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Related papers: Partial actions of groups on profinite spaces

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The notion of compact quantum subgroup is revisited and an alternative definition is given. Induced representations are considered and a Frobenius reciprocity theorem is obtained. A relationship between ergodic actions of compact quantum…

Operator Algebras · Mathematics 2013-09-24 Claudia Pinzari

We study profinite actions of residually finite groups in terms of weak containment. We show that two strongly ergodic profinite actions of a group are weakly equivalent if and only if they are isomorphic. This allows us to construct…

Group Theory · Mathematics 2011-09-20 Miklós Abért , Gábor Elek

By a coprime commutator in a profinite group $G$ we mean any element of the form $[x, y]$, where $x,y\in G$ and $(|x|,|y|)=1$. It is well-known that the subgroup generated by the coprime commutators of $G$ is precisely the pronilpotent…

Group Theory · Mathematics 2026-04-08 Cristina Acciarri , Pavel Shumyatsky

Partial actions of groups on C*-algebras and the closely related actions and coactions of Hopf algebras received much attention over the last decades. They arise naturally as restrictions of their global counterparts to non-invariant…

Operator Algebras · Mathematics 2018-11-14 Franziska Kraken , Paula Quast , Thomas Timmermann

Let $G$ be a finitely generated group acting faithfully and properly discontinuously by homeomorphisms on a planar surface $X \subseteq \mathbb{S}^2$. We prove that $G$ admits such an action that is in addition co-compact, provided we can…

Combinatorics · Mathematics 2019-05-17 Agelos Georgakopoulos

A space $X$ is called {\it selectively pseudocompact} if for each sequence $(U_{n})_{n\in \mathbb{N}}$ of pairwise disjoint nonempty open subsets of $X$ there is a sequence $(x_{n})_{n\in \mathbb{N}}$ of points in $X$ such that $cl_X(\{x_n…

General Topology · Mathematics 2017-06-16 S. Garcia-Ferreira , A. H. Tomita

Given a finitely generated group $G$, the possible actions of $G$ on the real line (without global fixed points), considered up to semi-conjugacy, can be encoded by the space of orbits of a flow on a compact space $(Y, \Phi)$ naturally…

Group Theory · Mathematics 2024-09-04 Joaquín Brum , Nicolás Matte Bon , Cristóbal Rivas , Michele Triestino

We introduce (continuous) partial category actions on sets (topological spaces) and show that each such action admits a universal globalization. Thereby, we obtain a simultaneous generalization of corresponding results for groups, by…

Rings and Algebras · Mathematics 2017-04-26 Patrik Nystedt

We organize fundamental properties of quasi-Hamiltonian spaces on which a finite group acts, and we apply them to the theory of moduli spaces of flat connections on an oriented compact surface with boundary.

Symplectic Geometry · Mathematics 2025-12-23 Keito Takegoshi

Suppose $R$ is a profinite ring. We construct a large class of profinite groups $\widehat{{\scriptstyle\bf L}'{\scriptstyle\bf H}_R}\mathfrak{F}$, including all soluble profinite groups and profinite groups of finite cohomological dimension…

Group Theory · Mathematics 2014-12-08 Ged Corob Cook

In this paper, we investigate properties of a reproducing kernel Hilbert space of a group action. In particular, we introduce an equivalence relation on a compact Hausdorff space $X$, and consequently establish three equivalent definitions…

Functional Analysis · Mathematics 2025-04-16 Tyler Blom , Samuel A. Hokamp , Alejandro Jimenez , Jacob Laubacher

The aim of this paper is to characterize the notion of internal category (groupoid) in the category of Leibniz algebras and investigate the properties of well-known notions such as covering groupoid and groupoid operations (actions) in this…

Category Theory · Mathematics 2018-08-17 Tunçar Şahan , Ayhan Erciyes

Consider a free ergodic measure preserving profinite action $\Gamma\curvearrowright X$ (i.e. an inverse limit of actions $\Gamma\curvearrowright X_n$, with $X_n$ finite) of a countable property (T) group $\Gamma$ (more generally of a group…

Group Theory · Mathematics 2008-05-21 Adrian Ioana

The first part of this paper is a refinement of Winkelmann's work on invariant rings and quotients of algebraic groups actions on affine varieties, where we take a more geometric point of view. We show that the (algebraic) quotient…

Commutative Algebra · Mathematics 2016-02-01 Emilie Dufresne , Hanspeter Kraft

For a positive integer r we prove that if G is a profinite group in which the centralizer of every nontrivial element has rank at most r, then G is either a pro-p group or a group of finite rank. Further, if G is not virtually a pro-p…

Group Theory · Mathematics 2022-07-19 Pavel Shumyatsky

We provide a systematic and in-depth study of compact group actions with the Rokhlin property. It is show that the Rokhlin property is generic in some cases of interest; the case of totally disconnected groups being the most satisfactory…

Operator Algebras · Mathematics 2018-02-06 Eusebio Gardella

We study several properties of expansive group actions on metric spaces and obtain relation between expansivity for subgroup and group actions. Through counter examples necessity of hypothesis are justified. We also study expansivity of…

Dynamical Systems · Mathematics 2018-08-01 Ali Barzanouni , Mahin Sadat Divandar , Ekta Shah

We show that the inverse limit and the orbit map commute for actions of compact groups on compact Hausdorff spaces.

General Topology · Mathematics 2011-07-07 Mahender Singh

A continuous action of a group G on a compact metric space has sensitive dependence on initial conditions if there is a number e>0 such that for any open set U we can find g in G such that g.U has diameter greater than e. We prove that if a…

Dynamical Systems · Mathematics 2009-07-16 Fabrizio Polo

It is proven that the orbit-equivalence class of any essentially free probability-measure-preserving action of a free group $G$ is weakly dense in the space of actions of $G$.

Dynamical Systems · Mathematics 2013-08-15 Lewis Bowen