论文标题
实用的多项式和广义的Hermite-Sylvester定理
Real-rooted polynomials and a generalised Hermite-Sylvester theorem
论文作者
论文摘要
如果多项式所有根都是真实的,则将其根深蒂固。对于{\ mathbf r} [t] $中的每个多项式$ f(t)\,Hermite-Sylvester定理将二次形式$φ_2$关联,使得$ f(t)$是真实的,并且只有$φ_2$是正面的。在此注释中,对于每个正整数$ m $,构建200万美元的$ $φ_{2M} $,以至于$ f(t)$仅当$φ_{2M {2M} $才能实现,当时仅是$ m $的$ m $,仅当$ m $ IF $ $; if $φ_{2M}(x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1,x_1, $ m $。
A polynomial is real-rooted if all of its roots are real. For every polynomial $f(t) \in {\mathbf R}[t]$, the Hermite-Sylvester theorem associates a quadratic form $Φ_2$ such that $f(t)$ is real-rooted if and only if $Φ_2$ is positive semidefinite. In this note, for every positive integer $m$, an $2m$-adic form $Φ_{2m}$ is constructed such that $f(t)$ is real-rooted if and only if $Φ_{2m}$ is positive semidefinite for some $m$ if and only if $Φ_{2m}(x_1,\ldots, x_n)$ is positive semidefinite for all $m$.