Critical structures of inner functions

Abstract

A celebrated theorem of M. Heins says that up to post-composition with a Möbius transformation, a finite Blaschke product is uniquely determined by its critical points. K. Dyakonov suggested that it may interesting to extend this result to infinite degree, however, one needs to be careful since inner functions may have identical critical sets. In this work, we try parametrizing inner functions by 1-generated invariant subspaces of the weighted Bergman space $A_1^2$. Our technique is based on the Liouville correspondence which provides a bridge between complex analysis and non-linear elliptic PDE.

15 pages