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Related papers: Finite Chow-Witt correspondences

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We show that semi-infinite cohomology of a finite dimensional graded algebra (satisfying some additional requirements) are a particular case of a general categorical construction. The motivating example is provided by small quantum groups…

Representation Theory · Mathematics 2007-05-23 Roman Bezrukavnikov

Let $G$ be a finite group and $K$ a finite field of characteristic $2$. Denote by $t$ the $2$-rank of the commutator factor group $G/G'$ and by $s$ the number of self-dual simple $KG$-modules. Then the Witt group of equivariant quadratic…

Number Theory · Mathematics 2022-08-26 Gabriele Nebe , Richard Parker

For a perfect field $k$, we construct a triangulated category of mixed motives over $k[t]/{(t^{m+1})}$. The ext groups in this category are given by higher Chow groups, and additive higher Chow groups.

Algebraic Geometry · Mathematics 2010-01-29 Amalendu Krishna , Jinhyun Park

Let $G$ be a residually finite, good group of finite virtual cohomological dimension. We prove that the natural monomorphism $G\hookrightarrow\hat{G}$ induces a bijective correspondence between conjugacy classes of finite $p$-subgroups of…

Group Theory · Mathematics 2024-10-29 Marco Boggi , Pavel Zalesskii

Let $R$ be a discrete valuation ring of mixed characteristics $(0,p)$, with finite residue field $k$ and fraction field $K$, let $k'$ be a finite extension of $k$, and let $X$ be a regular, proper and flat $R$-scheme, with generic fibre…

Algebraic Geometry · Mathematics 2011-09-13 Pierre Berthelot , Hélène Esnault , Kay Rülling

It is a classical result of Powell that pure mapping class groups of connected, orientable surfaces of finite type and genus at least three are perfect. In stark contrast, we construct nontrivial homomorphisms from infinite-genus mapping…

Geometric Topology · Mathematics 2024-03-11 Javier Aramayona , Priyam Patel , Nicholas G. Vlamis

We construct the Langlands correspondence for connected reductive groups over finite fields, which we call the finite Langlands correspondence. We discuss also its relation with the categorical local Langlands correspondence.

Number Theory · Mathematics 2025-08-22 Naoki Imai

We initiate a systematic study of the perfection of affine group schemes of finite type over fields of positive characteristic. The main result intrinsically characterises and classifies the perfections of reductive groups, and obtains a…

Representation Theory · Mathematics 2024-11-20 Kevin Coulembier , Geordie Williamson

Let A be a finitely generated algebra over a field K of characteristic p >0. We introduce a subring of the ring of Witt vectors W(A). We call it the ring of overconvergent Witt vectors. We prove that on a scheme X of finite type over K the…

Algebraic Geometry · Mathematics 2010-08-03 Christopher Davis , Andreas Langer , Thomas Zink

We explicitly calculate some Gromov--Witten correspondences determined by maps of labeled curves of genus zero to the moduli spaces of labeled curves of genus zero. We consider these calculations as the first step towards studying the…

Algebraic Geometry · Mathematics 2012-12-18 Yuri I. Manin , Maxim Smirnov

We prove several surjectivity criteria for $p$-adic representations. In particular, we classify all adjoint and simply connected group schemes $G$ over the Witt ring $W(k)$ of a finite field $k$ such that the epimorphism…

Number Theory · Mathematics 2007-05-23 Adrian Vasiu

We study the structure of the rational motivic stable homotopy category over general base schemes. Our first class of results concerns the six operations: we prove absolute purity, stability of constructible objects, and…

Algebraic Geometry · Mathematics 2021-03-15 Frédéric Déglise , Jean Fasel , Adeel A. Khan , Fangzhou Jin

We introduce a notion of proper morphism for schematic finite spaces and prove the analogue of Grothendieck's finiteness theorem for it by means of the classic result for schemes and general descent arguments. This result also generalizes…

Algebraic Geometry · Mathematics 2023-05-22 Javier Sánchez González

We introduce in this work the notion of the category of pure $\mathbf{E}$-Motives, where $\mathbf{E}$ is a motivic strict ring spectrum and construct twisted $\mathbf{E}$-cohomology by using six functors formalism of J. Ayoub. In…

K-Theory and Homology · Mathematics 2017-04-26 Le Dang Thi Nguyen

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

Following [14], we compute the motivic cohomology ring of the Nisnevich classifying space of the unitary group associated to the standard split hermitian form of a quadratic extension. This provides us with subtle characteristic classes…

Algebraic Geometry · Mathematics 2022-08-08 Fabio Tanania

In this article we analyze the structure of $2$-categories of symmetric projective bimodules over a finite dimensional algebra with respect to the action of a finite abelian group. We determine under which condition the resulting…

Representation Theory · Mathematics 2019-04-12 Volodymyr Mazorchuk , Vanessa Miemietz , Xiaoting Zhang

Given a field $K$ equipped with a set of discrete valuations $V$, we develop a general theory to relate reduction properties of skew-hermitian forms over a quaternion $K$-algebra $Q$ to quadratic forms over the function field $K(Q)$…

Algebraic Geometry · Mathematics 2020-08-26 Srimathy Srinivasan

We compute the Chow-Witt rings of split quadrics over a field of characteristic not two. We even determine the full bigraded I-cohomology and Milnor-Witt cohomology rings, including twists by line bundles. The results on I-cohomology…

K-Theory and Homology · Mathematics 2019-09-02 Jens Hornbostel , Heng Xie , Marcus Zibrowius

We show that for any integer n and any field k of characteristic different from 2 there are at most finitely many isomorphism classes of quadratic morphisms from the projective line over k to itself with a finite postcritical orbit of size…

Algebraic Geometry · Mathematics 2013-08-27 Richard Pink