Blaschke cocycles and generators (Q807920)

This paper is in the context of work by \textit{H. Helson} [J. Lond. Math. Soc., II. Ser. 1, 237-242 (1969; Zbl 0183.147), Stud. Math. 44, 493-505 (1972; Zbl 0215.471), Algebras Anal., Proc. Conf. Birmingham 1973, 1-62 (1975; Zbl 0321.43009)] to which reference is made. Here the author characterises singly generated invariant subspaces in terms of certain Blaschke cocycles. The key for this is a concept of multiplicity function.