### No Talk - PhD Defense

- Series
- Geometry Topology Working Seminar
- Time
- Friday, April 7, 2023 - 14:00 for
- Location
- Speaker

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- Series
- Geometry Topology Working Seminar
- Time
- Friday, April 7, 2023 - 14:00 for
- Location
- Speaker

- Series
- Stochastics Seminar
- Time
- Thursday, April 6, 2023 - 15:30 for 1 hour (actually 50 minutes)
- Location
- ONLINE
- Speaker
- Adrien Saumard – ENSAI and CREST – adrien.saumard@ensai.fr

- Series
- Colloquia
- Time
- Thursday, April 6, 2023 - 11:00 for 1 hour (actually 50 minutes)
- Location
- Skiles 006
- Speaker
- Gunther Uhlmann – University of Washington – gunther@math.washington.edu

We will consider the inverse problem of determining the sound

speed or index of refraction of a medium by measuring the travel times of

waves going through the medium. This problem arises in global seismology

in an attempt to determine the inner structure of the Earth by measuring

travel times of earthquakes. It also has several applications in optics

and medical imaging among others.

The problem can be recast as a geometric problem: Can one determine

the Riemannian metric of a Riemannian manifold with boundary by

measuring the distance function between boundary points? This is the

boundary rigidity problem.

We will also describe some recent results, joint with Plamen Stefanov

and Andras Vasy, on the partial data case, where you are making

measurements on a subset of the boundary.

- Series
- Analysis Seminar
- Time
- Wednesday, April 5, 2023 - 14:00 for 1 hour (actually 50 minutes)
- Location
- Skiles 005
- Speaker
- Natasha Blitvic – Queen Mary University of London

We will look at a number of interesting examples — some proven, others merely conjectured — of Hamburger moment sequences in combinatorics. We will consider ways in which this positivity may be expected, for instance in different types of combinatorial statistics on perfect matchings that turn out to encode moments in noncommutative analogues of the classical Central Limit Theorem. We will also consider situations in which this positivity may be surprising, and where proving it would open up new approaches to a class of very hard open problems in combinatorics.

- Series
- Geometry Topology Student Seminar
- Time
- Wednesday, April 5, 2023 - 14:00 for
- Location
- Skiles 006
- Speaker
- Alex Nolte – Rice

TBD

- Series
- Graph Theory Seminar
- Time
- Tuesday, April 4, 2023 - 15:45 for 1 hour (actually 50 minutes)
- Location
- Skiles 005
- Speaker
- Vishesh Jain – University of Illinois at Chicago – visheshj@uic.edu

We show that if each edge of the complete bipartite graph $K_{n,n}$ is given a random list of $C(\log n)$ colors from $[n]$, then with high probability, there is a proper edge coloring where the color of each edge comes from the corresponding list. We also prove analogous results for Latin squares and Steiner triple systems. This resolves several related conjectures of Johansson, Luria-Simkin, Casselgren-Häggkvist, Simkin, and Kang-Kelly-Kühn-Methuku-Osthus. I will discuss some of the main ingredients which go into the proof: the Kahn-Kalai conjecture, absorption, and the Lovasz Local Lemma distribution. Based on joint work with Huy Tuan Pham.

- Series
- PDE Seminar
- Time
- Tuesday, April 4, 2023 - 15:00 for 1 hour (actually 50 minutes)
- Location
- Skiles 006
- Speaker
- Ben Seeger – University of Texas at Austin – seeger@math.utexas.edu

TBA

- Series
- Algebra Seminar
- Time
- Monday, April 3, 2023 - 10:20 for 1.5 hours (actually 80 minutes)
- Location
- Skiles 005
- Speaker
- Thuy-Duong Vuong – Standford University – tdvuong@stanford.edu

TBD

- Series
- Combinatorics Seminar
- Time
- Friday, March 31, 2023 - 15:00 for 1 hour (actually 50 minutes)
- Location
- Skiles 249
- Speaker
- Zachary Hamaker – University of Florida

TBA

- Series
- Colloquia
- Time
- Friday, March 31, 2023 - 11:00 for 1 hour (actually 50 minutes)
- Location
- Skiles 249
- Speaker
- Weiqiang Wang – University of Virginia – ww9c@virginia.edu

**Please Note:** Special date and special room

We shall explain a simple remarkable stability phenomenon regarding the centers of the group algebras of the symmetric groups in n letters, as n goes to infinity. The same type of stability phenomenon extends to a wide class of finite groups including wreath products and finite general linear groups. Such stability has connections and applications to the cohomology rings of Hilbert schemes of n points on algebraic surfaces.