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Generalizing de Vries Compactification Theorem and strengthening Leader Local Compactification Theorem, we describe the partially ordered set $(\LL(X),\le)$ of all (up to equivalence) locally compact Hausdorff extensions of a Tychonoff…

General Topology · Mathematics 2009-10-20 Georgi Dimov

Previously, the authors used the insights of Robinson's non-standard analysis as a powerful tool to extend and simplify the construction of some compactifications of regular spaces. They now show that any Hausdorff compactification is…

General Topology · Mathematics 2020-09-11 Matt Insall , Peter A. Loeb , Malgorzata Aneta Marciniak

Etale groupoids arise naturally as models for leaf spaces of foliations, for orbifolds, and for orbit spaces of discrete group actions. In this paper we introduce a sheaf homology theory for etale groupoids. We prove its invariance under…

K-Theory and Homology · Mathematics 2007-05-23 Marius Crainic , Ieke Moerdijk

We present a higher index theorem for a certain class of etale one-dimensional complex-analytic groupoids. The novelty is the use of the local anomaly formula established in a previous paper, which represents the bivariant Chern character…

K-Theory and Homology · Mathematics 2009-06-12 Denis Perrot

Following work of Rieffel, we define the Cayley compactification of an abelian group with specified generating set. We investigate its structure using methods from discrete geometry and commutative algebra.

Combinatorics · Mathematics 2007-05-23 Mike Develin

We give a local characterization of the existence of Kazhdan projections for arbitary families of Banach space representations of a compactly generated locally compact group $G$. We also define and study a natural generalization of the Fell…

Functional Analysis · Mathematics 2021-03-25 Mikael de la Salle

We study the groupoid C*-algebras associated to the equivalence relation induced by a quotient map on a locally compact Hausdorff space. This C*-algebra is always a Fell algebra, and if the quotient space is Hausdorff, it is a…

Operator Algebras · Mathematics 2012-07-12 Lisa Orloff Clark , Astrid an Huef , Iain Raeburn

In this paper we introduce Hausdorff locally convex algebra topologies on subalgebras of the whole algebra of nonlinear generalized functions. These topologies are strong duals of Fr\'echet-Schwartz space topologies and even strong duals of…

Functional Analysis · Mathematics 2014-03-21 J. Aragona , J. F. Colombeau , S. O. Juriaans

We examine two classes of examples of Hausdorff \'etale factor groupoids; one comes from taking a quotient space of the unit space of an AF-groupoid, and the other comes from certain nonhomogeneous extensions of Cantor minimal systems…

Operator Algebras · Mathematics 2023-05-02 Mitch Haslehurst

In finite graphs, finite-order tangles offer an abstract description of highly connected substructures. In infinite graphs, infinite-order tangles compactify the graphs in the same way the ends compactify connected locally finite graphs.…

Combinatorics · Mathematics 2019-08-28 Jan Kurkofka

The Hodge decomposition is well-known for compact manifolds. The result has been extended by Kodaira to include non-compact manifolds and $L^2$ forms. We further extend the Hodge decomposition to the Sobolev space $H^1$ for general…

Differential Geometry · Mathematics 2019-01-01 Chi Hin Chan , Magdalena Czubak , Carlos Pinilla Suarez

We construct natural relative compactifications for the relative Jacobian over a family $X/S$ of reduced curves. In contrast with all the available compactifications so far, ours admit a universal sheaf, after an etale base change. Our…

alg-geom · Mathematics 2008-02-03 Eduardo Esteves

This note provides a correct proof of the result claimed by the second author that locally compact normal spaces are collectionwise Hausdorff in certain models obtained by forcing with a coherent Souslin tree. A novel feature of the proof…

General Topology · Mathematics 2019-08-15 Alan Dow , Franklin D. Tall

In this note we treat the equations of fractional elasticity. After establishing well-posedness, we show a compactness result related to the theory of homogenization. For this, a previous result in (abstract) homogenization theory of…

Analysis of PDEs · Mathematics 2013-09-19 Marcus Waurick

We consider the holographic computation of two dimensional conformal field theory partition functions on non-orientable surfaces. We classify the three dimensional geometries that give bulk saddle point contributions to the partition…

High Energy Physics - Theory · Physics 2016-09-07 Alexander Maloney , Simon F. Ross

In this work we describe horofunction compactifications of metric spaces and finite dimensional real vector spaces through asymmetric metrics and asymmetric polyhedral norms by means of nonstandard methods, that is, ultrapowers of the…

Metric Geometry · Mathematics 2023-05-05 Corina Ciobotaru , Linus Kramer , Petra Schwer

We discuss the `hd-compactification' of a semi-simple Lie group to a manifold with corners; it is the real analog of the wonderful compactification of deConcini and Procesi. There is a 1-1 correspondence between the boundary faces of the…

Differential Geometry · Mathematics 2019-10-08 Pierre Albin , Panagiotis Dimakis , Richard Melrose , David Vogan

We generalize the horofunction compactification to maps that are not distance functions. As an application we define a horofunction counterpart to the Teichm\"uller distance, and discuss its properties.

Geometric Topology · Mathematics 2025-12-30 Hidetoshi Masai

Localization methods are ubiquitous in cyclic homology theory, but vary in detail and are used in different scenarios. In this paper we will elaborate on a common feature of localization methods in noncommutative geometry, namely…

K-Theory and Homology · Mathematics 2022-12-29 Markus J. Pflaum

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