Abstract
For a Nevanlinna-Pick problem with more than one solution, Rolf Nevanlinna proved that all extremal solutions are inner functions. If the interpolation points are contained in finitely many cones terminating at the unit circle, it is shown that all extremal solutions are Blaschke products.
Citation
Arne Stray. "Blaschke products and Nevanlinna-Pick interpolation." Publ. Mat. 59 (1) 45 - 54, 2015.
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