LSU College of Science
LSU
Mathematics

Calendar


Time interval:   Events:

Today, Monday, October 15, 2018

Applied Analysis Seminar  Questions or comments?

Posted August 25, 2018
Last modified August 29, 2018

3:30 pm - 4:30 pm Lockett 233

Jiuyi Zhu, LSU
Nodal sets for Robin and Neumann eigenfunctions

We investigate the measure of nodal sets for Robin and Neumann eigenfunctions in the domain and on the boundary of the domain. A polynomial upper bound for the nodal sets is obtained for the Robin eigenfunctions. For the analytic domains, we show a sharp upper bound for the nodal sets on the boundary of the Robin and Neumann eigenfunctions. Furthermore, the sharp doubling inequality and vanishing order are obtained.

Wednesday, October 17, 2018

Informal Geometry and Topology Seminar  Questions or comments?

Posted August 27, 2018

1:30 pm - 3:00 pm Lockett 233

Lucas Meyers, Louisiana State University
TBA


Geometry and Topology Seminar  Seminar website

Posted August 14, 2018
Last modified September 17, 2018

3:30 pm - 4:30 pm Lockett 233

Joshua Sabloff, Haverford College
Length and Width of Lagrangian Cobordisms

Abstract: In this talk, I will discuss two measurements of Lagrangian cobordisms between Legendrian submanifolds in symplectizations: their length and their relative Gromov width. The Gromov width, in particular, is a fundamental global invariant of symplectic manifolds, and a relative version of that width helps understand the geometry of Lagrangian submanifolds of a symplectic manifold. Lower bounds on both the length and the width may be produced by explicit constructions; this talk will concentrate on upper bounds that arise from a filtered version of Legendrian contact homology, a Floer-type invariant. This is joint work with Lisa Traynor.

Monday, October 22, 2018

Algebra and Number Theory Seminar  Questions or comments?

Posted September 7, 2018
Last modified September 30, 2018

3:10 pm - 4:00 pm 232 Lockett

Armin Straub, University of South Alabama
The congruences of Fermat, Euler, Gauss and stronger versions thereof

The Gauss congruences are a natural generalization of the more familiar Fermat and Euler congruences. Interesting families of combinatorial and number theoretic sequences are known to satisfy these congruences. Though a general classification remains wide open, Minton characterized constant recursive sequences satisfying Gauss congruences. We consider the natural extension of this question to Laurent coefficients of multivariate rational functions. One of the motivations for studying Gauss congruences lies in the fact that a certain interesting class of sequences, related to Ap'ery-like constructions of linear forms in zeta values, conjecturally satisfies stronger versions of these congruences. We outline this story and indicate recent developments. The first part of this talk is based on joint work with Frits Beukers and Marc Houben, while the second part includes joint work with Dermot McCarthy and Robert Osburn.


Applied Analysis Seminar  Questions or comments?

Posted September 13, 2018

3:30 pm - 4:30 pm Lockett 233

Blaise Bourdin, Department of Mathematics, Louisiana State University
Variational phase-field models of fracture

Wednesday, October 24, 2018

Informal Geometry and Topology Seminar  Questions or comments?

Posted August 27, 2018

1:30 pm - 3:00 pm Lockett 233

Sudipta Ghosh, Louisiana State University
TBA


Geometry and Topology Seminar  Seminar website

Posted September 14, 2018
Last modified October 1, 2018

3:30 pm - 4:30 pm Lockett 233

Scott Baldridge, LSU
TBA

Thursday, October 25, 2018

Colloquium  Questions or comments?

Posted August 14, 2018

3:30 pm - 4:20 pm TBA

Hongjie Dong, Brown University
TBA

Monday, October 29, 2018

Applied Analysis Seminar  Questions or comments?

Posted August 29, 2018

3:30 pm - 4:30 pm Lockett 233

Robert Lipton, Mathematics Department, LSU
Predicting complex fracture evolution using nonlocal dynamics

The dynamic fracture of brittle solids is a particularly interesting collective interaction connecting both large and small length scales. Apply enough stress or strain to a sample of brittle material and one eventually snaps bonds at the atomistic scale leading to fracture of the macroscopic specimen. We discuss a nonlocal model for calculating dynamic fracture. The force interaction is derived from a double well strain energy density function, resulting in a non- monotonic material model. The material properties change in response to evolving internal forces eliminating the need for a separate phase field to model the fracture set. (However there is no free lunch and the discrete model is posed in terms of a dense matrix and parallel computation must be used to solve fracture problems.) The model can be viewed as a regularized fracture model. In the limit of zero nonlocal interaction, the model recovers a sharp interface evolution characterized by the classic Griffith free energy of brittle fracture with elastic deformation satisfying the linear elastic wave equation off the crack set. We conclude with a numerical analysis of the model which is joint work with Prashant Jha.

Tuesday, October 30, 2018

Computational Mathematics Seminar  

Posted September 5, 2018

3:30 pm - 4:30 pm 1034 Digital Media Center

Shawn Walker, LSU
TBA

Wednesday, October 31, 2018

Informal Geometry and Topology Seminar  Questions or comments?

Posted August 27, 2018

1:30 pm - 3:00 pm Lockett 233

Rima Chatterjee, Louisiana State University
TBA


Geometry and Topology Seminar  Seminar website

Posted August 14, 2018

3:30 pm - 4:30 pm Lockett 233

Matthew Haulmark, Vanderbilt
TBA

Monday, November 5, 2018

Applied Analysis Seminar  Questions or comments?

Posted August 29, 2018

3:30 pm - 4:30 pm Lockett 233

Robert Lipton, Mathematics Department, LSU
Understanding nonlocal models for fracture simulation

The peridynamic model is increasingly being used and developed for fracture simulation. In this talk we go "under the hood" to see how nonlocal models can capture the fracture process and to see how they relate to existing fracture models. Along the way we show how the peridynamic energy is related to the Griffiths fracture energy and how the nonlocal evolution satisfies the principle of least action.

Wednesday, November 7, 2018

Informal Geometry and Topology Seminar  Questions or comments?

Posted August 27, 2018

1:30 pm - 3:00 pm Lockett 233

Rob Quarles, Louisiana State University
TBA


Harmonic Analysis Seminar  Abstract and additional information

Posted September 12, 2018

3:30 pm - 4:20 pm Lockett 232

Anton Zeitlin, LSU
TBA


Geometry and Topology Seminar  Seminar website

Posted October 15, 2018

3:30 pm - 4:30 pm Lockett 233

Andrew McCullough, Georgia Institute of Technology
TBA

Thursday, November 8, 2018

Colloquium  Questions or comments?

Posted October 11, 2018

3:30 pm - 4:20 pm Lockett 232

Scott Ahlgren, University of Illinois at Urbana-Champaign
TBA

Monday, November 12, 2018

Applied Analysis Seminar  Questions or comments?

Posted September 10, 2018

3:30 pm - 4:30 pm Lockett 233

Yuri Antipov, Mathematics Department, LSU
TBA

Tuesday, November 13, 2018

Computational Mathematics Seminar  

Posted September 5, 2018

3:30 pm - 4:30 pm 1034 Digital Media Center

Andrew Gillette, University of Arizona
TBA

Wednesday, November 14, 2018

Informal Geometry and Topology Seminar  Questions or comments?

Posted August 27, 2018

1:30 pm - 3:00 pm Lockett 233

Nurdin Takenov, Louisiana State University
TBA


Geometry and Topology Seminar  Seminar website

Posted October 15, 2018

3:30 pm - 4:30 pm Lockett 233

Marco Marengon, UCLA
TBA