|Catalan combinatorics of arbitrary type|
Abstract: The Catalan numbers and their generalizations and refinements (Fuss numbers, Cayley-Kirkman numbers, Narayana numbers, etc.) can be viewed as
"type A" versions of more general numbers defined for an arbitrary finite Coxeter group. These numbers come up in a variety of combinatorial,
algebraic, and geometric contexts to be surveyed in the talk (hyperplane arrangements, noncrossing partitions, generalized associahedra, and so
on), suggesting connections that transcend mere numerology.