C&O Reading Group - Julian Romero

Monday, May 11, 2015 4:15 pm - 4:15 pm EDT (GMT -04:00)

Title: A positive semidefinite approximation for the cone of non-negative polynomials
( by Romero and Velasco)

Speaker: Julian Romero
Affiliation: University of Waterloo
Room: MC 6486

Abstract: This is a reminder for our next meeting that will take place on Monday in MC6486.

Door will open at 4pm. As usual we will have 15 mins for socializing and for eating pizza before the talk starts (at 4:15pm sharp).
Testing the non-negativity of multivariate polynomials is an
NP-complete problem that has various applications, see for example
http://www.princeton.edu/~amirali/Public/Publications/or_isos.pdf  .

In this talk I will discuss a method due to A. Barvinok et. al. to
approximate compact convex sets supporting a probability measure. The
method uses such measure to define a sequence of spectrahedra
converging to the original convex set and it has the advantage of
being possible to calculate how close is getting each element of the
sequence to the original set.

We will see that this method can be applied to find semidefinite
approximations for the cone of Non-negative Polynomials and I will
show some bounds on how close these approximations are for the cases
of quaternary quartics (polynomials on four variables of degree four)
and ternary sextics (polynomials on three variables of degree six).


The presentation will be based on the following manuscripts:
http://arxiv.org/abs/1409.8272

For more information about our reading group, please visit our webpage
http://www.math.uwaterloo.ca/~k2georgi/reading.htm