Combinatorics Seminar: Hyperplane arrangements and shuffling cards

Event details Date: Wednesday, October 7, 2026 Time: 4:30 PM to 5:20 PM Location: Kaprielian Hall (KAP) - 414 - 3620 South Vermont Avenue, Los Angeles, CA 90089 Type: Lecture / Talk / Workshop Campus: University Park Campus Department: Mathematics About this event Jason Fulman, USC Title: Hyperplane arrangements and shuffling cards Abstract: Bidigare, Hanlon, and Rockmore discovered a combinatorial notion of random walk on the chambers of a real hyperplane arrangement. Their construction includes shuffling methods such as the top to random shuffle and ordinary riffle shuffling. They obtain a combinatorial formula for the eigenvalues of the transition matrix of these Markov chains, which turn out to have all eigenvalues real despite being non-symmetric. There are also a number of extensions (random walk on oriented matroids, buildings, and left-regular bands). Official event details: https://calendar.usc.edu/event/combinatorics-seminar-hyperplane-arrangements-and-shuffling-cards