English
Related papers

Related papers: Once again on an analogue of the certain Voevodsky…

200 papers

The category of framed correspondences $Fr_*(k)$, framed presheaves and framed sheaves were invented by Voevodsky in his unpublished notes [12]. Based on the theory, framed motives are introduced and studied in [7]. The main aim of this…

Algebraic Geometry · Mathematics 2018-01-30 Grigory Garkusha , Ivan Panin

In this paper, we study the Nisnevich sheafification $\mathcal{H}^1_{\acute{e}t}(G)$ of the presheaf associating to a smooth scheme the set of isomorphism classes of $G$-torsors, for a reductive group $G$. We show that if $G$-torsors on…

Algebraic Geometry · Mathematics 2021-04-14 Elden Elmanto , Girish Kulkarni , Matthias Wendt

The strictly homotopy invariance of the associated Nisnevish sheave $\widetilde{\mathcal F}_{Nis}$ of a homotopy invariant presheave $\mathcal F$ with GW-transfers (or Witt-transfers) on the category of smooth varieties over a prefect field…

Algebraic Geometry · Mathematics 2018-01-23 Andrei Druzhinin

It is proved that for any cohomology theory A in the sense of [PS] and any essentially k-smooth semi-local X the Cousin complex is exact. As a consequence we prove that for any integer n the Nisnevich sheaf A^n_Nis, associated with the…

Algebraic Geometry · Mathematics 2017-07-07 Ivan Panin

Let k be a field. Let G be an absolutely almost simple simply connected k-group of type A_l, l>=2, or D_l, l>=4, containing a 2-dimensional split torus. If G is of type D_l, assume moreover that char k is different from 2. We show that the…

K-Theory and Homology · Mathematics 2015-12-01 Anastasia Stavrova

Let $X/K$ be a smooth projective variety defined over a number field, and let $f:X\to{X}$ be a morphism defined over $K$. We formulate a number of statements of varying strengths asserting, roughly, that if there is at least one point…

Number Theory · Mathematics 2024-05-31 Hector Pasten , Joseph H. Silverman

For a reductive group $G$ over a ring $A$, its affine Grassmannian $\mathrm{Gr}_G$ plays important roles in a wide range of subjects and is typically defined as the \'etale sheafification of the presheaf quotient $LG/L^+G$ of the loop group…

Algebraic Geometry · Mathematics 2025-05-20 Kestutis Cesnavicius

Given a perfect field of exponential characteristic $e$ and a functor $f:\mathcal A\to\mathcal B$ between symmetric monoidal strict $V$-categories of correspondences satisfying the cancellation property such that the induced morphisms of…

Algebraic Geometry · Mathematics 2018-11-13 Grigory Garkusha

We relate R-equivalence on tori with Voevodsky's theory of homotopy invariant Nisnevich sheaves with transfers and effective motivic complexes.

Algebraic Geometry · Mathematics 2015-02-03 Bruno Kahn

The rigidity theorem for homotopy invariant presheaves with Witt-transfers on the category of smooth affine varieties over a field $k$ with characteristic not equal to 2 is proved. Namely for such a presheaf $\mathcal F$ the isomorphism…

Algebraic Geometry · Mathematics 2017-04-14 Andrei Druzhinin

We provide a new proof of the following result: Let $X$ be a variety of finite type over an algebraically closed field $k$ of characteristic 0, let $Z\subset X$ be a proper closed subset. There exists a modification $f:X_1 \rar X$, such…

alg-geom · Mathematics 2015-06-30 Dan Abramovich , Johan de Jong

We study the \'etale sheafification of algebraic K-theory, called \'etale K-theory. Our main results show that \'etale K-theory is very close to a noncommutative invariant called Selmer K-theory, which is defined at the level of categories.…

K-Theory and Homology · Mathematics 2021-04-13 Dustin Clausen , Akhil Mathew

We develop some of the foundations of affinoid pre-adic spaces without Noetherian or finiteness hypotheses. We give some explicit examples of non-adic affinoid pre-adic spaces (including a locally perfectoid one). On the positive side, we…

Number Theory · Mathematics 2015-09-15 Kevin Buzzard , Alain Verberkmoes

Let $X$ be a smooth proper variety over a field $k$ and suppose that the degree map $\mathrm{CH}_0(X \otimes_k K) \to \mathbb{Z}$ is isomorphic for any field extension $K/k$. We show that $G(\mathrm{Spec} k) \to G(X)$ is an isomorphism for…

Algebraic Geometry · Mathematics 2021-09-09 Wataru Kai , Shusuke Otabe , Takao Yamazaki

Let G|V, G connected, reductive over C, be a stable polar representation in the sense of [DK], satisfying some mild additional hypotheses. Given a G-equivariant rank one local system L on the general fiber of the quotient map f : V --> V/G,…

Algebraic Geometry · Mathematics 2025-09-19 Mikhail Grinberg , Kari Vilonen , Ting Xue

Over a field of characteristic zero, we establish the homotopy invariance of the Nisnevich cohomology of homotopy invariant presheaves with oriented weak transfers, and the agreement of Zariski and Nisnevich cohomology for such presheaves.…

K-Theory and Homology · Mathematics 2014-05-02 Joseph Ross

We generalise Kahn, Miyazaki, Saito, Yamazaki's theory of modulus pairs to pairs $(X, D)$ consisting of a qcqs scheme $X$ equipped with an effective Cartier divisor $D$ representing a ramification bound. We develop theories of sheaves on…

Algebraic Geometry · Mathematics 2021-06-25 Shane Kelly , Hiroyasu Miyazaki

Given a stratified variety X with strata satisfying a cohomological parity-vanishing condition, we define and show the uniqueness of "parity sheaves", which are objects in the constructible derived category of sheaves with coefficients in…

Representation Theory · Mathematics 2016-03-31 Daniel Juteau , Carl Mautner , Geordie Williamson

We complete the proof of the Nisnevich conjecture in equal characteristic: for a smooth algebraic variety $X$ over a field $k$, a $k$-smooth divisor $D \subset X$, and a reductive $X$-group $G$ whose base change $G_D$ is totally isotropic,…

Algebraic Geometry · Mathematics 2025-12-09 Kestutis Cesnavicius

For a large class of cohomology theories, we prove that refined unramified cohomology is canonically isomorphic to the hypercohomology of a natural truncated complex of Zariski sheaves. This generalizes a classical result of Bloch and Ogus…

Algebraic Geometry · Mathematics 2024-10-14 Theodosis Alexandrou , Stefan Schreieder
‹ Prev 1 2 3 10 Next ›