English
Related papers

Related papers: Equivariant $A$-theory

200 papers

Both the Klein-Williams invariant $\ell_G(f)$ from \cite{KW2} and the generalized equivariant Lefschetz invariant $\lambda_G(f)$ from \cite{weber07} serve as complete obstructions to the fixed point problem in the equivariant setting. The…

Algebraic Topology · Mathematics 2025-05-29 Başak Küçük

The additivity theorem for derivateurs associated to complicial biWaldhausen categories is proved. Also, to any exact category in the sense of Quillen a K-theory space is associated. This K-theory is shown to satisfy the additivity,…

K-Theory and Homology · Mathematics 2007-05-23 Grigory Garkusha

We compute the trace of an endomorphism in equivariant bivariant K-theory for a compact group G in several ways: geometrically using geometric correspondences, algebraically using localisation, and as a Hattori-Stallings trace. This results…

K-Theory and Homology · Mathematics 2015-10-23 Ivo Dell'Ambrogio , Heath Emerson , Ralf Meyer

In 1998, Goresky, Kottwitz, and MacPherson showed that for certain projective varieties X equipped with an algebraic action of a complex torus T, the equivariant cohomology ring H_T(X) can be described by combinatorial data obtained from…

Algebraic Topology · Mathematics 2007-05-23 Megumi Harada , Andre Henriques , Tara S. Holm

We prove an equivariant version of the classical Menger-Nobeling theorem regarding topological embeddings: Whenever a group $G$ acts on a finite-dimensional compact metric space $X$, a generic continuous equivariant function from $X$ into…

Dynamical Systems · Mathematics 2024-07-03 Yonatan Gutman , Michael Levin , Tom Meyerovitch

We show that the algebraic K-theory space of stable infinity-categories is canonically functorial in polynomial functors. As a consequence, we obtain a new proof of B\"okstedt's calculation of $\mathrm{THH}(\mathbb{F}_p)$.

K-Theory and Homology · Mathematics 2022-05-20 Clark Barwick , Saul Glasman , Akhil Mathew , Thomas Nikolaus

This paper studies the foundations of the geometric fixed point functor in multiplicative equivariant stable homotopy theory. We introduce a new class of equivariant orthogonal spectra called generalized orbit desuspension spectra and…

Algebraic Topology · Mathematics 2024-12-23 Andrew J. Blumberg , Michael A. Mandell

A key tool for the study of an affine Hecke algebra $\mathcal{H}$ is provided by Springer theory of the Langlands dual group via the realization of $\mathcal{H}$ as equivariant $K$-theory of the Steinberg variety. We prove a similar…

Representation Theory · Mathematics 2024-10-08 Roman Bezrukavnikov , Ivan Karpov , Vasily Krylov

This book introduces a new context for global homotopy theory, i.e., equivariant homotopy theory with universal symmetries. Many important equivariant theories naturally exist not just for a particular group, but in a uniform way for all…

Algebraic Topology · Mathematics 2020-01-13 Stefan Schwede

Algebraic $kk$-theory, introduced by Corti\~nas and Thom, is a bivariant $K$-theory defined on the category $\mathrm{Alg}$ of algebras over a commutative unital ring $\ell$. It consists of a triangulated category $kk$ endowed with a functor…

K-Theory and Homology · Mathematics 2025-12-10 Eugenia Ellis , Emanuel Rodríguez Cirone

We identify the group of homomorphisms $\operatorname{Hom}_{\mathcal{GF}}(F,\mathbf{RU}_{\mathbb Q})$ in the category of ($\operatorname{fin}$)-global functors to the rationalization of the unitary representation ring functor and deduce…

Algebraic Topology · Mathematics 2018-08-15 Christian Wimmer

We introduce an equivariant algebraic cobordism theory \Omega^G for algebraic varieties with G-action, where G is a split diagonalizable group scheme over a field k. It is done by combining the construction of the algebraic cobordism theory…

Algebraic Geometry · Mathematics 2015-08-06 Chun Lung Liu

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

For a Lie group $G$ and a vector bundle $E$ we study those actions of the Lie group $TG$ on $E$ for which the action map $TG\times E \to E$ is a morphism of vector bundles, and call those \emph{affine actions}. We prove that the category…

Differential Geometry · Mathematics 2019-10-30 James Waldron

We classify quantum analogues of actions of finite subgroups G of SL_2(k) on commutative polynomial rings k[u,v]. More precisely, we produce a classification of pairs (H,R), where H is a finite dimensional Hopf algebra that acts inner…

Rings and Algebras · Mathematics 2014-07-03 Kenneth Chan , Ellen Kirkman , Chelsea Walton , James Zhang

We describe a connection between the combinatorics of generators for certain groups and the combinatorics of Helly's 1913 theorem on convex sets. We use this connection to prove fixed point theorems for actions of these groups on…

Group Theory · Mathematics 2008-06-11 Benson Farb

Let $G$ be a connected reductive algebraic group. Let $\mathcal{E}\rightarrow \mathcal{B}$ be a principal $G\times G$-bundle and $X$ be a regular compactification of $G$. We describe the Grothendieck ring of the associated fibre bundle…

Algebraic Geometry · Mathematics 2020-08-25 V. Uma

We compute the Borel equivariant cohomology ring of the left $K$-action on a homogeneous space $G/H$, where $G$ is a connected Lie group, $H$ and $K$ are closed, connected subgroups and $2$ and the torsion primes of the Lie groups are units…

Algebraic Topology · Mathematics 2025-12-24 Jeffrey D. Carlson

This submission is a PhD dissertation. It constitutes the summary of the author's work concerning the relations between cohomology rings of algebraic varieties and rings of functions on zero schemes and fixed point schemes. It includes the…

Algebraic Geometry · Mathematics 2024-07-23 Kamil Rychlewicz

We define a $K$-theory for pointed right derivators and show that it agrees with Waldhausen $K$-theory in the case where the derivator arises from a good Waldhausen category. This $K$-theory is not invariant under general equivalences of…

K-Theory and Homology · Mathematics 2016-12-21 Fernando Muro , George Raptis