Vasu Tewari
University of Washington
Abstract
Ascents and descents on binary trees and hyperplanearrangements
The descent statistic on permutations was intro-duced by MacMahon in the early 1900s, and has appeared invarious parts of mathematics since. We will discuss a general-ization of this statistic to labeled binary trees, and discuss con-nections with areas as diverse as enumeration of rook placementsto symmetric group actions on hyperplane arrangements.