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Related papers: Some remarks on profinite completion of spaces

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In this paper we establish affinizations and R-matrices in the language of pro-objects, and as an application, we construct reflection functors over the localizations of quiver Hecke algebras of arbitrary finite types. This reflection…

Representation Theory · Mathematics 2025-05-02 Masaki Kashiwara , Myungho Kim , Se-jin Oh , Euiyong Park

We initiate the study of profinite rigidity for modules over a Noetherian domain: to what extent are these objects determined by their finite images? We establish foundational statements in analogy to classical results in the category of…

Group Theory · Mathematics 2025-06-25 Julian Wykowski

We investigate the profinite completions of a certain family of groups acting on trees. It turns out that for some of the groups considered, the completions coincide with the closures of the groups in the full group of tree automorphisms.…

Group Theory · Mathematics 2007-05-23 Ekaterina Pervova

We prove that the sign of the Euler characteristic of arithmetic groups with CSP is determined by the profinite completion. In contrast, we construct examples showing that this is not true for the Euler characteristic itself and that the…

Group Theory · Mathematics 2019-01-23 Holger Kammeyer , Steffen Kionke , Jean Raimbault , Roman Sauer

We prove that any compact, orientable 3-manifold with empty or toral boundary is profinitely almost rigid among all compact, orientable 3-manifolds. In other words, the profinite completion of its fundamental group determines its…

Geometric Topology · Mathematics 2025-09-04 Xiaoyu Xu

We study the profinite genus of HNN-extensions whose associated subgroups are finite. We give precise formulas for the number of isomorphism classes of HNN(G,H,K,t,f) and of its profinite completion and compute the profinite genus of such…

Group Theory · Mathematics 2026-01-16 V. R. de Bessa , A. L. P. Porto , P. A. Zalesskii

We give a characterization of toral relatively hyperbolic virtually special groups in terms of the profinite completion. We also prove a Tits alternative for subgroups of the profinite completion $\hat G$ of a relatively hyperbolic…

Group Theory · Mathematics 2025-03-18 Pavel Zalesskii

We study equivariant sheaves over profinite spaces, where the group is also taken to be profinite. We resolve a serious deficit in the existing theory by constructing a good notion of equivariant presheaves, with a suitable equivariant…

Algebraic Topology · Mathematics 2022-04-06 David Barnes , Danny Sugrue

Coverings in the representation theory of algebras were introduced for the Auslander-Reiten quiver of a representation finite algebra by Riedtmann and later for finite dimensional algebras by Bongartz and Gabriel, R. Martinez-Villa and de…

Representation Theory · Mathematics 2010-11-01 Jose Antonio de la Peña , Maria Julia Redondo

We study Picard groups and Picard functors of perfectoid spaces which are limits of rigid spaces. For sufficiently large covers that are limits of rigid spaces of good reduction, we show that the Picard functor can be represented by the…

Algebraic Geometry · Mathematics 2024-11-22 Ben Heuer

Broadly speaking, a finiteness property of groups is any generalisation of the property of having finite order. A large part of infinite group theory is concerned with finiteness properties and the relationships between them. Profinite…

Group Theory · Mathematics 2010-02-16 Colin Reid

We give examples of closed, oriented 3-manifolds whose fundamental groups are not isomorphic, but yet have the same sets of finite quotient groups; hence the same profinite completions. We also give examples of compact, oriented 3-manifolds…

Geometric Topology · Mathematics 2014-10-06 John Hempel

We study homological approximations of the profinite completion of a limit group (see Thm.~A) and obtain the analogous of Bridson and Howie's Theorem for the profinite completion of a non-abelian limit group (see Thm.~B).

Group Theory · Mathematics 2018-03-02 Jhoel S. Gutierrez

This paper proves a result on the existence of finite flat scheme covers of Deligne-Mumford stacks. This result is used to prove that a large class of smooth Deligne-Mumford stacks with affine moduli space are quotient stacks, and in the…

Algebraic Geometry · Mathematics 2016-09-07 Andrew Kresch , Angelo Vistoli

We develop cohomological and homological theories for a profinite group $G$ with coefficients in the Pontryagin dual categories of pro-discrete and ind-profinite $G$-modules, respectively. The standard results of group (co)homology hold for…

Group Theory · Mathematics 2016-09-30 Marco Boggi , Ged Corob Cook

We prove a characterization of profinite algebras, i.e., topological algebras that are isomorphic to a projective limit of finite discrete algebras. In general profiniteness concerns both the topological and algebraic characteristics of a…

Logic · Mathematics 2020-08-25 Friedrich Martin Schneider , Jens Zumbrägel

Based on the action of the mapping class group on the space of measured foliations, we construct a new boundary of the mapping class group and study the structure of this boundary. As an application, for any point in Teichmuller space, we…

Geometric Topology · Mathematics 2023-02-15 Lixin Liu , Yaozhong Shi

In this ongoing work, we extend to a class of well-behaved pre-special hyperfields the work of J. Min\'a\v c and Spira (\cite{minac1996witt}) that describes a (pro-2)-group of a field extension that encodes the quadratic form theory of a…

Commutative Algebra · Mathematics 2024-04-08 Kaique Matias de Andrade Roberto , Hugo Luiz Mariano

Our aim is to transfer several foundational results from the modular representation theory of finite groups to the wider context of profinite groups. We are thus interested in profinite modules over the completed group algebra k[[G]] of a…

Representation Theory · Mathematics 2010-11-15 John MacQuarrie

We show that for a partial action $\eta$ with closed domain of a compact group $G$ on a profinite space $X$ the space of orbits $X/\!\sim_G$ is profinite, this leads to the fact that when $G$ is profinite the enveloping space $X_G$ is also…

General Topology · Mathematics 2023-02-15 Luis Martínez , Andrés Villamizar , Héctor Pinedo