Events for 10/12/2020 from all calendars

Geometry Seminar

Time: 3:00PM - 4:00PM

Location: zoom

Speaker: F. Gesmundo, U. Copenhage

Title: Approaching the boundary of tensor network varieties

Abstract: Tensor network states are particular tensors arising via contractions determined by the combinatorics of a weighted graph and are used as ansatz class for a number of problems in applied mathematics. If the graph contains cycles, the corresponding set of tensor network states is (often) not closed in the Zariski topology; its closure is usually referred to as the tensor network variety. There are several tensors of interest lying on the "boundary", that is the difference between the variety and the set itself. In recent work, we introduced sets of tensors, arising in a natural geometric way, which include tensors at the boundary and offer similar properties as the ansatz class of tensor network states. In this seminar, I will introduce the tensor network variety, will show some properties of the boundary and will illustrate how the new ansatz class comes into play. This is based on joint work with M. Christandl, D. Stilck-Franca and A. Werner.

Colloquium - Recent Advances concerning the Navier-Stokes and Euler Equations

Time: 4:00PM - 5:00PM

Location: Zoom

Speaker: Edriss Titi, Texas A&M University

Description: Abstract: In this talk I will discuss some recent progress concerning the Navier-Stokes and Euler equations of incompressible fluid. In particular, issues concerning the lack of uniqueness and the effect of physical boundaries on the potential formation of singularity. In addition, I will present a blow-up criterion based on a class of inviscid regularization for these equations.

Industrial and Applied Math

Time: 6:30PM - 7:30PM

Location: ZOOM

Speaker: Dr. Emma Goldberg, Theoretical Biology group at Los Alamos National Lab

Title: Inferring COVID-19 Epidemiology from the Phylogenetic Tree of Viral Relationships

Abstract: As a virus spreads from person to person, mutations arise in its genome and are transmitted to newly-infected people. This mutational trail of clues can be interpreted as a tree of relationships among viral samples taken from different people. The field of "phylodynamics" uses this type of data and applies mathematical models of viral growth and spread to estimate properties of an epidemic. I will discuss our efforts at phylodynamic modeling for the virus that causes COVID-19, focusing especially on identifying introductions of the virus into New Mexico and clusters of local spread within the state. By combining applied mathematical modeling with genetic sequencing technology and public health data, our team is uncovering actionable information about the spread of this virus.