Event
Ilani Axelrod-Freed (MIT)
Friday, December 19, 2025 11:00to12:00
Title: The Chute Moves Lattice.
Abstract:聽聽For each permutation聽w, we consider the set聽RP(w)聽of reduced pipe dreams for聽w, partially ordered so that cover relations correspond to (generalized) chute moves. Settling a conjecture of Rubey from 2012, we prove that聽RP(w)聽is a lattice. To establish this result, introduce another poset consisting of objects called Lehmer tableaux with relation given by entrywise comparison. We provide a global description of the partial order on聽RP(w)聽by showing that these two posets are isomorphic. In addition, we prove that聽RP(w)聽is a semidistributive polygonal lattice whose polygons are all diamonds or pentagons.
Room PK-4323 of UQAM鈥檚 Pr茅sident-Kennedy Building.