10/07/2026
By Joris Roos
The Department of Mathematics and Statistics invites you to attend a colloquium lecture by Sunita Chepuri, associate professor of mathematics at the University of Puget Sound.
- Title: "Orbitmesy and Promotion on Self-Dual Posets"
- Date: Wednesday, Oct. 7
- Time: 11 a.m. – noon
- Location: Southwick Hall, Room 350W
Everyone is welcome!
Abstract
Dynamical algebraic combinatorics studies the dynamics of actions on combinatorial objects with algebraic significance. One key phenomenon is homomesy, where a statistic has a constant average on each orbit of the action. In this talk, I will introduce the notion of orbitmesy, a generalization of homomesy. An orbit is said to be orbitmesic with respect to a statistic if the orbit’s average statistic value is equal to the global average. I will give some examples, provide a general framework for finding orbitmesies using a known homomesy, and present several results along these lines that give orbitmesic promotion orbits of self-dual posets. If time allows, I will share a classification of all the orbitmesic promotion orbits for the zig-zag poset with four elements.