Anders Claesson (05/02/16)

Sigurður Örn Stefánsson, February 2, 2016

Math Colloquium

Speaker: Anders Claesson
Title: Interval orders via combinatorial species and ballot matrices

Location: V-157, VRII.
Time: Friday, Februar 5 at 13:20.


We give a brief introduction to (some aspects of) combinatorial species.
Using this framework we introduce ballot matrices and present a subset
of them that is in bijection with labeled interval orders. Such ballot
matrices decompose naturally into a pair of permutations with related
properties, which leads to a new formula for the number of labeled
interval orders.

This talk is based on joint work with Stuart Hannah.