Abstract view
Transcendental Solutions of a Class of Minimal Functional Equations


Published:20110803
Printed: Jun 2013
Michael Coons,
University of Waterloo, Dept. of Pure Mathematics, Waterloo, ON, N2L 3G1
Abstract
We prove a result concerning power series
$f(z)\in\mathbb{C}[\mkern3mu[z]\mkern3mu]$
satisfying a functional equation of the form
$$
f(z^d)=\sum_{k=1}^n
\frac{A_k(z)}{B_k(z)}f(z)^k,
$$
where $A_k(z),B_k(z)\in
\mathbb{C}[z]$. In particular, we show that if $f(z)$ satisfies a
minimal functional equation of the above form with $n\geqslant 2$,
then $f(z)$ is necessarily transcendental. Towards a more complete
classification, the case $n=1$ is also considered.