Time: 16:00-17:00, Monday, October 20 2025
Venue: E10-315
Speaker: Laurent Lafforgue, Lagrange Center and Huawei Research Center
Title: Galois connections
Abstract: The notion of Galois connection can be formulated in so general and so simple terms that it would be good for all mathematicians to know it.
This general notion was extensively used in particular by Birkoff but remains widely unknown or forgotten, even though it makes the teaching of Galois theory more natural and can still be used to get new results.
The speaker will illustrate this last point by showing how simple Galois connections lead to the definitions of the notion of Grothendieck topology in a category and to the notion of topos as well as to dualities expressing the notion of topology in alternative terms and allowing to prove new general properties.
