Videos

Sums of squares and nonnegative polynomials in multigraded rings

Presenter
December 7, 2012
Keywords:
  • commutative algebra
  • algebraic combinatorics
  • Stanley-Reisner rings
  • sums of squares
  • positive polynomials
  • varieties of minimal degrees
  • toric varieties
  • multigraded rings
MSC:
  • 05-XX
  • 05EXX
  • 05E15
  • 05E40
  • 11E25
  • 42A82
  • 14M25
Abstract
A polynomial with real coefficients is nonnegative if it takes on only nonnegative values. For example, any sum of squares is obviously nonnegative. For a homogeneous polynomial with respect to the standard grading, Hilbert famously characterized when the converse statement hold, i.e. when every nonnegative homogeneous polynomial is a sum of squares. In this talk, we will examine this converse for homogenous polynomials with respect to a positive multigrading. In particular, we will provide many new examples in which every nonnegative homogeneous polynomial is a sum of squares.
Supplementary Materials