The Bonn-Münster-Düsseldorf GeSAMT (Gemeinsames Seminar Algebra und Modelltheorie)
takes place on a few times per year, each consisting of about 3 talks on various subjects around algebra and model theory.
The location usually alternates between Bonn, Düsseldorf and Münster.
For any questions and to receive announcements about the seminar, please contact either
(Düsseldorf).
Bonn, Düsseldorf and Münster are also part of the wider region participating in the
Saturday, 26.10.2024, in
Münster, Orléans-Ring 12, SRZ216/217.
10:30 - 11:00 Welcome coffee break
11:00 - 12:00 Akash Hossain (Paris): Forking in valued fields and related structures
show/hide abstract
Model theory of Henselian valued fields is an active area of research with rich connections with algebraic geometry and number theory, and several celebrated applications to those subjects. The (now numerous) contributions to model theory of valued fields typically use, or try to establish, "Ax-Kochen-Ershov" transfer principles between the valued field at hand and some underlying structures, notably its value group and its residue field.
This talk will be about several contributions to the study of the model-theoretic non-forking independence relation in valued fields, in their underlying structures, and the study of transfer principles for forking between them. Our work includes results on extension bases in Henselian valued fields, on forking in ordered Abelian groups (the value groups of valued fields), and general transfer principles for expansions of pure short exact sequences of Abelian structures (generalizations of RV in valued fields). We are particularly interested in algebraically closed valued fields of residue characteristic zero, and pseudo-local fields (the ultraproducts of the -adic fields) of residue characteristic zero.
12:15 - 14:00 Lunch
14:00 - 15:00 Silke Meißner (Münster):
2-ample theories and pseudo-buildings
show/hide abstract
Zilber showed that a strongly minimal theory is 1-ample if and only if it interprets a pseudoplane. We will describe a generalisation of this result to 2-ample theories and define the notion of a pseudo-building. This is joint work with Katrin Tent.
15:15 - 16:15 Yilong Zhang (Bonn):
Hrushovski construction in ordered fields
show/hide abstract
Hrushovski construction is a variant of amalgamation methods. It was invented to construct new examples of strongly minimal theories. The method was later adapted to expansions of fields, including colored fields and powered fields. In this talk, I will present our attempt to apply Hrushovski construction to ordered fields, in particular, expansions of RCF by a divisble multiplicative subgroup. I will construct a rich structure and give its axiomatization. By looking into strong extensions, we are able to study its model-theoretic properties, including dp-rank and open core. Assuming Schanuel conjecture, the constructed theory axiomatizes the expansion of the real field by dense logarithmic spirals. For our future plan, I will introduce Zilber's powered fields, and discuss the situation in the real field.
16:15 - 16:45 Coffee break
16:45 - 17:45 Blaise Boissonneau (Düsseldorf):
Enlarge your spine
show/hide abstract
(joint with F. Jahnke, A. de Mase & P. Touchard)
This team of four mathematicians has discovered a secret about ordered abelian groups! Attend this talk to learn about their one weird trick and its surprising consequences: They classify augmentable linear orders! They transfer augmentability from spines to groups! They define valuations! In this talk, I will teach you their method for FREE and explain, for any ordered abelian group , how to find an ordered abelian group such that .
Saturday, 28th of January in
Bonn, Endenicher Allee 60 in the Lipschitz-Saal at the Mathematical Institute.
All talks are one hour with an additional 15 minutes for questions:
11:45-12:45 Daniel Hoffmann(Münster/Warsaw/Dresden), A bit of model theory of finite group actions
13:00 Lunch
14:45-15:45 Alessandro Codenotti (Münster), Some examples of tame dynamical systems answering questions of Glasner and Megrelishvili
16:00-17:00 Francesco Gallinaro (Freiburg), Quasiminimality of Complex Powers
Saturday, 11th of June in
Münster, Einsteinstraße 64, Lecture Hall M4
All talks are one hour with an additional 15 minutes for questions:
10:30-11:00 Coffee
11:00-12:15 Silvain Rideau-Kikuchi (Paris),
Enriching stably embedded sets and expansions of the integers ;
12:15-14:30 Lunch at
Milano + Coffee
14:30-15:45 Simon André (Münster),
On the Tarski problem for hyperbolic groups ;
15:45-16:00 Coffee
16:00-17:15 Jan Moritz Petschick,
Nilpotent Groups with the Magnus property ;
Friday, 12.11. and Saturday, 13.11 2021, in
Düsseldorf, Universitätsstr. 1, Gebaude 25.22.
