Skip to main content
College of Sciences
Department of Mathematics

Events

Events Search and Views Navigation

Event Views Navigation

Today

Geometry and Topology Seminar: Eric Hanson, NC State, Topological data analysis via relative homological algebra

SAS 4201

One of the main approaches to topological data analysis is to study discrete invariants of (multiparameter) persistence modules. In this talk, we discuss recent research which utilizes techniques from (relative) homological algebra to interpret classical examples of invariants and define new invariants. The Hilbert function and (generalizations of) the rank invariant serve as our main…

Algebra and Combinatorics Seminar: Nick Mayers, NC State, The quantum k-Bruhat order

SAS 4201

Finding combinatorial interpretations for the structure constants of Schubert polynomials is a long-standing open problem in algebraic combinatorics. In the case where one of the Schubert polynomials is a Schur polynomial, the structure constants are encoded in a poset called the “k-Bruhat order”. In studying the k-Bruhat order, Bergeron and Sottile were led to introduce…

Differential Equations and Nonlinear Analysis Seminar: Jone Apraiz, Universidad del País Vasco, Inverse problem for a one-dimensional fluid-solid interaction model

Zoom

In this talk we will first briefly review some geometric inverse problems we have studied for the one-dimensional heat, wave and Burgers equations. Then, we will consider a one-dimensional fluid-solid interaction model governed by the Burgers equation with a time varying interface. This is a preliminary simplified version of other more complicate and more realistic…

Computational and Applied Mathematics: Isaac Harris, Purdue University, Transmission Eigenvalue Problems for a Scatterer with a Conductive Boundary

SAS 4201

In this talk, we will investigate the acoustic transmission eigenvalue problem associated with an inhomogeneous media with a conductive boundary. These are a new class of eigenvalue problems that are not elliptic, not self-adjoint, and nonlinear, which gives the possibility of complex eigenvalues. The talk will consider the case of an Isotropic and Anisotropic scatterer.…

Colloquium: Bojko Bakalov, NC State, Dynamical Lie algebras

SAS 4201

Quantum computers are physical machines that process information using the principles of quantum mechanics, which in turn is underpinned by linear algebra. The talk will start with a review of Lie algebras (consisting of matrices under the operation of commutator) and their role in quantum mechanics. The dynamical Lie algebra (DLA) of a quantum system…

Stochastics/Discrete Analysis Seminar: Peter Rudzis, UNC Chapel Hill, Well-posedness and stationarity of infinite systems of competing Brownian particles

SAS 4201

A number of continuous interacting particle systems can be described as collections of Brownian particles on the real line whose collision dynamics are mediated by the local times associated with the gaps between adjacent particles.  Examples of systems in this class include the ordered particle dynamics of rank-based diffusions and certain eigenvalue processes arising in…

Pure Math Graduate Student Seminar: Tim Ablondi, Investigating the $\widetilde{B}(V)$ Algebra From Hypertoric Geometry

SAS 2106

This talk will begin by constructing a new algebra based on a generalization of the set of relations for Ozsváth-Szabó's bordered Heegaard Floer algebra $B(n,k)$. Then, I will strengthen an existing result by establishing an isomorphism between our new algebra and the algebra $\widetilde{B}(\mathcal{V})$ associated with an arrangement of real affine hyperplanes. If time permits, I’ll…

Operations Research Seminar: Chao Chen, NC State, Efficient matrix computation for scientific computing and data analytics

4290 Fitts Woolard Hall

Matrix computations are ubiquitous in scientific computing and data science. However, many existing methods consume enormous computational resources for solving increasingly large and complex problems. In this talk, I will describe my work on exploiting mathematical structures and hardware capabilities to accelerate matrix computations. I will focus on a randomized algorithm, namely RChol, for computing…

Geometry and Topology Seminar: François Monard, UC Santa Cruz, The geodesic X-ray transform and boundary behavior

SAS 4201

On a Riemannian manifold with boundary, the X-ray transform integrates a function or a tensor field along all geodesics through the manifold. The reconstruction of the integrand of interest from its X-ray transform is the basis of important inverse problems in seismology and medical imaging. For this transform, statements of injectivity and microlocal stability in the interior of the domain were established some…

Algebra and Combinatorics Seminar: Hugh Thomas, Université du Québec à Montréal, Cyclic actions on noncrossing and nonnesting partitions

SAS 4201

Noncrossing partitions and nonnesting partitions are both counted by Catalan numbers. Noncrossing partitions on admit a natural cyclic action of order 2n, induced by the Kreweras complement. Nonnesting partitions admit a natural toggle-based action; in fact, they admit one such action for each choice of Coxeter element of the symmetric group. We prove that the latter actions all…

Special Event: Triangle Area Inverse Problems Weekend

SAS 4201

How to use mathematics to see inside something that is too large or too precious to be opened up? Would you like to learn about the mathematical theory behind medical and seismic imaging? Attend Triangle Area Inverse Problems Weekend at NC State University from Friday October 4 thru Sunday October 6 to learn more. The event is…

Applied Mathematics Graduate Student Seminar: Steven Maio, NC State, A Machine Learning Primal Heuristic for Mixed-Integer Programming

SAS 4201

Applications of machine learning (ML) in mixed-integer program (MIP) optimization is an active area of research. The human-designed heuristics used by MIP solvers rely on domain expertise and years of experience with the expectation of applicability to only a specific problem class. The underlying question is whether training can simulate expertise and experience. We consider…

Algebra and Combinatorics Seminar: John Graf, NC State, Symmetric Functions, Plethysm, and Schur’s Q-functions

SAS 4201

The Schur functions are an important basis of the ring of symmetric functions, and Schur’s Q-functions enjoy many analogous properties as a basis of the subring Gamma. We will begin by discussing various properties and bases of symmetric functions, before moving on to the comparisons between Schur functions and Schur’s Q-functions. In particular, plethysm is…

Differential Equations and Nonlinear Analysis Seminar: Silvia Villa, Università di Genova, Structured stochastic zeroth order optimization

Zoom

In the framework of black-box optimization, I will present new algorithms,  based on the stochastic estimation of the gradient via finite differences with structured directions. I will describe their convergence properties under various assumptions and show some numerical results. Speaker's website: https://www.dima.unige.it/~villa/ Zoom meeting: link