On the Shift Semigroup on the Hardy Space of Dirichlet Series
We develop a Wold decomposition for the shift semigroup on the Hardy space H-2 of square summable Dirichlet series convergent in the half-plane R(s) > 1/2. As an application we have that a shift invariant subspace of H-2 is unitarily equivalent to H-2 if and only if it has the form phi H-2 for some H-2-inner function phi.
