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Related papers: Compatible systems of $\ell$-adic sheaves

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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 $X$ be a smooth variety over a finite field $\mathbb{F}_q$. Let $\ell$ be a rational prime number invertible in $\mathbb{F}_q$. For an $\ell$-adic sheaf $\mathcal{F}$ on $X$, we construct a cycle supported on the singular support of…

Algebraic Geometry · Mathematics 2026-04-06 Daichi Takeuchi

We give a new definition of the derived category of constructible $\ell$-adic sheaves on a scheme, which is as simple as the geometric intuition behind them. Moreover, we define a refined fundamental group of schemes, which is large enough…

Algebraic Geometry · Mathematics 2014-12-18 Bhargav Bhatt , Peter Scholze

We show that certain ramification invariants associated to a compatible system of $\ell$-adic sheaves on a curve are independent of $\ell$.

Number Theory · Mathematics 2017-04-17 Chris Hall

In this article, we define the l-adic homology for a morphism of schemes satisfying certain finiteness conditions. This homology has these functors similar to the Chow groups: proper push-forward, flat pull-back, base change, cap-product,…

Algebraic Geometry · Mathematics 2008-10-23 Ting Li

We study the compatibility with proper push-forward of the characteristic cycles of a constructible complex on a smooth variety over a perfect field.

Algebraic Geometry · Mathematics 2020-03-24 Takeshi Saito

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

For a smooth morphism $f: X \longrightarrow \Sigma$ of real analytic manifolds and an $\mathbb{R}$-constructible sheaf $F$ on $X$ satisfying some condition, we define a family of Lagrangian cycles parameterized by $\Sigma$ that we call the…

Algebraic Geometry · Mathematics 2026-03-17 Ren Fernandes , Kazuki Kudomi , Kiyoshi Takeuchi

Let $S$ be a noetherian scheme and $f\colon X\to S$ be a smooth morphism of relative dimension 1. For a locally constant sheaf on the complement of a divisor in $X$ at over $S$, Deligne and Laumon proved that the universal local acyclicity…

Algebraic Geometry · Mathematics 2020-03-17 Daichi Takeuchi

Congruence families, i.e., $\ell$-adic convergence for well-defined arithmetic subsequences, is a commonplace phenomenon for the coefficients of modular forms. Such families superficially resemble one another, but they often vary…

Number Theory · Mathematics 2024-03-19 Nicolas Allen Smoot

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

We introduce a notion of constructibility for \'etale sheaves with torsion coefficients over a suitable class of adic spaces. This notion is related to the classical notion of constructibility for schemes via the nearby cycles functor. We…

Algebraic Geometry · Mathematics 2017-07-13 Ildar Gaisin , John Welliaveetil

For a scheme $X$ separated and of finite type over an excellent regular scheme $S$, we define wildly compatible systems of constructible sheaves of modules over finite fields on $X$ for certain vector spaces $V$. The main result is that for…

Algebraic Geometry · Mathematics 2019-02-18 Ning Guo

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

Deligne conjectured that a single l-adic lisse sheaf on a normal variety over a finite field can be embedded into a compatible system of l'-adic lisse sheaves with various l'. Drinfeld used Lafforgue's result as an input and proved this…

Number Theory · Mathematics 2017-02-01 Koji Shimizu

Continuation of algebraic structures in families of dynamical systems is described using category theory, sheaves, and lattice algebras. Well-known concepts in dynamics, such as attractors or invariant sets, are formulated as functors on…

Dynamical Systems · Mathematics 2022-07-14 K. Dowling , W. D. Kalies , R. C. A. M. Vandervorst

We study some properties of the characteristic cycle of a constructible complex on a smooth variety over a perfect field, push-forward and product.

Algebraic Geometry · Mathematics 2016-07-14 Takeshi Saito

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

We prove a purely local form of a result of Saito and Yatagawa. They proved that the characteristic cycle of a constructible \'etale sheaf is determined by wild ramification of the sheaf along the boundary of a compactification. But they…

Algebraic Geometry · Mathematics 2021-10-20 Hiroki Kato

The category of coherent sheaves over a noetherian scheme is very important for studying the properties of a given scheme. For noetherian schemes it is a well-known fact that the topology can be fully recovered from the corresponding…

Algebraic Geometry · Mathematics 2025-07-08 Ron Held
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