scholarly journals Asymptotic series and Stieltjes continued fractions for a gamma function ratio

1978 ◽  
Vol 4 (2) ◽  
pp. 105-111 ◽  
Author(s):  
K.O. Bowman ◽  
L.R. Shenton
Author(s):  
V. N. Singh

Ramanujan's Continued Fraction may be stated as follows: Let where there are eight gamma functions in each product and the ambiguous signs are so chosen that the argument of each gamma function contains one of the specified number of minus signs. Then where the products and the sums on the right range over the numbers α, β, γ, δ, ε: provided that one of the numbers β, γ, δ, ε is equal to ± ±n, where n is a positive integer. In 1935, Watson (3) proved the theorem by induction and also gave a basic analogue. In this paper we give a new proof of Ramanujan's Continued Fraction by using the transformation of Bauer and Muir in the theory of continued fractions (Perron (1), §7;(2), §2).


2010 ◽  
Vol 08 (03) ◽  
pp. 315-322 ◽  
Author(s):  
XIQUAN SHI ◽  
FENGSHAN LIU ◽  
HONGMIN QU

Different from the famous Stirling's formula [Formula: see text], Burnside presented another formula [Formula: see text]. In this paper, some estimations and a convergent asymptotic series of b(s) are obtained. At the same time, it is proved that both -b(s) and [Formula: see text] are completely monotonic on the interval (½, ∞).


2006 ◽  
Vol 195 (1-2) ◽  
pp. 134-154 ◽  
Author(s):  
Xiquan Shi ◽  
Fengshan Liu ◽  
Minghan Hu

Author(s):  
Gergő Nemes

In 1994 Boyd derived a resurgence representation for the gamma function, exploiting the 1991 reformulation of the method of steepest descents by Berry and Howls. Using this representation, he was able to derive a number of properties of the asymptotic expansion for the gamma function, including explicit and realistic error bounds, the smooth transition of the Stokes discontinuities and asymptotics for the late coefficients. The main aim of this paper is to modify Boyd’s resurgence formula, making it suitable for deriving better error estimates for the asymptotic expansions of the gamma function and its reciprocal. We also prove the exponentially improved versions of these expansions complete with error terms. Finally, we provide new (formal) asymptotic expansions for the coefficients appearing in the asymptotic series and compare their numerical efficacy with the results of earlier authors.


The Stokes lines for Г( z ) are the positive and negative imaginary axes, where all terms in the divergent asymptotic expansion for In Г( z ) have the same phase. On crossing these lines from the right to the left half-plane, infinitely many subdominant exponentials appear, rather than the usual one. The exponentials increase in magnitude towards the negative real axis (anti-Stokes line), where they add to produce the poles of Г( z ). Corresponding to each small exponential is a separate component asymptotic series in the expansion for In Г( z ). If each is truncated near its least term, its exponential switches on smoothly across the Stokes lines according to the universal error-function law. By appropriate subtractions from In Г( z ), the switching-on of successively smaller exponentials can be revealed. The procedure is illustrated by numerical computations.


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