## March 2020

## Ryan Vogt, Interface Problems and Binary Electromagnetic Cloaking Devices in Computation Electrodynamics

Chair: Zhilin Li (zhilin@ncsu.edu, contact for Zoom access)

Find out more## Owen Coss, Analyzing the Equilibria of Coupled Oscillators: Finding Stability of and Counting Equilibria for the Generalized Kuramoto Model

Chair: Hoon Hong (hong@ncsu.edu, contact for Zoom access)

Find out more## Seth Watkins, Realization of L(2/Lambda_0) for the Lie algebra A_{2n-1}^{(2)}

Chair: Kailash Misra (misra@ncsu.edu, contact for Zoom access)

Find out more## April 2020

## Benjamin Freedman, Existence and Qualitative Descriptions of Solutions to Nonlinear Boundary Value Problems

Chair: Jesús Rodríguez (rodrigu@ncsu.edu, contact for Zoom access)

Find out more## Isaac Suneri, Design and Sensitivity Analysis of Inverse Problems Governed by Partial Differential Equations

Chair: Alen Alexanderian (alexanderian@ncsu.edu, contact for Zoom access)

Find out more## Ilse Ipsen and Jo-Ann Cohen, Job Search Materials, Via Zoom

Contact Seth Sullivant (smsulli2@ncsu.edu) for more information.

Find out more## Jared Cook, Surrogate Model Construction, Data Assimilation, and Data-Driven Equation Learning to Enable Nonproliferation Capabilities

Chair: Ralph Smith (rsmith@ncsu.edu, contact for Zoom access)

Find out more## Gary Lavigne, Modeling and Quantifying Spatial Strategies of the Innate Immune Response to Viral Infection

Chair: Kevin Flores (kbflores@ncsu.edu, contact for Zoom access)

Find out more## Elizabeth Herman, Design of Inverse Problems and Surrogate Modeling in Complex Physical Systems

Chair: Alen Alexanderian (alexanderian@ncsu.edu, contact for Zoom access)

Find out more## May 2020

## Christine Mennicke, A Data-Driven Framework for Modeling the Neurogenesis-to-Gliogenesis Switch

Chair: Mansoor Haider (mahaider@ncsu.edu, contact for Zoom access)

Find out more## June 2020

## Claire Digirolamo, Applications of GPOPS-II to Optimal Control Problems with Delays

Chair: Stephen Campbell (steve slc@ncsu.edu, contact for Zoom access).

Find out more## Tricity Andrew, Lattice Based Models for Two Dimensional Particle Systems and Random Walks with Internal Collisions

Chair: Mansoor Haider (mahaider@ncsu.edu, contact for Zoom access)

Find out more## August 2020

## Fall 2020 Math Departmental Online Meeting Virtual/Zoom

There will be our usual beginning of the semester meeting next Wednesday, August 12, at 4:15 p.m. The meeting will be held online. Departmental staff and faculty will receive a link.

Find out more## Diversity and Inclusion Brown Bag Lunch via Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Peter McGrath, NC State, Quantitative Isoperimetric Inequalities on Riemannian Surfaces

In this talk, we introduce a scattering asymmetry which measures the asymmetry of a domain on a surface by quantifying its incompatibility with an isometric circle action. We prove a quantitative isoperimetric inequality involving the scattering asymmetry and characterize the…

Find out more## Seth Sullivant, Applying for Graduate Fellowships Virtual/Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Adam Lowrance, Vassar College, Extremal Khovanov homology of Turaev genus one links

The Turaev surface of a link diagram is a surface built from a cobordism between the all-A and all-B Kauffman states of the diagram. The Turaev surface can be seen as a Jones polynomial analogue of the Seifert surface. The…

Find out more## Michael Shearer, North Carolina State University, Riemann Problems for the BBM Equation

The BBM equation is a nonlinear dispersive scalar PDE related to the KdV equation. However, it has a non-convex dispersion relation that introduces a variety of novel wave structures. These waves are highlighted by considering numerical solutions of Riemann problems,…

