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Related papers: Embedding in a finite 2-generator semigroup

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We give an efficient algorithm for the enumeration up to isomorphism of the inverse semigroups of order n, and we count the number S(n) of inverse semigroups of order n<=15. This improves considerably on the previous highest-known value…

Combinatorics · Mathematics 2019-12-25 Martin E. Malandro

We show that labelled Thompson groups and twisted Brin--Thompson groups are all acyclic. This allows us to prove several new embedding results for groups. First, every group of type $F_n$ embeds quasi-isometrically as a subgroup of an…

Group Theory · Mathematics 2025-10-21 Martin Palmer , Xiaolei Wu

Working over an arbitrary field, we define compact semisimple 2-categories, and show that every compact semisimple 2-category is equivalent to the 2-category of separable module 1-categories over a finite semisimple tensor 1-category. Then,…

Quantum Algebra · Mathematics 2023-10-27 Thibault D. Décoppet

We consider embeddings of a finite complex in a sphere. We give a homotopy theoretic classification of such embeddings in a wide range.

Algebraic Topology · Mathematics 2007-05-23 John R. Klein

We provide non-isomorphic finite 2-groups which have isomorphic group algebras over any field of characteristic 2, thus settling the Modular Isomorphism Problem.

Rings and Algebras · Mathematics 2021-12-16 Diego García , Leo Margolis , Ángel del Río

Embeddings of word structures into matrix semigroups provide a natural bridge between combinatorics on words and linear algebra. However, low-dimensional matrix semigroups impose strong structural restrictions on possible embeddings.…

Formal Languages and Automata Theory · Computer Science 2026-04-20 Paul C. Bell , George Kenison , Reino Niskanen , Igor Potapov , Pavel Semukhin

In this paper we study the embedding problem of an operator into a strongly continuous semigroup. We obtain characterizations for some classes of operators, namely composition operators and analytic Toeplitz operators on the Hardy space…

Functional Analysis · Mathematics 2025-02-19 Isabelle Chalendar , Romain Lebreton

We define a numerical quasi-isometry invariant of a finitely generated group, whose values parametrize the difference between the group being uniformly embeddable in a Hilbert space and the reduced C*-algebra of the group being exact.

Operator Algebras · Mathematics 2007-05-23 Erik Guentner , Jerome Kaminker

In the paper we study (countably) compact and (absolutely) $H$-closed primitive topological inverse semigroups. We describe the structure of compact and countably compact primitive topological inverse semigroups and show that any countably…

Group Theory · Mathematics 2010-05-25 Tetyana Berezovski , Oleg Gutik , Kateryna Pavlyk

We survey the existing parts of a classification of finite groups generated by orthogonal transformations in a finite-dimensional Euclidean space whose fixed point subspace has codimension one or two and extend it to a complete…

Group Theory · Mathematics 2017-11-02 Christian Lange , Marina A. Mikhailova

A semigroup $S$ is called a permutable semigroup if $\alpha \circ \beta =\beta \circ \alpha$ is satified for all congruences $\alpha$ and $\beta$ of $S$. A semigroup is called a Putcha semigroup if it is a semilattice of archimedean…

Group Theory · Mathematics 2014-02-21 Attila Deák , Attila Nagy

In this paper, the complete algebraic structure of finite semisimple group algebra of a normally monomial group is described. The main result is illustrated by computing the explicit Wedderburn decomposition of finite semisimple group…

Rings and Algebras · Mathematics 2017-07-27 Shalini Gupta , Sugandha Maheshwary

Let $M$ be a finite von Neumann algebra. In the first part, we give asymptotic results about $M$-stable sequences of weak*-continuous mappings which are related with operators belonging to $M$. In the second part, we extend, by a shorter…

Operator Algebras · Mathematics 2007-05-23 Gilles Cassier

For any finite group Q not of prime power order, we construct a group G that is virtually of type F, contains infinitely many conjugacy classes of subgroups isomorphic to Q, and contains only finitely many conjugacy classes of other finite…

Group Theory · Mathematics 2014-11-11 Ian J Leary

Every countable group $G$ can be embedded in a finitely generated group $G^*$ that is hopfian and complete, i.e. $G^*$ has trivial centre and every epimorphism $G^*\to G^*$ is an inner automorphism. Every finite subgroup of $G^*$ is…

Group Theory · Mathematics 2024-11-20 Martin R. Bridson , Hamish Short

We show that pointlike sets are decidable for the pseudovariety of finite semigroups whose idempotent-generated subsemigroup is R-trivial. Notably, our proof is constructive: we provide an explicit relational morphism which computes the…

Group Theory · Mathematics 2022-04-21 Karsten Henckell , Samuel Herman

We show that, with some technical conditions, an abelian category can be embedded into the category of bimodules over a ring. The case of semisimple rigid monoidal categories is studied in more detail.

Category Theory · Mathematics 2007-05-23 Phung Ho Hai

Finite groups with given systems of permuteral and strongly permuteral subgroups are studied. New characterizations of w-supersoluble and supersoluble groups are received.

Group Theory · Mathematics 2013-05-14 A. F. Vasil'ev , V. A. Vasil'ev , T. I. Vasil'eva

We study a family of finitely generated residually finite small cancellation groups. These groups are quotients of $F_2$ depending on a subset $S$ of positive integers. Varying $S$ yields continuously many groups up to quasi-isometry.

Group Theory · Mathematics 2022-07-04 Hip Kuen Chong , Daniel T. Wise

The end compactification |\Gamma| of the locally finite graph \Gamma is the union of the graph and its ends, endowed with a suitable topology. We show that \pi_1(|\Gamma|) embeds into a nonstandard free group with hyperfinitely many…

Geometric Topology · Mathematics 2012-03-30 Isaac Goldbring , Alessandro Sisto