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 Affiliated with RC false Status 已發表Published Orthogonal polynomials, asymptotics, and Heun equations Chen，Yang1 ; Filipuk，Galina2; Zhan，Longjun3 2019-11-01 Source Publication Journal of Mathematical Physics ISSN 0022-2488 Volume 60Issue:11 Abstract The Painlevé equations arise from the study of Hankel determinants generated by moment matrices, whose weights are expressed as the product of "classical" weights multiplied by suitable "deformation factors," usually dependent on a "time variable" t. From ladder operators [see A. Magnus, J. Comput. Appl. Math. 57(1-2), 215-237 (1995)], one finds second order linear ordinary differential equations for associated orthogonal polynomials with coefficients being rational functions. The Painlevé and related functions appear as the residues of these rational functions. We will be interested in the situation when n, the order of the Hankel matrix and also the degree of the polynomials P(x) orthogonal with respect to the deformed weights, gets large. We show that the second order linear differential equations satisfied by P(x) are particular cases of Heun equations when n is large. In some sense, monic orthogonal polynomials generated by deformed weights mentioned below are solutions of a variety of Heun equations. Heun equations are of considerable importance in mathematical physics, and in the special cases, they degenerate to the hypergeometric and confluent hypergeometric equations. In this paper, we look at three types of weights: The Jacobi type, the Laguerre type, and the weights deformed by the indicator function of χ(x) and the step function θ(x). In particular, we consider the following Jacobi type weights: (1.1) x(1-x)e, x a [0, 1], α, β, t > 0; (1.2) x(1-x)e, x a (0, 1], α, β, t > 0; (1.3) (1-x2)α(1-k2x2)β, xa[-1,1], α,β>0, k2a(0,1); the Laguerre type weights: (2.1) x(x + t)e, x a [0, ∞), t, α, λ > 0; (2.2) xe, x a (0, ∞), α, t > 0; and another type of deformation when the classical weights are multiplied by χ(x) or θ(x): (3.1) e-x2(1-χ(-A,a)(x)), xaR, a>0; (3.2) (1-x2)α(1-χ(-A,a)(x)), xa[-1,1], aa(0,1), α>0; (3.3) xe(A + Bθ(x-t)), x a [0, ∞), α, t > 0, A ≥ 0, A + B ≥ 0. The weights mentioned above were studied in a series of papers related to the deformation of "classical" weights. DOI 10.1063/1.5102102 URL View the original Language 英語English Scopus ID 2-s2.0-85074712874 Fulltext Access Citation statistics Cited Times [WOS]:6   [WOS Record]     [Related Records in WOS] Document Type Journal article Collection DEPARTMENT OF MATHEMATICS Corresponding Author Chen，Yang Affiliation 1.Department of Mathematics,University of Macau,Taipa,Avenida da Universidade,Macao2.Faculty of Mathematics,Informatics and Mechanics,University of Warsaw,Warsaw,Banacha 2,02-097,Poland3.School of Mathematical Science,Fudan University,Shanghai,200433,China First Author Affilication University of Macau Corresponding Author Affilication University of Macau Recommended CitationGB/T 7714 Chen，Yang,Filipuk，Galina,Zhan，Longjun. Orthogonal polynomials, asymptotics, and Heun equations[J]. Journal of Mathematical Physics,2019,60(11). APA Chen，Yang,Filipuk，Galina,&Zhan，Longjun.(2019).Orthogonal polynomials, asymptotics, and Heun equations.Journal of Mathematical Physics,60(11). MLA Chen，Yang,et al."Orthogonal polynomials, asymptotics, and Heun equations".Journal of Mathematical Physics 60.11(2019).
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