Past Events
Scientific, Seminar
PIMS-CORDS SFU Operations Research Seminar: Yohan Song
June 20, 2024
Simon Fraser University
A skew shape is a difference of two Young diagrams where one diagram contains the other. In 2017, Jenna Rajchgot, Matthew Satriano, and Wanchun Shen showed that skew shapes can be used to study the Gerstenhaber problem, a matrix algebra problem in...
Scientific, Seminar
Optimization and Data Seminar: Amitabh Basu
June 3, 2024
University of Washington
We consider the problem of minimizing a convex function under convex constraints, where some or all of the decision variables are constrained to be integer, with access to first-order oracles for the objective function and separation oracles for the...
Scientific, Seminar
UW Combinatorics and Geometry Seminar: Fiona Young
May 29, 2024
University of Washington
One way to define an integer polymatroid ρ is via its independent set polytope, whose faces are parallel translations of the independent set polytopes of the minors of ρ. To better understand the interior of this polytope, we endow a structure on...
Scientific, Seminar
UBC DG MP PDE Seminar: Gang Tian
May 28, 2024
University of British Columbia
In this talk, I will discuss a long-standing problem on type II singularity of Ricc flow. First I recall some known results on long-time behavior of Ricci flow, then I will present our solution to the above problem. I may also discuss a related...
Scientific, Seminar
SFU Mathematics of Computation, Application and Data ("MOCAD") Seminar: Gregor Maier
May 24, 2024
Simon Fraser University
Over the past few years, operator learning – the approximation of mappings between infinite dimensional function spaces using ideas from machine learning – has attracted increased research attention. Approximate operators, learned from data, hold...
Scientific, Seminar
Kantorovich Initiative Seminar: Laetitia Chapel
May 23, 2024
University of Washington
Optimal transport operates on empirical distributions which may contain acquisition artifacts, such as outliers or noise, thereby hindering a robust calculation of the OT map. Additionally, it necessitates equal mass between the two distributions...
Scientific, Seminar
UW Combinatorics and Geometry Seminar: Kevin Liu
May 22, 2024
University of Washington
In this talk, we consider colored permutation groups ℤm≀Sn, which contain the symmetric groups Sn≅ℤ1≀Sn and the signed symmetric groups Bn≅ℤ2≀Sn as special cases. Like in Sn, colored permutations in ℤm≀Sn have a notion of cycle type that classifies...
Scientific, Seminar
05C50 Online Seminar: Minerva Catral
May 17, 2024
Online
A sign pattern (matrix) has entries in {+, -, 0}. We investigate eigenvalue properties of a sign pattern of order 2n where two of the blocks are prescribed sign patterns of order n, and the other two (order n) blocks are the positive diagonal sign...
Scientific, Seminar
PIMS-UVic Discrete Math Seminar: Amarpreet Rattan
May 16, 2024
University of Victoria
For fixed n, consider the symmetric group S_n on the symbols 1,...,n and the set of *star* transpositions, the transpositions that contain the symbol n. A *star factorization* of a permutation b in S_n of length k is the writing of b as the product...
Scientific, Seminar
UW Combinatorics and Geometry Seminar: Hailun Zheng
May 15, 2024
University of Washington
A d-polytope is called (d−i)-simplicial if all of its (d−i)-faces are simplices. It is i-simple if every (d−i−1)-face belongs to exactly i+1 facets. A few low-dimensional examples of (d−i)-simplicial i-simple polytopes arising from regular polytopes...