PIMS-UVic Discrete Math Seminar: Annie Raymond

  • Date: 02/11/2021
  • Time: 10:00
Annie Raymond, University of Massachusetts



Graph Density Inequalities, Sums of Squares and Tropicalization [video]


Establishing inequalities among graph densities is a central pursuit in extremal graph theory. One way to certify the nonnegativity of a graph density expression is to write it as a sum of squares or as a rational sum of squares. In this talk, we will explore how one does so and we will then identify simple conditions under which a graph density expression cannot be a sum of squares or a rational sum of squares. Tropicalization will play a key role for the latter, and will turn out to be an interesting object in itself. This is joint work with Greg Blekherman, Mohit Singh, and Rekha Thomas.

Other Information: 

This seminar took place via zoom and a recording is available on mathtube.org.