Monomials as sums of powers: the Real binary case
arXiv:1005.3050
Abstract
We generalize an example, due to Sylvester, and prove that any monomial of degree $d$ in $\mathbb R[x_0, x_1]$, which is not a power of a variable, cannot be written as a linear combination of fewer than $d$ powers of linear forms.
5 pages