Kristina Garrett
St. Olaf College


Title:

   Permutation Tableau, pattern-avoidance and set partitions.

Abstract:

   Permutation tableaux are a relatively new class of tableaux that are naturally in
bijection with certain permutations and are a distinguished set of the
(reverse)L-diagrams of Postnikov. In this talk we will consider William &
Steingrimsson's bijection between permutation tableaux and permutations with a fixed
number of weak excedances.  We will describe some newly discovered properties of
permutation tableaux and explore the connections between subsets of permutation tableaux
and 231-avoiding permutations, Stirling number and Bell numbers.