Abstract: Inspired by Margulis’ super-rigidity theorem about finite dimensional representations of lattices in higher rank semisimple Lie groups, Zimmer formulated the so-called Zimmer Program which calls for the study and potential classification of actions of higher rank semisimple Lie groups, and their lattices on manifolds. I will report on much recent progress, especially when the dynamics of the action is complicated, with lots of…
Title: Admmissible sets for Erdos sieves
Abstract: When considering a set of pairwise coprime numbers b_1,b_2,... the admissible sets, those which don't contain every congruence class mod b_i for any i, correspond to the closure of the shift {F+n} with n an integer and F those numbers not divisible by any b_i. When considering a generalization for Erdos sieves, this does not hold anymore. In this…
Prime numbers and prime twins Maths circle meeting on 24 May 2025
Room and time: virtual/online with the video conferencing software Zoom (Paderborn University campus licence) from 10:00 to 13:00
Leader of the workshop: Dr. Kerstin Hesse
Description: A prime number is a natural number greater than or equal to 2 that has only the number 1 and itself as its only positive divisors. We prove that there are infinitely many prime numbers and we…
Abstract: tba
Bei Interesse an einer online-Teilnahme (sei es regelmäßig oder auch nur an einem bestimmten Vortrag) bitten wir vorab mit Tobias Weich oder Benjamin Delarue Kontakt aufzunehmen, damit der Teilnahmelink geteilt werden kann.
Geometric figures in the square grid
Maths circle meeting on 14 June 2025
Room and time: virtual/online with the video conferencing software Zoom (Paderborn University campus licence) from 10:00 to 13:00
Leader of the workshop: Dr Kerstin Hesse
Description: We consider a rectangular square grid in which all points of the grid have a distance of 1 to the direct link to the neighbouring points. The grid points are therefore (m,n), where m, n…
