# Borel morphisms between cardinal characteristics, parts 1 and 2

Boise Set Theory Seminar, April 2019

Abstract: A cardinal characteristic is the cardinality of some special subset of the continuum. Vojtas introduced a categorical framework in which to study cardinal characteristics and their relationships. In this talk we introduce the objects and morphisms of this framework. We then consider a variation of this framework where the objects are morphisms are Borel definable.