Computing Stieltjes constants using complex integration
Langue
en
Article de revue
Ce document a été publié dans
Mathematics of Computation. 2019, vol. 88, n° 318
American Mathematical Society
Résumé en anglais
The generalized Stieltjes constants $\gamma_n(v)$ are, up to a simple scaling factor, the Laurent series coefficients of the Hurwitz zeta function $\zeta(s,v)$ about its unique pole $s = 1$. In this work, we devise an ...Lire la suite >
The generalized Stieltjes constants $\gamma_n(v)$ are, up to a simple scaling factor, the Laurent series coefficients of the Hurwitz zeta function $\zeta(s,v)$ about its unique pole $s = 1$. In this work, we devise an efficient algorithm to compute these constants to arbitrary precision with rigorous error bounds, for the first time achieving this with low complexity with respect to the order~$n$. Our computations are based on an integral representation with a hyperbolic kernel that decays exponentially fast. The algorithm consists of locating an approximate steepest descent contour and then evaluating the integral numerically in ball arithmetic using the Petras algorithm with a Taylor expansion for bounds near the saddle point. An implementation is provided in the Arb library. We can, for example, compute $\gamma_n(1)$ to 1000 digits in a minute for any $n$ up to $n=10^{100}$. We also provide other interesting integral representations for $\gamma_n(v)$, $\zeta(s)$, $\zeta(s,v)$, some polygamma functions and the Lerch transcendent.< Réduire
Mots clés en anglais
Complex integration
Integral representation
Riemann zeta function
Hurwitz zeta function
Complexity
Numerical integration
Stieltjes constants
Arbitrary-precision arithmetic
Rigorous error bounds
Origine
Importé de halUnités de recherche