Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-19T22:02:16.864Z Has data issue: false hasContentIssue false

Positivity of more Jacobi polynomial sums

Published online by Cambridge University Press:  24 October 2008

Gavin Brown
Affiliation:
Department of Pure Mathematics, University of Adelaide, Adelaide 5005, South Australia
Stamatis Koumandos
Affiliation:
Department of Pure Mathematics, University of Adelaide, Adelaide 5005, South Australia
Kun-Yang Wang
Affiliation:
Department of Mathematics, Beijing Normal University, Beijing 100875, China

Extract

Our main result can be stated as follows:

Theorem.

for all λ ≥ λ0, where λ0 is the unique root in (0, 1) of the equation

andis the Gegenbauer polynomial of degree 2k and order λ. The only cases of equality in (1·1) are when θ = 0 and n is odd.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1]Askey, R.. Positive Jacobi polynomial sums. Tôhoku Math. Journ. 24 (1972), 109119.CrossRefGoogle Scholar
[2]Askey, R.. Orthogonal polynomials and special functions. Regional Conf. Lect. Appl. Math. 21, SIAM, Philadelphia, 1975.Google Scholar
[3]Askey, R. and Fitch, J.. Integral representations for Jacobi polynomials and some applications. J. Math. Anal. Appl. 26 (1969), 411437.CrossRefGoogle Scholar
[4]Askey, R. and Gasper, G.. Positive Jacobi polynomial sums, II. Amer. J. Math. 98 (1976), 709737.CrossRefGoogle Scholar
[5]Askey, R.. Problems which interest and/or annoy me. J. Comp. Appl. Math. 48 (1993), 315.CrossRefGoogle Scholar
[6]Brown, G., Wang, K.-Y. and Wilson, D. C.. Positivity of some basic cosine sums. Math. Proc. Camb. Phil. Soc. 114 (1993), 383391.CrossRefGoogle Scholar
[7]Brown, G., Koumandos, S. and Wang, K.-Y.. Positivity of basic sums of ultraspherical polynomials, submitted.Google Scholar
[8]Burnside, W. S. and Panton, A. W.. Theory of Equations (Dublin University Press, 1886).Google Scholar
[9]Char, B. W., Geddes, K. O., Gonnet, G. H., Leong, B. L., Monagan, M. B. and Watt, S. M.. Maple V first leaves, A tutorial introduction to Maple V and library reference manual. (Springer-Verlag, 1992).Google Scholar
[10]Erdélyi, A., Magnus, W., Oberhettinger, F. and Tricomi, F. G.. Higher transcendental functions, Vol. 2 (McGraw-Hill, 1953).Google Scholar
[11]Fejér, L.. Sur les fonctions bornées et intégrables. C.R. Acad. Sci. Paris 131 (1900), 984987.Google Scholar
Gesammelte Arbeiten, I, 3741 (Birkhäuser Verlag, 1970).Google Scholar
[12]Fejér, L.. Sur le développement d'une fonction arbitraire suivant les fonctions de Laplace. C.R. Acad. Sci. Paris, (1908), 224227;Google Scholar
Gesammelte Arbeiten I, 319322 (Birkhäuser Verlag, 1970).Google Scholar
[13]Feldheim, E.. On the positivity of certain sums of ultraspherical polynomials. J. Analyse. Math. 11 (1963), 275284;CrossRefGoogle Scholar
reprinted in Szegö, G. collected papers Vol. 3 (Birkhäuser, 1982), 821830.Google Scholar
[14]Gasper, G.. Positive sums of the classical orthogonal polynomials. SIAM J. Math. Anal. 8 (1977), 423447.CrossRefGoogle Scholar
[15]Gronwall, T. H.. Über die Gibbssche Erscheinung und die trigonometrischen Summen sin x + ½ sin 2x+…+sin nx/n. Math. Ann. 72 (1912), 228243.CrossRefGoogle Scholar
[16]Jackson, D.. Uber eine trigonometrische Summe. Rend. Circ. Math. Palermo 32 (1911), 257262.CrossRefGoogle Scholar
[17]Szegö, G.. Orthogonal polynomials. Amer. Math. Soc. Colloq. Publ. 23, 4th edition, Amer. Math. Soc., Providence, R.I., 1975.Google Scholar
[18]Zygmund, A.. Trigonometric series. 2nd edition (Cambridge University Press, 1959).Google Scholar