Let Ω∈ C^n be a bounded starlike circular domain with 0 ∈ Ω. In this paper, we introduce a class of holomorphic mappings Mg on Ω. Let f(z) be a normalized locally biholomorphic mapping on Ω such that Jf^-1 (z...Let Ω∈ C^n be a bounded starlike circular domain with 0 ∈ Ω. In this paper, we introduce a class of holomorphic mappings Mg on Ω. Let f(z) be a normalized locally biholomorphic mapping on Ω such that Jf^-1 (z) f(z) ∈Mg and z = 0 is the zero of order k+1 of f(z) - z. We obtain the growth and covering theorems for f(z). Especially, as corollaries, we unify and generalize many known results. Moreover, in view of proofs of corollaries, the essential relations among the subclasses of starlike mappings are shown.展开更多
Liczberski-Starkov firstfound a lower bound for ||D(f)|| near the origin, where f(z)=(F(z1),√F1(z1)z2,…,√F'(z1)zn)'is the Roper-Suffridge operator on the unit ball Bn in Cn and F is a normalized c...Liczberski-Starkov firstfound a lower bound for ||D(f)|| near the origin, where f(z)=(F(z1),√F1(z1)z2,…,√F'(z1)zn)'is the Roper-Suffridge operator on the unit ball Bn in Cn and F is a normalized convex function on the unit disk. Later, Liczberski-Starkov and Hamada-Kohr proved the lower bound holds on the whole unit ball using a complex computation. Here we provide a rather short and easy proof for the lower bound. Similarly, when F is a normalized starlike function on the unit disk, a lower bound of ||D(f)|| is obtained again.展开更多
基金Supported by NNSF of China(10571164)Supported by SRFDP of Higher Education(20050358052)
文摘Let Ω∈ C^n be a bounded starlike circular domain with 0 ∈ Ω. In this paper, we introduce a class of holomorphic mappings Mg on Ω. Let f(z) be a normalized locally biholomorphic mapping on Ω such that Jf^-1 (z) f(z) ∈Mg and z = 0 is the zero of order k+1 of f(z) - z. We obtain the growth and covering theorems for f(z). Especially, as corollaries, we unify and generalize many known results. Moreover, in view of proofs of corollaries, the essential relations among the subclasses of starlike mappings are shown.
基金Foundation item: Supported by the National Natural Science Foundation of China(10826083) Supported by the Zhejiang Provincial Natural Science Foundation of ChinaCD7080080)
文摘Liczberski-Starkov firstfound a lower bound for ||D(f)|| near the origin, where f(z)=(F(z1),√F1(z1)z2,…,√F'(z1)zn)'is the Roper-Suffridge operator on the unit ball Bn in Cn and F is a normalized convex function on the unit disk. Later, Liczberski-Starkov and Hamada-Kohr proved the lower bound holds on the whole unit ball using a complex computation. Here we provide a rather short and easy proof for the lower bound. Similarly, when F is a normalized starlike function on the unit disk, a lower bound of ||D(f)|| is obtained again.