Introduction to the Theory of Quasi-orthogonal Integrals (Researches on isometries from various viewpoints)

Abstract

We give a brief introduction to the theory of continuous quasi-orthogonal decomposition, which is one of the major ingredients of the proof of the Bieberbach conjecture by L. de Branges. However, since it seems that the original text including this theory is no longer available, we refer mainly to Vasyunin-Nikol skiĭ [5]. Furthermore, there is a slight difference between our article and [5]. Our approach to main results is based on the formulation of Ando [1].