English
Related papers

Related papers: Equivariant Kasparov theory and generalized homomo…

200 papers

We show that for every symmetric space G/K of compact type with K connected, the K-action on G/K by left translations is equivariantly formal.

Differential Geometry · Mathematics 2012-03-01 Oliver Goertsches

A generalization of the double commutator lemma for normal subgroups is shown for invariant random subgroups of a countable group acting faithfully on a Hausdorff space. As an application, we classify ergodic invariant random subgroups of…

Group Theory · Mathematics 2020-01-22 Tianyi Zheng

In this short note, we prove a G-equivariant generalisation of McDuff-Segal's group-completion theorem for finite groups G. A new complication regarding genuine equivariant localisations arises and we resolve this by isolating a simple…

Algebraic Topology · Mathematics 2024-05-31 Kaif Hilman

Let $\pi$ be a group equipped with an action of a second group $G$ by automorphisms. We define the equivariant cohomological dimension ${\sf cd}_G(\pi)$, the equivariant geometric dimension ${\sf gd}_G(\pi)$, and the equivariant…

Algebraic Topology · Mathematics 2020-04-24 Mark Grant , Ehud Meir , Irakli Patchkoria

We study the torus equivariant K-homology ring of the affine Grassmannian $\mathrm{Gr}_G$ where $G$ is a connected reductive linear algebraic group. In type $A$, we introduce equivariantly deformed symmetric functions called the K-theoretic…

Representation Theory · Mathematics 2024-08-21 Takeshi Ikeda , Mark Shimozono , Kohei Yamaguchi

This paper constitutes a first step in the author's program to investigate the question of when a homotopy of 2-cocycles $\omega = \{\omega_t\}_{t \in [0,1]}$ on a locally compact Hausdorff groupoid $\mathcal{G}$ induces an isomorphism of…

Operator Algebras · Mathematics 2014-09-09 Elizabeth Gillaspy

We compute the equivariant $KO$-homology of the classifying space for proper actions of $\textrm{SL}_3(\mathbb{Z})$ and $\textrm{GL}_3(\mathbb{Z})$. We also compute the Bredon homology and equivariant $K$-homology of the classifying spaces…

K-Theory and Homology · Mathematics 2022-01-05 Sam Hughes

For T an abelian compact Lie group, we give a description of T-equivariant K-theory with complex coefficients in terms of equivariant cohomology. In the appendix we give applications of this by extending results of Chang-Skjelbred and…

Algebraic Topology · Mathematics 2009-03-10 Ioanid Rosu , Allen Knutson

We define and study square-integrable coactions of locally compact quantum groups on Hilbert modules, generalising previous work for group actions. As special cases, we consider square-integrable Hilbert space corepresentations and…

Operator Algebras · Mathematics 2015-10-23 Alcides Buss , Ralf Meyer

An important ingredient in the completion theorem of equivariant K-theory given by S. Jackowski is that the representation ring R(Gamma) of a compact Lie group satisfies two restriction properties called (N) and (R\_{F}). We give in this…

Algebraic Topology · Mathematics 2007-05-23 Abdelouahab Arouche

Equivariant $K$-theory is a generalized equivariant cohomology theory which is a hybrid of the $K$-theory of a topological space and the representation theory of the group acting on it. In this article, we review the basics of equivariant…

K-Theory and Homology · Mathematics 2023-09-19 Chi-Kwong Fok

Let $A$ be a graded C*-algebra. We characterize Kasparov's K-theory group $\hat{K}_0(A)$ in terms of graded *-homomorphisms by proving a general converse to the functional calculus theorem for self-adjoint regular operators on graded…

Operator Algebras · Mathematics 2016-09-07 Jody Trout

Let T be the circle and A be a T-C*-algebra. Then the T-equivariant K-theory of A is a module over the representation ring of the circle. The latter is a Laurent polynomial ring. Using the support of the module as an invariant, and…

K-Theory and Homology · Mathematics 2013-03-21 Heath Emerson

Let $Y$ be a cubic threefold with a non-Eckardt type involution $\tau$. Our first main result is that the $\tau$-equivariant category of the Kuznetsov component $\mathcal{K}u_{\mathbb{Z}_2}(Y)$ determines the isomorphism class of $Y$ for…

Algebraic Geometry · Mathematics 2024-10-22 Sebastian Casalaina-Martin , Xianyu Hu , Xun Lin , Shizhuo Zhang , Zheng Zhang

We introduce a global equivariant refinement of algebraic K-theory; here `global equivariant' refers to simultaneous and compatible actions of all finite groups. Our construction turns a specific kind of categorical input data into a global…

Algebraic Topology · Mathematics 2022-07-05 Stefan Schwede

Motivated by representation theory and geometry, we introduce and develop an equivariant generalization of Ehrhart theory, the study of lattice points in dilations of lattice polytopes. We prove representation-theoretic analogues of…

Combinatorics · Mathematics 2014-12-05 Alan Stapledon

Ehrhart theory is the study of the enumeration of lattice points in lattice polytopes. Equivariant Ehrhart theory is a generalization of Ehrhart theory that takes into account the action of a finite group acting via affine transformations…

Combinatorics · Mathematics 2025-09-26 Alan Stapledon

We introduce two families of symmetric functions generalizing the factorial Schur $P$- and $Q$- functions due to Ivanov. We call them $K$-theoretic analogues of factorial Schur $P$- and $Q$- functions. We prove various combinatorial…

Combinatorics · Mathematics 2013-05-27 Takeshi Ikeda , Hiroshi Naruse

We consider functors from the category of locally convex algebras to abelian groups and prove invariance under smooth homotopies for weakly J-stable algebras, where J is a harmonic operator ideal. This applies in particular to negative…

K-Theory and Homology · Mathematics 2007-05-23 Joachim Cuntz , Andreas Thom

A cornerstone of algebraic K-theory is the equivalence between the K-theory machines of May, Segal, and Elmendorf and Mandell. Equivariant algebraic K-theory enriches the theory with group actions, making it more powerful and complex. There…

Algebraic Topology · Mathematics 2025-11-12 Donald Yau