Skip to main content
Log in

Strong asymptotics for Jacobi polynomials with varying nonstandard parameters

  • Published:
Journal d’Analyse Mathematique Aims and scope

Abstract

Strong asymptotics on the whole complex plane of a sequence of monic Jacobi polynomialsP n α n β n are studied, assuming that

$$\mathop {\lim }\limits_{n \to \infty } \frac{{\alpha _n }}{n} = A, \mathop {\lim }\limits_{n \to \infty } \frac{{\beta _n }}{n} = B,$$
(1)

withA andB satisfyingA>−1,B>−1,A+B<−1. The asymptotic analysis is based on the non-Hermitian orthogonality of these polynomials and uses the Deift/Zhou steepest descent analysis for matrix Riemann-Hilbert problems. As a corollary, asymptotic zero behavior is derived. We show that in a generic case, the zeros distribute on the set of critical trajectories Γ of a certain quadratic differential according to the equilibrium measure on Γ in an external field. However, when either α n β n or α n n are geometrically close to ℤ, part of the zeros accumulate along a different trajectory of the same quadratic differential.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. M. Abramowitz and I. A. Stegun,Handbook of Mathematical Functions, Dover Publications, New York, 1968.

    Google Scholar 

  2. A. I. Aptekarev,Sharp constants for rational approximations of analytic functions, Sb. Math.193 (2002), no. 1–2, 1–72.

    Article  MATH  MathSciNet  Google Scholar 

  3. J. Baik, P. Deift, K. T.-R. McLaughlin, P. Miller and X. Zhou,Optimal tail estimates for directed last passage site percolation with geometric random variables. Adv. Theor. Math. Phys.5 (2001), 1207–1250.

    MATH  MathSciNet  Google Scholar 

  4. C. Bosbach and W. Gawronski,Strong asymptotics for Jacobi polynomials with varying weights, Methods Appl. Anal.6 (1999), 39–54.

    MATH  MathSciNet  Google Scholar 

  5. L.-C. Chen and M. E. H. Ismail,On asymptotics of Jacobi polynomials, SIAM J. Math. Anal.22 (1991), 1442–1449.

    Article  MATH  MathSciNet  Google Scholar 

  6. P. A. Deift,Orthogonal Polynomials and Random Matrices: A Riemann-Hilbert Approach, New York University Courant Institute of Mathematical Sciences, New York, 1999.

    Google Scholar 

  7. P. Deift, T. Kriecherbauer, K. T.-R. McLaughlin, S. Venakides and X. Zhou,Strong asymptotics of orthogonal polynomials with respect to exponential weights, Comm. Pure Appl. Math.52 (1999), 1491–1552.

    Article  MATH  MathSciNet  Google Scholar 

  8. P. Deift, T. Kriecherbauer, K. T.-R. McLaughlin, S. Venakides and X. Zhou,Uniform asymptotics for polynomials orthogonal with respect to varying exponential weights and applications to universality questions in random matrix theory, Comm. Pure Appl. Math.52 (1999), 1335–1425.

    Article  MATH  MathSciNet  Google Scholar 

  9. P. Deift and X. Zhou,A steepest descent method for oscillatory Riemann-Hilbert problems: asymptotics for the MKdV equation, Ann. of Math. (2)137 (1993), 295–368.

    Article  MathSciNet  Google Scholar 

  10. H. Dette and W. J. Studden,Some new asymptotic properties for the zeros of Jacobi, Laguerre, and Hermite polynomials, Constr. Approx.11 (1995), 227–238.

    Article  MATH  MathSciNet  Google Scholar 

  11. K. Driver and P. Duren,Asymptotic zero distribution of hypergeometric polynomials, Numer. Algorithms21 (1999), 147–156.

    Article  MATH  MathSciNet  Google Scholar 

  12. K. Driver and P. Duren,Trajectories of the zeros of hypergeometric polynomials F(−n, b; 2b; z) for b<−1/2, Constr. Approx.17 (2001), 169–179.

    Article  MATH  MathSciNet  Google Scholar 

  13. K. Driver and M. Möller,Zeros of hypergeometric polynomials F(−n, b; −2n; z), J. Approx. Theory110 (2001), 74–87.

    Article  MATH  MathSciNet  Google Scholar 

  14. P. Duren and K. Boggs,Zeros of hypergeometric functions, Comput. Methods Funct. Theory1 (2001), 275–287.

    MATH  MathSciNet  Google Scholar 

  15. P. Duren and B. J. Guillou,Asymptotic properties of zeros of hypergeometric polynomial, J. Approx. Theory111 (2001), 329–343.

