowed with the structure of left right B - B Hilbert module after identifying similar units by the suitable equivalence…

Operator Algebras · Mathematics 2015-12-15 Dragoljub J. Kečkić , Biljana Vujošević

This paper presents a reformulation of the Leibniz product rule as a finite sum that expresses the fractional derivative of the product of two differentiable functions. This paper then proves the cases for when the product consists of an…

General Mathematics · Mathematics 2024-03-18 Ryan Wilis

We consider abelain subgroups of small index in finite groups. More generally, we consider subgroups such that the product of their index by the index of their centralizer is small.

Group Theory · Mathematics 2021-01-21 Avinoam Mann

We construct the first example of a finitely-presented, residually-finite group that contains an infinite sequence of non-isomorphic finitely-presented subgroups such that each of the inclusion maps induces an isomorphism of profinite…

Group Theory · Mathematics 2015-01-08 Martin R. Bridson

The aim of this paper is sketch a theory of divisibility and factorisation in topological monoids, where finite products are replaced by convergent products. The algebraic case can then be viewed as the special case of discretely…

General Topology · Mathematics 2007-05-23 Jan Snellman

We consider general bilinear products defined by positive semidefinite matrices. Typically non-commutative, non-associative, and non-unital, these products preserve positivity and include the classical Hadamard, Kronecker, and convolutional…

Functional Analysis · Mathematics 2026-01-05 Dominique Guillot , Javad Mashreghi , Prateek Kumar Vishwakarma

We show that a profinite group with the same first-order theory as the direct product over all odd primes $p$ of the dihedral group of order $2p$, is necessarily isomorphic to this direct product.

Group Theory · Mathematics 2016-08-09 Or Ben Porath , Mark Shusterman

We extend Matui's notion of almost finiteness to general etale groupoids and show that the reduced groupoid C*-algebras of minimal almost finite groupoids have stable rank one. The proof follows a new strategy, which can be regarded as a…

Operator Algebras · Mathematics 2020-11-10 Yuhei Suzuki

We present a new proof, which is independent of the finite simple group classification and applies also to infinite groups, that quasiprimitive permutation groups of simple diagonal type cannot be embedded into wreath products in product…

Group Theory · Mathematics 2017-06-01 Cheryl E. Praeger , Csaba Schneider

In this paper, the (infinite) direct product of fields is investigated. In particular, the finiteness of a given set is characterized in terms of some ring-theoretic observations. Next, a certain localization (whose multiplicative set…

Commutative Algebra · Mathematics 2024-09-11 Abolfazl Tarizadeh

We classify the finite groups $G$ such that the group of units of the integral group ring ${\mathbb Z} G$ has a subgroup of finite index which is a direct product of free-by-free groups.

Group Theory · Mathematics 2007-05-23 Eric Jespers , Antonio Pita , Angel del Rio , Manuel Ruiz , Pavel Zalesski

We establish a general criterion for the finite presentability of subdirect products of groups and use this to characterize finitely presented residually free groups. We prove that, for all $n\in\mathbb{N}$, a residually free group is of…

Group Theory · Mathematics 2008-09-23 Martin R. Bridson , James Howie , Charles F. Miller , Hamish Short

It is known that the spatial product of two product systems is intrinsic. Here we extend this result by analyzing subsystems of the tensor product of product systems. A relation with cluster systems is established. In a special case, we…

Functional Analysis · Mathematics 2015-02-12 Mithun Mukherjee

We determine all the ways in which a direct product of two finite groups can be expressed as the set-theoretical union of proper subgroups in a family of minimal cardinality.

Group Theory · Mathematics 2012-11-26 Andrea Lucchini , Martino Garonzi

Permutation products and their various "fat diagonal" subspaces are studied from the topological and geometric point of view. We describe in detail the stabilizer and orbit stratifications related to the permutation action, producing a…

Algebraic Topology · Mathematics 2012-09-17 Sadok Kallel , Walid Taamallah

The method of direct computation of universal (fibred) product in the category of commutative associative algebras of finite type with unity over a field is given and proven. The field of coefficients is not supposed to be algebraically…

Algebraic Geometry · Mathematics 2016-07-15 Nadezda V. Timofeeva