Asymptotic expansions and converging factors I. General theory and basic converging factors

It is shown that by the application of Borel’s method of summation to the later terms of an asymptotic expansion, the ‘sum’ of such terms can normally be replaced by an easily calculable series involving ‘basic converging factors’. As particular consequences, [i] the remainder in a truncated asymptotic expansion can be written down once the general term in the expansion is known; [ii] the converging factor for a given asymptotic expansion can conveniently be calculated from the basic converging factors; and [iii] the Stokes phenomenon is simply expressed in terms of discontinuities in these basic quantities. Formulae and tables are given for the basic converging factors.

2010 ◽  
Vol 77 (3) ◽  
Author(s):  
Claire David ◽  
Marine Marcilhac ◽  
Alain Rigolot

The classical strength of materials for beams is represented through the first two terms of the asymptotic expansion of the solution of Navier’s equations. The method of asymptotic expansions with respect to the inverse of the slenderness of the beam permits us to obtain an approximate solution of Saint-Venant’s problem. For the elasticity of the second order, the displacement field is obtained as the sum of a series, the general term of which at the nth order is the solution of a differential recursive system. We presently propose a general way of solving this kind of system. The exact solution is given explicitly in the case of a slender field (beam).


Author(s):  
OLGA BALKANOVA ◽  
DMITRY FROLENKOV ◽  
MORTEN S. RISAGER

Abstract The Zagier L-series encode data of real quadratic fields. We study the average size of these L-series, and prove asymptotic expansions and omega results for the expansion. We then show how the error term in the asymptotic expansion can be used to obtain error terms in the prime geodesic theorem.


1997 ◽  
Vol 29 (02) ◽  
pp. 374-387 ◽  
Author(s):  
V. Čekanavičius

The accuracy of the Normal or Poisson approximations can be significantly improved by adding part of an asymptotic expansion in the exponent. The signed-compound-Poisson measures obtained in this manner can be of the same structure as the Poisson distribution. For large deviations we prove that signed-compound-Poisson measures enlarge the zone of equivalence for tails.


2017 ◽  
Vol 13 (08) ◽  
pp. 2097-2113 ◽  
Author(s):  
Shubho Banerjee ◽  
Blake Wilkerson

We study the Lambert series [Formula: see text], for all [Formula: see text]. We obtain the complete asymptotic expansion of [Formula: see text] near [Formula: see text]. Our analysis of the Lambert series yields the asymptotic forms for several related [Formula: see text]-series: the [Formula: see text]-gamma and [Formula: see text]-polygamma functions, the [Formula: see text]-Pochhammer symbol and the Jacobi theta functions. Some typical results include [Formula: see text] and [Formula: see text], with relative errors of order [Formula: see text] and [Formula: see text] respectively.


2011 ◽  
Vol 52 ◽  
pp. 359-364
Author(s):  
Algimantas Bikelis ◽  
Kazimieras Padvelskis ◽  
Pranas Vaitkus

Althoug Chebyshev [3] and Edeworth [5] had conceived of the formal expansions for distribution of sums of independent random variables, but only in Cramer’s work [4] was laid a proper foundation of this problem. In the case when random variables are lattice Esseen get the asymptotic expansion in a new different form. Here we extend this problem for quasi-lattice random variables.  


2007 ◽  
Vol 39 (4) ◽  
pp. 1070-1097 ◽  
Author(s):  
J. Blanchet ◽  
P. Glynn

Consider a sequence X = (Xn: n ≥ 1) of independent and identically distributed random variables, and an independent geometrically distributed random variable M with parameter p. The random variable SM = X1 + ∙ ∙ ∙ + XM is called a geometric sum. In this paper we obtain asymptotic expansions for the distribution of SM as p ↘ 0. If EX1 > 0, the asymptotic expansion is developed in powers of p and it provides higher-order correction terms to Renyi's theorem, which states that P(pSM > x) ≈ exp(-x/EX1). Conversely, if EX1 = 0 then the expansion is given in powers of √p. We apply the results to obtain corrected diffusion approximations for the M/G/1 queue. These expansions follow in a unified way as a consequence of new uniform renewal theory results that are also developed in this paper.


Author(s):  
Kusum Soni

SynopsisA uniform asymptotic expansion of the Laplace integrals ℒ(f, s) with explicit remainder terms is given. This expansion is valid in the whole complex s−plane. In particular, for s = −ix, it provides the Fourier integral expansion.


We develop a technique for systematically reducing the exponentially small (‘superasymptotic’) remainder of an asymptotic expansion truncated near its least term, for solutions of ordinary differential equations of Schrödinger type where one transition point dominates. This is achieved by repeatedly applying Borel summation to a resurgence formula discovered by Dingle, relating the late to the early terms of the original expansion. The improvements form a nested sequence of asymptotic series truncated at their least terms. Each such ‘hyperseries’ involves the terms of the original asymptotic series for the particular function being approximated, together with terminating integrals that are universal in form, and is half the length of its predecessor. The hyperasymptotic sequence is therefore finite, and leads to an ultimate approximation whose error is less than the square of the original superasymptotic remainder. The Stokes phenomenon is automatically and exactly incorporated into the scheme. Numerical computations confirm the efficacy of the technique.


2018 ◽  
Vol 41 ◽  
Author(s):  
Benjamin Beit-Hallahmi

AbstractSingh places the understanding of shamanism within the cognitive/evolutionary psychology of religion but is then sidetracked by presenting unhelpful analogies. The concepts of “superstition” as a general term for religious rituals and of “superstitious learning” as a mechanism accounting for the creation of rituals in humans reflect an underestimation of the human imagination, which is guided by cognitive/evolutionary constraints. Mentalizing, hypervigilance in agent detection, and anthropomorphism explain the behaviors involved in religious illusions (or delusions).


1998 ◽  
Vol 50 (2) ◽  
pp. 412-425 ◽  
Author(s):  
Richard J. McIntosh

AbstractFor the q–series we construct a companion q–series such that the asymptotic expansions of their logarithms as q → 1– differ only in the dominant few terms. The asymptotic expansion of their quotient then has a simple closed form; this gives rise to a new q–hypergeometric identity. We give an asymptotic expansion of a general class of q–series containing some of Ramanujan's mock theta functions and Selberg's identities.


Sign in / Sign up

Export Citation Format

Share Document