Combinatorics of the Permutahedra, Associahedra, and Friends
Résumé
I present an overview of the research I have conducted for the past ten years in algebraic, bijective, enumerative, and geometric combinatorics. The two main objects I have studied are the permutahedron and the associahedron as well as the two partial orders they are related to: the weak order on permutations and the Tamari lattice. This document contains a general introduction (Chapters 1 and 2) on those objects which requires very little previous knowledge and should be accessible to non-specialist such as master students. Chapters 3 to 8 present the research I have conducted and its general context. You will find:
* a presentation of the current knowledge on Tamari interval and a precise description of the family of Tamari interval-posets which I have introduced along with the rise-contact involution to prove the symmetry of the rises and the contacts in Tamari intervals;
* my most recent results concerning q, t-enumeration of Catalan objects and Tamari intervals in relation with triangular partitions;
* the descriptions of the integer poset lattice and integer poset Hopf algebra and their relations to well known structures in algebraic combinatorics;
* the construction of the permutree lattice, the permutree Hopf algebra and permutreehedron;
* the construction of the s-weak order and s-permutahedron along with the s-Tamari lattice and s-associahedron.
Chapter 9 is dedicated to the experimental method in combinatorics research especially related to the SageMath software. Chapter 10 describes the outreach efforts I have participated in and some of my approach towards mathematical knowledge and inclusion.
Origine : Fichiers produits par l'(les) auteur(s)
