Calendar

Time interval: Events:

Monday, October 19, 2026

Posted October 16, 2026

2:30 pm – 3:30 pm Lockett 233

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

Tuesday, October 20, 2026

Posted September 20, 2026

Algebra and Number Theory Seminar Questions or comments?

3:00 pm – 4:00 pm Lockett 233 or click here to attend on Zoom

Murtadha Aljanabi, LSU
TBA

Posted September 29, 2026

Computational Mathematics Seminar

3:30 pm – 4:20 pm LDMC, Room 1034

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

Wednesday, October 21, 2026

Posted August 26, 2026
Last modified October 16, 2026

Informal Analysis Seminar Questions or comments?

12:30 pm – 1:20 pm Lockett 233

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

1:30 pm – 2:30 pm Lockett 233

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

Informal Geometry and Topology Seminar Questions or comments?

3:30 pm Lockett Hall 233

Huong Vo, Louisiana State University
TBD

TBD

Tuesday, October 27, 2026

Posted September 28, 2026

Algebra and Number Theory Seminar Questions or comments?

3:00 pm – 4:00 pm Lockett 233 or click here to attend on Zoom

Yifeng Huang, Emory University
TBA

Wednesday, October 28, 2026

Posted August 26, 2026
Last modified October 6, 2026

Informal Analysis Seminar Questions or comments?

12:30 pm – 1:20 pm Lockett 233

Majid Abubakar, Louisiana State University
Asymptotic Analysis of Integral Functionals of Ergodic Jump-Diffusion Processes under Discretization

tbd

Event contact: Laura Kurtz

Posted September 15, 2026
Last modified October 13, 2026

Geometry and Topology Seminar Seminar website

1:30 pm – 2:30 pm Lockett 233

Colby Kelln, University of Minnesota
Filling flatly fibered cusps of hyperbolic $n$-manifolds

Dehn filling is a classical tool for producing negatively curved manifolds from cusped hyperbolic 3-manifolds, and results of Mosher-Sageev and Fujiwara-Manning extend this idea to higher dimensions when cusp cross sections are tori. In this talk, I will discuss a generalization to hyperbolic manifolds whose cusps can have more complicated cross sections---ones that admit a Riemannian submersion onto a flat base with totally geodesic fiber. Filling along the fibers of such a cusp can still produce a nonpositively (and in some cases negatively) curved space, provided that the fibers have large enough systole. Group theoretically, this filling takes a relatively hyperbolic fundamental group and creates a related hyperbolic one. I'll introduce the Ratcliffe-Tschantz hyperbolic 5-manifold, whose cusps are bundles with Hantzsche-Wendt fiber over the circle, and show how the filling result, coupled with some group theory, gives information about the geometry of its cusps.

Event contact: Jagerynn Ting Verano

Posted August 27, 2026

Informal Geometry and Topology Seminar Questions or comments?

3:30 pm Lockett Hall 233

Krishnendu Kar, Louisiana State University
TBD

TBD

Friday, October 30, 2026

Posted September 21, 2026

Control and Optimization Seminar Questions or comments?

10:30 am – 11:20 am Zoom: https://lsu.zoom.us/j/98176468969

Tim Hoheisel, McGill University, Canada
A Computational Framework for Linear Inverse Problems via the Maximum Entropy on the Mean Method

We present a framework for solving linear inverse problems that is computationally tractable and has mathematical certificates. To this end, we interpret the ground truth of a linear inverse problem as a random vector with unknown distribution. We solve for a distribution which is close to a prior P (guessed or data-driven) measured in the KL-divergence while also having an expectation that yields high fidelity with the given data that defines the problem. After reformulation this yields a strictly convex, finite dimensional optimization problem whose regularizer, the MEM functional, is paired in duality with the log-moment generating function of the prior P. We exploit this computationally via Fenchel-Rockafellar duality. When no obvious guess for P is available, we use data to generate an empirical prior. Using techniques from variational analysis and stochastic optimization, we show that, and at what rate, the solution of the empirical problems converges (as the sample size grows) to the solution of the problem with known prior. Moreover, we show how stochastic subgradient methods can be brought to bear on the MEM dual. This is joint work with Rustum Choksi (McGill), Matthew King-Roskamp (McGill), and Gabriel Rioux (Imperial College).

