-convexity and duality for almost summing operators.
Kadec norms and Borel sets in a Banach space
We introduce a property for a couple of topologies that allows us to give simple proofs of some classic results about Borel sets in Banach spaces by Edgar, Schachermayer and Talagrand as well as some new results. We characterize the existence of Kadec type renormings in the spirit of the new results for LUR spaces by Moltó, Orihuela and Troyanski.
Kolmogorov diameters and orthogonality in non-Archimedean normed spaces.
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.
König-Witstock quasi-norms on quasi-Banach spaces.