Local monodromy in non-archimedean analytic geometry
Soient un espace analytique affinoïde réduit sur un corps complet pour une valeur absolue non archimédienne, sa réduction canonique et un point de la variété algébrique affine . Ce travail décrit la singularité du point à l’aide d’objets associés à l’espace : la localisation formelle qui est une -algèbre noethérienne de spectre maximal et dont la réduction est ; un complété formel qui est une -algèbre noethérienne dont la réduction est . Les résultats essentiels sont obtenus...
We construct some locally unbounded topological fields having topologically nilpotent elements; this answers a question of Heine. The underlying fields are subfields of fields of formal power series. In particular, we get a locally unbounded topological field for which the set of topologically nilpotent elements is an open additive subgroup. We also exhibit a complete locally unbounded topological field which is a topological extension of the field of p-adic numbers; this topological field is a...
We give lower bounds on the number of effective divisors of degree with respect to the number of places of certain degrees of an algebraic function field of genus defined over a finite field. We deduce lower bounds for the class number which improve the Lachaud - Martin-Deschamps bounds and asymptotically reaches the Tsfasman-Vladut bounds. We give examples of towers of algebraic function fields having a large class number.