Find out more## NCSU Math Department Staff, Meet the Staff Virtual/Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Diversity and Inclusion Brown Bag Lunch via Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Felipe Gonçalves, University of Bonn, Germany, Sign Uncertainty

We will talk about the recent developments of the sign uncertainty principle and its relation with sphere packing and quadrature formulas. The talk will mainly be a report of the paper New Sign Uncertainty Principles, joint work with J. P.…

Find out more## September 2020

## Paris Perdikaris, University of of Pennsylvania, When and why physics-informed neural networks fail to train: A neural tangent kernel perspective

Physics-informed neural networks (PINNs) have lately received great attention thanks to their flexibility in tackling a wide range of forward and inverse problems involving partial differential equations. However, despite their noticeable empirical success, little is known about how such constrained…

Find out more## Geometry/Topology Social Hour

Come chat with other geometers/topologists. This is a good chance for graduate students to meet the geometry/topology faculty, especially our newest members, Peter McGrath and Teemu Saksala. Host: Tye Lidman (tlid@math.ncsu.edu) Instructions to join: Zoom invitation is sent to…

Find out more## Luis Briceno, Universidad Técnica Federico Santa María, Chile, Splitting algorithms for non-smooth convex optimization: Review, projections, and applications

In this talk we review some classical algorithms for solving structured convex optimization problems, passing from gradient descent to proximal iterations and going further to modern proximal primal-dual splitting algorithms in the case of more complicated objective functions. We put…

Find out more## Peter McGrath and Ralph Smith Virtual/ Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Piotr Nayar, University of Warsaw, Poland, Sharp variance-entropy comparison for Gaussian quadratic forms

We show that among nonnegative quadratic forms in n independent standard normal random variables, a diagonal form with equal coefficients maximizes differential entropy when variance is fixed. We also discuss some related open problems. Website: https://sites.google.com/view/paw-seminar Host: Paata Ivanisvili pivanis@ncsu.edu

Find out more## Teemu Saksala NC State, Probing an unknown elastic body with waves that scatter once. An inverse problem in anisotropic elasticity.

We consider a geometric inverse problem of recovering some material parameters of an unknown elastic body by probing with elastic waves that scatter once inside the body. That is we send elastic waves from the boundary of an open bounded domain. The…

Find out more## Boris Muha, University of Zagreb, Croatia, Analysis of Moving Boundary Fluid-Structure Interaction Problems Arising in Hemodynamics

Fluid-structure interaction (FSI) problems describe the dynamics of multi-physics systems that involve fluid and solid components. These are everyday phenomena in nature, and arise in various applications ranging from biomedicine to engineering. Mathematically, FSI problems are typically non-linear systems of…

Find out more## Jo-Ann Cohen and Ilse Ipsen, Diversity Statement Workshop Virtual/Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Diversity and Inclusion Brown Bag Lunch via Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Miruna-Stefana Sorea, Max-Planck-Institut für Mathematik in den Naturwissenschaften, The shapes of level curves of real polynomials near strict local minima

We consider a real bivariate polynomial function vanishing at the origin and exhibiting a strict local minimum at this point. We work in a neighbourhood of the origin in which the non-zero level curves of this function are smooth Jordan…

Find out more## Konstantin Tikhomirov, Georgia Institute of Technology, USA, Littlewood-Offord inequalities, and random matrices

I will discuss some aspects of two recent results on singularity of Bernoulli matrices. I will emphasize the use of new Littlewood-Offord-type inequalities in the proofs of the results. Partially based on a joint work with A.Litvak. Zoom meeting…

Find out more## Irina Kogan and Andrew Papanicolaou Virtual/ Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Zakhar Kabluchko, University of Münster, Germany, Expected f-vector of the Poisson Zero Cell

The Poisson hyperplane process describes, roughly speaking, infinitely many hyperplanes thrown uniformly at random into the d-dimensional Euclidean space. The hyperplanes dissect the space into countably many cells. The a.s. unique cell containing the origin is called the Poisson zero…

Find out more## Rupert L. Frank, California Institute of Technology, A ‘liquid-solid’ phase transition in a simple model for swarming

