Calendar
Posted September 17, 2026
Last modified September 30, 2026
Informal Combinatorics Seminar
2:30 pm – 3:30 pm Lockett 233
Cayleigh Ritter, LSU
Explanation and Proof of the Five-Color Theorem with Application on the Louisiana Parish Map
Given a geographical map, it is possible to properly color each region a distinct color. Mathematicians have been investigating the minimum number of distinct colors that can be used to properly color a geographical map for centuries. We discuss Heawood’s Five-Color theorem with proof, then apply our results to create an algorithm for coloring a geographical map. Specifically, coloring a parish map of the state of Louisiana.
Event contact: jgarc86@lsu.edu
Posted August 22, 2026
Last modified September 9, 2026
Algebra and Number Theory Seminar Questions or comments?
3:00 pm – 4:00 pm Lockett 233 or click here to attend on Zoom
Paresh Singh Arora, LSU
Reductions of Certain Well-Poised Hypergeometric Character Sums
Whipple’s classical reduction formulas express well-poised hypergeometric series either as products and quotients of gamma values or as gamma factors multiplied by hypergeometric functions, typically of smaller length. Building on work by Greene, McCarthy, and Li–Long–Tu, we establish finite field analogues of three very well-poised identities corresponding to $_4F_3(-1)$, $_5F_4(1)$, and $_6F_5(-1)$. We show that the associated $\ell$-adic Galois representations constructed by Katz and Beukers–Cohen–Mellit are reducible, explicitly identifying one of their constituents in a way that reflects the corresponding Whipple decompositions. As an application, we obtain new correspondences between well-poised hypergeometric data and modular forms.
Event contact: Gene Kopp
Posted August 26, 2026
Last modified September 22, 2026
Informal Analysis Seminar Questions or comments?
12:30 pm – 1:20 pm Wednesday, September 9, 2026 Lockett 233
Elijah Okemwa
The Brachistochrone Problem
In 1696,John Bernoulli posed this problem to folks in the mathematical community at the time. Thus, he asked; If a bead is strung on a wire and acted upon by gravity, and sliding down between two points, what shape should the wire be given so as to minimize the resulting time of descent? Using Euler Lagrange equation and other relevant conditions, we seek to answer this question.
Event contact: Laura Kurtz
Posted August 27, 2026
Last modified September 21, 2026
Informal Geometry and Topology Seminar Questions or comments?
3:30 pm Lockett Hall 233
Adithyan Pandikkadan, Louisiana State University
Exact Couples, Convergence, and Topological Filtrations
We continue our discussion of spectral sequences by looking at exact couples, their convergence, and maps between spectral sequences. After a concrete example, we will see how these ideas arise naturally from filtrations of topological spaces, setting up for the topological constructions ahead.
Posted October 1, 2026
12:30 pm – 1:30 pm Coates 236Optimization in Deep Learning
In this talk, we will introduce some fundamental optimization techniques in deep learning.
Event contact: Keegan Kirk
Posted September 21, 2026
Combinatorics Seminar Questions or comments?
2:30 pm – 3:30 pm Zoom
Sophie Spirkl, University of Waterloo
Cliques and colouring in tournaments
Tournaments are orientations of complete graphs, and many graph theory questions — in particular, from the world of induced subgraphs — have analogues in tournaments. In particular, notions of colouring (due to Neumann-Lara) and clique number (Aboulker, Aubian, Charbit, Lopes) exist. I will tell you what these are, as well as some of what we know about them, and questions that remain.
Posted October 1, 2026
3:30 pm – 4:30 pm Lockett 232
Scott Baldridge, Louisiana State University
Exploring a paper, result, or research direction with AI
Starting from mathematics you already know—a paper, draft, theorem, calculation, or new idea—we’ll use AI to identify related mathematics, explore connections to other areas, generate useful questions, compare with known approaches, test possible generalizations, and distinguish promising leads from superficial associations.
Posted September 24, 2026
Last modified September 30, 2026
Informal Combinatorics Seminar
2:30 pm – 3:30 pm Lockett 233
Hailey Jay Garcia, Louisiana State University
Wild and Domestic Combinatorial Species
Many everyday combinatorial objects, from graphs to permutations, can be realised as a structure known as a combinatorial species. Intuition for these species is varied, with some species simple to define axiomatically, others algorithmically, and still others through functional equations. We discuss the basic operations and definitions of combinatorial species, especially exploring their close relationship with generating functions. We demonstrate instructive examples, and, time permitting, a particular species encountered in the wild.
Event contact: jgarc86@lsu.edu
Posted August 26, 2026
Last modified September 28, 2026
Informal Analysis Seminar Questions or comments?
12:30 pm – 1:20 pm Lockett 233
Hayden Bromley, Louisiana State University
A Peridynamic Field Theory for Damage and Plasticity in Quasi-Brittle Materials.
