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Related papers: Generic groups and the weak amalgamation property

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The purpose of this article is to present a survey of our recent results on length commensurable and isospectral locally symmetric spaces. The geometric questions led us to the notion of "weak commensurability" of two Zariski-dense…

Differential Geometry · Mathematics 2008-09-16 Gopal Prasad , Andrei S. Rapinchuk

Generic computability has been studied in group theory and we now study it in the context of classical computability theory. A set A of natural numbers is generically computable if there is a partial computable function f whose domain has…

Group Theory · Mathematics 2014-02-26 Carl G. Jockusch , Paul E. Schupp

We show that the classes of partial isometries in finite-dimensional polyhedral spaces and in finite-dimensional rational polyhedral spaces do not have the weak amalgamation property. This implies that the linear isometry group of the…

Logic · Mathematics 2025-12-03 Ondřej Kurka , Maciej Malicki

Generalized topological spaces are not necessarily closed under finite intersections. Moreover, the whole universe does not need to be open. We use modified version of this framework to establish certain models for non-normal modal logics.…

Logic · Mathematics 2020-05-28 Tomasz Witczak

We give a topological framework for the study of Sela's limit groups: limit groups are limits of free groups in a compact space of marked groups. Many results get a natural interpretation in this setting. The class of limit groups is known…

Group Theory · Mathematics 2007-05-23 Christophe Champetier , Vincent Guirardel

In this paper we study probabilistic aspects such as subgroup commutativity degree and cyclic subgroup commutativity degree of the (generalized) dicyclic groups. We find explicit formulas for these concepts and we provide another example of…

Group Theory · Mathematics 2016-12-07 Marius Tărnăuceanu , Mihai-Silviu Lazorec

Using generating functions, we enumerate regular semisimple conjugacy classes in the finite classical groups. For the general linear, unitary, and symplectic groups this gives a different approach to known results; for the special…

Group Theory · Mathematics 2012-09-18 Jason Fulman , Robert Guralnick

We define a class of spaces on which one may generalise the notion of compactness following motivating examples from higher-dimensional number theory. We establish analogues of several well-known topological results (such as Tychonoff's…

General Topology · Mathematics 2019-02-11 Raven Waller

A generalized numerical semigroup is a submonoid of $\mathbb{N}^d$ with finite complement in it. In this work we study some properties of three different classes of generalized numerical semigroups. In particular, we prove that the first…

Combinatorics · Mathematics 2025-03-27 Carmelo Cisto , Francesco Navarra

In this paper we give an algebraic characterization of assemblies in terms of bands of groups. We also consider substructures and homomorphisms of assemblies. We give many examples and counterexamples.

Group Theory · Mathematics 2023-09-21 Ulderico Dardano , Bruno Dinis , Giuseppina Terzo

A countable group is C*-simple if its reduced C*-algebra is a simple algebra. Since Powers recognised in 1975 that non-abelian free groups are C*-simple, large classes of groups which appear naturally in geometry have been identified,…

Operator Algebras · Mathematics 2007-05-23 Pierre de la Harpe

In this note we show that groups with definable generics in a separably closed valued of finite imperfection degree can be embedded into groups definable in their algebraic closure.

Logic · Mathematics 2017-11-07 Silvain Rideau

We describe the K-ring of the classifying space of the generalized quaternion group in terms of generators and the minimal set of relations. We also compute the order of the main generator in the truncated rings.

K-Theory and Homology · Mathematics 2013-01-04 Mehmet Kirdar , Sevilay Özdemir

We consider the class of groups called identity excluding which has the property that any non-trivial irreducible unitary representation restricted to a dense subgroup does not weakly contain the trivial representation. For adapted and…

Representation Theory · Mathematics 2007-05-23 C. R. E. Raja

In this paper we define a new algebraic object: the disguised-groups. We show the main properties of the disguised-groups and, as a consequence, we will see that disguised-groups coincide with regular semigroups. We prove many of the…

Group Theory · Mathematics 2020-06-08 Eduardo Blanco-Gómez

A number of models of linear logic are based on or closely related to linear algebra, in the sense that morphisms are "matrices" over appropriate coefficient sets. Examples include models based on coherence spaces, finiteness spaces and…

Logic in Computer Science · Computer Science 2022-04-25 Takeshi Tsukada , Kazuyuki Asada

In this document we achieve exact and asymptotic enumeration of words, compositions over a finite group, and/or integer compositions characterized by local restrictions and, separately, subsequence pattern avoidance. We also count…

Combinatorics · Mathematics 2019-04-19 Andrew MacFie

Let G be a closed subgroup of the isometry group of a proper CAT(0)-space X. We show that if G is non-elementary and contains a rank-one element then its second bounded cohomology group with coefficients in the regular representation is…

Group Theory · Mathematics 2009-02-11 Ursula Hamenstaedt

We introduce the notion of semigroup with a tight ideal series and investigate their closures in semitopological semigroups, particularly inverse semigroups with continuous inversion. As a corollary we show that the symmetric inverse…

Group Theory · Mathematics 2009-03-19 Oleg Gutik , Jimmie Lawson , Dušan Repovš

We develop the basic theory of geometrically closed rings as a generalisation of algebraically closed fields, on the grounds of notions coming from positive model theory and affine algebraic geometry. For this purpose we consider several…

Rings and Algebras · Mathematics 2013-09-24 Jean Berthet
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