English

Beyond Descartes' rule of signs

Classical Analysis and ODEs 2023-06-23 v1

Abstract

We consider real univariate polynomials with all roots real. Such a polynomial with cc sign changes and pp sign preservations in the sequence of its coefficients has cc positive and pp negative roots counted with multiplicity. Suppose that all moduli of roots are distinct; we consider them as ordered on the positive half-axis. We ask the question: If the positions of the sign changes are known, what can the positions of the moduli of negative roots be? We prove several new results which show how far from trivial the answer to this question is.

Keywords

Cite

@article{arxiv.2302.05127,
  title  = {Beyond Descartes' rule of signs},
  author = {Vladimir Petrov Kostov},
  journal= {arXiv preprint arXiv:2302.05127},
  year   = {2023}
}