SHARP ESTIMATES OF QUASI-CONVEX MAPPINGS OF TYPE B AND ORDER α

In this paper, we first establish several sharp inequalities of homogeneous expansion for biholomorphic quasi-convex mappings of type B and order α on the unit ball E in a complex Banach space X by applying the method and technique of complex analysis. Then, as the application of these sharp inequalities, we derive the sharp estimate of third homogeneous expansions for the above mappings defined on the unit polydisk U^n in C^n.

SHARP ESTIMATES OF ALL HOMOGENEOUS EXPANSIONS FOR A SUBCLASS OF QUASI-CONVEX MAPPINGS OF TYPE B AND ORDER α IN SEVERAL COMPLEX VARIABLES

In this article, first, the sharp estimates of all homogeneous expansions for a subclass of quasi-convex mappings of type B and order B on the unit ball in complex Ba- nach spaces are given. Second, the sharp estimates of all homogeneous expansions for the above generalized mappings on the unit polydisk in （in are also established. In particular, the sharp estimates of all homogeneous expansions for a subclass of quasi-convex mappings （include quasi-convex mappings of type A and quasi-convex mappings of type B） in several complex variables are get accordingly. Our results state that a weak version of the Bieber- bach conjecture for quasi-convex mappings of type B and order a in several complex variables is proved, and the derived conclusions are the generalization of the classical results in one complex variable.

A SUBCLASS OF QUASI-CONVEX MAPPINGS ON A REINHARDT DOMAIN IN C^n

Let D p 1,p 2,⋯,p n={z∈C n:∑l=1 n|z l|p l<1},p l>1,l=1,2,⋯,n.In this article,we first establish the sharp estimates of the main coefficients for a subclass of quasi-convex mappings(including quasi-convex mappings of type A and quasi-convex mappings of type B)on D p 1,p 2,⋯,p n under some weak additional assumptions.Meanwhile,we also establish the sharp distortion theorems for the above mappings.The results that we obtain reduce to the corresponding classical results in one dimension.

Fekete and Szego problem for a subclass of quasi-convex mappings in several complex variables

Let K be the familiar class of normalized convex functions in the unit disk. Keogh and Merkes proved the well-known result that maxf∈A ｜a3 - λa22｜ ≤ max{1/3, ｜λ - 1}, ,λ ∈ C, and the estimate is sharp for each ∈. We investigate the corresponding problem for a subclass of quasi-convex mappings of type B defined on the unit ball in a complex Banach space or on the unit polydisk in Cn. The proofs of these results use some restrictive assumptions, which in the case of one complex variable are automatically satisfied.

The Estimates of All Homogeneous Expansions for a Subclass of Biholomorphic Mappings Which Have Parametric Representation in Several Complex Variables

In this paper, we obtain the estimates of all homogeneous expansions for a subclass of bi- holomorphic mappings which have parametric representation on the unit ball of complex Banach spaces. Meanwhile, we also establish the estimates of all homogeneous expansions for the above generalized mappings on the unit polydisk in Cn. Especially, the above estimates are only sharp for biholomorphic starlike mappings and starlike mappings of order α under restricted conditions. Our derived results generalize many known results.

C^n中单位多圆柱上一类B型α次准凸映射齐次展开式各项的精确估计

本文给出Cn中单位多圆柱上一类B型α次准凸映射f(z)齐次展开式各项的精确估计,其中f(z)=(f1(z),f2(z),...,fn(z))T是k折对称映射(或z=0是f(z)-z的k+1阶零点),且满足sup∥z∥=1,∥w∥=1∥Dmf(0)(zm-1,w)∥=sup∥z∥=1∥Dmf(0)(zm)∥,m=2,3,...所得到的估计包含已有文献的许多结论.