Author/Authors :
Ragnhild J. Rensaa*، نويسنده , , Ragnhild Johanne، نويسنده ,
Abstract :
In the family S of normalized, univalent functions, an omitted point in F⊂S is a complex number w0, such that there is at least one function f∈F, satisfyingf(z)≠w0 for all |z|<1.Let a set of m distinct complex numbers w1,w2,…,wm all ≠0, be given such that 0⩽arg w1<arg w2<⋯<arg wm<2π. The tuple (w1,w2,…,wm) shall be called an omitted tuple for F if there exists at least one f∈F such that f(z)≠wi, ∀i=1,2,…,m and all |z|<1. In this paper we shall be concerned with the question whether (tw1,tw2,…,twm), t an arbitrary positive number, is an omitted tuple in S or not, more precisely the number of functions omitting the tuple for different values of t. An answer to this question in full generality will not be offered, but some partial results are given. Moreover, two subfamilies where complete solutions are obtained, are briefly mentioned.