2020/11/07 by R. B. Paris, Paris, R B
Mathematics · #33E20 #34E05 #41A60 #Classical Analysis and ODEs (math.CA) #FOS: Mathematics #Mathematical functions and polynomials
paper · pdf · doi:10.48550/arxiv.2011.05156
openalex publication_date 2020/11/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We obtain the asymptotic expansion for large integer n of a generalised sine-integral ∫0^∞((sin x)/(x))ndx by utilising the saddle-point method. This expansion is shown to agree with recent results of J. Schlage-Puchta in \it Commun. Korean Math. Soc. \bf 35 (2020) 1193--1202 who used a different approach. An asymptotic estimate is obtained for another related sine-integral also involving a large power n. Numerical results are given to illustrate the accuracy of this approximation. We also revisit the asymptotics of Ball's integral involving the Bessel function Jν(x), which reduces to the above integral when ν=1/2.