Anders Claesson: Interval orders via combinatorial species and ballot matrices
Tid: On 2015-11-25 kl 10.15 - 11.15
Plats: Room 3418
Medverkande: Anders Claesson, Univ. of Strathclyde
Abstract:
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. This allows for a new formula for the number of labeled
interval orders.
The talk is based on joint work with Stuart Hannah.