$F$-等晶体的抛物性猜想

A note on rank 1 log extendable isocrystals on simply connected open varieties

In 2010 de Jong proposed a $p$-adic version of Gieseker's conjecture: if $X$ is a smooth, simply connected projective variety, then any isocrystal on $X$ is constant. This was proven by Esnault and Shiho under some additional assumptions. We show that the conjecture holds in the case of a non-proper variety with trivial tame fundamental group and for rank 1 log extendable isocrystals.

Incarnations of Berthelot's conjecture

In this article we give a survey of the various forms of Berthelot's conjecture and some of the implications between them. By proving some comparison results between pushforwards of overconvergent isocrystals and those of arithmetic $\mathcal{D}$-modules, we manage to deduce some cases of the conjecture from Caro's results on the stability of overcoherence under pushforward via a smooth and proper morphism of varieties. In particular, we show that Ogus' convergent pushforward of an overconvergent $F$-isocrystal under a smooth and projective morphism is overconvergent.

Rigid connections and $F$-isocrystals

An irreducible integrable connection $(E,\nabla)$ on a smooth projective complex variety $X$ is called rigid if it gives rise to an isolated point of the corresponding moduli space $\mathcal{M}_{dR}(X)$. According to Simpson's motivicity conjecture, irreducible rigid flat connections are of geometric origin, that is, arise as subquotients of a Gauß-Manin connection of a family of smooth projective varieties defined on an open dense subvariety of $X$. In this article we study mod $p$ reductions of irreducible rigid connections and establish results which confirm Simpson's prediction. In particu…

Maximal tori of monodromy groups of $F$-isocrystals and an application to abelian varieties

Let $X_0$ be a smooth geometrically connected variety defined over a finite field $\mathbb F_q$ and let $\mathcal E_0^{\dagger}$ be an irreducible overconvergent $F$-isocrystal on $X_0$. We show that if a subobject of minimal slope of the associated convergent $F$-isocrystal $\mathcal E_0$ admits a non-zero morphism to $\mathcal O_{X_0}$ as a convergent isocrystal, then $\mathcal E_0^{\dagger}$ is isomorphic to $\mathcal O^{\dagger}_{X_0}$ as an overconvergent isocrystal. This proves a special case of a conjecture of Kedlaya. The key ingredient in the proof is the study of the monodromy group …

Images directes III: F-isocristaux surconvergents

This article is the third one of a series of three articles devoted to direct images of isocrystals: here we consider overconvergent isocrystals with Frobenius structure. For a liftable proper smooth morphism we establish the overconvergence of direct images, owing to the first article and the existence of lifts of Frobenius. This result partially answers a conjecture of Berthelot on the overconvergence of direct images of overconvergent F-isocrystals under a proper smooth morphism.

Hodge 型 Shimura 簇上的 Hecke 轨道

Hecke orbits on Shimura varieties of Hodge type

本文在奇素数好约化条件下证明 Hodge 型 Shimura 簇的 Chai–Oort Hecke 轨道猜想，核心工具包括几何来源 F-等晶体的局部单值群结果、非交换 Serre–Tate 坐标及 Cartier–Witt 栈。

Langlands program for $p$-adic coefficients and the petites camarades conjecture

In this paper, we prove that, if Deligne's "petites camarades conjecture" holds, then a Langlands type correspondence holds also for $p$-adic coefficients on a smooth curve over a finite field. We also prove that any overconvergent $F$-isocrystal of rank less than or equal to 2 on a smooth variety is $ι$-mixed.

Images directes I: Espaces rigides analytiques et images directes

This article is the first one of a series of three articles devoted to direct images of isocrystals: here we consider isocrystals without Frobenius structure; in the second one (resp. the third one), we will introduce a Frobenius structure in the convergent (resp. overconvergent) context. For a liftable proper smooth morphism we establish the overconvergence of direct images, owing to a base change theorem for a proper morphism between rigid analytic spaces. This result partially answers a conjecture of Berthelot on the overconvergence of direct images under a proper smooth morphism.

Fonctions L en géométrie rigide I: F-modules convergents ou surconvergents et conjecture de Dwork

This article is the first one of a series of three articles devoted to L-functions. In this one we give a definition of the L-functions of convergent or overconvergent F-modules with the help of Teichmüller liftings and we establish the meromorphy of the L-functions of convergent F-modules in the closed unit disk. Wan has established Dwork conjecture in a series of three articles; owing to an isogeny theorem of Katz, his proof reduces to the ordinary case: here we prove, on two explicit examples related to families of elliptic curves, that the slope filtration on an ordinary overconvergent F-m…