Introduction à l’analyse -adique
The Kolmogorov n-diameter of a bounded set B in a non-archimedean normed space, as defined by the first author in a previous paper, is studied in terms of the norms of orthogonal subsets of B with n + 1 points.
In set theory without the Axiom of Choice ZF, we prove that for every commutative field , the following statement : “On every non null -vector space, there exists a non null linear form” implies the existence of a “-linear extender” on every vector subspace of a -vector space. This solves a question raised in Morillon M., Linear forms and axioms of choice, Comment. Math. Univ. Carolin. 50 (2009), no. 3, 421-431. In the second part of the paper, we generalize our results in the case of spherically...