06-12【Christophe MARGERIN】五教5307 中法班讨论班系列报告033


题目:On a family of remarkable quadratic forms

报告人:Christophe MARGERIN, École Polytechnique(巴黎综合理工大学)

时间:2024年6月12日(周三)16:00-17: 00



I'll show how arithmetics of quadratic forms can be used to derive obstructions and settle non-trivial questions in topology, and then proceed to give further interesting -if not surprising- arithmetic properties of the associated lattices, a complete characterization of their minimal lengths and of their sets of shortest vectors included. 

I'll finally explain how Wu vectors are related to our problem, and solve the question of characterizing the shortest Wu vectors of the quadratic forms under concern, so giving access to their Elkies-Lannes's invariants which I will prove to be surprisingly large.