This week, the Math/Stats Colloquium welcomes Dominique Guillot (Stanford) to talk about “Critical exponents of graphs: Analysis, combinatorics, and statistics”. Given a positive semidefinite matrix A and a real number a, the entrywise power of A is obtained by taking the ath power of each entry of A. Whether or not the resulting matrix must be positive semidefinite is a non-trivial problem solved in 1977 by FitzGerald and Horn. Motivated by applications in statistics, we examine when powering-up matrices having a given structure of zeros preserves positivity. This talk will discuss the history of the problem, present new results that characterize when entrywise powers preserve positivity, and discuss applications to high-dimensional statistics. Joint with Apoorva Khare and Bala Rajaratnam (Stanford).
Background: One semester linear algebra and one semester analysis.
- Date: Wed Apr 22
- Time: 3-3:50pm
- Room: MH320
- Snacks: 2:30pm in MH331B
For more information, click here to see the full flyer, suitable for printing and posting.
Hope to see you there!
Upcoming events:
- Mon Apr 27: Math/Stats Teaching Career Day, 3:00-4:15pm, MH320
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Wed Apr 29: Dick Canary, U. Michigan (visiting MSRI)“Non-Euclidean sports and the geometry of surfaces”
- Wed May 06: Erica Flapan, Pomona College visiting MSRI
“Topological and Geometric Symmetries of Molecular Structures”