2005/11/03 by Ernst Joachim Weniger, Weniger, Ernst Joachim
Mathematics · Physics and Astronomy · #11M06 #33C05 #33C70 #Classical Analysis and ODEs (math.CA) #FOS: Mathematics #Mathematical functions and polynomials #Numerical methods for differential equations #Scientific Research and Discoveries
paper · pdf · doi:10.48550/arxiv.math/0511074
openalex publication_date 2005/11/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Asymptotic approximations (n → ∞) to the truncation errors rn = - ∑ν=0∞ aν of infinite series ∑ν=0∞ aν for special functions are constructed by solving a system of linear equations. The linear equations follow from an approximative solution of the inhomogeneous difference equation Δrn = an+1. In the case of the remainder of the Dirichlet series for the Riemann zeta function, the linear equations can be solved in closed form, reproducing the corresponding Euler-Maclaurin formula. In the case of the other series considered -- the Gaussian hypergeometric series 2 F1 (a, b; c; z) and the divergent asymptotic inverse power series for the exponential integral E1 (z) -- the corresponding linear equations are solved symbolically with the help of Maple. The practical usefulness of the new formalism is demonstrated by some numerical examples.