Strong and ratio asymptotics for Laguerre polynomials revisited

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• 作者：Alfredo Deañ ; o^a ; ^{alfredo.deano@cs.kuleuven.be} ; ^{alfredo.deanho@uc3m.es} ; Edmundo J. Huertas^b ; ^{ehuertasce@gmail.com} ; Francisco Marcellá ; n^b ; ^{pacomarc@ing.uc3m.es}
• 关键词：Laguerre orthogonal polynomials ; Asymptotic expansions
• 刊名：Journal of Mathematical Analysis and Applications
• 出版年：2013
• 出版时间：15 July, 2013
• 年：2013
• 卷：403
• 期：2
• 页码：477-486
• 全文大小：404 K

文摘

In this paper we consider the strong asymptotic behavior of Laguerre polynomials in the complex plane. The leading behavior is well known from Perron and Mehler-Heine formulas, but higher order coefficients, which are important in the context of Krall-Laguerre or Laguerre-Sobolev-type orthogonal polynomials, are notoriously difficult to compute. In this paper, we propose the use of an alternative expansion, due to Buchholz, in terms of Bessel functions of the first kind. The coefficients in this expansion can be obtained in a straightforward way using symbolic computation. As an application, we derive extra terms in the asymptotic expansion of ratios of Laguerre polynomials in .