2006 seminar talk: All creatures great and small
Talk held by Martin Goldstern (TU Wien) at the KGRC seminar on 2006-03-30.
For any regular uncountable cardinal lambda I will describe a
"creature-based" lambda^+-complete forcing notion that introduces
a "wild" ultrafilter on lambda.
Assuming 2^lambda=lambda^+, we can find a sufficiently generic filter on this forcing notion; this allows us to construct a clone on lambda which is not contained in any coatom of the clone lattice, solving an old problem in clone theory. (These notions will be explained in the talk.)
I have sketched a corresponding result for lambda=omega in my talk in November 2002. Both results are a joint work with Saharon Shelah.
I will give a related talk (that concentrates on the algebraic rather than set-theoretic background) in the algebra seminar at TU Wien on April 7, 2006.