asymptotic expansion

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asymptotic expansion

[ā‚sim′täd·ik ik′span·shən]
(mathematics)
A series of the form a0+ (a1/ x) + (a2/ x 2) + · · · + (an / xn) + · · · is an asymptotic expansion of the function f (x) if there exists a number N such that for all nN the quantity xn [f (x) -Sn (x)] approaches zero as x approaches infinity, where Sn (x) is the sum of the first n terms in the series. Also known as asymptotic series.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Their topics include solitary wave generation due to passage through the local resonance, asymptotic expansions of singular perturbation theory, the Kelvin-Helmholtz instability, and nonlinear Cauchy problems for elliptic equations.
By the asymptotic expansions above we find that [[rho].sub.OO0]([k.sub.min], L, [eta],p, a, b) > [[rho].sub.OO0]([k.sub.min], L, [eta],p*, a, b) if [C.sub.p] > [C*.sub.p] and [[rho].sub.OO0]([bar.k](L, [eta],p),L,[eta],p, a, b) > [[rho].sub.OO0]([bar.k](L, [eta],p*), L, [eta],p*, a, b,) if [C.sub.p] < [C*.sub.p], which concludes the proof of the asymptotic optimality.
Although the Lindstedt-Poincare method gives uniformly valid asymptotic expansions for periodic solutions of weakly nonlinear oscillations, i.e., 0 < [epsilon] < [C.sub.1], the technique does not work if the amplitude of the oscillation is a function of time (see [16, 17]).
Next lemma unveils the asymptotic expansions of [mathematical expression not reproducible], where
Erdelyi, Asymptotic Expansions, Dover, New York, NY, USA, 1956.
First we give the asymptotic expansions of [mathematical expression not reproducible] for [xi] [right arrow] 0.
Various methods are employed to solve singular perturbation problems analytically, numerically, or asymptotically such as the method of matched asymptotic expansions (MMAE), the method of multiple scales, the method of WKB approximation, Poincare-Lindstedt method and periodic averaging method.
The search for asymptotic expansions and approximations of special functions is a very classical vein of research and is of great relevance in pure mathematics, in numerical analysis, mathematical physics, and the applied sciences (see, for instance, of course with no pretence of completion [1-4]).
So, guess what does it take to calculate these numbers and their corresponding asymptotic expansions?
Our current effort in this paper is to further explore the limiting behavior of the process [x.sup.[epsilon], [delta]](x) by constructing asymptotic expansions of its probability densities, which are associated with the adjoint operator [L.sup.*].

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