1,041 research outputs found
Asymptotics of a polynomial associated with the Catalan-Larcombe-French sequence
The large behaviour of the hypergeometric polynomial
\FFF{-n}{\sfrac12}{\sfrac12}{\sfrac12-n}{\sfrac12-n}{-1} is considered by
using integral representations of this polynomial. This polynomial is
associated with the Catalan-Larcombe-French sequence. Several other
representations are mentioned, with references to the literature, and another
asymptotic method is described by using a generating function of the sequence.
The results are similar to those obtained by Clark (2004) who used a binomial
sum for obtaining an asymptotic expansion.Comment: 10 pages, 1 figure. Accepted for publication in {\em Analysis and
Applications
American Indians and Christian Missions: Studies in Cultural Conflict
Reviewed Book: Bowden, Henry Warner. American Indians and Christian Missions: Studies in Cultural Conflict. [S.l.]: Univ of Chicago Press, 1981. Chicago History of American Religion
Uniform asymptotics for the incomplete gamma functions starting from negative values of the parameters
We consider the asymptotic behavior of the incomplete gamma functions
gamma(-a,-z) and Gamma(-a,-z) as a goes to infinity. Uniform expansions are
needed to describe the transition area z~a in which case error functions are
used as main approximants. We use integral representations of the incomplete
gamma functions and derive a uniform equation by applying techniques used for
the existing uniform expansions for gamma(a,z) and Gamma(a,z). The result is
compared with Olver's uniform expansion for the generalized exponential
integral. A numerical verification of the expansion is given in a final
section
Remarks on Slater's asymptotic expansions of Kummer functions for large values of the parameter
In Slater's 1960 standard work on confluent hypergeometric functions, also
called Kummer functions, a number of asymptotic expansions of these functions
can be found. We summarize expansions derived from a differential equation for
large values of the parameter. We show how similar expansions can be
derived by using integral representations, and we observe discrepancies with
Slater's expansions.Comment: To appear in Advances in Dynamical Systems and Applications.
Proceedings of the International Conference on Differential Equations,
Difference Equations and Special Functions, Patras, Greece, September 3 - 9,
2012, dedicated to the memory of Panayiotis D. Siafarikas. 13 page
Numerical and Asymptotic Aspects of Parabolic Cylinder Functions
Several uniform asymptotics expansions of the Weber parabolic cylinder
functions are considered, one group in terms of elementary functions, another
group in terms of Airy functions. Starting point for the discussion are
asymptotic expansions given earlier by F.W.J. Olver. Some of his results are
modified to improve the asymptotic properties and to enlarge the intervals for
using the expansions in numerical algorithms. Olver's results are obtained from
the differential equation of the parabolic cylinder functions; we mention how
modified expansions can be obtained from integral representations. Numerical
tests are given for three expansions in terms of elementary functions. In this
paper only real values of the parameters will be considered.Comment: 16 pages, 1 figur
Jesus in Latin America
Reviewed Book: Sobrino, Jon. Jesus in Latin America. Maryknoll, NY: Orbis Books, 1987
Uniform Asymptotic Methods for Integrals
We give an overview of basic methods that can be used for obtaining
asymptotic expansions of integrals: Watson's lemma, Laplace's method, the
saddle point method, and the method of stationary phase. Certain developments
in the field of asymptotic analysis will be compared with De Bruijn's book {\em
Asymptotic Methods in Analysis}. The classical methods can be modified for
obtaining expansions that hold uniformly with respect to additional parameters.
We give an overview of examples in which special functions, such as the
complementary error function, Airy functions, and Bessel functions, are used as
approximations in uniform asymptotic expansions.Comment: 31 pages, 3 figure
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