Patrick Meurin:
Keisler‘s Order and Boolean Ultrapowers
Zeit und Ort
Dienstag, 20.9.22, 14:30-15:30, Raum 404, Ernst-Zermelo-Str. 1
Zusammenfassung
In 1967, Keisler introduced a partial order on first-order theories, that depends, roughly speaking, on whether certain ultrapower models of the theories in question are \(\blambda^+\)-saturated. In a pre-print of 2018, Douglas Urich introduced among other things a Compactness Theorem for Boolean-valued structures, generalized the machinery developed previously by Malliaris and Shelah and provided more flexible tools for proving or disproving propositions of the form ``\(T_0 \btrianglelefteq T_1\)‘‘, making use of Boolean ultrapowers for more general complete Boolean algebras. Our thesis consists in a detailed walk-through of Ulrich‘s results and we will briefly present some of them in this talk.