Nous construisons dans cet article les classes de Chern et les classes de cycles en cohomologie rigide. Nous démontrons par la suite que ces constructions vérifient bien les propriétés attendues. La cohomologie rigide est donc une cohomologie de Weil.
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...
The tempered fundamental group of a -adic analytic space classifies covers that are dominated by a topological cover (for the Berkovich topology) of a finite étale cover of the space. Here we construct cospecialization homomorphisms between versions of the tempered fundamental groups of the fibers of a smooth family of curves with semistable reduction. To do so, we will translate our problem in terms of cospecialization morphisms of fundamental groups of the log fibers of the log reduction and...