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Related papers: $H$-closed quasitopological groups

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In this article, we construct a band of topological groups from a cryptogroup. Also, we prove that a band of topological groups is metrizable if and only if each $\mathcal{H}$-class is metrizable. Finally, we demonstrate that if $S$ is a…

Group Theory · Mathematics 2025-06-09 Sunil Kumar Maity , Monika Paul

In this paper, we study the uniformities on the double coset spaces in topological groups. As an implication, the quotient spaces of topological groups with a $q$-point are studied. It mainly shows that: (1) Suppose that $G$ is a…

General Topology · Mathematics 2023-11-16 Li-Hong Xie , Hai-Hua Lin , Piyu Li

The Zariski topology on a group G is the coarsest topology such that all sets of the form $\{x \in G | 1_G \neq g_0 x^{k_0} g_1 ... g_{l-1} x^{k_{l-1}} g_l\}$ are open. Originally introduced by Bryant as the verbal topology, it serves as a…

Group Theory · Mathematics 2026-03-23 Luna Elliott

We show that the identity component of the group of diffeomorphisms of a closed oriented surface of positive genus admits many unbounded quasi-morphisms. As a corollary, we also deduce that this group is not uniformly perfect and its…

Geometric Topology · Mathematics 2020-03-31 Jonathan Bowden , Sebastian Hensel , Richard Webb

A semisimple element $s$ of a connected reductive group $G$ is said {\it quasi-isolated} (respectively {\it isolated}) if $C_G(s)$ (respectively $C_G^0(s)$) is not contained in a Levi subgroup of a proper parabolic subgroup of $G$. We study…

Group Theory · Mathematics 2007-05-23 Cédric Bonnafé

In \cite{Kramer11} Kramer proves for a large class of semisimple Lie groups that they admit just one locally compact $\sigma$-compact Hausdorff topology compatible with the group operations. We present two different methods of generalising…

Group Theory · Mathematics 2014-11-06 Rupert McCallum

The quasi-redirecting (QR) boundary is a close generalization of the Gromov boundary to all finitely generated groups. In this paper, we establish that the QR boundary exists as a topological space for several well-studied classes of…

Group Theory · Mathematics 2025-04-01 Hoang Thanh Nguyen , Yulan Qing

Let $(U, R)$ be an approximation space with $U$ being non-empty set and $R$ being an equivalence relation on $U$, and let $\overline{G}$ and $\underline{G}$ be the upper approximation and the lower approximation of subset $G$ of $U$. A…

General Topology · Mathematics 2020-03-03 Fucai Lin , Qianqian Sun , Yujin Lin , Jinjin Li

We introduce quasi-Hopf $*$-algebras i.e. quasi-Hopf algebras equipped with a conjugation (star) operation. The definition of quasi-Hopf $*$-algebras proposed ensures that the class of quasi-Hopf $*$-algebras is closed under twisting and…

Quantum Algebra · Mathematics 2007-05-23 M. D. Gould , T. Lekatsas

In this paper we focus on the set-open topologies on the group $\mathcal{H}(X)$ of all self-homeomorphisms of a topological space $X$ which yield continuity of both the group operations, product and inverse function. As a consequence, we…

General Topology · Mathematics 2020-02-20 Alexander V. Osipov

In this paper we consider a large family of graphs of hierarchically hyperbolic groups (HHG) and show that their fundamental groups admit HHG structures. To do that, we will investigate the notion of hierarchical quasi convexity and show…

Group Theory · Mathematics 2018-01-08 Davide Spriano

Let $G$ be a finite almost simple group and let $H$ be a Sylow $p$-subgroup of $G$. As a special case of a theorem of Zenkov, there exist $x,y \in G$ such that $H \cap H^x \cap H^y = 1$. In fact, if $G$ is simple, then a theorem of Mazurov…

Group Theory · Mathematics 2025-11-13 Timothy C. Burness , Hong Yi Huang

Groups with a topology that is in consistent one way or another with the algebraic structure are considered. Classical groups with a topology are topological, paratopological, semitopological, and quasitopological groups. We also study…

General Topology · Mathematics 2022-09-13 Evgenii Reznichenko

The main objects of study in this article are pairs $(G, \mathcal{H})$ where $G$ is a topological group with a compact open subgroup, and $\mathcal{H}$ is a finite collection of open subgroups. We develop geometric techniques to study the…

Group Theory · Mathematics 2023-05-11 Shivam Arora , Eduardo Martínez-Pedroza

Our main result is to show that every infinite, countable, residually finite group $G$ admits a Hausdorff group topology which is neither discrete nor precompact.

Group Theory · Mathematics 2023-07-04 Eli Glasner , Benjamin Weiss

We show that a topological semigroup of finite partial bijections $\mathscr{I}_\lambda^n$ of an infinite set with a compact subsemigroup of idempotents is absolutely $H$-closed and any countably compact topological semigroup does not…

Group Theory · Mathematics 2009-12-11 Oleg Gutik , Kateryna Pavlyk , Andriy Reiter

In this paper we extend the theory of H-closed extensions of Hausdorff spaces to a class of non-Hausdorff spaces, defined in \cite{B}, called $n$-Hausdorff spaces. The notion of H-closed is generalized to an $n$-H-closed space. Known…

General Topology · Mathematics 2018-08-24 Fortunata Aurora Basile , Maddalena Bonanzinga , Nathan Carlson , Jack Porter

We introduce a notion of quasimorphism between two arbitrary groups, generalizing the classical notion of Ulam. We then define and study the category of homogeneous quasigroups, whose objects are groups and whose morphisms are equivalence…

Group Theory · Mathematics 2014-03-13 Tobias Hartnick , Pascal Schweitzer

We study topological groups having all closed subgroups (totally) minimal and we call such groups c-(totally) minimal. We show that a locally compact c-minimal connected group is compact. Using a well-known theorem of Hall and Kulatilaka…

General Topology · Mathematics 2021-06-29 Wenfei Xi , Menachem Shlossberg

The completion $\overline{A}[\tau]$ of a locally convex *-algebra $A [ \tau ]$ with not jointly continuous multiplication is a *-vector space with partial multiplication $xy$ defined only for $x$ or $y \in A_{0}$, and it is called a…

Mathematical Physics · Physics 2009-04-07 F. Bagarello , A. Inoue , C. Trapani