The Pythagoras number of function fields
Talk, Seminar on Arithmetic Geometry and Algebraic Groups, online
Talks and presentations
Here is a list of talks and presentations I have given, and for which slides, recordings, or other material are available. Past blackboard talks for which no digital material is available are not contained in this list. If you believe something is missing or broken, or if have any questions or feedback about the content, do not hesitate to contact me.Hilbert’s 10th Problem and Decidability in Algebra and Number Theory
Colloquium talk, Charles University MFF, Algebra Colloquium, Prague, Czechia
A shortened version of this talk was given at the Belgian Mathematical Society’s Young Scholar Day on December 20, 2023.
How many quantifiers are needed to existentially define a given subset of a field?
Talk, IMJ-PRG Séminaire Général de Logique, Paris, France
Based on joint work with Philip Dittmann and Arno Fehm. Earlier, this talk was given twice online, once on July 18, 2022 for the Oberseminar ‘Complexity Theory, Model Theory, Set Theory’, and once on June 18, 2021 at SMTH2.
A universal definition of Z in Q
Talk, Universität Augsburg, Oberseminar zur Algebra und Zahlentheorie, Augsburg, Germany (online)
A variation of this talk was also given at the Algebra and Number Theory Seminar at Penn State on October 7, 2020.
Model-theoretic tools for the busy algebraist
Colloquium talk, University of Antwerp, Algebra Colloquium, Antwerp, Belgium
Defining valuation and holomorphy rings in function fields using quadratic forms
Talk, MSRI Decidability, definability and computability in number theory -- Seminar Series, Berkeley, USA (online)
ALGAR 2020: Lecture series
Lecture series, University of Antwerp, ALGAR2020: Valuations, quadratic forms and definability , Antwerp, Belgium (online)