Compact Sets of Baire Class One Functions and Maximal Almost Disjoint Families

Haim Horowitz, Stevo Todorcevic

Published 2019-05-15Version 1

We provide a proof that analytic almost disjoint families of infinite sets of integers cannot be maximal using a result of Bourgain about compact sets of Baire class one functions. Inspired by this and related ideas, we then provide a new proof of that there are no maximal almost disjoint families in Solovay's model. We then use the ideas behind this proof to provide an extension of a dichotomy result by Rosenthal and by Bourgain, Fremlin and Talagrand to general pointwise bounded functions in Solovay's model. We then show that the same conclusions can be drawn about the model obtained when we add a generic selective ultrafilter to the Solovay model.