Abstract
Erdös and Turán established in [4] a qualitative result on the distribution of the zeros of a monic polynomial, the norm of which is known on [−1, 1]. We extend this result to a polynomial bounded on a systemE of Jordan curves and arcs. If all zeros of the polynomial are real, the estimates are independent of the number of components ofE for any regular compact subsetE ofR. As applications, estimates for the distribution of the zeros of the polynomials of best uniform approximation and for the extremal points of the optimal error curve (generalizations of Kadec's theorem) are given.
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Communicated by Dieter Gaier.
Dedicated to the memory of Peter Henrici
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Blatt, H.P., Grothmann, R. Erdös-Turán theorems on a system of Jordan curves and arcs. Constr. Approx 7, 19–47 (1991). https://doi.org/10.1007/BF01888145
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DOI: https://doi.org/10.1007/BF01888145