Calendar
Posted June 18, 2026
1:00 pm – 4:00 pm Lockett 232Algebra Qualifying Exam
Event contact: Pallavi Dani
Posted June 18, 2026
1:00 pm – 4:00 pm Lockett 232Applied Mathematics Qualifying Exam
Event contact: Pallavi Dani
Posted August 17, 2026
Last modified August 21, 2026
Informal Geometry and Topology Seminar Questions or comments?
3:30 pm Lockett Hall 233
Krishnendu Kar, Louisiana State University
Matthew Lemoine, Louisiana State University
Organizational Meeting
Please join us on August 26, to discuss the upcoming semester in the Informal Geometry and Topology Seminar. We will be deciding which topic, paper, textbook, or subject, we want to learn more about. For more information, please email Matthew Lemoine or Krishnendu Kar.
Posted August 28, 2026
2:00 pm Lockett 232Seminar Introduction and Organizational Meeting
Event contact: Ben Fehrman
Posted August 27, 2026
Discussion and Training in Combinatorics
2:30 pm – 3:30 pm Lockett 233
Joy Harris
Intro to Graphs and Matroids
We will give a brief introduction to both Matroid Theory and Graph Theory. From the basic ideas of linear independence, we will define, in many equivalent ways, matroids derived from matrices. We will then discuss core definitions of Graph Theory, important properties and classes, and the way that all graphs give rise to matroids.
Event contact: Sean Boros
Posted August 26, 2026
Last modified August 31, 2026
Informal Analysis Seminar Questions or comments?
12:30 pm – 1:20 pm Lockett 233
Christopher Bunting, LSU
Ergodicity for Stochastic Navier-Stokes Equations with Nonlinear Viscosity
In this talk, we consider the stochastic Navier-Stokes equations with nonlinear viscosity and investigate its long-term statistical behavior. After recalling the concepts of invariant and ergodic measures, we focus mainly on the uniqueness of an ergodic invariant measure using a coupling method. An important step in the proof of uniqueness involves a change of drift which allows us to control the trajectory of the solution. These results show that the combined action of stochastic forcing and nonlinear dissipation yields a unique statistical steady state.
Event contact: Laura Kurtz
Posted August 27, 2026
Last modified September 1, 2026
Informal Geometry and Topology Seminar Questions or comments?
3:30 pm Lockett Hall 233
Fabian Espinoza de Osambela, Louisiana State University
What Is a Spectral Sequence? Filtrations, Convergence, and First Examples
This talk kicks off our tour through A User's Guide to Spectral Sequences with Chapter 2. We'll start from a filtration on a chain complex and see how it forces a sequence of successive approximations to the complex's homology, motivating the formal definition of a spectral sequence as a sequence of differential bigraded objects. Along the way, I'll talk a bit about convergence, i.e. what it means for a spectral sequence to converge to a graded object. I'll also weave in motivating examples and framing from Chapter 1 to help set the stage. I likely won't get to everything in the chapter, but the goal is to leave the room comfortable with what a spectral sequence is and why filtrations are the natural place they come from.
Posted August 23, 2026
Last modified August 24, 2026
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom: https://lsu.zoom.us/j/98176468969
Heinz Bauschke, University of British Columbia, Canada
SIAM Fellow
On the Strong Convergence of Some Optimization Algorithms in the Linear Case
Many algorithms in optimization generate a sequence that converges weakly to a solution. Under linearity assumptions, sometimes one obtains more: strong convergence and a formula for the limit. In this talk, I will report on recent work (joint with Sedi Bartz, Yuan Gao, and Walaa Moursi) on the classical KM method and some accelerated algorithms.
Posted September 4, 2026
12:30 pm – 1:30 pm 236 Coates HallStochastic gradient descent
In this talk, we will introduce some fundamental optimization techniques in deep learning.
Event contact: Benjamin Fehrman
Posted September 1, 2026
Faculty Meeting Questions or comments?
1:30 pm – 2:30 pm 232 Lockett HallFaculty Meeting
Posted September 2, 2026
Combinatorics Seminar Questions or comments?
