Comparaison des facteurs duaux des isocristaux surconvergents
Soit un modèle entier en un premier d’une variété de Shimura de type PEL, ayant bonne réduction associée à un groupe réductif . On peut associer aux -représentations du groupe deux types de faisceaux : des cristaux sur la fibre spéciale de , et des systèmes locaux pour la topologie étale sur la fibre générique. Nous établissons un théorème de comparaison entre la cohomologie de ces deux types de faisceaux.
We show that the natural morphism between the fundamental group scheme of the generic fiber of a scheme over a connected Dedekind scheme and the generic fiber of the fundamental group scheme of is always faithfully flat. As an application we give a necessary and sufficient condition for a finite, dominated pointed -torsor over to be extended over . We finally provide examples where is an isomorphism.
We prove a comparison theorem between Fourier transform without support and and Fourier transform with compact support in the context of arithmetic -modules.
We present a panorama of comparison theorems between algebraic and analytic De Rham cohomology with algebraic connections as coefficients. These theorems have played an important role in the development of -module theory, in particular in the study of their ramification properties (irregularity...). In part I, we concentrate on the case of regular coefficients and sketch the new proof of these theorems given by F. Baldassarri and the author, which is of elementary nature and unifies the complex...