We survey the definition and fundamental properties of the family of short core models, which extend the core model K of Dodd and Jensen to include α-sequences of measurable cardinals . The theory is applied to various combinatorial principles to get lower bounds for their consistency strengths in terms of the existence of sequences of measurable cardinals. We consider instances of Chang's conjecture, ‘accessible’ Jónsson cardinals, the free subset property for small cardinals, a canonization property of ω ω , and (...) a non-closure property of elementary embeddings of the universe. In some cases, equiconsistencies are obtained. (shrink)

We prove the independence of a strong partition relation on ℵ ω , answering a question of Erdos and Hajnal. We then give an almost complete answer to the free subset problem.

We improve the canonization theorems generalizing the Erdos-Rado theorem, and as a result complete the answer to "When does a Hausdorff space of cardinality χ necessarily have a discrete subspace of cardinality κ?" We also improve the results on existence of free subsets.

We give for ordinals α a lower bound for the least ordinal α such that Frordξ,β) and show that given enough measurable cardinals there are forcing extensions where the given bounds are sharp.