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Nikishin Systems Are Perfect

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Abstract

K. Mahler introduced the concept of perfect systems in the general theory he developed for the simultaneous Hermite–Padé approximation of analytic functions. We prove that Nikishin systems are perfect, providing by far the largest class of systems of functions for which this important property holds. As consequences, in the context of Nikishin systems, we obtain: an extension of Markov’s theorem to simultaneous Hermite–Padé approximation, a general result on the convergence of simultaneous quadrature rules of Gauss–Jacobi type, the logarithmic asymptotics of general sequences of multiple orthogonal polynomials, and an extension of the Denisov–Rakhmanov theorem for the ratio asymptotics of mixed type multiple orthogonal polynomials.

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References

  1. Apéry, R.: Irrationalité de ζ(2) et ζ(3). Astérisque 61, 11–13 (1979)

    MATH  Google Scholar 

  2. Angelesco, M.A.: Sur deux extensions des fractions continues algébriques. C.R. Acad. Sci. Paris 18, 262–263 (1919)

    Google Scholar 

  3. Aptekarev, A.I.: Asymptotics of simultaneously orthogonal polynomials in the Angelesco case. Mat. Sb. 136, 56–84 (1988) (Russian); English translation in Math. USSR Sb. 64, 57–84 (1989)

    Google Scholar 

  4. Aptekarev, A.I.: Strong asymptotics of multiply orthogonal polynomials for Nikishin systems. Mat. Sb. 190, 3–44 (1999) (Russian); English translation in Sbornik: Mathematics 190, 631–669 (1999)

    MathSciNet  Google Scholar 

  5. Aptekarev, A.I.: Sharp estimates for rational approximations of analytic functions. Mat. Sb. 193, 1–72 (2002) (Russian); English translation in Sbornik: Mathematics 193, 3–72 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  6. Aptekarev, A.I., López Lagomasino, G., Rocha, I.A.: Ratio asymptotic of Hermite–Padé orthogonal polynomials for Nikishin systems. Mat. Sb. 196, 3–20 (2005) (Russian); English translation in Sbornik: Mathematics 196, 1089–1107 (2005)

    Google Scholar 

  7. Bleher, P.M., Kuijlaars, A.B.J.: Random matrices with external source and multiple orthogonal polynomials. Int. Math. Res. Not. 2004(3), 109–129 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  8. Beukers, F.: Padé approximation in number theory. Lecture Notes in Math., vol. 888. Springer, Berlin, (1981), pp. 90–99

    Google Scholar 

  9. Borges, C.F.: On a class of Gauss-like quadrature rules. Numer. Math. 67, 271–288 (1994)

    Article  MathSciNet  MATH  Google Scholar 

  10. Branquinho, A., Bustamante, J., Foulquié, A., López Lagomasino, G.: Normal indices in Nikishin systems. J. Approx. Theory 124, 254–263 (2003)

    Article  MathSciNet  MATH  Google Scholar 

  11. Bustamante, J.: Asymptotics for Angelesco Nikishin systems. J. Approx. Theory 85, 43–68 (1996)

    Article  MathSciNet  MATH  Google Scholar 

  12. Bustamante, J., López Lagomasino, G.: Hermite–Padé approximation for Nikishin systems of analytic functions. Mat. Sb. 183, 117–138 (1992) (Russian); English translation in Russian Acad. Sci. Sb. Math. 77, 367–384 (1994)

    Google Scholar 

  13. Coates, J.: On the algebraic approximation of functions. I, II, III. Indag. Math. 28, 421–461 (1966)

    MathSciNet  Google Scholar 

  14. Daems, E., Kuijlaars, A.B.J.: Multiple orthogonal polynomials of mixed type and non intersecting Brownian motions. J. Approx. Theory 146, 91–114 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  15. Denisov, S.A.: On Rakhmanov’s theorem for Jacobi matrices. Proc. Am. Math. Soc. 132, 847–852 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  16. Driver, K., Stahl, H.: Normality in Nikishin systems. Indag. Math. 5, 161–187 (1994)

    Article  MathSciNet  MATH  Google Scholar 

  17. Driver, K., Stahl, H.: Simultaneous rational approximants to Nikishin systems. I. Acta Sci. Math. 60, 245–263 (1995)

    MathSciNet  MATH  Google Scholar 

  18. Driver, K., Stahl, H.: Simultaneous rational approximants to Nikishin systems. II. Acta Sci. Math. 61, 261–284 (1995)

