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Related papers: Witt groups of complex cellular varieties

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We compute the topological Witt groups of every complex flag manifold of ordinary type, and thus the interesting (i.e. torsion) part of the KO-groups of these manifolds. Equivalently, we compute Balmer's Witt groups of each flag variety of…

Algebraic Topology · Mathematics 2019-02-05 Tobias Hemmert

In this note, we show that the units in Grothendieck-Witt rings extend to an unramified strictly A^1-invariant sheaf of abelian groups on the category of smooth schemes. This implies that there is an A^1-local classifying space of spherical…

Algebraic Topology · Mathematics 2013-04-23 Matthias Wendt

Hermitian K-theory and Witt-theory are cellular in the sense of stable motivic homotopy theory over any base scheme without points of characteristic two.

Algebraic Topology · Mathematics 2016-03-17 Oliver Röndigs , Markus Spitzweck , Paul Arne Østvær

In arxiv:1602.04254, we have defined polynomial Witt vectors functor from vector spaces over a perfect field $k$ of positive characteristic $p$ to abelian groups. In this paper, we use polynomial Witt vectors to construct a functorial…

K-Theory and Homology · Mathematics 2016-04-07 D. Kaledin

In this paper we study the Witt groups of symmetric and anti-symmetric forms on perverse sheaves on a finite-dimensional topologically stratified space with even dimensional strata. We show that the Witt group has a canonical decomposition…

Algebraic Topology · Mathematics 2020-01-15 Jörg Schürmann , Jon Woolf

We advance the understanding of K-theory of quadratic forms by computing the slices of the motivic spectra representing hermitian K-groups and Witt-groups. By an explicit computation of the slice spectral sequence for higher Witt-theory, we…

K-Theory and Homology · Mathematics 2017-05-31 Oliver Röndigs , Paul Arne Østvær

We compute the $\mathbb{G}W$-spectrum (Karoubi--Grothendieck--Witt spectrum) of Grassmannians over divisorial schemes defined over fields of characteristic zero, and, as a corollary, determine their stabilized $\mathbb{L}$-theory spectrum.…

K-Theory and Homology · Mathematics 2026-03-24 Sunny Sood , Chunkai Xu

We prove localization and Zariski-Mayer-Vietoris for higher Grothendieck-Witt groups, alias hermitian $K$-groups, of schemes admitting an ample family of line-bundles. No assumption on the characteristic is needed, and our schemes can be…

K-Theory and Homology · Mathematics 2008-12-01 Marco Schlichting

We describe the Witt invariants of a Weyl group over a field $k_0$ by giving generators for the $W(k_0)$-module of Witt invariants, under the assumption that the characteristic of $k_0$ does not divide the order of the group. For the Weyl…

Rings and Algebras · Mathematics 2024-08-06 Tamar Blanks

Given a singular Schubert variety Z in a compact Hermitian symmetric space it is a longstanding question to determine when Z is homologous to a smooth variety Y. We identify those Schubert varieties for which there exist first-order…

Differential Geometry · Mathematics 2011-02-10 C. Robles , D. The

We complement our previous computation of the Chow-Witt rings of classifying spaces of special linear groups by an analogous computation for the general linear groups. This case involves discussion of non-trivial dualities. The computation…

Algebraic Geometry · Mathematics 2024-03-27 Matthias Wendt

We obtain a combinatorial expression for the coefficients of the boundary map of real isotropic and odd orthogonal Grassmannians providing a natural generalization of the formulas already obtained for Lagrangian and maximal isotropic…

Algebraic Topology · Mathematics 2023-03-10 Jordan Lambert , Lonardo Rabelo

We present type-independent computations of the KO-groups of full flag varieties, i.e. of quotient spaces G/T of compact Lie groups by their maximal tori. Our main tool is the identification of the Witt ring, a quotient of the KO-ring, of…

K-Theory and Homology · Mathematics 2015-02-18 Marcus Zibrowius

This paper investigates the Witt groups of triangulated categories of sheaves (of modules over a ring R in which 2 is invertible) equipped with Poincare-Verdier duality. We consider two main cases, that of perfect complexes of sheaves on…

Algebraic Topology · Mathematics 2007-08-28 Jonathan Woolf

We develop the Witt group for certain braided monoidal categories with duality. In case of a braided fusion category over an algebraically closed field of characteristic zero, we explicitly describe this structure. We then use this…

K-Theory and Homology · Mathematics 2014-12-11 Isar Goyvaerts , Ehud Meir

Classification results for complex Riemannian foliations are obtained. For open subsets of irreducible Hermitian symmetric spaces of compact type, where one has explicit control over the curvature tensor, we completely classify such…

Differential Geometry · Mathematics 2019-05-07 Thomas Murphy , Paul-Andi Nagy

The category of effective Grothendieck-Witt-motives $\mathbf{DM}^{GW}_{\mathrm{eff},-}(k)$ (and Witt-motives $\mathbf{DM}^W_{\mathrm{eff},-}(k)$) by Voevodsky-Suslin method starting with some category of GW-correspondences (and…

Algebraic Geometry · Mathematics 2018-03-30 Andrei Druzhinin

Using combinatorial properties of symmetric polynomials, we compute explicitly the Soergel modules for some permutations whose corresponding Schubert varieties are rationally smooth. We build from them diagram algebras whose module…

Representation Theory · Mathematics 2013-11-28 Antonio Sartori

Over a perfect field $k$ of characteristic $p > 0$, we construct a ``Witt vector cohomology with compact supports'' for separated $k$-schemes of finite type, extending (after tensorisation with $\mathbb{Q}$) the classical theory for proper…

Algebraic Geometry · Mathematics 2007-05-23 Pierre Berthelot , Spencer Bloch , Hélène Esnault

Witt group of real algebraic curves has been studied since Knebusch in 1970s. But few results are known if the base field is non-Archimedean except the hyperelliptic case by works of Parimala, Arason et al.. In this paper, we compute the…

Algebraic Geometry · Mathematics 2026-03-11 Nanjun Yang