English

On the set of fixed points for NRS($m$)

Combinatorics 2025-09-18 v1

Abstract

Let f(z)f(z) be a degree dd polynomial with zeros ziz_i. For arbitrary mm we construct explicit set of fixed points (attractors) of NRS(mm), and prove a factored formula for the Jacobian at these points. We prove that if NRS(2), when applied to ff with an arbitrary starting point, converges to a point (w0,w1)(w_0, w_1), then w0w_0 is of the form zi+zjz_i+z_j for some iji \neq j. As a corollary, we prove a formula expressing the elementary symmetric expansion of the function 1i<jd(zzizj) \prod_{1\leq i < j \leq d} (z - z_i -z_j) in the variables ziz_i in terms of non-intersecting paths on certain directed graphs, using the Lindstr\"om-Gessel-Veinnot Lemma.

Keywords

Cite

@article{arxiv.2509.14176,
  title  = {On the set of fixed points for NRS($m$)},
  author = {Mario DeFranco},
  journal= {arXiv preprint arXiv:2509.14176},
  year   = {2025}
}