Bonn Topology Group - Abstracts
General Information - Members - Activities - Topology Seminar - Graduiertenkolleg
Talk
Diarmuid Crowley (HIM Bonn): Some new calculations for the Gromoll filtration (17 May 2011)
Abstract
Let \Gamma_n denote the group of oriented homotopy n-spheres, n > 4. There
is a decreasing filtration of \Gamma_n due to Gromoll:
\Gamma = \Gamma_{n, 2} \supset \Gamma_{n, 3} \supset ... \supset \Gamma_{n, n-3} = 0
The determination of the Gromoll filtration is a difficult open problem (it seems to be
unknown for any n > 6, n \neq 12) which has many interesting applications in geometric
topology.
In this talk I will survey approaches to finding elements deeper in the Gromoll
filtration: plumbing and compostion and also obstructions to finding such elements
from pseudo-isotopy theory. Then I will report on new computations for certain
Gromoll groups. As time permits I will discuss applications and open problems.
Many of the new results are part of joint work with with Thomas Schick.
Back to seminar page
Aktuelles
Bonner Mathematik schneidet bei QS-Ranking wieder hervorragend ab
Stefan Schwede eingeladener Sprecher auf dem ECM 2024 in Sevilla
Cole Prize für Jessica Fintzen
Regula Krapf erhält Lehrpreis der Universität
Catharina Stroppel in Nordrhein-Westfälische Akademie der Wissenschaften und Künste aufgenommen.
Daniel Huybrechts erhält Compositio Prize für die Periode 2017-2019
Catharina Stroppel erhält Gottfried Wilhelm Leibniz-Preis 2023
Stipendien für Mathematikstudierende aus der Ukraine
Jessica Fintzen erhält einen Whitehead Prize der London Mathematical Society