Amalgamations of classes of Banach spaces with a monotone basis
Tom 234 / 2016
Streszczenie
It was proved by Argyros and Dodos that, for many classes $ \mathcal {C} $ of separable Banach spaces which share some property $ P $, there exists an isomorphically universal space that satisfies $ P $ as well. We introduce a variant of their amalgamation technique which provides an isometrically universal space in the case that $ \mathcal {C} $ consists of spaces with a monotone Schauder basis. For example, we prove that if $ \mathcal {C} $ is a set of separable Banach spaces which is analytic with respect to the Effros Borel structure and every $ X \in \mathcal {C} $ is reflexive and has a monotone Schauder basis, then there exists a separable reflexive Banach space that is isometrically universal for $ \mathcal {C} $.