    MathSciNet  MATH  Google Scholar 

  19. Fadeev, L.D., Gonchar, A.A., et al.: Evgenii Mikhailovich Nikishin (obituary). Usp. Mat. Nauk 42, 183–188 (1987) (Russian); English translation in Russian Math. Surveys 42(5), 153–160 (1987)

    Google Scholar 

  20. Fidalgo, U., López Lagomasino, G.: On perfect Nikishin systems. Comput. Methods Funct. Theory 2, 415–426 (2002)

    MathSciNet  MATH  Google Scholar 

  21. Fidalgo, U., López Lagomasino, G.: Rate of convergence of generalized Hermite–Padé approximants of Nikishin systems. Constr. Approx. 23, 165–196 (2006)

    Article  MathSciNet  MATH  Google Scholar 

  22. Fidalgo, U., López Lagomasino, G.: General results on the convergence of multipoint-Padé approximants of Nikishin systems. Constr. Approx. 25, 89–107 (2007)

    Article  MathSciNet  MATH  Google Scholar 

  23. Fidalgo, U., Illán, J., López Lagomasino, G.: Hermite–Padé approximants and simultaneous quadrature formulas. J. Approx. Theory 126, 171–197 (2004)

    Article  MathSciNet  MATH  Google Scholar 

  24. Fidalgo, U., López, A., López Lagomasino, G., Sorokin, V.N.: Mixed type multiple orthogonal polynomials for two Nikishin systems. Constr. Approx. 32, 255–306 (2010)

    Article  MathSciNet  MATH  Google Scholar 

  25. Gonchar, A.A.: On the convergence of generalized Padé approximants of meromorphic functions. Mat. Sb. 98, 564–577 (1975) (Russian); English translation in Math. USSR Sb. 27, 503–514 (1975)

    MathSciNet  Google Scholar 

  26. Gonchar, A.A.: In: Rational approximations of analytic functions, Berkeley, CA, 1986. Proc. Internat. Congress Math., vol. I, pp. 739–748. Amer. Math. Soc., Providence (1987)

    Google Scholar 

  27. Gonchar, A.A., Rakhmanov, E.A.: On convergence of simultaneous Padé approximants for systems of functions of Markov type. Tr. Mat. Inst. Steklova 157, 31–48 (1981) (Russian); English translation in Proc. Steklov Inst. Math. 157, 31–50 (1983)

    MathSciNet  MATH  Google Scholar 

  28. Gonchar, A.A., Rakhmanov, E.A.: Equilibrium distributions and degree of rational approximation of analytic functions. Mat. Sb. 134, 305 (1987) (Russian); English translation in Math. USSR Sb. 62, 305–348 (1989)

    Google Scholar 

  29. Gonchar, A.A., Rakhmanov, E.A., Sorokin, V.N.: Hermite–Padé approximants for systems of Markov-type functions. Mat. Sb. 188, 33–58 (1997) (Russian); English translation in Sb. Math. 188, 33–58 (1997)

    MathSciNet  Google Scholar 

  30. Helms, L.L.: Introduction to Potential Theory. Wiley-Interscience, New York (1969)

    MATH  Google Scholar 

  31. Hermite, Ch.: Sur la fonction exponentielle, C. R. Acad. Sci. Paris 77, 18–24, 74–79, 226–233, 285–293 (1873); reprinted in his Oeuvres, Tome III, Gauthier-Villars, Paris 150–181 (1912)

  32. Jager, H.: A simultaneous generalization of the Padé table. I–VI. Indag. Math. 26, 193–249 (1964)

    MathSciNet  Google Scholar 

  33. Krein, M.G., Nudel’man, A.A.: The Markov Moment Problem and Extremal Problems. Transl. Math. Monogr., vol. 50. Amer. Math. Soc, Providence (1977)

    MATH  Google Scholar 

  34. Kuijlaars, A.B.J.: Multiple orthogonal polynomial ensembles. In: Arvesú, J., Marcellán, F., Martínez-Finkelshtein, A. (eds.) Recent Trends in Orthogonal Polynomials and Approximation Theory. Contemporary Mathematics, vol. 507, pp. 155–176. Am. Math. Soc, Providence (2010)

    Google Scholar 

  35. Kuijlaars, A.B.J.: Multiple orthogonal polynomials in random matrix theory. In: Proc. Internat, Hydebarad, India. Congress Math., vol. III, pp. 1417–1432 (2010)

    Google Scholar 

  36. López García, A., López Lagomasino, G.: Ratio asymptotic of Hermite–Padé orthogonal polynomials for Nikishin systems. II. Adv. Math. 218, 1081–1106 (2008)