2:30 pm – 3:30 pm Lockett 233 (Simulcast via Zoom)
Hailey Garcia, Louisiana State University
On some structural properties of graphs with non-negative resistance curvature
Resistance curvature is a discrete analogue of curvature on graphs, defined in terms of effective resistance. A graph is called resistance nonnegative (RN), respectively resistance positive (RP), if it admits positive edge weights such that all vertex resistance curvatures are nonnegative, respectively positive. We study the structure of RN and RP graphs in relation to toughness, traceability, and Cartesian products. We disprove a conjecture of Fiedler and answer a question of Devriendt in the negative by constructing, for every n≥11, an n-vertex 1-tough graph that is not RN. We show that RP graphs need not be traceable by proving that Thomassen's 34-vertex graph is RP but not traceable. We characterize RP graphs in terms of the dimension of a polytope associated to the graph. Finally, we introduce the notion of a sprawling graph and resolve a conjecture of Devriendt on grid graphs by proving that all Cartesian products of paths are sprawling and thus RN.
Posted September 4, 2026
Algebra and Number Theory Seminar Questions or comments?
3:00 pm – 4:00 pm Lockett 233 or click here to attend on Zoom
Alexander Betz, LSU
Actions of Fusion Category on Algebras
Fusion categories are rich mathematical objects that generalize finite groups and their representation categories. What does it mean for a fusion category to act on an algebra? Do these actions generalize group actions on algebras? In this talk, we will define an action of a fusion category on an algebra and show how it relates to group actions on algebras. Then, as an application of this theory, we will apply our results to study actions of fusion categories on path algebras.
Posted August 26, 2026
Last modified September 8, 2026
Informal Analysis Seminar Questions or comments?
12:30 pm – 1:20 pm Lockett 233
Long Teng, LSU
Quantitative uniqueness for bi-Laplace equations with potentials
We study quantitative unique continuation for the bi-Laplace equation $\Delta^2u+V(x)u=0$, where the potential (V) may be complex-valued. By introducing new weighted frequency functions adapted to the fourth-order scaling, we establish quantitative three-ball inequalities and upper bounds on the vanishing order of solutions. For bounded potentials, the estimates depend on $|V|{L^\infty}^{1/3}$, while for Hölder continuous potentials this dependence improves to $|V|{C^{0,\beta}}^{1/4}$. A key feature of the argument is that the rescaling-invariant three-ball inequalities and the vanishing-order estimates require related but different choices of frequency functions. This is joint work with Zhiwei Wang and Jiuyi Zhu.
Event contact: Laura Kurtz
Posted August 27, 2026
Last modified September 8, 2026
Informal Geometry and Topology Seminar Questions or comments?
3:30 pm Lockett Hall 233
Matthew Lemoine, Louisiana State University
Kunneth Theorem and Spectral Sequences
In this talk, we will have a recap of our discussion last week on Spectral Sequences. Then we will dive into the Kunneth Theorem and how spectral sequences apply to this theorem. This corresponds to Chapter 2.3 and some of 2.4 in the textbook we are following.
Posted September 9, 2026
Mathematical Physics and Representation Theory Seminar
3:30 pm – 4:20 pm Nicholson Hall 109
Scott Baldridge, Louisiana State University
Quantum invariants of multitudes on manifolds
Aristotle distinguished quantities as either magnitudes or multitudes. Modern geometry has an elegant language for magnitudes: on a manifold 𝑀, one chooses a metric 𝑔, and from that choice one extracts invariants such as curvature 𝑅_𝑔. But there is no comparably natural geometry on manifolds designed to encode discrete invariants. In this talk I introduce a new structure on a smooth manifold 𝑀 called an arithmic 𝜅. Like a metric, an arithmic is additional geometry on the smooth structure, but it is tuned to multitudes rather than magnitudes. Fixing an arithmic canonically produces quantum-information-type data for the pair (𝑀, 𝜅). These invariants play an analogous role as curvature 𝑅(𝑀, 𝑔) does for the pair (𝑀, 𝑔). I will illustrate the theory on smooth 2-manifolds via an explicit arithmic invariant built from a normalized Penrose polynomial 𝑃(𝑀, 𝜅). This suggests that arithmics capture a genuinely new layer of structure on smooth manifolds—one that has not previously been visible through the usual geometry of magnitudes. This lecture is colloquium style with lots of history, pictures, and some crafts.