A field theory developed from a peridynamic approach and designed for predicting damage and plasticity in quasi-brittle materials will be presented. The model is developed from a nonlocal form of the elastic wave equation wherein we replace spatial differential operators with integral operators. Damage and plasticity are captured through a history-dependent two point phase field, so that no separate evolution equation for the phase field is needed. A detailed look at how the model is formulated will be given as well as a terse outline showing well-posedness of a solution. After this, numerical results will be presented exhibiting agreement with experiments both qualitatively and quantitatively. This is joint work with Robert Lipton.
Event contact: Laura Kurtz
Posted August 27, 2026
Informal Geometry and Topology Seminar Questions or comments?
3:30 pm Lockett Hall 233
Evan Short, Louisiana State University
TBD
TBD
Posted August 27, 2026
Last modified October 5, 2026
Informal Geometry and Topology Seminar Questions or comments?
3:30 pm Lockett Hall 233TBD
TBD (SPEAKER TBD AS WELL)
Posted September 29, 2026
Combinatorics Seminar Questions or comments?
2:30 pm – 3:30 pm Lockett 233 (Simulcast via Zoom)
Ann Clifton, Louisiana Tech University
Dissectible Graphs: A Recursive Partitioning Problem
A connected graph, $G$, of order $n$ is said to be \textsl{arbitrarily partitionable} if, for every integer partition $(a_1,\dots,a_k)$ of $n$, there exists an $(a_1,\dots,a_k)$-partition of $V(G)$ so that each subgraph induced on the selected $a_i$ vertices is connected. The study of arbitrarily partitionable graphs is motivated by a resource allocation problem in computer science where $k$ users sharing a network are each competing for $a_i$ resources. In this presentation, we consider a recursive version of this problem, originally conceived by Dean Hoffman, in which the network resources must be distributed as evenly as possible to exactly two users. A graph is said to be \textsl{dissectible} if its vertex set can be partitioned into two balanced subsets (differing in size by at most one) such that each part induces a connected subgraph that is itself dissectible. Although every traceable graph is dissectible, dissectible and arbitrarily partitionable graphs are incomparable, even among trees. We will show that a graph is dissectible if and only if one of its spanning trees is, give a sharp bound on the maximum degree of a dissectible tree, and characterize the dissectible complete bipartite graphs and spiders with a leg of length one. We conclude with a discussion of non-traceable polyhedra and open problems.
Posted October 1, 2026
3:30 pm – 4:30 pm Lockett 232Lab session
We will spend the hour experimenting with the ideas from last week's session. Please bring a paper, result, or research project of your own to work with during the session.
Event contact: Keegan Kirk
Posted October 1, 2026
Informal Combinatorics Seminar
2:30 pm – 3:30 pm Lockett 233
Sean Boros, Louisiana State University
Matroid Connectivity
In this talk, we explore what it means for a matroid to be 2-connected or 3-connected. We will relate this idea to graphs and see when minors of our matroid maintain 2-connectivity or 3-connectivity.
Event contact: jgarc86@lsu.edu
Posted October 1, 2026
Faculty Meeting Questions or comments?
2:30 pm ZoomMeeting of the Tenured Faculty
Posted October 3, 2026
Last modified October 6, 2026
Colloquium Questions or comments?
3:30 pm – 4:20 pm B5 Lockett Hall
Wilhelm Schlag, Yale University
Many questions, few answers; the mathematics community in the AI age
The speaker will share some data on the current mathematical landscape that is changing rapidly. Over the past two months we have witnessed enormous advances both in the power of LLMs, a steep increase in the number of submissions to arxiv, as well as to many journals. Editorial boards are searching for strategies to cope with these challenges. The talk will present some of the thoughts that have come up in this process. You will be asked to participate by sharing your ideas and concerns.
Event contact: Rui Han
Posted October 9, 2026
Informal Combinatorics Seminar
2:30 pm – 3:30 pm Lockett 233
Gyaneshwar Agrahari, LSU
Graph Connectivity: Connections Within and Beyond
How hard is it to disconnect a graph? This simple question leads to some of the central ideas in graph theory. We will explore vertex and edge connectivity, see how disjoint paths provide another way to understand robustness through Menger’s theorem, and look at what stronger connectivity assumptions force a graph to look like. We will finish with examples from planar graphs and triangulations, where high connectivity creates especially rigid structure. The talk will be informal and picture-driven, with an emphasis on intuition rather than technical proofs.
Event contact: jgarc86@lsu.edu
Posted August 26, 2026
Last modified October 12, 2026
Informal Analysis Seminar Questions or comments?
12:30 pm – 1:20 pm Lockett 233
Shrinkal Wagle, Louisiana State University
Introduction to Kinetic Theory
This presentation focuses on the mathematical and physical aspects of kinetic theory, particularly the Boltzmann equation, which describes the evolution of the statistical distribution of a dilute gas. The goal is to provide a first introduction to the Boltzmann equation and the mathematical framework of collisional kinetic theory, assuming no prior background.
