Tuesday, September 30, 2025

Autumn 2025


3 and 10  October

Viska Arbogast

Numbers as Equations



Sunday, September 7, 2025

Autumn 2025

 

From Wikipedia


11, 18, 25  Sep 2025

Jerzy Kocik

Coxeter groups, and an unconventional view on the unimodular group (with pictures)



Part 1:  Coxeter groups (the idea)

Part 2:  Modular group as a Coxeter group

Part 3:  "Supermodular" group and an unexpected application 


For part 1, you may consult a nicely written text by J. Baez:  Coxeter and Dynkin diagrams