    Article  MATH  MathSciNet  Google Scholar 

  16. A. Fokas, A. Its and A. Kitaev,The isomonodromy approach to matrix models in 2D quantum gravity, Comm. Math. Phys.147 (1992), 395–430.

    Article  MATH  MathSciNet  Google Scholar 

  17. W. Gawronski and B. Shawyer,Strong asymptotics and the limit distribution of the zeros of Jacobi polynomials P n(an+α,bn+β) , inProgress in Approximation Theory (P. Nevai and A. Pinkus, eds.), Academic Press, New York, 1991, pp. 379–404.

    Google Scholar 

  18. A. A. Gonchar and E. A. Rakhmanov,Equilibrium distributions and rate of the rational approximation of analytic functions, Mat. USSR Sbornik62 (1989), 305–348; translation from Mat. Sb., Nov. Ser.134(176), No. 3 (11) (1987), 306–352.

    Article  MATH  MathSciNet  Google Scholar 

  19. S. Kamvissis, K. T.-R. McLaughlin and P. D. Miller,Semiclassical Soliton Ensembles for the Focusing Nonlinear Schrödinger Equation, Annals of Mathematics Studies 154, Princeton University Press, Princeton, 2003.

    MATH  Google Scholar 

  20. A. B. J. Kuijlaars, A. Martínez-Finkelshtein and R. Orive,Orthogonality of Jacobi polynomials with general parameters, Electron. Trans. Numer. Anal. to appear; preprint math. CA/0301037.

  21. A. B. J. Kuijlaars and K. T.-R. McLaughlin,Asymptotic zero behavior of Laguerre polynomials with negative parameter, Constr. Approx.20 (2004), 497–523.

    Article  MATH  MathSciNet  Google Scholar 

  22. A. B. J. Kuijlaars and K. T.-R. McLaughlin,Riemann-Hilbert analysis for Laguerre polynomials with large negative parameter, Comput. Methods Funct. Theory1 (2001), 205–233.

    MATH  MathSciNet  Google Scholar 

  23. A. B. J. Kuijlaars and W. Van Assche,The asymptotic zero distribution of orthogonal polynomials with varying recurrence coefficients, J. Approx. Theory99 (1999), 167–197.

    Article  MATH  MathSciNet  Google Scholar 

  24. A. B. J. Kuijlaars, W. Van Assche and F. Wielonsky,Quadratic Hermite-Padé approximation to the exponential function: a Riemann-Hilbert approach, Constr. Approx., to appear; preprint math.CA/0302357.

  25. A. Martínez-Finkelshtein, P. Martínez-González and R. Orive,Zeros of Jacobi polynomials with varying non-classical parameters, inSpecial Functions (Hong Kong, 1999), World Sci. Publishing, River Edge, NJ, 2000, pp. 98–113.

    Google Scholar 

  26. D. S. Moak, E. B. Saff and R. S. Varga,On the zeros of Jacobi polynomials P n α n β n , Trans. Amer. Math. Soc.249 (1979), 159–162.

    Article  MATH  MathSciNet  Google Scholar 

  27. F. W. J. Olver,Asymptotics and Special Functions, Academic Press, Boston, 1974.

    Google Scholar 

  28. C. Pommerenke,Univalent Functions, Vandenhoeck & Ruprecht, Göttingen, 1975.

    MATH  Google Scholar 

  29. E. B. Saff and V. Totik,Logarithmic Potentials with External Fields, Springer-Verlag, Berlin, 1997.

    MATH  Google Scholar 

  30. H. Stahl,Orthogonal polynomials with complex-valued weight function. I, II, Constr. Approx.2 (1986), 225–240, 241–251.

    Article  MATH  MathSciNet  Google Scholar 

  31. K. Strebel,Quadratic Differentials, Springer-Verlag, Berlin, 1984.

    MATH  Google Scholar 

  32. G. Szegö,Orthogonal Polynomials, fourth ed., Amer. Math. Soc., Providence, RI, 1975.

    MATH  Google Scholar 

  33. N. M. Temme,Large parameter cases of the Gauss hypergeometric function, J. Comput. Appl. Math.153 (2003), 441–462.

    Article  MATH  MathSciNet  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to A. B. J. Kuijlaars.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kuijlaars, A.B.J., Martínez-Finkelshtein, A. Strong asymptotics for Jacobi polynomials with varying nonstandard parameters. J. Anal. Math. 94, 195–234 (2004). https://doi.org/10.1007/BF02789047

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF02789047

Keywords

Navigation