Matrix Completion Problems and Sums of Squares

Series
Research Horizons Seminar
Time
Wednesday, October 26, 2016 - 12:00pm for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Greg Blekherman – Georgia Institute of Technology – https://sites.google.com/site/grrigg/
Organizer
Timothy Duff
A matrix completion problem starts with a partially specified matrix, where some entries are known and some are not. The goal is to find the unknown entries (“complete the matrix”) in such a way that the full matrix satisfies certain properties. We will mostly be interested in completing a partially specified symmetric matrix to a full positive semidefinite matrix. I will give some motivating examples and then explain connections to nonnegative polynomials and sums of squares.