English
Related papers

Related papers: A note on effective descent for overconvergent iso…

200 papers

In this article, we introduce the notion of a functor on coarse spaces being coarsely excisive- a coarse analogue of the notion of a functor on topological spaces being excisive. Further, taking cones, a coarsely excisive functor yields a…

Algebraic Topology · Mathematics 2014-10-01 Paul D. Mitchener

A characteristic property of cohomology with compact support is the long exact sequence that connects the compactly supported cohomology groups of a space, an open subspace and its complement. Given an arbitrary cohomology theory of…

Algebraic Geometry · Mathematics 2023-08-30 Josefien Kuijper

We determine a strong form of the decomposition theorem for proper toric maps over finite fields.

Algebraic Geometry · Mathematics 2015-06-12 Mark Andrea de Cataldo

In this paper, we establish a criterion for an overconvergent isocrystal on a smooth variety over a field of characteristic $p>0$ to extend logarithmically to its smooth compactification whose complement is a strict normal crossing divisor.…

Number Theory · Mathematics 2009-06-03 Atsushi Shiho

We give an abstract criterion for pasting pseudofunctors on two subcategories of a category into a pseudofunctor on the whole category. As an application we extend the variance theory of the twisted inverse image $(-)^!$ over schemes to…

Algebraic Geometry · Mathematics 2007-05-23 Suresh Nayak

Let $\mathbb{A}$ be a $2$-category with suitable opcomma objects and pushouts. We give a direct proof that, provided that the codensity monad of a morphism $p$ exists and is preserved by a suitable morphism, the factorization given by the…

Category Theory · Mathematics 2023-11-13 Fernando Lucatelli Nunes

We prove a version of faithfully flat descent in rigid analytic geometry, for almost perfect complexes and without finiteness assumptions on the rings involved. This extends results of Drinfeld for vector bundles.

Algebraic Geometry · Mathematics 2021-09-14 Akhil Mathew

Given a smooth affine curve X over a field k of positive characteristic, and an overconvergent F-isocrystal on X, we prove after replacing k by a finite purely inseparable extension, there exists a finite separable cover of X, the pullback…

Number Theory · Mathematics 2007-05-23 Kiran S. Kedlaya

We prove model completeness for the theory of addition and the Frobenius map for certain subrings of rational functions in positive characteristic. More precisely: Let $p$ be a prime number, $\mathbb{F}_{p}$ the prime field with $p$…

Logic · Mathematics 2021-07-26 Dimitra Chompitaki , Manos Kamarianakis , Thanases Pheidas

We investigate how the \'etale fundamental group controls local systems in characteristic $p$, namely $F$-divided sheaves. In analogy with Grothendieck-Malcev's results for discrete groups, we show that if a morphism $f \colon Y \to X$ of…

Algebraic Geometry · Mathematics 2025-09-30 Xiaotao Sun , Lei Zhang

In the framework of Berthelot's theory of arithmetic $\mathcal{D}$-modules, we prove that Berthelot's characteristic variety associated with a holonomic $\mathcal{D}$-modules endowed with a Frobenius structure has pure dimension. As an…

Algebraic Geometry · Mathematics 2017-02-07 Daniel Caro

For a conformal vector field on a closed, real-analytic, Lorentzian manifold we prove that the flow is locally isometric -- that it preserves a metric in the conformal class on a neighborhood of any point -- or the metric is everywhere…

Differential Geometry · Mathematics 2025-11-06 Sorin Dumitrescu , Charles Frances , Karin Melnick , Vincent Pecastaing , Abdelghani Zeghib

Given a group, we construct a fundamental additive functor on its orbit category. We prove that any isomorphism conjecture valid for this fundamental isomorphism functor holds for all additive functors, like K-theory, cyclic homology,…

K-Theory and Homology · Mathematics 2012-02-29 Paul Balmer , Goncalo Tabuada

We prove that for an indecomposable convergent or overconvergent F-isocrystal on a smooth irreducible variety over a perfect field of characteristic p, the gap between consecutive slopes at the generic point cannot exceed 1. (This may be…

Algebraic Geometry · Mathematics 2018-10-02 Vladimir Drinfeld , Kiran Kedlaya

We generalise a theorem on the existence of Frobenius isocrystal and Fontaine-Laffaille module structures on rigid flat connections to the non-proper setting. The proof is based on a new strategy of a point-set topological flavour, which…

Algebraic Geometry · Mathematics 2023-11-23 Hélène Esnault , Michael Groechenig

We introduce a valuation-theoretic approach to the problem of semistable reduction (i.e., existence of logarithmic extensions on suitable covers) of overconvergent isocrystals with Frobenius structure. The key tool is the quasicompactness…

Number Theory · Mathematics 2014-01-14 Kiran S. Kedlaya

Let $G$ be a connected reductive group over a non-archimedean local field $F$ of residue characteristic $p$, $P$ be a parabolic subgroup of $G$, and $R$ be a commutative ring. When $R$ is artinian, $p$ is nilpotent in $R$, and…

Representation Theory · Mathematics 2018-03-28 Julien Hauseux

We propose a conjectural extension to positive characteristic case of a well known Deligne's theorem on the existence of super fiber functors. We prove our conjecture in the special case of semisimple categories with finitely many…

Category Theory · Mathematics 2015-03-06 Victor Ostrik

We prove the overholonomicity of overconvergent $F$-isocrystals over smooth varieties. This implies that the notions of overholonomicity and devissability in overconvergent $F$-isocrystals are equivalent. Then the overholonomicity is stable…

Algebraic Geometry · Mathematics 2008-03-17 Daniel Caro , Nobuo Tsuzuki

Let $k$ be a perfect field of positive characteristic and $Z$ an effective Cartier divisor in the projective line over $k$ with complement $U$. In this note, we establish some results about the formal deformation theory of overconvergent…

Algebraic Geometry · Mathematics 2020-11-26 Shishir Agrawal