On the composition of Frostman Blaschke products
We construct an infinite uniform Frostman Blaschke product B such that B composed with itself is also a uniform Frostman Blaschke product. We also show that the set of uniform Frostman Blaschke products is open in the set of inner functions with the uniform norm.
Gorkin, Pamela and Akeroyd, John r.. "On the composition of Frostman Blaschke products." Studia Mathematica 219, (2013) : 177-191.