Beautiful pairs of unstable theories and spaces of definable types

Basic data for this talk

Type of talkscientific talk
Name der VortragendenHils, Martin
Date of talk26/07/2021
Talk languageEnglish

Information about the event

Name of the eventWorkshop on Trends in Pure and Applied Model Theory
Event period26/07/2021 - 30/07/2021
Event locationThe Fields Institute, Toronto, Kanada
Event websitehttp://www.fields.utoronto.ca/activities/21-22/model-theory-trends

Abstract

By classical results of Poizat, the theory of beautiful pairs of models of a stable theory T is "meaningful" precisely when the set of all definable types in T is strict pro-definable, which is the case if and only if T is nfcp. We transfer the notion of beautiful pairs to unstable theories and study them in particular in henselian valued fields, establishing Ax-Kochen-Ershov principles for various questions in this context. Using this, we show that the theory of beautiful pairs of models of ACVF is "meaningful" and infer the strict pro-definability of various spaces of definable types in ACVF, e.g., the model theoretic analogue of the Huber analytification of an algebraic variety. This is joint work with Pablo Cubides Kovacsics and Jinhe Ye.
Keywordsmodel theory; definable types; valued fields

Speakers from the University of Münster

Hils, Martin
Professorship for Mathematical Logic (Prof. Hils)