Event contact: Laura Kurtz
Posted September 15, 2026
Last modified October 12, 2026
Geometry and Topology Seminar Seminar website
1:30 pm – 2:30 pm Virtual
Ian Cavey, University of Massachusetts Amherst
Combinatorial wall-crossing for Hilbert schemes
I will discuss the minimal model program for the Hilbert scheme of points on the blowup of the affine plane at a point, and for nested Hilbert schemes of points in the plane. I will give explicit descriptions of the resulting birational models for this space and the wall-crossing phenomena relating them. This talk is based on joint work with Eugene Gorsky, Alexei Oblomkov, and Joshua Turner.
Event contact: Kyle Binder
Posted August 27, 2026
Last modified October 13, 2026
Informal Geometry and Topology Seminar Questions or comments?
3:30 pm Lockett Hall 233
Fabian Espinoza de Osambela, Louisiana State University
The Grothendieck Spectral Sequence
Many of the most useful spectral sequences in homological algebra and algebraic geometry turn out to be special cases of a single construction. Given additive functors $F : \mathcal{A} \to \mathcal{B}$ and $G : \mathcal{B} \to \mathcal{C}$ between abelian categories, with $\mathcal{A}$ and $\mathcal{B}$ having enough injectives and $F$ sending injectives to $G$-acyclic objects, Grothendieck’s spectral sequence relates the derived functors of the composite $GF$ to those of $F$ and $G$ separately: $$E_2^{p,q} = R^pG(R^qF(A)) \;\Rightarrow\; R^{p+q}(GF)(A).$$ In this talk I’ll explain where this spectral sequence comes from and discuss the hypotheses that make the construction work, especially the acyclicity condition on $F$. I’ll then look at some of its well-known special cases, such as the Leray spectral sequence. If we have time, I'll also work through some example computations.
Posted September 30, 2026
Last modified October 8, 2026
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom: https://lsu.zoom.us/j/98176468969
Franco Blanchini, University of Udine, Italy
IEEE Fellow, IFAC Fellow
Control Theory and Mechanisms
Mathematics has recently gained recognition as a language for addressing problems in biology, biochemistry, and medicine. Control theory is a branch of mathematics that draws on tools from several mathematical disciplines. Many techniques originally developed to solve control problems can be adapted to address new and relevant questions, both practical and curiosity-driven, in other fields. This talk focuses on the structural analysis of control systems, with the aim of understanding how mechanisms work, why they behave in a certain way, and to what extent they can perform their intended functions reliably, even in the presence of perturbations and disturbances. The first part introduces motivating examples from disciplines outside control theory, illustrating how a control-theoretic approach can provide powerful insights into their underlying principles. The second part introduces the notions of structural and robust properties, discussing paradigmatic case studies from the literature. Robust stability analysis is approached from an inverse perspective: "We know that this system is stable, but why is it so remarkably stable?" Other fundamental concepts, such as (perfect) adaptation, structural steady-state analysis, graph-based loop analysis, and aggregation, are also discussed. The third part presents applications from biology and biochemistry, illustrating the potential impact that control theory, suitably adapted, can have on these disciplines. It highlights how interdisciplinary research can bring fresh perspectives and new challenges to control theorists.
Posted October 15, 2026
Combinatorics Seminar Questions or comments?
2:30 pm – 3:30 pm Zoom
Wayne Ge, Auburn University
Turán problems for matroids representable over finite fields
We review classical Turán-type theorems in graph theory and explore their connections with matroid theory, additive combinatorics, and card games. We then discuss recent developments in extremal problems for matroids representable over finite fields, highlighting how ideas from graph theory extend to this setting.
Posted October 6, 2026
2:30 pm – 3:30 pm Keisler Lounge
Jeremy Shahan, Louisiana State University
Industry Speaker
Jeremy Shahan, who graduated with his Ph.D from LSU in 2025, is visiting to give a talk about his work as a Finite Element Developer at Deep South Crane and Rigging, LLC.
Posted October 16, 2026
3:30 pm – 4:30 pm Lockett 232Practical AI in Math: Auditing a Mathematical Paper with AI
We will try out a new system called AMMA (Adversarial Mathematical Manuscript Audit), developed using ChatGPT. AMMA is designed to read a mathematical paper, identify its main theorems and proof dependencies, and locate mathematical "pressure points" that deserve closer examination. It can then prepare independent blind audit packages that can be run in separate conversations and returned for evaluation. Our initial goal will be to understand the paper's mathematical structure and identify potential pressure points. We will also explore how AMMA prepares multiple blind Audit Units so that different parts of a paper can be checked independently and simultaneously. Zoom Link: https://lsu.zoom.us/j/94717528574?pwd=ntIJF1xWe3ohCMrZelGXVUkjKVTLPk.1 Passcode: 079041
Event contact: Keegan Kirk
Posted October 16, 2026
Informal Combinatorics Seminar
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