In their seminal work, Haskell, Hrushovski and Macpherson gave a classification of imaginaries (i.e. quotient objects in the definable category) in an algebraically closed valued field K by the so-called geometric sorts, namely the valued field sort…
Categoria evento: Logic Seminar
L’ordine di Rudin-Keisler e ultrafiltri Tukey-massimali su algebre di Boole – Francesco Parente (Università degli Studi di Torino)
In questo seminario, presenterò alcuni risultati ottenuti in collaborazione con Jörg Brendle. Nella prima parte, introdurrò il concetto di Tukey-riducibilità, discutendo in particolare l’esistenza di ultrafiltri non massimali. Nella seconda parte,…
Asymptotic Combinatorics, Stability and Ultrafilters – EVENTO ANNULLATO – Amador Martin-Pizzarro (Albert-Ludwigs-Universität Freiburg)
A finite subset A of a group G is said to have doubling K if the set A\cdot A consisting of products a\cdot b, with a and b in A has size at most KA. Extreme examples of sets with small doubling are cosets of subgroups. Theorems of Freiman-Ruzsa…
(Cancellato) Characterizing o-minimal groups in tame expansions of o-minimal structures – Panteleimon Eleftheriou (University of Konstanz)
Il seminario è stato cancellato. Sarà riprogrammato in altra data. Alessandro Berarducci P. Eleftheriou, “Characterizing o-minimal groups in tame expansions of o-minimal structures”, Journal of the Institute of Mathematics of Jussieu, Online first…
Generic derivations on o-minimal structures – Antongiulio Fornasiero (Università di Firenze)
Generic derivations on o-minimal structures Given an o-minimal theory, we define what is a derivation “compatible” with T. We show that the theory of compatible derivations has a model completion, and describe some of its properties.…
Definably amenable NIP groups – Pierre Simon (CNRS, Université Lyon)
A group is definably amenable if there is a translation-invariant measure on the algebra of definable sets. This notion is particularly fruitful in the NIP context, where definable amenability is equivalent to the existence of some kind of generic…
Measures in NIP theories and applications to combinatorics – Pierre Simon (CNRS, Université Lyon)
The study of NIP theories has brought forth a new tool in model theory : Keisler measures, or finitely additive measures on definable sets. In this talk, I will introduce both NIP and Keisler measures and survey the most notable results concerning…
NONSTANDARD METHODS, ASYMPTOTIC DENSITY AND SUMSETS – Steven Leth (Univ. North. Colorado (USA))
In this talk I will outline some of the basics of nonstandard analysis and discuss how nonstandard methods can be applied to obtain new results in combinatorial number theory. We will look at a recent result obtained jointly with Di Nasso,…