English

On Hilbert's construction of positive polynomials

Algebraic Geometry 2007-07-17 v1 Number Theory

Abstract

In 1888, Hilbert described how to find real polynomials in more than one variable which take only non-negative values but are not a sum of squares of polynomials. His construction was so restrictive that no explicit examples appeared until the late 1960s. We revisit and generalize Hilbert's construction and present many such polynomials.

Keywords

Cite

@article{arxiv.0707.2156,
  title  = {On Hilbert's construction of positive polynomials},
  author = {Bruce Reznick},
  journal= {arXiv preprint arXiv:0707.2156},
  year   = {2007}
}
R2 v1 2026-06-21T08:58:21.863Z