Locally univalent functions and coefficient distortions
We look at functions \(f(z) = z + \displaystyle\sum_{n=2}^\infty a_nz^n\) satisfying \(\displaystyle\sum_{n=2}^\infty n \vert a_n\vert > 1\) and determine conditions for which the arguments of the coefficients may vary without affecting the univalence of the function. A bound on the radius of starlikeness for the convolution of functions taken from the closed convex hull of convex functions and a special subclass of starlike functions is also obtained.
scientific article; zbMATH DE number 3556395