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Andres Forero
Mon Jan 23, 2012
4:00 pm
The construction of the Martin-Solovay tree will be presented
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Cynthia Northrup
Mon Jan 9, 2012
4:00 pm
Basic facts on towers and homogeneity systems will be presented.
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Cynthia Northrup
Mon Nov 28, 2011
4:00 pm
Basic facts on towers and homogeneity systems will be presented.
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Cynthia Northrup
Mon Nov 21, 2011
4:00 pm
Basic theory of homogeneity systems and homogeneous trees will be presented.
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Cynthia Northrup
Mon Nov 14, 2011
4:00 pm
Basic theory of ultrapowers for towers of measures will be presented.
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Geoff Galgon and Garett Ervin
Mon Nov 7, 2011
4:00 pm
The Shoenfield absoluteness theorem states that if M is any transitive model of set theory containing all countable ordinals then M agrees on the truth of \Sigma^1_2 sentences with V. We present the proof of the theorem and discuss several related results.
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Geoff Galgon and Garrett Ervin
Mon Oct 31, 2011
4:00 pm
Given a lightface $\Sigma^1_2$ set of reals A we present the construction of a tree on $\omega\times\omega_1$ such that A is the projection of T. Moreover, the tree T is an element of any transitive model of ZF-PowerSetAxiom that has $\omega_1$ as element.
