Events for 12/04/2020 from all calendars

Colloquium - Alexandru Hening

Time: 1:00PM - 2:00PM

Location: Zoom

Speaker: Alexandru Hening, Tufts University

Description:
Title: A general theory of coexistence for ecological communities
Abstract: A fundamental question from population biology is finding conditions under which interacting species coexist or go extinct. I present results that lay the foundation for a general theory of stochastic coexistence. This theory extends and makes rigorous Modern Coexistence Theory and leads to resolving a number of conjectures due to Chesson, Ellner, and Palis. I explain how this theory can be used to complete the classification of three-species stochastic ecological systems and end with an important example that shows that random environmental fluctuations can rescue species from extinction.

Geometry Seminar

Time: 4:00PM - 5:00PM

Location: zoom

Speaker: A. Pal, TAMU

Title: Tensors of minimal border rank

Abstract: We know if a collection of square matrices are simultaneously diagonalizable then they commute, however the converse does not hold. It has been a classical problem in linear algebra to classify the closure of the space of simultaneously diagonalizable matrices. This problem is closely related to a problem regarding tensors. In this talk, I shall describe the problem, the relation to the classical question, and recent progress towards classifying minimal border rank tensors. This is joint work with JM Landsberg and Joachim Jelisiejew.