IPM Calendar 
Sunday 11 April 2021   Today  
Events for day: Wednesday 03 March 2021    
           15:30 - 17:30     Mathtematical Logic Weekly Seminar
Finite Support Iteration and Small Models


Starting from a model of ZFC+GCH, iterated forcing is a method of building a new larger model in which (for example) the continuum hypothesis fails and in fact the continuum $c$ (the cardinality of the set R of real numbers) can become arbitrarily large. Several other so called "cardinal characteristics" may be changed as well: for example, the number cov(null) (the smallest size of a family of Lebesgue null sets whose union is all of R) or the similarly defined number cov(meager), where null sets are replaced by meager sets (or equivalently: by closed nowhere dense sets. For example, iterating Cohen's original forcing one can get a ...