Kurt Gödel Research Center

2015 seminar talk: Maximal independent sets in forcing extensions

Talk held by David Schrittesser (University of Copenhagen, Denmark) at the KGRC seminar on 2015-10-15.

Abstract

In recent work with Asger Törnquist, we constructed a maximal orthogonal family of measures which has a very simple definition (i.e. it is effectively co-analytic) even in a situation where there are non-constructible reals (see my previous talk at the KGRC).

In this talk I will discuss the problem of obtaining a Hamel basis in the Sacks extension, at the same level of definability (effectively co-analytic). While the problem has a very similar flavour, it requires some new ideas.