An upper bound for the least critical values of finite Blaschke products

Abstract

For the finite Blaschke products B of degree n ⩾ 2 such that B(0) = 0 and B ′ (0) ̸ = 0, the supremum of the minimum moduli of their critical values is found which depends only on n and |B ′ (0)|.Bibliography: 12 titles.