Séminaires à venir

Meanders are mathematical objects that can be defined both geometrically and combinatorially. Combinatorially, they are pair of noncrossing partitions of {1,...,n} made of blocks of size at most two. Even though they are relatively simple objects, various problems about them are still open. In this talk, after defining them and giving motivations, I will enumerate some of those open problems. Then we will focus on a subfamily of meanders called bi-rainbow meanders, which have more structure, and for which we can develop tools to help us in answering some questions. If time allows, I will discuss a possible generalization of meanders by replacing the line by a tree. This talk is in part based on a joint paper with Mélodie Lapointe, Yann Palu, Pierre-Guy Plamondon, Christophe Reutenauer and Hugh Thomas which can be found in arXiv:2301.07222, and in part based on a separate individual project.