English
Related papers

Related papers: Equivariant Cobordism for Torus Actions

200 papers

We obtain an explicit presentation of the equivariant cobordism ring of a complete flag variety. An immediate corollary is a Borel presentation of the ordinary cobordism ring. Another application is an equivariant Schubert calculus in…

Algebraic Geometry · Mathematics 2014-06-06 Valentina Kiritchenko , Amalendu Krishna

We consider the cobordism ring of involutions of a field of characteristic not two, whose elements are formal differences of classes of smooth projective varieties equipped with an involution, and relations arise from equivariant K-theory…

Algebraic Geometry · Mathematics 2021-08-10 Olivier Haution

The equivariant coarse index is well-understood and widely used for actions by discrete groups. We extend the definition of this index to general locally compact groups. We use a suitable notion of admissible modules over $C^*$-algebras of…

K-Theory and Homology · Mathematics 2022-07-05 Hao Guo , Peter Hochs , Varghese Mathai

Motivated by localization theorems on moduli spaces, we prove a structural classification of Deligne-Mumford stacks with an action of a torus where the induced action on the coarse moduli space is trivial. We also establish a general local…

Algebraic Geometry · Mathematics 2024-02-19 Jarod Alper , Felix Janda

We study the K-theory of actions of diagonalizable group schemes on noetherian regular separated algebraic spaces: our main result shows how to reconstruct the K-theory ring of such an action from the K-theory rings of the loci where the…

Algebraic Geometry · Mathematics 2007-05-23 Gabriele Vezzosi , Angelo Vistoli

We give details of models for rational torus equivariant homotopy theory based on (a) all subgroups, connected subgroups or dimensions of subgroups and (b) on pairs or general flags. We provide comparison functors and show the models are…

Algebraic Topology · Mathematics 2016-04-19 J. P. C. Greenlees

We introduce an equivariant Pontrjagin-Thom construction which identifies equivariant cohomotopy classes with certain fixed point bordism classes. This provides a concrete geometric model for equivariant cohomotopy which works for any…

Algebraic Topology · Mathematics 2018-11-22 Daniel Grady

We study $T$-linear schemes, a class of objects that includes spherical and Schubert varieties. We provide a localization theorem for the equivariant Chow cohomology of these schemes that does not depend on resolution of singularities.…

Algebraic Geometry · Mathematics 2015-04-29 Richard Gonzales

This is a survey on natural local torus actions which arise in integrable dynamical systems, and their relations with other subjects, including: reduced integrability, local normal forms, affine structures, monodromy, global invariants,…

Dynamical Systems · Mathematics 2007-05-23 Nguyen Tien Zung

Considering the potential equivariant formality of the left action of a connected Lie group $K$ on the homogeneous space $G/K$, we arrive through a sequence of reductions at the case $G$ is compact and simply-connected and $K$ is a torus.…

Algebraic Topology · Mathematics 2023-11-28 Jeffrey D. Carlson

Let $G$ be a connected linear algebraic group over a field $k$ of characteristic zero. For a principal $G$-bundle $\pi: E \to X$ over a scheme $X$ of finite type over $k$ and a parabolic subgroup $P$ of $G$, we describe the rational…

Algebraic Geometry · Mathematics 2010-07-08 Amalendu Krishna

The fixed points of a natural torus action on the Hilbert schemes of points in C^2 are quiver varieties of infinite type A. The equivariant cohomology of the Hilbert schemes and quiver varieties can be given the structure of bosonic and…

Representation Theory · Mathematics 2011-07-13 Alistair Savage

A twist is a datum playing a role of a local system for topological $K$-theory. In equivariant setting, twists are classified into four types according to how they are realized geometrically. This paper lists the possible types of twists…

Algebraic Topology · Mathematics 2017-03-09 Kiyonori Gomi

We develop the formalism of universal torsors in equivariant birational geometry and apply it to produce new examples of nonbirational but stably birational actions of finite groups.

Algebraic Geometry · Mathematics 2022-04-08 Brendan Hassett , Yuri Tschinkel

We extend the derived Algebraic bordism of Lowrey and Sch\"urg to a bivariant theory in the sense of Fulton and MacPherson, and establish some of its basic properties. As a special case, we obtain a completely new theory of cobordism rings…

Algebraic Geometry · Mathematics 2019-11-28 Toni Annala

We investigate what information on the orbit type stratification of a torus action on a compact space is contained in its rational equivariant cohomology algebra. Regarding the (labelled) poset structure of the stratification we show that…

Algebraic Topology · Mathematics 2024-03-27 Oliver Goertsches , Leopold Zoller

We systematically produce algebraic varieties with torus action by constructing them as suitably embedded subvarieties of toric varieties. The resulting varieties admit an explicit treatment in terms of toric geometry and graded ring…

Algebraic Geometry · Mathematics 2021-02-04 Juergen Hausen , Christoff Hische , Milena Wrobel

We compute rational equivariant Chow rings with respect to a torus of quiver moduli spaces. We derive a presentation in terms of generators and relations, use torus localization to identify it as a subring of the Chow ring of the fixed…

Algebraic Geometry · Mathematics 2020-10-01 Hans Franzen

We will discuss the equivariant cohomology of a manifold endowed with the action of a Lie group. Localization formulae for equivariant integrals are explained by a vanishing theorem for equivariant cohomology with generalized coefficients.…

Differential Geometry · Mathematics 2007-05-23 Michele Vergne

We determine all restrictions on the dimension of the fixed locus of a diagonalizable group acting on a smooth projective variety that arise from the Chern numbers of the ambient variety. We reduce the problem to finding lower bounds for…

Algebraic Geometry · Mathematics 2026-02-20 Olivier Haution