Article ID Journal Published Year Pages File Type
4620162 Journal of Mathematical Analysis and Applications 2009 9 Pages PDF
Abstract

We study local analytic solutions f of the generalized Dhombres functional equation f(zf(z))=φ(f(z)), where φ is holomorphic at w0≠0, f is holomorphic in some open neighborhood of 0, depending on f, and f(0)=w0. After deriving necessary conditions on φ for the existence of nonconstant solutions f with f(0)=w0 we describe, assuming these conditions, the structure of the set of all formal solutions, provided that w0 is not a root of 1. If |w0|≠1 or if w0 is a Siegel number we show that all formal solutions yield local analytic ones. For w0 with 0<|w0|<1 we give representations of these solutions involving infinite products.

Related Topics
Physical Sciences and Engineering Mathematics Analysis