All Questions
Tagged with stability polynomials
3 questions
10
votes
1
answer
478
views
Symmetric polynomials that detect positivity
Imagine there are numbers $a_1,\ldots,a_n \in \mathbb R$ and you want to know whether they are all positive. You cannot access the numbers themselves, but you can choose any symmetric polynomials you ...
3
votes
0
answers
62
views
Part 2: When does the maximal root of this polynomial have unit magnitude? Prove an inverse linear relation between parameters
Examine the polynomial
$$
x^{\tau+1}-\left(1+m\right)x^{\tau}+mx^{\tau-1}+\left(1-m\right)\alpha=0\,.
$$
with positive parameters $\tau,\alpha$ and $m<1$, and denote $\left|x_{\max}\left(\tau,\...
4
votes
1
answer
126
views
When does the maximal root of this polynomial have unit magnitude? Prove an inverse linear relation between parameters
Examine the polynomial
$$
x^{\tau+1}-x^{\tau}+\alpha=0\,
$$
and denote by $\left|x_{\max}\left(\tau,\alpha\right)\right|$ as the
maximal magnitude of a root of this equation. For $\tau>1$, I ...