Generalizations of Koga's version of the Wiener-Ikehara theorem
Bin Chen, Jasson Vindas
TL;DR
The paper generalizes the Wiener-Ikehara Tauberian theorem by imposing boundary conditions on the real part of the Laplace transform rather than full analytic continuation, extending Koga's 2021 results and replacing monotonicity with log-linearly slowly decreasing behavior. It develops a local pseudofunction boundary framework, proves Laplace-transform, Laplace-Stieltjes-transform, and power-series versions, and provides a rapid renewal-theorem proof (Blackwell) as a key application. Central contributions include new theorems ensuring $S(x)\sim a e^{x}$ under weaker hypotheses, and corollaries that translate these results to renewal theory and Dirichlet-series contexts. The approach broadens Tauberian tools, offering streamlined proofs and potential extensions to Beurling primes and related harmonic-analytic settings with practical impact on renewal theory and analytic number theory.
Abstract
We establish new versions of the Wiener-Ikehara theorem where only boundary assumptions on the real part of the Laplace transform are imposed. Our results generalize and improve a recent theorem of T. Koga [J. Fourier Anal. Appl. 27 (2021), Article No. 18]. As an application, we give a quick Tauberian proof of Blackwell's renewal theorem.
