Ordinal definability in
arXiv:2012.07185 · doi:10.1017/jsl.2025.10099
Abstract
Let be a tame mouse modelling ZFC. We show that satisfies " for some real ", and that the restriction of the extender sequence of to indices above is definable without parameters over the universe of . We show that has universe , where is the initial segment of of height (including ), and that is the universe of a premouse over some . We also show that has no proper grounds via strategically -closed forcings. We then extend some of these results partially to non-tame mice, including a proof that many natural -minimal mice model "", assuming a certain fine structural hypothesis whose proof has almost been given elsewhere.
48 pages. Added hypotheses to Thms 1.4 and 1.6, to bridge minor gaps in their former "proofs". Appeal to [6, Thm 0.2] (in paper's references) for Thm 4.2 clarified. Last part of proof of Thm 4.7 clarified. Added Lem 8.14 and strengthened Lem 8.13, to establish what was claimed to be an "immediate consequence" of STH in previous version. Other minor corrections and improvements in exposition