English

An entire function connected with the approximation of the golden ratio

Complex Variables 2019-06-11 v3 Functional Analysis

Abstract

In 1987, R. B. Paris uses the analytic function \labelmaing(w)=limn(2φ)n(1+1+...1+wnφ),   φ=1+52,\label{main} g(w)=\lim_{n\to\infty}(2\varphi)^n\biggl(\underbrace{\sqrt{1+\sqrt{1+...\sqrt{1+w}}}}_n-\varphi\biggr),\ \ \ \varphi=\frac{1+\sqrt{5}}2, to estimate the convergence of nested squares to the golden ratio. The function gg is non-entire and, perhaps, can not be expressed in terms of some standard known functions. We show that f(z):=g1(z)f(z):=g^{-1}(z) is an entire function satisfying Poincare equality. While ff has zeros of various multiplicities, it can be expressed in terms of its simple zeros, forming fractal structures similar to Julia sets.

Keywords

Cite

@article{arxiv.1906.01059,
  title  = {An entire function connected with the approximation of the golden ratio},
  author = {Anton A. Kutsenko},
  journal= {arXiv preprint arXiv:1906.01059},
  year   = {2019}
}

Comments

Article illustrates in simple manner a connection between recurrent formulas, entire functions, polynomial dynamics, and corresponding Julia sets