Calendar

Posted October 16, 2026

Informal Combinatorics Seminar

Sean Boros, Louisiana State University
Hailey Jay Garcia, Louisiana State University
SageMath for Combinatorialists

SageMath is a free, open-source computer algebra system. In this workshop, we'll tour what it offers combinatorialists (focusing on graphs and matroids), then split into small groups to get hands-on experience. No experience or install of Sage or Python is needed. Bring a laptop.

Event contact: jgarc86@lsu.edu

Posted September 20, 2026

Algebra and Number Theory Seminar Questions or comments?

Murtadha Aljanabi, LSU
TBA

Posted September 29, 2026

Computational Mathematics Seminar

Mansur Shakipov, University of Houston
A Stokes–Cahn–Hilliard Model of a Phase-Separated Fluid Membrane: Analysis and Discretization

We study the surface Stokes–Cahn–Hilliard system governing tangential flow and phase separation in viscous fluid membranes. The equations are posed on a closed stationary surface embedded in 3D. We first address the questions of well-posedness, continuous dependence and higher-regularity. We then propose an unfitted finite element method with a novel stabilization term that eliminates spurious velocity components associated with Killing fields in the numerical solution. Assuming geometric exactness, we derive error estimates in the energy and L2 norms for the spatially-discrete method. Finally, we explore the model computationally.

Event contact: Shawn Walker

Posted August 26, 2026
Last modified October 16, 2026

Informal Analysis Seminar Questions or comments?

Sayandeep Sarkar, Louisiana State University
Specular reflection limits of the confined Vlasov-Boltzmann equation

In In this talk, we continue our study of the Boltzmann equation, focusing on the behavior of gas particles under different boundary conditions. One important boundary condition is specular reflection, which describes how particles bounce off a solid wall while preserving their speed. We consider a different approach to modeling this behavior by introducing a Vlasov-type potential into the Boltzmann equation. Instead of imposing a reflecting boundary directly, we use a strong potential barrier that pushes particles back into the domain. As the potential barrier becomes stronger, we expect the particles to behave increasingly like those undergoing specular reflection. Our main goal is to study how the solution of this modified Vlasov–Boltzmann equation converges to the solutions of the classical Boltzmann equation with specular reflection boundary conditions. We discuss the mathematical ideas behind this convergence, beginning with a simple half-space domain and considering possible extensions to more general domains.

Event contact: Laura Kurtz

Posted September 15, 2026
Last modified October 14, 2026

Geometry and Topology Seminar Seminar website

Emily Stark, Wesleyan University
Rigidity for hyperbolic groups with Pontryagin sphere boundary

The Pontryagin sphere is a homogeneous, nowhere planar, compact 2-dimensional fractal constructed as an inverse limit of closed orientable surfaces. The Pontryagin sphere arises naturally as the boundary at infinity of the fundamental group of a 3-dimensional hyperbolic pseudo-manifold. We prove that if the conformal dimension of the boundary is less than four, then such a group is action rigid: if it acts geometrically on the same proper metric space as another group, then the groups are virtually isomorphic. A key component of the proof is a generalization of Yang's Theorem regarding the structure of p-adic actions on a tree of manifolds. This is joint work with Chris Cashen, Pallavi Dani, and Kevin Schreve.

Event contact: Kevin Schreve

Posted August 27, 2026
Last modified October 17, 2026

Informal Geometry and Topology Seminar Questions or comments?

Huong Vo, Louisiana State University
Whitehead complexes and free splittings

In this talk, I will introduce the Whitehead complex constructed from a non-positively curved cube complex. The Whitehead complex can then be used to detect the free splittings of the cube complex's fundamental group.

Posted October 18, 2026

Harmonic Analysis Seminar

Vishwa Dewage, University of Vienna, Vienna, Austria
Quantum harmonic analysis on the weighted Bergman space of a bounded symmetric domain

In Werner's Quantum harmonic analysis (QHA) we develop notions in classical harmonic analysis, such as convolutions and the Fourier transform for operators in place of functions. In this work, we set up QHA on the weighted Bergman space of a bounded symmetric domain, where Toeplitz operators and Berezin transforms arise naturally as convolutions. Using the $\alpha$-Berezin transform, we obtain a characterization of Toeplitz operators and approximation results by Toeplitz operators, including a description of the radial Toeplitz algebra. We then introduce invariant differential operators that act on operators on the Bergman space. A key role is played by an explicit invariant differential operator that shifts the $\alpha$-Berezin transform, which leads to a discrete heat-type equation and a further characterization of the radial Toeplitz algebra through its domain. This is joint work with Matthew Dawson and Gestur Ólafsson.