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Related papers: Relation algebras containing Thompson groups

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In this paper we apply a recently proposed algebraic theory of integration to projective group algebras. These structures have received some attention in connection with the compactification of the $M$ theory on noncommutative tori. This…

Mathematical Physics · Physics 2009-10-31 R. Casalbuoni

A series of nonrepresentable relation algebras is constructed from groups. We use them to prove that there are continuum many subvarieties between the variety of representable relation algebras and the variety of coset relation algebras. We…

Logic · Mathematics 2025-02-12 H. Andréka , S. Givant , I. Németi

We investigate topologies on groups which arise naturally from their algebraic structure, including the Frech\'et-Markov, Hausdorff-Markov, and various kinds of Zariski topologies. Answering a question by Dikranjan and Toller, we show that…

Group Theory · Mathematics 2025-06-24 S. Bardyla , L. Elliott , J. D. Mitchell , Y. Péresse

If $\mathcal{C}$ is a category of algebras closed under finite direct products, and $M_\mathcal{C}$ the commutative monoid of isomorphism classes of members of $\mathcal{C},$ with operation induced by direct product, A.Tarski defined a…

Rings and Algebras · Mathematics 2026-04-28 George M. Bergman

We provide a characterization of those relation algebras which are isomorphic to the algebras of compatible relations of some $\Z_2$-set. We further prove that this class is finitely axiomatizable in first-order logic in the language of…

Logic · Mathematics 2025-04-01 Jeremy F. Alm , John W. Snow

We introduce the notion of relation type of an affine algebra and prove that it is well defined by using the Jacobi-Zariski exact sequence of Andr\'e-Quillen homology. In particular, the relation type is an invariant of an affine algebraic…

Commutative Algebra · Mathematics 2014-04-11 Francesc Planas-Vilanova

We classify all the simple modules for the algebra of relations on a finite set, give their dimension, and find the dimension of the Jacobson radical of the algebra.

Rings and Algebras · Mathematics 2019-02-11 Serge Bouc , Jacques Thévenaz

This dissertation is about rearrangement groups: a class of groups of homeomorphisms of fractal topological spaces. Introduced in 2019 by J. Belk and B. Forrest, this class generalizes the famous trio of Thompson groups $F$, $T$ and $V$ and…

Group Theory · Mathematics 2024-12-04 Matteo Tarocchi

The tangled closure of a collection of subsets of a topological space is the largest subset in which each member of the collection is dense. This operation models a logical `tangle modality' connective, of significance in finite model…

Logic · Mathematics 2018-11-08 Robert Goldblatt , Ian Hodkinson

Let $V_r(\Sigma)$ be the generalised Thompson group defined as the automorphism group of a valid, bounded, and complete Cantor algebra. We show that that for every $n>0$ there is a $k>n,$ such that there exists a $k$-dimensional…

Group Theory · Mathematics 2018-07-11 Conchita Martínez-Pérez , Brita Nucinkis

This paper deals with $n$-dimensional algebras, over any field, which have only trivial derivation (automorphism) and simple algebras. It is shown that the corresponding sets of algebras are not empty and, in algebraically closed field…

Rings and Algebras · Mathematics 2025-03-12 U. Bekbaev

In 2001 Ivanov and Kerov associated with the infinite permutation group $S_\infty$ certain commutative associative algebra $A_\infty$ called the algebra of conjugacy classes of partial elements. A standard basis of $A_\infty$ is labeled by…

Group Theory · Mathematics 2013-12-10 Andrei V. Alexeevski , Sergey M. Natanzon

Last years a number of papers were devoted to describing automorphisms of semigroups of endomorphisms of free finitely generated universal algebras of some varieties: groups, semigroups, associative commutative algebras, inverse semigroups,…

General Mathematics · Mathematics 2007-05-23 Grigori Zhitomirski

As an appropriate generalisation of the features of the classical (Schein) theory of representations of inverse semigroups in $\mathscr{I}_{X}$, a theory of representations of inverse semigroups by homomorphisms into complete atomistic…

Group Theory · Mathematics 2021-02-22 D. G. FitzGerald

We discuss condensed left-orderings and develop new techniques to show that the conjugacy relation on the space of left-orderings is not smooth. These techniques apply to the solvable Baumslag Solitar groups and to Thompson's group F.

Group Theory · Mathematics 2024-10-01 Filippo Calderoni , Adam Clay

In this paper, we apply the theory of algebraic cohomology to study the amenability of Thompson's group $\mathcal{F}$. We introduce the notion of unique factorization semigroup which contains Thompson's semigroup $\mathcal{S}$ and the free…

Operator Algebras · Mathematics 2022-02-08 Linzhe Huang

We will show that almost all nonassociative relation algebras are symmetric and integral (in the sense that the fraction of both labelled and unlabelled structures that are symmetric and integral tends to 1), and using a Fra\"iss\'e limit,…

Logic · Mathematics 2022-02-07 James Koussas

In this lecutre note, we consider infinite dimensional Lie algebras of generalized Jacobi matrices $\mathfrak{g}J(k)$ and $\mathfrak{gl}_\infty(k)$, which are important in soliton theory, and their orthogonal and symplectic subalgebras. In…

Representation Theory · Mathematics 2020-03-11 Alice Fialowski , Kenji Iohara

Let G be a reductive algebraic group over a field of prime characteristic. One can associate to G (or subgroups thereof) its Lie algebra, its Frobenius kernels, and the finite Chevalley group of points over a finite field. The…

Representation Theory · Mathematics 2023-07-10 Christopher P. Bendel

Four-dimensional, oriented Lie algebras $\mathfrak{g}$ which satisfy the tame-compatible question of Donaldson for all almost complex structures $J$ on $\mathfrak{g}$ are completely described. As a consequence, examples are given of…

Differential Geometry · Mathematics 2015-12-09 Andres Cubas , Tedi Draghici