We consider a non-local optimization problem, which is motivated by a simple model for swarming and other self-assembly/aggregation models, and prove the existence of different phases. In particular, we show that in the large mass regime the ground state density…

Find out more## Ilse Ipsen, CV Workshop Virtual/Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Jordan Altmeter, NC State, Hypercube Graph Associahedra

The associahedron is a well-studied polytope. For n dimensions, its vertices are counted by the n-th Catalan number, a sequence starting 1,1,2,5,14,42,... and which counts many, many, many combinatorial objects, such as Dyck paths, planar binary trees, noncrossing set partitions,…

Find out more## Thomas Courtade, UC Berkeley

Website: https://sites.google.com/view/paw-seminar Host: Paata Ivanisvili pivanis@ncsu.edu

Find out more## Darrick Lee Affiliation, University of Pennsylvania, Path Signatures on Lie Groups

Path signatures are powerful nonparametric tools for time series analysis, shown to form a universal and characteristic feature map for Euclidean valued time series data. The theory of path signatures can be lifted to the setting of Lie group valued time series while retaining…

Find out more## Petronela Radu, University of Nebraska-Lincoln, USA, Nonlocal models: theoretical and applied aspects

The emergence of nonlocal theories as promising models in different areas of science (continuum mechanics, biology, image processing) has led the mathematical community to conduct varied investigations of systems of integro-differential equations. In this talk I will present some recent…

Find out more## Craig Douglas, University of Wyoming, Applications of Data Assimilation Methods on a Coupled Dual Porosity Stokes Model

Porous media and conduit coupled systems are heavily used in a variety of areas such as groundwater system, petroleum extraction, and biochemical transport. A coupled dual porosity Stokes model has been proposed to simulate the fluid flow in a dual-porosity media and conduits…

Find out more## October 2020

## Dr. Missy Gaddy, SIAM Mathematics in Industry Seminar

Zoom link: https://ncsu.zoom.us/j/91930283621

Find out more## Andy DeRoin (NCSU GLBT Center), GLBT 101 Virtual/Zoom

We will have a presentation in the graduate training modules. Andy DeRoin from the NCSU GLBT center will give a presentation "GLBT 101". Find out some general information about what it means to be a GLBT person, and how you…

Find out more## Diversity and Inclusion Brown Bag Lunch via Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Oanh Nguyen, Princeton University

Website: https://sites.google.com/view/paw-seminar Host: Paata Ivanisvili pivanis@ncsu.edu

Find out more## Rayanne Luke, University of Delaware, Parameter Identification for Tear Film Thinning and Breakup

Millions of Americans experience dry eye syndrome, a condition that decreases quality of vision and causes ocular discomfort. A phenomenon associated with dry eye syndrome is tear film breakup (TBU), or the formation of dry spots on the eye. The…

Find out more## Roman Aranda, University of Iowa, Diagrams of $\star$-trisections

A trisection of a smooth, connected 4-manifold is a decomposition into three standard pieces. Like the case of Heegaard splittings in dimension three, a trisection is described by a trisection diagram: three sets of curves in a surface satisfying some…

Find out more## Teemu Saksala, North Carolina State University, Generic uniqueness and stability for the mixed ray transform

We consider the mixed ray transform of tensor fields on a three-dimensional compact simple Riemannian manifold with boundary. We prove the injectivity of the transform, up to natural obstructions, and establish stability estimates for the normal operator on generic three…

Find out more## Alen Alexanderian and Paata Ivanisvili Virtual/ Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Diversity and Inclusion Brown Bag Lunch via Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Joseph Cummings, University of Kentucky, Well-Poised Embeddings of Arrangement Varieties

An affine variety is said to be well-poised if is prime for every . Arrangement varieties are a special class of -varieties built from a hyperplane arrangement decorated by polyhedra. We will show that arrangement varieties always have a well-poised embedding and explore their…

Find out more## Sergei Treil, Brown University

Website: https://sites.google.com/view/paw-seminar Host: Paata Ivanisvili pivanis@ncsu.edu

Find out more## Alex Chandler, University of Vienna, Torsion in Thin Regions of Khovanov Homology

