The Largest Countable Inductive Set is a Mouse Set
Rudominer, Mitch
J. Symbolic Logic, Tome 64 (1999) no. 1, p. 443-459 / Harvested from Project Euclid
Let $\kappa^\mathbb{R}$ be the least ordinal $\kappa$ such that L$_\kappa(\mathbb{R})$ is admissible. Let $A = \{x \in \mathbb{R} \mid (\exists\alpha < \kappa^\mathbb{R})$ such that x is ordinal definable in $L_\alpha (\mathbb{R})\}$. It is well known that (assuming determinacy) A is the largest countable inductive set of reals. Let T be the theory: ZFC - Replacement + "There exists $\omega$ Woodin cardinals which are cofinal in the ordinals." T has consistency strength weaker than that of the theory ZFC + "There exists $\omega$ Woodin cardinals", but stronger than that of the theory ZFC + "There exists n Woodin Cardinals", for each $n \in \omega$. Let $\mathcal{M}$ be the canonical, minimal inner model for the theory T. In this paper we show that A = $\mathbb{R} \cap \mathcal{M}$. Since $\mathcal{M}$ is a mouse, we say that A is a mouse set. As an application, we use our characterization of A to give an inner-model-theoretic proof of a theorem of Martin which states that for all n, every $\Sigma^*_n$ real is in A.
Publié le : 1999-06-14
Classification:  Large Cardinals,  Descriptive Set Theory,  Inner Model Theory
@article{1183745786,
     author = {Rudominer, Mitch},
     title = {The Largest Countable Inductive Set is a Mouse Set},
     journal = {J. Symbolic Logic},
     volume = {64},
     number = {1},
     year = {1999},
     pages = { 443-459},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1183745786}
}
Rudominer, Mitch. The Largest Countable Inductive Set is a Mouse Set. J. Symbolic Logic, Tome 64 (1999) no. 1, pp.  443-459. http://gdmltest.u-ga.fr/item/1183745786/