Outer-function characterization in the upper half-plane
Let be a compactification, let be a continuous function with bounded spectrum contained in , and let . Then extends to an entire function bounded in the upper half-plane. The function is outer when it satisfies the outer-function integral condition
Outer-function characterization. The function above is outer if and only if has no zeros in the open upper half-plane.
This connects Hardy-space factorization on the compactification with zero-freeness of the associated entire function. The excerpt presents the assertion without indicating whether it is proved or remains open.
References
Primary source
Wayne Lawton, “Distribution of Small Values of Bohr Almost Periodic Functions with Bounded Spectrum”, arXiv:1904.09373 (2019).
Progress summary
Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.
Solutions 0
No solutions have been posted yet.