### Duality and the PCF theory

by Shelah and Zapletal. [ShZa:791]

Math Research Letters, 2002

We consider natural cardinal invariants hm_n and
prove several duality theorems, saying roughly: if I is a suitably
definable ideal and provably cov (I) >= hm_n,
then non (I) is provably small. The proofs integrate the
determinacy theory, forcing and pcf theory.

Back to the list of publications