Min-plus dot products and greedy multiplication of permutations by Nathan Pflueger, Amherst College

Min-plus dot products and greedy multiplication of permutations by Nathan Pflueger, Amherst College, Friday April 5, 1:00 – 1:50pm, North Science Building 015, Wachenheim, Mathematics Seminar

Abstract:
The usual multiplication rule for integer permutations is given by function composition. However, permutations also possess an intriguing associative operation called the Demazure or 0-Hecke product, characterized by a greedy algorithm. I keep encountering this product quite accidentally while doing geometry. I will describe some of these encounters with the Demazure product, which stem from a surprising alternative description of it in terms of dot products in the min-plus (or tropical) semiring.

This talk is for colloquium credit.