A problem on completeness of exponentials (Q375296)

From the abstract: ``Let \(\mu\) be a finite positive measure on the real line. For \(a>0\), denote by \(E_a\) the family of exponential functions \(\{e^{ist}: s\in[0,a]\}\). The exponential type of \(\mu\) is the infimum of all numbers \(a\) such that the finite linear combinations of the exponentials from from \(E_a\) are dense in \(L^2(\mu)\).'' In the paper under review the well-known problem of finding the exponential type of \(\mu\) in terms of \(\mu\) is solved. A broad picture of the related problems and their interplay is one of the advantages of the paper.