In the integral Khovanov homology of links, the presence of odd torsion is rare. Homologically thin links, that is links whose Khovanov homology is supported on two adjacent diagonals, are known to contain only 2-torsion. In this paper, we prove…

Find out more## Oliver Tse, Eindhoven University of Technology, Jump processes as generalized gradient flows

The study of evolution equations in spaces of measures has seen tremendous growth in the last decades, of which resulted in general metric space theories for analyzing variational evolutions—evolutions driven by one or more energies/entropies. On the other hand, physics…

Find out more## Nikki Inglis (NC State University Counseling Center Ambassador), Mental Wellbeing in Graduate School: Navigating Uncertainty Virtual/Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Trivia Night

Next week Friday night from 6-8pm, AMS will host a Trivia Night via Zoom. Unfortunately due to the pandemic, this will be a "bring your own snacks" event. This event is a great way for us to connect as a department…

Find out more## Gennady Uraltsev, University of Virginia, Some results in Banach space-valued time frequency analysis

SIO (Singular Integral Operator) theory and, Calderón-Zygmund theory specifically, developed starting from the '60s, provides a vast array of tools for dealing with operators that resemble the Hilbert transform, an ubiquitous operator in Complex Analysis, semi-linear PDEs, and many other…

Find out more## Abner J. Salgado, University of Tennessee, Knoxville, Fractional Gradient Flows

We consider a so-called fractional gradient flow: an evolution equation aimed at the minimization of a convex and l.s.c. energy, but where the evolution has memory effects. This memory is characterized by the fact that the negative of the (sub)gradient…

Find out more## Beibei Liu, Max Planck Institute / Georgia Tech, The four-ball genus of links via the Heegaard Floer homology

The Heegaard Floer homology introduced by Ozsvath and Szabo provides a lot of link invariants to study links in the three-sphere and its surgery manifolds. In this talk, we exact some invariants from the package to give bounds for the four-ball…

Find out more## Francisco J. Silva, Université de Limoges, Analytical and numerical aspects of variational mean field games

Mean Field Games (MFGs) have been introduced independently by Lasry-Lions and Huang, Malhamé and Caines in 2006. The main purpose of this theory is to simplify the analysis of stochastic differential games with a large number of small and indistinguishable…

Find out more## SIAM Mathematics in Industry Seminar: Make a Difference: Mathematical Sciences R&D Careers at Sandia National Laboratories

Brian Adams and colleagues will conduct a mathematics and statistics-specific information session including a brief overview of SNL’s mission, R&D areas, and opportunities in mathematics, statistics, and computational science. Staff and project profiles will demonstrate the ways you can contribute to high-impact…

Find out more## Zhilin Li and Teemu Saksala Virtual/ Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Diversity and Inclusion Brown Bag Lunch via Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Asgar Jamneshan, UCLA, On some aspects of uncountable ergodic theory

The talk aims at providing an introduction into some basic problems occurring in the ergodic theory of uncountable group actions and a setup and a few tools on how to resolve these issues. This part of the talk shall be…

Find out more## Yahe Yu, Machine learning approach to biological applications: STI strategies for HIV and evolutionary genetics

Chair: Hien Tran (tran@ncsu.edu, contact for Zoom access)

Find out more## John Lagergren, Data-driven discovery and augmentation of mathematical models

Chair: Kevin Flores (kbflores@ncsu.edu, contact for Zoom access).

Find out more## Eric Geiger, NC State, Non-congruent non-degenerate curves with identical signatures

This talk will focus on using the Euclidean Signature to determine whether two smooth planar curves are congruent under the Special Euclidean group. Work done by Emilio Musso and Lorenzo Nicolodi emphasizes that signatures must be used with caution by constructing 1-parameter families of…

Find out more## Braxton Osting, University of Utah, Consistency of archetypal analysis

Archetypal analysis is an unsupervised learning method that uses a convex polytope to summarize multivariate data. For fixed k, the method finds a convex polytope with k vertices, called archetype points, such that the polytope is contained in the convex…

