English

Hyperbolic polynomials and canonical sign patterns

Classical Analysis and ODEs 2022-03-16 v1

Abstract

A real univariate polynomial is hyperbolic if all its roots are real. By Descartes' rule of signs a hyperbolic polynomial (HP) with all coefficients nonvanishing has exactly cc positive and exactly pp negative roots counted with multiplicity, where cc and pp are the numbers of sign changes and sign preservations in the sequence of its coefficients. We discuss the question: If the moduli of all c+pc+p roots are distinct and ordered on the positive half-axis, then at which positions can the pp moduli of negative roots be depending on the positions of the positive and negative signs of the coefficients of the polynomial? We are especially interested in the choices of these signs for which exactly one order of the moduli of the roots is possible.

Keywords

Cite

@article{arxiv.2006.14458,
  title  = {Hyperbolic polynomials and canonical sign patterns},
  author = {Vladimir Petrov Kostov},
  journal= {arXiv preprint arXiv:2006.14458},
  year   = {2022}
}
R2 v1 2026-06-23T16:37:35.515Z