In this paper, we first study the local rings of a Berkovich analytic space
from the point of view of commutative algebra. We show that those rings are
excellent ; we introduce the notion of a an analytically separable extension of
non-archimedean complete fields (it includes the case of the finite separable
extensions, and also the case of any complete extension of a perfect complete
non-archimedean field) and show that the usual commutative algebra properties
(Rm, Sm, Gorenstein, Cohen-Macaulay, Complete Intersection) are stable under
analytically separable ground field extensions; we also establish a GAGA
principle with respect to those properties for any finitely generated scheme
over an affinoid algebra.
A second part of the paper deals with more global geometric notions : we
define, show the existence and establish basic properties of the irreducible
components of analytic space ; we define, show the existence and establish
basic properties of its normalization ; and we study the behaviour of
connectedness and irreducibility with respect to base change.Comment: This is the (almost) definitive version of the paper, which is going
to appear in "Annales de l'institut Fourier