Friday
10:30 - 11:10 Beginning and tea in
Lecture Hall 5F
Talks
Lecture Hall 5F:
11:10 - 12:25: Pablo Cubides Kovacsics (Düsseldorf),
Beautiful pairs and pro-definability;
Abstract
Lunch
Talks in
25.22.U1-34 :
14:35 - 15:50: Anna-Maria Ammer (Münster),
First-order theory of free generalized n-gons;
Abstract
Longer coffee break;
16:30 - 17:45: Philip Dittmann (Dresden),
Existential rank and essential dimension of definable sets;
Abstract
Saturday
Talks
Lecture Hall 5G:
09:25 - 10:40: Tingxiang Zou (Münster),
Generalized measurable H-structures;
Abstract
Coffee break
11:10 - 12:25: Nadja Valentin (Düsseldorf),
Non-degenerate n-linear forms and n-dependence;
Abstract
Lunch break;
14:35 - 15:50: Jan Dobrowolski (Münster),
Neostability in positive logic;
Abstract
Final coffee
Saturday, 30. November 2019, in Düsseldorf, Universitätsstr. 1, Gebaude 25.22.
Talks in building 25.22, on this map, close to metro "Uni Ost/Botanischer Garten".
10:30 - 10:55: Welcome / Coffee / Tea in
25.22.03.69.
Talks in room
25.22.02.81:
11:00 - 12:15: Amador Martin-Pizarro (Freiburg),
Open core in dense pairs of geometric topological structures;
Abstract
Lunch
14:15 - 15:30: Franziska Jahnke (Münster),
Characterising NIP henselian fields;
Abstract
Coffee / Tea break;
16:00 - 17:15: Tim Clausen (Münster),
Geometries in sharply 2-transitive groups of finite Morley rank.
Friday, 30. November 2018, in Münster, Einsteinstr. 62.
Talks in
Room N2.
Coffee / Tea in the
Lichthof.
10:30 - 11:00: Welcome / Coffee / Tea in the Lichthof;
11:00 - 12:00: Pierre Touchard (Münster),
Burden in mixed characteristic Henselian
valued fields;
Lunch
13:30 - 14:30: Matteo Vannacci (Düsseldorf),
Pro-p groups with quadratic -cohomology and generalised p-RAAGs;
14:30 - 15:14: Coffee / Tea break;
15:15 - 16:15: Peter Arndt (Düsseldorf),
Ranges of functors and elementary classes via topos theory.
The
Lichthof is on the 8th floor of the 8-storey block. From the stairs or lift, find it half-way along the corridor.
If you are searching for
N2, that is at ground level in an appropriate choice of building next to the 8-storey block.
A local bus stop is
P+R Coesfelder Kreuz.
Some relevant maps can be found
here.
Friday, 14. July 2017, in Düsseldorf.
Talks in building 25.22, on this map, close to metro "Uni Ost/Botanischer Garten".
Room 25.22.03.72
12.10-13.10: Florian Severin (Düsseldorf),
Variants of Hensel's lemma;
Lunch
14.05-15.05: Tim Clausen (Münster),
Dp-minimal profinite groups;
15.15-16.15: Martin Bays (Münster),
Definability in the group of infinitesimal rotations.
Friday, 3. February 2017, in Düsseldorf.
Talks in building 25.22, on this map, close to metro "Uni Ost/Botanischer Garten".
Room 25.22.00.72
11.30-12.30: Immanuel Halupczok (Düsseldorf),
A new analogue of o-minimality for valued fields;
Room 25.22.02.81
14.00-15.00: Aleksandra Kwiatkowska (Münster),
Cyclically dense conjugacy classes in topological groups;
15.05-16.05: Mohammad Bardestani (Münster),
Orbit methods and faithful representation of groups.
16:45 - 17:45: Particpants may also be interested in the
colloquium, held today in room
25.22 HS 5H.
Friday, 4. November 2016, in Münster.
Talks in room M6
11.00-12.00: Katrin Tent (Münster), Building like geometries
of finite Morley rank;
13.30-14.30: Gönenç Onay (Münster), On the theory of modules of F_p((T));
14.45-15.45: David Bradley-Williams (Düsseldorf), Definable relations and syzygetic subsets of trees.