    Article  MathSciNet  MATH  Google Scholar 

  37. Mahler, K.: Perfect systems. Compos. Math. 19, 95–166 (1968)

    MathSciNet  MATH  Google Scholar 

  38. Markov, A.A.: Deux demonstrations de la convergence de certains fractions continues. Acta Math. 19, 93–104 (1895)

    Article  MathSciNet  Google Scholar 

  39. Nikishin, E.M.: A system of Markov functions. Vestnik Moskov. Univ. Ser. I Mat. Mekh. 4, 60–63 (1979) (Russian); English translation in Moscow Univ. Math. Bull. 34, 63–66 (1979)

    MathSciNet  Google Scholar 

  40. Nikishin, E.M.: On simultaneous Padé approximants. Mat. Sb. 113, 499–519 (1980) (Russian); English translation in Math. USSR Sb. 41, 409–425 (1982)

    MathSciNet  Google Scholar 

  41. Nikishin, E.M.: Asymptotics of linear forms for simultaneous Padé approximants. Izv. Vysš. Učebn. Zaved., Mat. 2, 33–41 (1986) (Russian); English translation in Soviet Math. (Iz. VUZ) 30, 43–52 (1986)

    MathSciNet  Google Scholar 

  42. Nikishin, E.M., Sorokin, V.N.: Rational Approximations and Orthogonality. Transl. Math. Monogr., vol. 92. Am. Math. Soc., Providence (1991)

    MATH  Google Scholar 

  43. Nuttall, J.: Asymptotics of diagonal Hermite–Padé polynomials. J. Approx. Theory 42, 299–386 (1984)

    Article  MathSciNet  MATH  Google Scholar 

  44. Rakhmanov, E.A.: On the asymptotic of the ratio of orthogonal polynomials. Mat. Sb. 103, 237–252 (1977) (Russian); English translation in Math. USSR Sb. 32, 199–213 (1977)

    MathSciNet  Google Scholar 

  45. Rakhmanov, E.-A.: On the asymptotic of the ratio of orthogonal polynomials II. Mat. Sb. 118, 104–117 (1982) (Russian); English translation in Math. USSR Sb. 46, 105–117 (1983)

    MathSciNet  Google Scholar 

  46. Rakhmanov, E.A.: On asymptotic properties of orthogonal polynomials on the unit circle with weights not satisfying Szegő’s condition. Mat. Sb. 130, 151–169 (1986) (Russian); English translation in Math. USSR Sb. 58, 149–167 (1987)

    MathSciNet  Google Scholar 

  47. Sorokin, V.N.: On simultaneous approximation of several linear forms. Vestnik Moskov. Univ. Ser. I Mat. Mekh. 1, 44–47 (1983) (Russian); English translation in Moscow Univ. Math. Bull. 38, 53–56 (1983)

    MathSciNet  Google Scholar 

  48. Sorokin, V.N.: Hermite–Padé approximants for polylogarithms. Izv. Vysš. Učebn. Zaved., Mat. 2, 49–59 (1994) (Russian); English translation in Russian Math. (Iz. VUZ) 38, 47–57 (1994)

    MathSciNet  Google Scholar 

  49. Saff, E.B., Totik, V.: Logarithmic Potentials with External Fields. Series of Comprehensive Studies in Mathematics, vol. 316. Springer, New York (1997)

    MATH  Google Scholar 

  50. Stahl, H.: Best uniform rational approximation of x α on [0, 1]. Acta Math. 90, 241–306 (2003)

    Article  MathSciNet  Google Scholar 

  51. Stahl, H., Totik, V.: General Orthogonal Polynomials. Cambridge University Press, Cambridge (1992)

    Book  MATH  Google Scholar 

  52. Szegő, G., Orthogonal Polynomials. Coll. Pub. Amer. Math. Soc., vol. XXIII, 4th edn. Amer. Math. Soc., Providence (1975)

    Google Scholar 

  53. Van Assche, W.: Analytic number theory and rational approximation. In: Branquinho, A., Foulquié, A. (eds.) Coimbra Lecture Notes on Orthogonal Polynomials, pp. 197–229. Nova Science Pub., New York (2008)

    Google Scholar 

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Correspondence to G. López Lagomasino.

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Communicated by Vilmos Totik.

Dedicated to the memory of the outstanding Russian mathematician E.M. Nikishin, who died on December 17, 1987, at the early age of 42. See [19] for a brief account of his results and a list of publications.

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Fidalgo Prieto, U., López Lagomasino, G. Nikishin Systems Are Perfect. Constr Approx 34, 297–356 (2011). https://doi.org/10.1007/s00365-011-9139-6

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