Posted September 8, 2026
LSU AWM Student Chapter LSU AWM Student Chapter Website
12:30 pm – 1:30 pm Keiser Lounge, Lockett Hall 3rd floorWelcome/Informational Meeting
The Association for Women in Mathematics at LSU is having our first meeting for anyone who supports women in Mathematics. Drop by if you want to learn about who we are, what we do, and how you can join us to build the community together. Food and drinks are provided.
Event contact: lkurtz2@lsu.edu
Posted September 8, 2026
Combinatorics Seminar Questions or comments?
2:30 pm – 3:30 pm ZoomMinor-closed classes of transversal matroids
Transversal matroids are a natural class of matroids, yet their behaviour under contraction remains poorly understood. Several minor-closed subclasses of transversal matroids are now well-studied, including the classes of bicircular and lattice path matroids. In this talk, I will explain some key features of both of these classes, describe some recent progress characterising their intersection, and summarise some subsequent work of Bastida and Toft on contractions of transversal matroids that has culminated in the new minor-closed class of path-circular matroids, which generalises both lattice-path and bicircular matroids. I will conclude with a number of problems that remain open in this area. This talk is based in part on joint work with Charles Semple.
Posted September 10, 2026
Discussion and Training in Combinatorics
2:30 pm – 3:30 pm Lockett 233
Teegan Bailey, LSU
Legends, Tales, and Minor Figures: The Mythology of Graph Theory
The Greeks had Zeus, Hercules, Jason, the Sirens, and more. The Vikings had Odin, Loki, the Valkries, and Ragnarok. We have Ramsey, Dilsworth, Menger, Szemer\'edi, and Erd\'os. Our talk will focus on a lesser known mythos, the lore of Graph Theory. Our story will begin with the tale of creation in K\"onigsberg. We will then proceed to present a broad overview of the cornerstone tales that every practicing graph theorist is familiar with. Time permitting, audience members can expect to walk away from this talk knowing not only the basic terminology essential to this diverse field, but also some of the fundamental questions and results central to studying and conducting research in Graph Theory. This talk will primarily be expository and no background in graph theory will be assumed. The main purpose of this talk will be to equip audience members with the essential definitions needed to attend other talks or presentations on Graph Theory. Minor elementary results may be proved to give a flavor of what a ``typical'' Graph Theory result entails.
Event contact: jgarc86@lsu.edu
Posted August 22, 2026
Last modified September 15, 2026
Algebra and Number Theory Seminar Questions or comments?
3:00 pm – 4:00 pm Lockett 233 or click here to attend on Zoom
Aniketh Sivakumar, Tulane University
Interpolation Problems and the Asymptotic Growth of Minimum Degrees
Interpolation problems study the hypersurfaces in projective space that pass through a given number of points under certain constraints. Among the main questions are determining the minimum degree of such a hypersurface and understanding the number of independent conditions imposed by the points on hypersurfaces of a fixed degree. In this talk, I will begin with the classical formulation of these interpolation problems and introduce some of the tools used to study them. We will then explore the setting where these points are assigned multiplicities and how this is encoded algebraically. This naturally leads us to the Demailly and Chudnovsky conjectures, which describe how the minimum degree grows asymptotically as the multiplicities grow. Finally, we will discuss recent proofs of these conjectures and their connection to containment problems in commutative algebra.
Event contact: Gene Kopp
Posted August 26, 2026
Last modified September 9, 2026
Informal Analysis Seminar Questions or comments?
