Fall 2020 Math Departmental Online Meeting Virtual/Zoom
ZoomThere 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.
Events
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Diversity and Inclusion Brown Bag Lunch via Zoom
ZoomOrganizer: Seth Sullivant smsulli2@ncsu.edu
Peter McGrath, NC State, Quantitative Isoperimetric Inequalities on Riemannian Surfaces
ZoomIn 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 domains with vanishing scattering asymmetry by their rotational symmetry. We also give a new proof…
Seth Sullivant, Applying for Graduate Fellowships Virtual/Zoom
ZoomOrganizer: Seth Sullivant smsulli2@ncsu.edu
Adam Lowrance, Vassar College, Extremal Khovanov homology of Turaev genus one links
ZoomThe 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 Turaev genus of a link is the minimum genus of the Turaev surface for any…
Michael Shearer, North Carolina State University, Riemann Problems for the BBM Equation
ZoomThe 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, in which a smoothed step function initial condition u(x,0) exhibits long-time behavior that is a…
NCSU Math Department Staff, Meet the Staff Virtual/Zoom
ZoomOrganizer: Seth Sullivant smsulli2@ncsu.edu
Diversity and Inclusion Brown Bag Lunch via Zoom
ZoomOrganizer: Seth Sullivant smsulli2@ncsu.edu
Felipe Gonçalves, University of Bonn, Germany, Sign Uncertainty
ZoomWe 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. Ramos and D. Oliveira e Silva. Website: https://sites.google.com/view/paw-seminar Host: Paata Ivanisvili pivanis@ncsu.edu
Paris Perdikaris, University of of Pennsylvania, When and why physics-informed neural networks fail to train: A neural tangent kernel perspective
ZoomPhysics-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 neural networks behave during their training via gradient descent. More importantly, even less is known…
Geometry/Topology Social Hour
ZoomCome 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 the geometry and topology seminar list. If you are not on the list, please, contact the…
Luis Briceno, Universidad Técnica Federico Santa María, Chile, Splitting algorithms for non-smooth convex optimization: Review, projections, and applications
ZoomIn 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 special attention to constrained convex optimization, in which we accelerate the performance of the algorithms…
Peter McGrath and Ralph Smith Virtual/ Zoom
ZoomOrganizer: Seth Sullivant smsulli2@ncsu.edu
Piotr Nayar, University of Warsaw, Poland, Sharp variance-entropy comparison for Gaussian quadratic forms
ZoomWe 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
Teemu Saksala NC State, Probing an unknown elastic body with waves that scatter once. An inverse problem in anisotropic elasticity.
ZoomWe 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 waves propagate inside the domain and scatter from an unknown point scatterer. We measure the entering…
Boris Muha, University of Zagreb, Croatia, Analysis of Moving Boundary Fluid-Structure Interaction Problems Arising in Hemodynamics
ZoomFluid-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 partial differential equations (PDEs) of mixed hyperbolic-parabolic type, defined on time-changing domains. In this lecture…
Jo-Ann Cohen and Ilse Ipsen, Diversity Statement Workshop Virtual/Zoom
ZoomOrganizer: Seth Sullivant smsulli2@ncsu.edu
Diversity and Inclusion Brown Bag Lunch via Zoom
ZoomOrganizer: Seth Sullivant smsulli2@ncsu.edu
Varun Jog, University of Wisconsin-Madison, Reverse Euclidean and Gaussian isoperimetric inequalities for parallel sets with applications
The r-parallel set of a measurable set A is the set of all points whose distance from A is at most r. In this talk, we discuss some recent results that establish upper bounds on the Euclidean and Gaussian surface areas of r-parallel sets. We also discuss a reverse form of the Brunn-Minkowski inequality for…