On an Example of the Nikishin System

Resumo

An example of a Markov function f = const + \(\hat \sigma \) such that the three functions f, f², and f³ constitute a Nikishin systemis given. It is conjectured that there exists aMarkov function f such that, for each n ∈ N, the system of f, f²,..., fⁿ is a Nikishin system.