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Category forcings, MM+++MM^{+++}, and generic absoluteness for the theory of strong forcing axioms

Abstract

We introduce a category whose objects are stationary set preserving complete boolean algebras and whose arrows are complete homomorphisms with a stationary set preserving quotient. We show that the cut of this category at a rank initial segment of the universe of height a super compact which is a limit of super compact cardinals is a stationary set preserving partial order which forces MM++MM^{++} and collapses its size to become the second uncountable cardinal. Next we argue that any of the known methods to produce a model of MM++MM^{++} collapsing a superhuge cardinal to become the second uncountable cardinal produces a model in which the cutoff of the category of stationary set preserving forcings at any rank initial segment of the universe of large enough height is forcing equivalent to a presaturated tower of normal filters. We let MM+++MM^{+++} denote this statement and we prove that the theory of L(Ordω1)L(Ord^{\omega_1}) with parameters in P(ω1)P(\omega_1) is generically invariant for stationary set preserving forcings that preserve MM+++MM^{+++}. Finally we argue that the work of Larson and Asper\'o shows that this is a next to optimal generalization to the Chang model L(Ordω1)L(Ord^{\omega_1}) of Woodin's generic absoluteness results for the Chang model L(Ordω)L(Ord^{\omega}). It remains open whether MM+++MM^{+++} and MM++MM^{++} are equivalent axioms modulo large cardinals and whether MM++MM^{++} suffices to prove the same generic absoluteness results for the Chang model L(Ordω1)L(Ord^{\omega_1}).Comment: - to appear on the Journal of the American Mathemtical Societ

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