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We prove a sharp, quantitative analogue of Helgason's conjecture at the level of distributions: For a semisimple Lie group $G$ of real rank one, Poisson transforms map a Sobolev space on $P\backslash G$ boundedly with closed range to an…

K-Theory and Homology · Mathematics 2026-04-08 Heiko Gimperlein , Magnus Goffeng

We prove the Banach strong Novikov conjecture for groups having polynomially bounded higher-order combinatorial functions. This includes all automatic groups.

K-Theory and Homology · Mathematics 2018-04-11 Alexander Engel

In this paper, we prove the integrality conjecture for quotient stacks arising from weakly symmetric representations of reductive groups. Our main result is a decomposition of the cohomology of the stack into finite-dimensional components…

Representation Theory · Mathematics 2026-01-21 Lucien Hennecart

We document some versions, in real K-theory, of well-known properties of the coarse assembly map in complex K-theory. These results are well-known, but difficult to find in the literature.

K-Theory and Homology · Mathematics 2013-08-13 John Roe

We study weakly invertible cells in weak $\omega$-categories in the sense of Batanin-Leinster, adopting the coinductive definition of weak invertibility. We show that weakly invertible cells in a weak $\omega$-category are closed under…

Category Theory · Mathematics 2024-11-22 Soichiro Fujii , Keisuke Hoshino , Yuki Maehara

This article is concerned with the convexity properties of universal covers of projective varieties. We study the relation between the convexity properties of the universal cover of X and the properties of the pullback map sending vector…

Algebraic Geometry · Mathematics 2007-05-23 F. Bogomolov , B. De Oliveira

We develop an Eilenberg-Moore spectral sequence to compute Bredon cohomology of spaces with an action of a group given as a pullback. Using several other spectral sequences, and positive results on the Baum-Connes Conjecture, we are able to…

K-Theory and Homology · Mathematics 2014-08-19 Noe Barcenas , Daniel Juan-Pineda , Mario Velasquez

We introduce a category of inverse semigroup actions and a category of \'etale groupoids. We show that there are three functors which send inverse semigroups to their spectral actions, inverse semigroup actions to their transformation…

Operator Algebras · Mathematics 2024-10-29 Takuto Fujieda , Takeshi Katsura , Tomoki Uchimura

We extend our previous results on generalized Dixmier-Douady theory to graded $C^*$-algebras, as means for explicit computations of the invariants arising for bundles of ungraded $C^*$-algebras. For a strongly self-absorbing $C^*$-algebra…

Operator Algebras · Mathematics 2026-01-08 Marius Dadarlat , Ulrich Pennig

The infinitesimal counterpart of a Lie groupoid is its Lie algebroid. As a vector bundle, it is given by the source vertical tangent bundle restricted to the identity bisection. Its sections can be identified with the invariant vector…

Category Theory · Mathematics 2025-11-11 Lory Aintablian , Christian Blohmann

We prove a compact embedding theorem in a class of spaces of piecewise H1 functions subordinated to a class of shape regular, but not necessarily quasi-uniform triangulations of a polygonal domain. This result generalizes the…

Numerical Analysis · Mathematics 2013-03-01 Sheng Zhang

The Farrell-Jones and the Baum-Connes Conjecture say that one can compute the algebraic K- and L-theory of the group ring and the topological K-theory of the reduced group C^*-algebra of a group G in terms of these functors for the…

K-Theory and Homology · Mathematics 2007-05-23 Arthur Bartels , Wolfgang Lueck

We introduce a K\"unneth class in the quantum equivariant setting inspired by the pioneer work by J. Chabert, H. Oyono-Oyono and S. Echterhoff, which allows to relate the quantum Baum-Connes property with the K\"unneth formula by…

Operator Algebras · Mathematics 2024-12-30 Rubén Martos

For closed oriented manifolds, we establish oriented homotopy invariance of higher signatures that come from the fundamental group of a large class of orientable 3-manifolds, including the ``piecewise geometric'' ones in the sense of…

Algebraic Topology · Mathematics 2007-05-23 Michel Matthey , Hervé Oyono-Oyono , Wolfgang Pitsch

The classical integral localization formula for equivariantly closed forms (Theorem 7.11 in [BGV]) is well-known and requires the acting Lie group to be compact. It is restated here as Theorem 2. In this article we extend this result to…

Differential Geometry · Mathematics 2007-09-23 Matvei Libine

We describe Universal Coefficient Theorems for the equivariant Kasparov theory for C*-algebras with an action of the group of integers or over a unique path space, using KK-valued invariants. We compare the resulting classification up to…

K-Theory and Homology · Mathematics 2020-11-04 Ralf Meyer

We propose the notion of a supercategory as an alternative approach to supermathematics. We show that this setting is rich to carry out many of the basic constructions of supermathematics. We also prove generalizations of a number of…

Quantum Algebra · Mathematics 2008-02-08 Martin Andler , Siddhartha Sahi

In this work, we study groupoids and their approximation properties, generalizing both the definitions and some known results for the group case. More precisely, we introduce weak amenability for groupoids using the definition of the…

Operator Algebras · Mathematics 2025-03-21 Tomás Pacheco

Let G be a locally compact group, let X be a universal proper G-space, and let Z be a G-equivariant compactification of X that is H-equivariantly contractible for each compact subgroup H of G. Let W be the resulting boundary. Assuming the…

K-Theory and Homology · Mathematics 2015-10-23 Heath Emerson , Ralf Meyer

For an $r$-discrete Hausdorff groupoid ${\cal G}$ and an inverse semigroup $S$ of slices of ${\cal G}$ there is an isomorphism between ${\cal G}$-equivariant $KK$-theory and compatible $S$-equivariant $KK$-theory. We use it to define…

K-Theory and Homology · Mathematics 2012-11-22 Bernhard Burgstaller