English
Related papers

Related papers: Rigidity for equivariant pseudo pretheories

200 papers

We present a description of the equivariant $K$-theory of a smooth projective spherical variety. This provides an integral $K$-theory version of Brion's calculation of equivariant Chow-cohomology of such varieties. We consider the…

K-Theory and Homology · Mathematics 2017-02-14 S. Banerjee , Mahir Bilen Can

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

In this paper, we study some basic geometric properties of pseudohermitian submanifolds of the Heisenberg groups. In particular, we obtain the uniqueness and existence theorems, and some rigidity theorems.

Differential Geometry · Mathematics 2018-02-14 Hung-Lin Chiu

We establish an Atiyah-Hirzebruch type spectral sequence relating real morphic cohomology and real semi-topological K-theory and prove it to be compatible with the Atiyah-Hirzebruch spectral sequence relating Bredon cohomology and Atiyah's…

Algebraic Geometry · Mathematics 2010-08-24 Jeremiah Heller , Mircea Voineagu

Over the complex numbers, we compute the $C_2$-equivariant Bredon motivic cohomology ring with $\mathbb{Z}/2$ coefficients. By rigidity, this extends Suslin's calculation of the motivic cohomology ring of algebraically closed fields of…

Algebraic Geometry · Mathematics 2023-11-01 Jeremiah Heller , Mircea Voineagu , Paul Arne Østvær

This text is an introduction to equivariant cohomology, a classical tool for topological transformation groups, and to equivariant intersection theory, a much more recent topic initiated by D. Edidin and W. Graham. It is based on lectures…

Algebraic Geometry · Mathematics 2007-05-23 Michel Brion

We consider parahoric Bruhat-Tits group schemes over a smooth projective curve and torsors under them. If the characteristic of the ground field is either zero or positive but not too small and the generic fiber is absolutely simple and…

Algebraic Geometry · Mathematics 2023-11-01 Georgios Pappas , Michael Rapoport

Chevalley's theorem states that every smooth connected algebraic group over a perfect field is an extension of an abelian variety by a smooth connected affine group. That fails when the base field is not perfect. We define a pseudo-abelian…

Algebraic Geometry · Mathematics 2013-02-28 Burt Totaro

We extend the work of Ash and Stevens [Ash-Stevens 97] on p-adic analytic families of p-ordinary arithmetic cohomology classes for GL(N,Q) by introducing and investigating the concept of p-adic rigidity of arithmetic Hecke eigenclasses. An…

Number Theory · Mathematics 2014-02-26 Avner Ash , David Pollack , Glenn Stevens

Replaces Previous version. Includes comments on poincare duality for twisted equivariant in the context of proper and discrete actions and the Baum-Connes Conjecture. We use a spectral sequence proposed by C. Dwyer and previous work by…

K-Theory and Homology · Mathematics 2013-08-23 Noe Barcenas , Mario Velasquez

I use local differential geometric techniques to prove that the algebraic cycles in certain extremal homology classes in Hermitian symmetric spaces are either rigid (i.e., deformable only by ambient motions) or quasi-rigid (roughly…

Differential Geometry · Mathematics 2007-05-23 Robert L. Bryant

We prove that for any field k of characteristic p>0, any separated scheme X of finite type over k, and any overconvergent F-isocrystal E over X, the rigid cohomology H^i(X, E) and rigid cohomology with compact supports H^i_c(X,E) are finite…

Algebraic Geometry · Mathematics 2007-05-23 Kiran S. Kedlaya

We prove a rigidity theorem in Poisson geometry around compact Poisson submanifolds, using the Nash-Moser fast convergence method. In the case of one-point submanifolds (fixed points), this immediately implies a stronger version of Conn's…

Differential Geometry · Mathematics 2015-02-02 Ioan Marcut

We study algebraic varieties parametrized by topological spaces and enlarge the domains of Lawson homology and morphic cohomology to this category. We prove a Lawson suspension theorem and splitting theorem. A version of Friedlander-Lawson…

Algebraic Geometry · Mathematics 2012-01-04 J. H. Teh

Let $A$ be a commutative ring, and assume every non-trivial ideal of $A$ has finite-index. We show that if ${\rm{SL}}_n(A)$ has bounded elementary generation then every conjugation-invariant norm on it is either discrete or precompact. If…

Group Theory · Mathematics 2025-04-07 Leonid Polterovich , Yehuda Shalom , Zvi Shem-Tov

We define, for a regular scheme $S$ and a given field of characteristic zero $\KK$, the notion of $\KK$-linear mixed Weil cohomology on smooth $S$-schemes by a simple set of properties, mainly: Nisnevich descent, homotopy invariance,…

Algebraic Geometry · Mathematics 2012-03-20 Denis-Charles Cisinski , Frédéric Déglise

Consider a Hamiltonian action of a compact Lie group on a symplectic manifold which has the strong Lefschetz property. We establish an equivariant version of the Merkulov-Guillemin $d\delta$-lemma and an improved version of the…

Symplectic Geometry · Mathematics 2007-05-23 Yi Lin , Reyer Sjamaar

Equivariant elliptic cohomology with complex coefficients was defined axiomatically by Ginzburg, Kapranov and Vasserot and constructed by Grojnowski. We give an invariant definition of S^1-equivariant elliptic cohomology, and use it to give…

Algebraic Topology · Mathematics 2007-05-23 Ioanid Rosu

We prove that Schubert and Richardson varieties in flag manifolds are uniquely determined by their equivariant cohomology classes, as well as a stronger result that replaces Schubert varieties with closures of Bialynicki-Birula cells under…

Algebraic Geometry · Mathematics 2025-08-27 Anders S. Buch , Pierre-Emmanuel Chaput , Nicolas Perrin

In the present paper we introduce and study the notion of an equivariant pretheory: basic examples include equivariant Chow groups, equivariant K-theory and equivariant algebraic cobordism. To extend this set of examples we define an…

Algebraic Geometry · Mathematics 2013-02-07 Stefan Gille , Kirill Zainoulline