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Related papers: A remark on Deligne's finiteness theorem

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Revised: just some typos, reorganized a bit the article. It will be published in the VIASM Annual meeting, Hanoi. We give a detailed account of Deligne's letter to Drinfeld dated June 18, 2011, in which he shows that there are finitely many…

Algebraic Geometry · Mathematics 2012-12-03 Hélène Esnault , Moritz Kerz

We show that compatible systems of $\ell$-adic sheaves on a scheme of finite type over the ring of integers of a local field are compatible along the boundary up to stratification. This extends a theorem of Deligne on curves over a finite…

Algebraic Geometry · Mathematics 2019-11-13 Qing Lu , Weizhe Zheng

Let K and F be complete discrete valuation fields of residue characteristic p>0. Let m be a positive integer no more than their absolute ramification indices. Let s and t be their uniformizers. Let L/K and E/F be finite extensions such that…

Number Theory · Mathematics 2019-02-20 Shin Hattori

As an application of P. Delgine's theorem (Esnault and Kerz in Acta Math. Vietnam. 37:531-562, 2012) on a finiteness of $l$-adic sheaves on a variety over a finite field, we show the finiteness of \'etale coverings of such a variety with…

Number Theory · Mathematics 2016-12-12 Toshiro Hiranouchi

Given a coherent sheaf E on a scheme of finite type X over a perfect field, we introduce a category of complexes of \'etale sheaves on X with logarithmic conductors bounded by E and study its compatibilities with finite push-forward.

Algebraic Geometry · Mathematics 2026-04-15 Haoyu Hu , Jean-Baptiste Teyssier

We prove that $\bar {\mathbb Q}_\ell$-local systems of bounded rank and ramification on a smooth variety $X$ defined over an algebraically closed field $k$ of characteristic $p\neq \ell$ are tamified outside of codimension $2$ by a finite…

Algebraic Geometry · Mathematics 2021-08-03 Hélène Esnault , Vasudevan Srinivas

We show that bounding ramification at infinity bounds fierce ramification. This answers positively a question of Deligne posed to the first named author.

Algebraic Geometry · Mathematics 2018-12-11 Hélène Esnault , Lars Kindler , Vasudevan Srinivas

We apply methods of derived and non-commutative algebraic geometry to understand ramification phenomena on arithmetic schemes. As an application, we prove the Deligne-Milnor conjecture and, in the pure characteristic case, a generalization…

Algebraic Geometry · Mathematics 2024-10-04 Dario Beraldo , Massimo Pippi

This article is devoted to studying the ramification of Galois torsors and of $\ell$-adic sheaves in characteristic $p>0$ (with $\ell\not=p$). Let $k$ be a perfect field of characteristic $p>0$, $X$ be a smooth, separated and quasi-compact…

Algebraic Geometry · Mathematics 2011-10-25 Ahmed Abbes , Takeshi Saito

We define generalizations of classical invariants of wild ramification for coverings on a variety of arbitrary dimension over a local field. For an l-adic sheaf, we define its Swan class as a 0-cycle class supported on the wild ramification…

Number Theory · Mathematics 2013-05-20 Kazuya Kato , Takeshi Saito

In this article, we prove that the Swan conductor of an \'etale sheaf on a smooth variety defined by Abbes and Saito's logarithmic ramification theory can be computed by its classical Swan conductors after restricting it to curves. It…

Algebraic Geometry · Mathematics 2017-04-18 Haoyu Hu

Deligne's regularity criterion for an integrable connection $\nabla$ on a smooth complex algebraic variety $X$ says that $\nabla$ is regular along the irreducible divisors at infinity in some fixed normal compactification of $X$ if and only…

Algebraic Geometry · Mathematics 2007-05-23 Yves André , Francesco Baldassarri

For a constructible \'etale sheaf on a smooth variety of positive characteristic ramified along an effective divisor, the largest slope in Abbes and Saito's ramification theory of the sheaf gives a divisor with rational coefficients called…

Algebraic Geometry · Mathematics 2022-04-27 Haoyu Hu

Deligne's regularity criterion for an integrable connection $\nabla$ on a smooth complex algebraic variety $X$ says that $\nabla$ is regular along the irreducible divisors at infinity in some fixed normal compactification of $X$ if and only…

Algebraic Geometry · Mathematics 2007-05-23 Yves André

We generalize Deligne's approach to tame geometric class field theory to the case of a relative curve, with arbitrary ramification.

Algebraic Geometry · Mathematics 2019-08-21 Quentin Guignard

One extends P. Deligne's notion of integrality over a finite field for a $\ell$-adic sheaf on a scheme of finite type over a local field with finite residue field. One shows that this integrality notion is preserved by $Rf_!$, as it is over…

Number Theory · Mathematics 2007-05-23 Pierre Deligne , Hélène Esnault

Using twisted nearby cycles, we define a new notion of slopes for complex holonomic D-modules. We prove a boundedness result for these slopes, study their functoriality and use them to characterize regularity. For a family of (possibly…

Algebraic Geometry · Mathematics 2019-02-20 Jean-Baptiste Teyssier

A finite \'etale map between irreducible, normal varieties is called tame, if it is tamely ramified with respect to all partial compactifications whose boundary is the support of a strict normal crossings divisor. We prove that if the…

Algebraic Geometry · Mathematics 2016-06-29 Lars Kindler

The goal of this paper is to motivate a boundedness conjecture on nearby slopes of $\ell$-adic sheaves in positive characteristic, and to prove it for smooth curves. For a constructible $\ell$-adic sheaf, we prove the finiteness of the set…

Algebraic Geometry · Mathematics 2015-06-10 Jean-Baptiste Teyssier

Let X be a smooth variety over $F_p$. Let E be a number field. For each nonarchimedean place $\lambda$ of E prime to p consider the set of isomorphism classes of irreducible lisse $\bar{E}_{\lambda}$-sheaves on X with determinant of finite…

Number Theory · Mathematics 2018-03-02 Vladimir Drinfeld
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