English

A simplification of the C-realizability criterion for the Nonnegative Inverse Eigenvalue Problem for integers

Spectral Theory 2024-01-17 v1

Abstract

A multiset Λ={λ1,,λn}\Lambda=\{\lambda_1,\ldots,\lambda_n\} of complex numbers is said to be realizable whenever there exists a nonnegative matrix of order nn with spectrum Λ\Lambda. One of the broadest criterion that guarantees realizability is the CC-realizability. It says that Λ\Lambda, with real numbers, is CC-realizable if it can be obtained starting from nn basic multisets {0},,{0}\{0\},\ldots,\{0\} by successively applying any finite number of times any of the following rules: (a) join two of the multisets; (b) increase by ϵ>0\epsilon>0 the Perron root of one of the multisets; (c) increase by ϵ>0\epsilon>0 the Perron root of one of the multisets and simultaneously increase or decrease by ϵ\epsilon any other value of the same multiset.

Keywords

Cite

@article{arxiv.2401.07857,
  title  = {A simplification of the C-realizability criterion for the Nonnegative Inverse Eigenvalue Problem for integers},
  author = {Alberto Borobia and Roberto Canogar},
  journal= {arXiv preprint arXiv:2401.07857},
  year   = {2024}
}