Wednesday, November 4, 2026

Posted August 26, 2026

Informal Analysis Seminar Questions or comments?

12:30 pm – 1:20 pm Lockett 233

Jackson Knox, Louisiana State University
TBD (Dynamical Systems)

Event contact: Laura Kurtz

Posted September 25, 2026
Last modified October 17, 2026

Geometry and Topology Seminar Seminar website

1:30 pm – 2:30 pm Lockett 233

Steven Clontz, University of South Alabama
Database-Driven Mathematical Inquiry in Topology

Recent advances in computing have changed not only the nature of mathematical computation, but mathematical proof and inquiry itself. While artificial intelligence and formalized mathematics have been the major topics of this conversation, this talk will explore another class of tools for advancing mathematics research: databases of mathematical objects that enable semantic search, particularly the π-Base community database of topological counterexamples

Posted August 27, 2026

Informal Geometry and Topology Seminar Questions or comments?

3:30 pm Lockett Hall 233

Michael Young, Louisiana State University
TBD

TBD

Thursday, November 5, 2026

Posted October 16, 2026

Student Colloquium

10:30 pm TBD

Steven Clontz, University of South Alabama
Accessible and Interactive Mathematical Documents for Instruction

Beginning April 26, 2027, all public universities will be required to ensure digital documents posted online must be accessible to screenreader users. Compliance with the Americans with Disabilities Act can be quite tricky in mathematics, given our reliance on intricate formulas and graphics, and even interactive elements such as code or three-dimensional renders, for research and education. In this talk we will explore three particular tools for meeting this upcoming accessibility requirement: PreTeXt, Prefigure, and Doenet.

Friday, November 6, 2026

Posted September 30, 2026

Control and Optimization Seminar Questions or comments?

10:30 am – 11:20 am Zoom: https://lsu.zoom.us/j/98176468969

Daniel Wachsmuth, University of Wuerzburg, Germany
Solution Algorithms for Nonsmooth Optimal Control Problems Based on the Pontryagin Maximum Principle

The talk is motivated by optimal control problems for partial differential equations. The main interest is in problems that involve integral functions of the type \[\int_\Omega g(u(x)) \ dx,\] where $g : \mathbb R \to \mathbb R$ is nonsmooth and nonconvex, and $u$ is the control variable. Examples involve $L^{\scriptscriptstyle r}$-pseudonorms with $r\in [0,1)$ or problems with the constraint $u(x) \in \mathbb Z$ for $x\in \Omega$. Due to the nonconvexity of $g$, the existence of solutions in $L^{\scriptscriptstyle p}$-spaces cannot be proven. Local solutions (if they exist) can be proven to satisfy the Pontryagin maximum principle. A distinctive feature of this result is that no differentiability with respect to the control variable $u$ is required. The maximum principle serves as a starting point to develop an implementable solution algorithm. We prove that the residual in the maximum principle vanishes along the iterates produced by the algorithm. Under additional assumptions, the iterates are a minimizing sequence.

Tuesday, November 10, 2026

Posted August 22, 2026

Algebra and Number Theory Seminar Questions or comments?

3:00 pm – 4:00 pm Lockett 233 or click here to attend on Zoom

Isabella Negrini, University of Toronto
TBA

Event contact: Gene Kopp

Wednesday, November 11, 2026

Posted August 26, 2026

Informal Analysis Seminar Questions or comments?

12:30 pm – 1:20 pm Lockett 233

Ruben Acevedo Acevedo, Louisiana State University
TBD (Spectral Theory)

Posted September 15, 2026