Geodesic
Extremal rational functions on several arcs of the unit circle with zeros on these arcs
Izvestiya of Saratov University. Mathematics. Mechanics. Informatics, Tome 9 (2009) no. 1, pp. 8-13 Cet article a éte moissonné depuis la source Math-Net.Ru

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The solution of an extremal problem about rational function with fixed denominator and leading coefficient of nominator which is deviated least from zero on several arcs of the unit circle is given under restrictions on the location of zeros and additional conditions on mutual position of the arcs and zeros of denominator. The extremal function is represented in terms of the density of harmonic measure. 
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A. L. Lukashov; S. V. Tyshkevich. Extremal rational functions on several arcs of the unit circle with zeros on these arcs. Izvestiya of Saratov University. Mathematics. Mechanics. Informatics, Tome 9 (2009) no. 1, pp. 8-13. http://geodesic.mathdoc.fr/item/ISU_2009_9_1_a1/

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