English

The disconnectedness of certain sets defined after uni-variate polynomials

Classical Analysis and ODEs 2022-09-26 v3

Abstract

We consider the set of monic real univariate polynomials of a given degree dd with non-vanishing coefficients, with given signs of the coefficients and with given quantities pospos of their positive and negneg of their negative roots (all roots are distinct). For d=6d=6 and for signs of the coefficients (+,,+,+,+,,+)(+,-,+,+,+,-,+), we prove that the set of such polynomials having two positive, two negative and two complex conjugate roots, is not connected. For pos+neg3pos+neg\leq 3 and for any dd, we give the exhaustive answer to the question for which signs of the coefficients there exist polynomials with such values of pospos and negneg.

Keywords

Cite

@article{arxiv.2109.07182,
  title  = {The disconnectedness of certain sets defined after uni-variate polynomials},
  author = {Vladimir Petrov Kostov},
  journal= {arXiv preprint arXiv:2109.07182},
  year   = {2022}
}
R2 v1 2026-06-24T05:58:56.826Z