## Combinatorics Seminar

When: Sunday December 31, 10am
Where: Schreiber 309
Speaker: Doron Puder, Tel Aviv University
Title: Meanders and Non-Crossing Partitions
## Abstract:

Imagine a long river and a closed (non-self-intersecting) racetrack
that crosses the river by bridges 2n times. This is called a meander.
How many meanders are there with 2n bridges (up to homeomorphisms
of the plane that stabilize the river)? This challenging question,
which is open for several decades now, has connections to several
fields of mathematics.
I will show the connection of this question to the lattice of
non-crossing partitions, mention some new results and present quite
a few open questions.
Based on joint work with Alexandru Nica and Ian Goulden.