12:30 pm – 1:20 pm Lockett 233
Zhiwei Wang, Louisiana State University
Quantitative Volume Estimates for Boundary Singular Sets of Dini--$L^p$ elliptic equations
Let $\Omega \subset \mathbb{R}^n$ be a bounded, connected $C^{1,\mathrm{Dini}}$ domain, and let $u \in W_0^{1,2}(\Omega)$ be a nontrivial solution of \[ \Delta u + V(x)u = 0 \quad \text{in } \Omega, \qquad V \in L^p(\Omega),\ p > n . \] We prove that the singular set $\mathcal{S}_\Omega(u) = \{x \in \Omega : u(x) = 0,\ \nabla u(x) = 0\}$ satisfies the codimension-two volume bound \[ \bigl| \mathcal{T}_r(\mathcal{S}_\Omega(u)) \bigr| \lesssim r^2 \] uniformly up to $\partial\Omega$, with a constant depending only on $n$, $p$, the quantitative $C^{1,\mathrm{Dini}}$ character of $\Omega$, and $\|V\|_{L^p}$ --- but not on $u$. Consequently $\mathcal{S}_\Omega(u)$ has finite $(n-2)$-dimensional Minkowski content and $\dim_{\mathrm{Mink}} \mathcal{S}_\Omega(u) \le n-2$. This extends the harmonic theory of Kenig--Zhao to Schr\"odinger operators with $L^p$ potentials. The new ingredient is an interior singular-set estimate for equations with Dini-continuous leading coefficients, proved via harmonic approximation, cone splitting, and a degree-reducing stopping-time packing argument. Flattening and odd reflection then transfer the estimate to the boundary. This is a joint work with Jiuyi Zhu.
Event contact: Laura Kurtz
Posted August 21, 2026
Geometry and Topology Seminar Seminar website
1:30 pm – 2:30 pm Virtual
Claudia He Yun, UiT The Arctic University of Norway
Computing stable homology representations of graph configuration spaces
Configuration spaces parametrize distinct labelled points in a topological space. They have rich geometry and have been studied extensively. In 2011, Church and Farb introduce the idea of representation stability for a sequence of representations $V_n$ of groups $G_n$. Configuration spaces lend themselves naturally to this framework. In this talk, we will focus on configuration spaces of families of graphs with a fixed number of points and discuss their stability behavior, where $V_n$ is taken to be the rational homology and $G_n$ the automorphism group of the underlying graph. We carry out extensive computational work to determine the stable homology representations for several families with 2 points, such as the star graphs, the complete graphs, and the complete bipartite graphs. We also give combinatorial interpretations to some stable subrepresentations. This is joint work with Eric Ramos. Our paper can be found on the arXiv with handle 2606.13813.
Event contact: Christin Bibby
Posted August 27, 2026
Last modified September 14, 2026
Informal Geometry and Topology Seminar Questions or comments?
3:30 pm Lockett Hall 233
Hailey Garcia, Louisiana State University
Convergence, weak and strong; or, how to recover your modules
We continue our discussion of spectral sequences by considering DGAs with filtrations that are weakly or strongly convergent. Alongside a surprising detour into point-set topology (and a sensible condition on filtrations), we show that spectral sequences of filtered DGAs are unique up to completion.
Posted August 26, 2026
Last modified September 3, 2026
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom: https://lsu.zoom.us/j/98176468969
Pelin Guven Geredeli, Clemson University
Qualitative Properties of Multilayered Structure-Fluid Interaction Coupled PDE Dynamics
We consider a composite structure (multilayered) and fluid interaction PDE system which arises in multi-physics problems, and particularly in biofluidic applications related to the mammalian blood transportation process. The PDE system under consideration consists of the interactive coupling of 3D Stokes flow and 3D elastic dynamics which gives rise to an additional 2D elastic equation on the boundary interface between these 3D PDE systems. We first show the existence-uniqueness properties of the coupled system by means of a nonstandard mixed variational formulation and linear semigroup theory. In the second part, we analyze the long-time behavior of the solutions to such FSI coupled system and address the issue of asymptotic decay of this solution to the zero state via a frequency domain approach.
Posted September 14, 2026
Combinatorics Seminar Questions or comments?
2:30 pm – 3:30 pm Lockett 233
Peter Ramsey, Louisiana State University
The Orlik-Solomon Algebra of a Matroid Prescheme
The Orlik–Solomon algebra is a well-known algebraic invariant of a matroid that, for a matroid arising from a hyperplane arrangement, recovers the cohomology ring of the arrangement complement. Matroid preschemes are locally matroidal combinatorial objects that describe the combinatorics of a more general type of arrangement known as an abelian arrangement. However, the usual definition of the Orlik–Solomon algebra fails to capture all of the relevant data in this setting. We introduce a generalization of the Orlik–Solomon algebra for matroid preschemes and explain how it captures the combinatorial structure of the cohomology ring of abelian arrangements.