49 research outputs found

    An inner model proof of the strong partition property of \delta^2_1

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    We prove the strong partition property for \delta^2_1 using methods from inner model theory.Comment: submitte

    Negative results on precipitous ideals on omega_1

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    We show that in extender models there are no generic embeddings with critical point ω1\omega_1 that resemble the stationary tower at the second Woodin cardinal

    The Largest Suslin Axiom

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    We develop the basic fine structure theory of the minimal model of the Largest Suslin Axiom. In particular, we prove that that the minimal model of the Largest Suslin Axiom satisfies the Mouse Set Conjecture, and that the Proper Forcing Axiom implies the minimal model of the Largest Suslin Axiom exists

    Unreachability of Inductive-Like Pointclasses in L(R)L(\mathbb{R})

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    Hjorth proved from ZF+AD+DCZF + AD + DC that there is no sequence of distinct Σ21\Sigma^1_2 sets of length δ21\delta^1_2. Sargsyan extended Hjorth's technique to show there is no sequence of distinct Σ2n1\Sigma^1_{2n} sets of length δ2n1\delta^1_{2n}. Sargsyan conjectured an analogous property is true for any regular Suslin pointclass in L(R)L(R) -- i.e. if κ\kappa is a regular Suslin cardinal in L(R)L(R), then there is no sequence of distinct κ\kappa-Suslin sets of length κ+\kappa^+ in L(R)L(R). We prove this in the case that the pointclass S(κ)S(\kappa) is inductive-like
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