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In this paper we develop the theory of strongly singular subalgebras of von Neumann algebras, begun in earlier work. We mainly examine the situation of type $\tto$ factors arising from countable discrete groups. We give simple criteria for…

Operator Algebras · Mathematics 2013-02-26 Guyan Robertson , Allan M. Sinclair , Roger R. Smith

In this paper, we determine the descriptive complexity of subsets of the Polish space of marked groups defined by various group theoretic properties. In particular, using Grigorchuk groups, we establish that the sets of solvable groups,…

Group Theory · Mathematics 2020-11-04 Mustafa Gökhan Benli , Burak Kaya

In this work we employ machine learning to understand structured mathematical data involving finite groups and derive a theorem about necessary properties of generators of finite simple groups. We create a database of all 2-generated…

Machine Learning · Computer Science 2024-04-16 Yang-Hui He , Vishnu Jejjala , Challenger Mishra , Em Sharnoff

On a homogeneous group, we characterize the one-parameter groups of dilations whose associated Hardy spaces in the sense of Folland and Stein are the same.

Classical Analysis and ODEs · Mathematics 2024-07-16 Tommaso Bruno , Jordy Timo van Velthoven

The fixed-point theory and its applications to various areas of science are well known. In this paper we present some existence and uniqueness theorems for fixed circles of self-mappings on metric spaces with geometric interpretation. We…

Metric Geometry · Mathematics 2025-06-03 Nihal Yilmaz Özgür , Nihal Taş

We investigate the finite soluble groups $G$ with the following property (replacement property): for every irredundant generating set $\{g_1,\dots,g_m\}$ of maximal size and for any $1\neq g\in G$ there exists an $i\in \{1,\dots,m\}$ so…

Group Theory · Mathematics 2017-10-31 A. Lucchini

We analyze the classification problem for finitely generated orderable groups from the viewpoint of descriptive set theory. We analyze the standard Borel space of finitely generated left-orderable groups, and the subspace of finitely…

Group Theory · Mathematics 2026-05-11 Filippo Calderoni , Adam Clay

We study singularity confinement phenomena in examples of delay-differential Painlev\'e equations, which involve shifts and derivatives with respect to a single independent variable. We propose a geometric interpretation of our results in…

Exactly Solvable and Integrable Systems · Physics 2020-10-28 Alexander Stokes

We establish several results on the word problem for just infinite groups. First, for finitely generated just infinite groups we show that the word problem is uniformly decidable for presentations with recursively enumerable sets of…

Group Theory · Mathematics 2026-03-30 Alexey Talambutsa

We prove that in every finitely generated profinite group, every subgroup of finite index is open; this implies that the topology on such groups is determined by the algebraic structure. This is deduced from the main result about finite…

Group Theory · Mathematics 2007-05-23 Nikolay Nikolov , Dan Segal

Uniformly finite homology is a coarse invariant for metric spaces; in particular, it is a quasi-isometry invariant for finitely generated groups. In this article, we study uniformly finite homology of finitely generated amenable groups and…

Group Theory · Mathematics 2016-01-20 Matthias Blank , Francesca Diana

We call $i$ a fixed point of a given sequence if the value of that sequence at the $i$-th position coincides with $i$. Here, we enumerate fixed points in the class of restricted growth sequences. The counting process is conducted by…

Combinatorics · Mathematics 2021-06-25 Toufik Mansour , Reza Rastegar

We explore the notion of sectional number of a group homomorphism, leading to a generalization of the covering number of a group, and present several characterizations when the sectional number is finite, providing estimates for computing…

Group Theory · Mathematics 2025-09-22 Cesar A. Ipanaque Zapata , Joe Palacios

We prove that the genus of a finite-dimensional division algebra is finite whenever the center is a finitely generated field of any characteristic. We also discuss potential applications of our method to other problems, including the…

Rings and Algebras · Mathematics 2019-02-05 Vladimir I. Chernousov , Andrei S. Rapinchuk , Igor A. Rapinchuk

We suggest a few projects for studying vertex algebras with emphasis on finite group viewpoints.

Rings and Algebras · Mathematics 2019-03-22 Robert L. Griess,

It is shown that there exist finitely generated infinite simple groups of infinite commutator width and infinite square width on which there exists no stably unbounded conjugation-invariant norm, and in particular stable commutator length…

Group Theory · Mathematics 2010-09-08 Alexey Muranov

We consider an arbitrary representation of the additive group over a field of characteristic zero and give an explicit description of a finite separating set in the corresponding ring of invariants.

Commutative Algebra · Mathematics 2013-02-05 Emilie Dufresne , Jonathan Elmer , Müfit Sezer

Let $G$ be a group. We can topologize the spaces of left-orderings $LO(G)$ and bi-orderings $O(G)$ of $G$ with the product topology. These spaces may or may not have isolated points. It is known that $LO(F_2)$ has no isolated points, where…

Group Theory · Mathematics 2023-04-12 Kyrylo Muliarchyk , Serhii Dovhyi

Let $H$ be an extension of a finite group $Q$ by a finite group $G$. Inspired by the results of duality theorems for \'etale gerbes on orbifolds, we describe the number of conjugacy classes of $H$ that maps to the same conjugacy class of…

Group Theory · Mathematics 2014-08-19 Xiang Tang , Hsian-hua Tseng

We discuss Suslin's singular homology and cohomology. In the first half we examine the p-part in characteristic p, and the situation over non-algebraically closed fields. In the second half we focus on finite base fields. We study finite…

Algebraic Geometry · Mathematics 2009-12-08 Thomas H. Geisser