Week of May 5, 2024

Wed May 8, 2024
2:00pm to 3:00pm - 510R Rowland Hall - Combinatorics and Probability
John Peca-Medlin - (University of Arizona)
Random permutations using GEPP

Gaussian elimination with partial pivoting (GEPP) remains the most used dense linear solver. For a nxn matrix A, GEPP results in the factorization PA = LU where L and U are lower and upper triangular matrices and P is a permutation matrix. If A is a random matrix, then the associated permutation from the P factor is random. When is this a uniform permutation? How many disjoint cycles are in its cycle decomposition (which equivalently answers how many GEPP pivot movements are needed on A)? What is the longest increasing subsequence of this permutation? We will provide some statistical answers to these questions for select random matrix ensembles and transformations. For particular butterfly permutations, we will present full distributional descriptions for these particular statistics. Moreover, we introduce a random butterfly matrix ensemble that induces the Haar measure on the full 2-Sylow subgroup of the symmetric group on a set of size 2ⁿ.

Fri May 10, 2024
3:00pm to 4:00pm - ISEB 1310 -
Alessandra Pantano, Adityakrishnan Radhakrishnan, Anna Ma - (UCI)
STEM Equity Learning Community (SELC) Project: Towards equitable outcomes for Math Majors

The Introduction to Abstract Mathematics (Math 13) class is a cornerstone of the undergraduate mathematics curriculum and creates the foundation for most upper-division courses. In this talk, we discuss the question: Does Math 13 have equitable outcomes? To do so, we present the findings of our STEM Equity Learning Community (SELC) team, which are based on three data sources: Equity Reports from the SEISMIC Collaboration, midquarter evaluations, and interviews of current Math Majors who have taken Math 13. This talk aims to have a constructive discussion and call to action to continue studying, designing, and implementing interventions for more equitable outcomes for Math Majors.