Vorträge des SFB 1442

|
juschult

Oberseminar Topologie: Markus Hausmann (Universität Bonn), Vortrag: Global group laws and the equivariant Quillen thorem

Wednesday, 14.04.2021 16:00 im Raum ZOOM: https://www.uni-muenster.de/FB10srvi/persdb/zoomtitle.php?id=12

Mathematik und Informatik

Abstract: I will discuss an equivariant version of Quillen's theorem that the complex bordism ring carries the universal formal group law, both over a fixed abelian group and in a global equivariant setting



Angelegt am Wednesday, 07.04.2021 14:10 von juschult
Geändert am Tuesday, 13.04.2021 13:37 von juschult
[Edit | Vorlage]

Oberseminare und sonstige Vorträge
Vorträge des SFB 1442
|
juschult

Seminar Geometrische Gruppentheorie: Alice Kerr; Vortrag: Quasi-trees and product set growth

Thursday, 15.04.2021 15:00 im Raum https://www.uni-muenster.de/IVV5WS/WebHop/user/ggardam/ggt_seminar.html

Mathematik und Informatik

Abstract: A standard question in group theory is to ask if we can categorise the subgroups of a group in terms of their growth. In this talk we will be asking this question for uniform product set growth, a property that is stronger than the more widely studied notion of uniform exponential growth. We will see how quasi-trees could help us answer this question for acylindrically hyperbolic groups, and give a particular application to right-angled Artin groups



Angelegt am Tuesday, 13.04.2021 13:41 von juschult
Geändert am Tuesday, 13.04.2021 13:43 von juschult
[Edit | Vorlage]

Vorträge des SFB 1442
Oberseminare und sonstige Vorträge
|
mathsekr

Wilhelm Killing Kolloquium: Prof. Dr. Joel Fine (Université Libre de Bruxelles): per ZOOM: Knots and minimal surfaces

Thursday, 15.04.2021 16:30 per ZOOM: Link to Zoom info

Mathematik und Informatik

A minimal surface is one whose area is stationary under small perturbations. If you dip a loop of wire in soapy water and pull it out, the soap film will naturally form a minimal surface. The Plateau problem is to find a minimal surface which bounds a given closed loop. From the point of view of analysis, this involves solving a non-linear PDE. I will explain how counting the number of solutions to a version of the Plateau problem can lead to knot invariants. Given a knot K in the three-sphere, one can count minimal surfaces in 4-dimensional hyperbolic space which are asymptotic at infinity to K and the answer does not change when you deform the knot. I will explain a conjecture that this count of minimal surfaces actually recovers the "HOMFLYPT" polynomial of the knot. This polynomial is purely combinatorial and simple to calculate from a planar diagram of the knot. If the conjecture is true, it would mean that easy combinatorial calculations can give existence of minimal surfaces! I will assume no knowledge of either minimal surfaces or knots. There will be lots of pictures



Angelegt am Thursday, 11.03.2021 11:20 von mathsekr
Geändert am Wednesday, 14.04.2021 11:19 von mathsekr
[Edit | Vorlage]

Vorträge des SFB 1442
Kolloquium Wilhelm Killing
|
harenbrh

Oberseminar p-adische Arithmetik: Verena Edenfeld: Smooth mod-p representations and the mod-p Satake transform

Tuesday, 20.04.2021 16:15 per ZOOM: Link

Mathematik und Informatik

ZOOM-Link: https://wwu.zoom.us/j/65940821521?pwd=cFB6cVUwSDhtSFloaStiUUJpQzJ6Zz09#success Meeting-ID: 65940821521 Kenncode: 516480



Angelegt am Wednesday, 14.04.2021 15:14 von harenbrh
Geändert am Wednesday, 14.04.2021 15:14 von harenbrh
[Edit | Vorlage]

Oberseminare und sonstige Vorträge
Vorträge des SFB 1442
|
mathsekr

Wilhelm Killing Kolloquium: Prof. Dr. Henry Wilton (University of Cambridge): per ZOOM: Negative immersions and one-relator groups

Thursday, 22.04.2021 16:30 per ZOOM: Link to Zoom info

Mathematik und Informatik

Abstract: One-relator groups G=F/<> pose a challenge to geometric group theorists. On the one hand, they satisfy strong algebraic constraints. On the other hand, they are not susceptible to geometric techniques, since some of them ? such as the famous Baumslag?Solitar groups ? exhibit extremely pathological behaviour. I will relate the subgroup structure of one-relator groups to a measure of complexity for the relator w introduced by Puder ? the *primitivity rank* \pi(w). A sample application is that every subgroup of G of rank < \pi(w) is free. These results in turn provoke geometric conjectures that suggest a beginning of a geometric theory of one-relator groups. This is joint work with Larsen Louder.



Angelegt am Thursday, 11.03.2021 11:22 von mathsekr
Geändert am Wednesday, 14.04.2021 11:11 von boeckena
[Edit | Vorlage]

Kolloquium Wilhelm Killing
Vorträge des SFB 1442
|
juschult

Obersminar Topologie: Gijs Heuts (Universität Utrecht)

Wednesday, 28.04.2021 16:00 im Raum https://www.uni-muenster.de/FB10srvi/persdb/zoomtitle.php?id=12

Mathematik und Informatik



Angelegt am Wednesday, 14.04.2021 12:49 von juschult
Geändert am Wednesday, 14.04.2021 12:49 von juschult
[Edit | Vorlage]

Oberseminare und sonstige Vorträge
Vorträge des SFB 1442
|
mathsekr

Wilhelm Killing Kolloquium: Prof. Dr. Roman Sauer (Universität Karlsruhe): per ZOOM: Actions on Cantor spaces, volume and macroscopic scalar curvature

Thursday, 29.04.2021 16:30 per ZOOM: Link to Zoom info

Mathematik und Informatik

We introduce the macroscopic point of view for questions around scalar curvature. Then we discuss the macroscopic cousins of three conjectures: 1) a conjectural bound of the simplicial volume of a Riemannian manifold in the presence of a lower scalar curvature bound, 2) the conjecture that rationally essential manifolds do not admit metrics of positive scalar curvature, 3) a conjectural bound of ?²-Betti numbers of aspherical Riemannian manifolds in the presence of a lower scalar curvature bound. Group actions on Cantor spaces surprisingly play an important role in the proof. The talk is based on joint work with Sabine Braun.



Angelegt am Wednesday, 17.03.2021 09:57 von mathsekr
Geändert am Wednesday, 14.04.2021 11:07 von boeckena
[Edit | Vorlage]

Kolloquium Wilhelm Killing
Vorträge des SFB 1442