an:01006728
Zbl 0881.11068
Queff??lec, H.
H. Bohr's vision of ordinary Dirichlet series; old and new results
EN
J. Anal. 3, 43-60 (1995).
00036755
1995
j
11M41 40A05 11K99 43A46 60G15 60E15 30B50
Dirichlet series; probabilistic estimate; abscissa of uniform convergence; open questions
The author discusses briefly a theorem of Harald Bohr from 1913: \(\sum_{n=1}^\infty a_nn^{-s}\) has a finite abscissa of uniform convergence \(\sigma_u\) implies \(\sum_{p\text{ prime}}|a_p|p^{-s}\) converges for \(\sigma>\sigma_u\), and a theorem of Hewitt and Williamson about ordinary Dirichlet series representations of the reciprocals of absolutely convergent Dirichlet series. He proves a substantial generalization of Bohr's result which leads to a probabilistic estimate connected with the determination of the abscissa of uniform convergence.
The author also obtains a new proof of the result of \textit{E. Hille} and \textit{H. F. Bohnenblust} [Ann. Math., II. Ser. 32, 600-622 (1931; Zbl 0001.12901)] that Bohr's estimate \(\sigma_a- \sigma_u\leq 1/2\) (where \(\sigma_a\) is the abscissa of absolute convergence and \(\sigma_u\) as above) is best possible. This is based on a new result improving an earlier one of his. He also gives a novel proof of the result of Hewitt and Williamson using Bohr's ``vision''. The paper closes with some open questions.
S.L.Segal (Rochester)
Zbl 0001.12901