Find out more## Panel of Faculty and Postdocs Interview Strategies Virtual/Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## November 2020

## Kasso Okoudjou, Tufts University, On the HRT Conjecture

Given a non-zero square-integrable function $g$ and $\Lambda=\{(a_k, b_k)\}_{k=1}^N \subset \mathbb{R}^2$ let $\mathcal{G}(g, \Lambda)=\{e^{2\pi i b_k \cdot}g(\cdot - a_k)\}_{k=1}^N.$ The Heil-Ramanathan-Topiwala (HRT) Conjecture is the question of whether $\mathcal{G}(g, \Lambda)$ is linearly independent. For the last two decades, very little…

Find out more## Noemi Petra, UC Merced, Inferring the basal sliding coefficient field for the Stokes ice sheet model under rheological uncertainty

We consider the problem of inferring the basal sliding coefficient field for an uncertain Stokes ice sheet forward model from surface velocity measurements. The uncertainty in the forward model stems from unknown (or uncertain) auxiliary parameters (e.g., rheology parameters). This inverse problem is posed within…

Find out more## Keijo Mönkkönen, University of Jyväskylä, Finland, Geometric inverse problems and ray transforms

I give an introductory talk about geometric inverse problems and ray transforms (no proofs are involved). I mainly focus on the Euclidean X-ray transform of scalar fields and vector fields, but also introduce the basic properties of the X-ray transform…

Find out more## Nick Barron, University of Loyola, Applications of Quasiconvex functions to HJ Equations and Optimal Control

Quasiconvex functions, a major generalization of convex functions, naturally arise in calculus of variations, optimal control and differential games in L-infinity. This connection with HJ equations, representation formulas, obstacle problems, and reach-avoid problems will be discussed. Zoom meeting ID: 802…

Find out more## Diversity and Inclusion Brown Bag Lunch via Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Christoph Thäle, Ruhr-Universität Bochum, Germany, Random Cones

Let $U_1,\ldots,U_n$ be independent random vectors which are uniformly distributed on the unit sphere. The random hyperplanes $U_1^\perp,\ldots,U_n^\perp$ dissect the space into a collection of random cones. A uniform random cone $S_n$ from this collection is called the Schläfli random…

Find out more## Mihaela Paun, University of Glasgow, Assessing model mismatch and model selection in a Bayesian uncertainty quantification analysis of a fluid-dynamics model of pulmonary blood circulation

In this talk I will present a Bayesian approach to quantify the uncertainty of model parameters and hemodynamic predictions in a one-dimensional fluid-dynamics model of the pulmonary system by integrating mouse imaging data and hemodynamic data. The long-term aim is…

Find out more## Geng Chen, University of Kansas, Poiseuille flow of nematic liquid crystals via Ericksen-Leslie model

In this talk, we will discuss a recent global existence result on the Poiseuille flow of nematic liquid crystals via full Ericksen-Leslie model. The existing results on the Ericksen-Leslie model for the liquid crystals mainly focused on the parabolic and…

Find out more## Mariusz Mirek, Rutgers University, Dimension free estimates for the discrete Hardy–Littlewood maximal functions

I will discuss recent progress on dimension-free estimates for the Hardy--Littlewood maximal functions in the continuous and discrete settings. Website: https://sites.google.com/view/paw-seminar Host: Paata Ivanisvili pivanis@ncsu.edu

Find out more## Paata Ivanisvili, North Carolina State University, Enflo’s problem

A nonlinear analogue of the Rademacher type of a Banach space was introduced in classical work of Enflo. The key feature of Enflo type is that its definition uses only the metric structure of the Banach space, while the definition…

Find out more## Diversity and Inclusion Brown Bag Lunch via Zoom

Organizer: Seth Sullivant smsulli2@ncsu.edu

Find out more## Bobby Wilson, University of Washington, Marstrand’s Theorem in general Banach spaces

We will discuss Marstrand's classical theorem concerning the interplay between density of a measure and the Hausdorff dimension of the measure's support in the context of finite-dimensional Banach spaces. This is joint work with David Bate and Tatiana Toro. Website:…

Find out more