IPM Calendar 
Sunday 29 November 2020   Today  
Events for day: Wednesday 18 November 2020    
           17:00 - 19:00     Mathtematical Logic Weekly Seminar
Generalized Descriptive Set Theory under I0


At the beginning of the 20th century some �pathological� sets appeared in the theory of the reals, like the Vitali set and the Bernstein set, that were somewhat counterintuitive. Descriptive set theory was developed initially to make sense of this: it creates a hierarchy of sets of reals, from the simplest ones to the most complex, both from logical and topological points of view. It turns out that �simple� sets are well-behaved, and they agree to our intuition (for example, all Borel sets are Lebesgue measurable). The question is, then, where exactly is the border, in the hierarchy, between well-behaved and pathol ...