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We introduce a notion of Gieseker stability for coherent sheaves on tame Deligne-Mumford stacks with projective moduli scheme and some chosen generating sheaf on the stack in the sense of Olsson and Starr \cite{MR2007396}. We prove that…

Algebraic Geometry · Mathematics 2009-09-22 Fabio Nironi

For any base field and integer $l$ invertible in $k$, we prove that $\Omega^\infty_{\mathbb{G}_m}$ and $\Omega^\infty_{\mathbb{P}^1}$ commute with hyper \'etale sheafification $L_{\acute{e}t}$ and Betti realization through infinite loop…

Algebraic Geometry · Mathematics 2024-08-20 Andrei Druzhinin , Ola Sande

We prove a new convergence result for the slice spectral sequence, following work by Levine and Voevodsky. This verifies a derived variant of Voevodsky's conjecture on convergence of the slice spectral sequence. This is, in turn, a…

K-Theory and Homology · Mathematics 2021-10-05 Tom Bachmann , Elden Elmanto , Paul Arne Østvær

We prove an effective stabilization result for the sheaf cohomology groups of line bundles on flag varieties parametrizing complete flags in k^n, as well as for the sheaf cohomology groups of polynomial functors applied to the cotangent…

Algebraic Geometry · Mathematics 2026-02-10 Claudiu Raicu , Keller VandeBogert

We define a one-dimensional family of "Euler" stability conditions on $\mathbb{P}^n$ which are conjectured to converge to Gieseker stability for coherent sheaves. Here, we focus on ${\mathbb P}^3$, first identifying Euler stability…

Algebraic Geometry · Mathematics 2022-01-03 Dapeng Mu

We study the process of $\ell$-adic completion of motivic sheaves. We observe that, in equal characteristic, when restricted to constructible objets, it is compatible with the six operations. This implies that one can reconstruct…

Algebraic Geometry · Mathematics 2025-04-25 Denis-Charles Cisinski

Let S be a Noetherian scheme and f:X -> S a proper morphism. By SGA 4 XIV, for any constructible sheaf F of Z/nZ-modules on X, the sheaves of Z/nZ-modules R^if_*F obtained by direct image (for the etale topology) are also constructible:…

Algebraic Geometry · Mathematics 2019-03-27 Fabrice Orgogozo

Let k be an algebraically closed field of characteristic p>0. Let W(k) be the ring of Witt vectors with coefficients in k. We prove a motivic conjecture of Milne that relates, in the case of abelian schemes, the \'etale cohomology with…

Number Theory · Mathematics 2012-01-25 Adrian Vasiu

Let X be a Noetherian scheme of finite dimension and denote by rho the (additive inverse of the) morphism in SH(X) from S to Gm corresponding to the unit -1. Here SH(X) denotes the motivic stable homotopy category. We show that the category…

K-Theory and Homology · Mathematics 2019-02-20 Tom Bachmann

V. Voevodsyky laid the groundwork of delooping motivic spaces in order to provide a new, more computation-friendly, construction of the stable motivic category $SH(k)$, G. Garkusha and I. Panin made that project a reality, while…

Algebraic Geometry · Mathematics 2020-03-17 Aleksei Tsybyshev

We prove the Gersten conjecture for $p$-adic \'etale Tate twists for a smooth scheme $X$ in mixed characteristic in the Nisnevich topology. Our main observation is that, while $p$-adic \'etale Tate twists are not $\mathbb A^1$-invariant,…

Algebraic Geometry · Mathematics 2024-11-06 Morten Lüders

In this paper, we initiate a study of motivic homotopy theory at infinity. We use the six functor formalism to give an intrinsic definition of the stable motivic homotopy type at infinity of an algebraic variety. Our main computational…

Algebraic Geometry · Mathematics 2021-04-08 Adrien Dubouloz , Frédéric Déglise , Paul Arne Østvær

This is the first of a series of papers, where we investigate hierarchies of generalized {L}\"{u}roth problems on the hierarchy of rationality, starting with the obvious hierarchy between the rationality and the ruledness. Our primary goal…

Algebraic Geometry · Mathematics 2022-10-31 Norihiko Minami

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

Let $f : X \rightarrow Y$ be a generically smooth nonconstant morphism between irreducible projective curves, defined over an algebraically closed field, which is \'etale on an open subset of $Y$ that contains both the singular locus of $Y$…

Algebraic Geometry · Mathematics 2024-01-04 Indranil Biswas , Manish Kumar , A. J. Parameswaran

We describe additive (unstable) operations from a theory A^* obtained from Algebraic Cobordism of M.Levine-F.Morel by change of coefficients to any oriented cohomology theory B^*. We prove that there is 1-to-1 correspondence between the set…

Algebraic Geometry · Mathematics 2017-11-15 Alexander Vishik

We establish a kind of "degree zero Freudenthal Gm-suspension theorem" in motivic homotopy theory. From this we deduce results about the conservativity of the P^1-stabilization functor. In order to establish these results, we show how to…

K-Theory and Homology · Mathematics 2022-01-12 Tom Bachmann

In this article, we give a construction of the (un-)stable motivic homotopy category of an algebraic stack in the spirit of Morel-Voevodsky. We prove that this new construction agrees with the stable motivic homotopy category defined by…

Algebraic Geometry · Mathematics 2025-11-04 Neeraj Deshmukh , Felix Sefzig

In this paper we prove the Rigidity Theorem for motives of rigid analytic varieties over a non-Archimedean valued field $K$. We prove this theorem both for motives with transfers and without transfers in a relative setting. Applications…

Algebraic Geometry · Mathematics 2023-06-22 Federico Bambozzi , Alberto Vezzani

We combine several mini miracles to achieve an elementary understanding of infinite loop spaces and very effective spectra in the algebro-geometric setting of motivic homotopy theory. Our approach combines $\Gamma$-spaces and framed…

Algebraic Geometry · Mathematics 2022-04-22 Grigory Garkusha , Ivan Panin , Paul Arne Østvær