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Nikishin systems on star-like sets: Ratio asymptotics of the associated multiple orthogonal polynomials, II

https://doi.org/10.1016/j.jat.2019.105320Get rights and content
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Abstract

In this paper we continue the investigations initiated in López-García and López Lagomasino (2018) on ratio asymptotics of multiple orthogonal polynomials and functions of the second kind associated with Nikishin systems on star-like sets. We describe in detail the limiting functions found in López-García and López Lagomasino (2018), expressing them in terms of certain conformal mappings defined on a compact Riemann surface of genus zero. We also express the limiting values of the recurrence coefficients, which are shown to be strictly positive, in terms of certain values of the conformal mappings. As a consequence, the limits depend exclusively on the location of the intervals determined by the supports of the measures that generate the Nikishin system.

MSC

primary
42C05
30E10
secondary
47B39

Keywords

Multiple orthogonal polynomial
Nikishin system
Ratio asymptotics
Conformal mapping

Cited by (0)

1

The second author received partial support from the Spanish Ministerio de Ciencia, Innovación y Universidades through grant PGC2018-096504-B-C33.