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We study final group topologies and their relations to compactness properties. In particular, we are interested in situations where a colimit or direct limit is locally compact, a k_\omega-space, or locally k_\omega. As a first application,…

Group Theory · Mathematics 2015-03-27 Helge Glockner , Ralf Köhl , Tobias Hartnick

A version of group cohomology for locally compact groups and Polish modules has previously been developed using a bar resolution restricted to measurable cochains. That theory was shown to enjoy analogs of most of the standard algebraic…

Group Theory · Mathematics 2012-11-27 Tim Austin , Calvin C. Moore

We present a discussion about the local isometric rigidity problem in codimension 2 with a concrete example. We show the necessity of extending the notions of genuine and honest rigidity in order to have the transitivity property. In order…

Differential Geometry · Mathematics 2023-12-05 Diego Guajardo

We analyze and compare different dynamical systems and groupoids which can be obtained from projection point patterns. We define the cohomology of a point pattern as the cocycle cohomology of the pattern groupoid. We describe this…

Algebraic Topology · Mathematics 2007-05-23 Alan Forrest , John Hunton , Johannes Kellendonk

We examine sufficient conditions for the dual of a topological group to be metrizable and locally compact.

General Topology · Mathematics 2016-03-01 Frédéric Mynard , Mikhail Tkachenko

Classical finite association schemes lead to a finite-dimensional algebras which are generated by finitely many stochastic matrices. Moreover, there exist associated finite hypergroups. The notion of classical discrete association schemes…

Group Theory · Mathematics 2019-05-21 Michael Voit

This paper aims to examine the version of the topological group structure in proximity and especially descriptive proximity spaces, that is, the concepts of proximal group and descriptive proximal group are introduced. In addition, the…

General Topology · Mathematics 2023-09-06 Melih İs

We consider quotients of complete flag manifolds in Cn and Rn by an action of the symmetric group on n objects. We compute their cohomology with field coefficients of any characteristic. Specifically, we show that these topological spaces…

Algebraic Topology · Mathematics 2023-12-20 Lorenzo Guerra , Santanil Jana

We define 2-gerbes bound by complexes of braided group-like stacks. We prove a classification result in terms of hypercohomology groups with values in abelian crossed squares and cones of morphisms of complexes of length 3. We give an…

Category Theory · Mathematics 2008-08-28 Ettore Aldrovandi

This paper is a continuation of our paper about boundary rigidity and filling minimality of metrics close to flat ones. We show that compact regions close to a hyperbolic one are boundary distance rigid and strict minimal fillings. We also…

Differential Geometry · Mathematics 2019-12-19 Dmitri Burago , Sergei Ivanov

We define and study the invariant linear and nonlinear horizontal double complexes of a local Lie group.

Differential Geometry · Mathematics 2011-10-27 Ercüment Ortaçgil

The Hochschild and (cotriple) cyclic homologies of crossed modules of (not-necessarily-unital) associative algebras are investigated. Wodzicki's excision theorem is extended for inclusion crossed modules in the category of crossed modules…

K-Theory and Homology · Mathematics 2008-12-04 Guram Donadze , Nick Inassaridze , Emzar Khmaladze , Manuel Ladra

By recent work on some conjectures of Pillay, each definably compact group in a saturated o-minimal structure is an expansion of a compact Lie group by a torsion free normal divisible subgroup, called its infinitesimal subgroup. We show…

Logic · Mathematics 2007-11-16 Alessandro Berarducci

We explain some interesting relations in the degree three bounded cohomology of surface groups. Specifically, we show that if two faithful Kleinian surface group representations are quasi-isometric, then their bounded fundamental classes…

Geometric Topology · Mathematics 2020-05-13 James Farre

We study cocycles of countable groups $\Gamma$ of Borel automorphisms of a standard Borel space $(X, \mathcal{B})$ taking values in a locally compact second countable group $G$. We prove that for a hyperfinite group $\Gamma$ the subgroup of…

Dynamical Systems · Mathematics 2021-08-16 Sergey Bezuglyi , Shrey Sanadhya

A class of topological spaces is topologically rigid if any two spaces with the same fundamental group are also homeomorphic. Topological rigidity, in addition to its intrinsic interest, has been useful for solving abstract commensurability…

Geometric Topology · Mathematics 2023-09-21 Yandi Wu

The goal of this paper is to study the geometry of cusped complex hyperbolic manifolds through their compactifications. We characterize toroidal compactifications with non-nef canonical divisor. We derive effective very ampleness results…

Differential Geometry · Mathematics 2015-06-12 Gabriele Di Cerbo , Luca F. Di Cerbo

A homology and cohomology theory for topological quandles are introduced. The relation between these (co)homology groups and quandle (co)homology groups are studied. The 1 - topological quandle cocycles are used to compute state sum…

Geometric Topology · Mathematics 2022-08-03 Georgy C. Luke , B. Subhash

A locally compact contraction group is a pair (G,f) where G is a locally compact group and f an automorphism of G which is contractive in the sense that the forward orbit under f of each g in G converges to the neutral element e, as n tends…

Group Theory · Mathematics 2018-04-05 Helge Glockner , George A. Willis

We compute the local intersection cohomology of the irreducible components of varieties of complexes, by using Lusztig's geometric approach to quantum groups and explicit constructions of elements of Lusztig's canonical bases.

Algebraic Geometry · Mathematics 2025-02-12 Xin Fang , Markus Reineke