Events for 04/24/2019 from all calendars

Min Wang thesis defense

Time: 09:00AM - 10:00AM

Location: BLOC 612

Speaker: Min Wang, Texas A&M University

Number Theory Seminar

Time: 1:45PM - 2:45PM

Location: BLOC 220

Speaker: Ian Petrow, ETH Zürich

Title: The Weyl law for algebraic tori

Abstract: A basic but difficult question in the analytic theory of automorphic forms is: given a reductive group G and a representation r of its L-group, how many automorphic representations of bounded analytic conductor are there? In this talk I will present an answer to this question in the case that G is a torus over a number field.

URL: Event link

Numerical Analysis Seminar

Time: 3:00PM - 4:00PM

Location: BLOC 628

Speaker: Soeren Bartels, University of Freiburg

Title: Approximating gradient flow evolutions of self-avoiding inextensible curves and elastic knots

Abstract: We discuss a semi-implicit numerical scheme that allows for minimizing the bending energy of curves within certain isotopy classes. To this end we consider a weighted sum of a bending energy and a so-called tangent-point functional. We define evolutions via the gradient flow for the total energy within a class of arclength parametrized curves, i.e., given an initial curve we look for a family of inextensible curves that solves the nonlinear evolution equation. Our numerical approximation scheme for the evolution problem is specified via a semi-implicit discretization of the equation with an explicit treatment of the tangent-point functional and a linearization of the arclength condition. The scheme leads to sparse systems of linear equations in the time steps for cubic splines and a nodal treatment of the constraints. The explicit treatment of the nonlocal and nonlinear tangent-point functional avoids working with fully populated matrices and furthermore allows for a straightforward parallelization of its computation. Based on estimates for the second derivative of the tangent-point functional and a uniform bi-Lipschitz radius, we prove a stability result implying energy decay during the evolution as well as maintenance of arc length parametrization. We present some numerical experiments exploring the energy landscape, targeted to the question how to obtain global minimizers of the bending energy in certain knot classes, so-called elastic knots. This is joint work with Philipp Reiter (University of Georgia).

Committee P Meeting

Time: 4:00PM - 5:00PM

Location: BLOC 220

AMUSE

Time: 5:00PM - 7:00PM

Location: BLOC 220

Speaker: A Group of Undergraduate Students, Department of Mathematics, TAMU

Title: Directed Reading Program Presentations

Abstract: 5:00 - 5:15PM Introductions and food; 5:15 - 5:30PM James Woodcock; 5:30 - 5:45PM Guadalupe Valles; 5:45 - 6:00PM Jackson Haynes; 6:00 - 6:15PM Break; 6:15 - 6:30PM Melissa Cruz; 6:30 - 6:45PM Trevor Hollister; 6:45 - 7:00PM Bailey Johnson

First Year Graduate Student Seminar

Time: 5:30PM - 6:30PM

Location: BLOC 628

Speaker: Peter Howard

Title: Summer 2019 and the Years Ahead