In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded dilation.Then,...In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded dilation.Then,using these results,we present better estimations for the Bloch constants of certain harmonic mappings L(f),where f is a K-quasiregular harmonic or open harmonic.Finally,we establish three versions of BlochLandau type theorem for biharmonic mappings of the form L(f).These results are sharp in some given cases and improve the related results of earlier authors.展开更多
The aim of this article is twofold.One aim is to establish the precise forms of Landau-Bloch type theorems for certain polyharmonic mappings in the unit disk by applying a geometric method.The other is to obtain the p...The aim of this article is twofold.One aim is to establish the precise forms of Landau-Bloch type theorems for certain polyharmonic mappings in the unit disk by applying a geometric method.The other is to obtain the precise values of Bloch constants for certain log-p-harmonic mappings.These results improve upon the corresponding results given in Bai et al.(Complex Anal.Oper.Theory,13(2):321-340,2019).展开更多
This note addresses monotonic growths and logarithmic convexities of the weighted （（1-t2）αdt2, -∞〈α〈∞, 0〈t〈1） integral means Aα,β（ f ,·） and Lα,β（ f ,·） of the mixed area （πr2）-βA（ f...This note addresses monotonic growths and logarithmic convexities of the weighted （（1-t2）αdt2, -∞〈α〈∞, 0〈t〈1） integral means Aα,β（ f ,·） and Lα,β（ f ,·） of the mixed area （πr2）-βA（ f ,r） and the mixed length （2πr）-βL（ f ,r） （0≤β≤1 and 0〈r〈1） of f （rD） and？f （rD） under a holomorphic map f from the unit disk D into the finite complex plane C.展开更多
设f(z)=h(z)+g(z)=z+sum (a_nz_n) from n=2 to +∞+sum(b_nz^n)from n=1 to +∞为定义在单位圆盘U上的调和映照,满足条件sum(np) from n=2 to +∞(|an|+|bn|)≤1-|b1|,证明当0<p≤1时,f(z)在圆盘|z|<r0=1/(21-p)内单叶;当1<p...设f(z)=h(z)+g(z)=z+sum (a_nz_n) from n=2 to +∞+sum(b_nz^n)from n=1 to +∞为定义在单位圆盘U上的调和映照,满足条件sum(np) from n=2 to +∞(|an|+|bn|)≤1-|b1|,证明当0<p≤1时,f(z)在圆盘|z|<r0=1/(21-p)内单叶;当1<p≤2时,(z)在圆盘|z|<R=1/(22-p)内为凸像函数.所得结果推广了M.Jahangiri等和M.ztürk等的结论.展开更多
基金supported by the Natural Science Foundation of Guangdong Province(2021A1515010058)。
文摘In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded dilation.Then,using these results,we present better estimations for the Bloch constants of certain harmonic mappings L(f),where f is a K-quasiregular harmonic or open harmonic.Finally,we establish three versions of BlochLandau type theorem for biharmonic mappings of the form L(f).These results are sharp in some given cases and improve the related results of earlier authors.
基金supported by Guangdong Natural Science Foundation(2018A030313508)。
文摘The aim of this article is twofold.One aim is to establish the precise forms of Landau-Bloch type theorems for certain polyharmonic mappings in the unit disk by applying a geometric method.The other is to obtain the precise values of Bloch constants for certain log-p-harmonic mappings.These results improve upon the corresponding results given in Bai et al.(Complex Anal.Oper.Theory,13(2):321-340,2019).
基金in part supported by NSERC of Canada and the Finnish Cultural Foundation
文摘This note addresses monotonic growths and logarithmic convexities of the weighted （（1-t2）αdt2, -∞〈α〈∞, 0〈t〈1） integral means Aα,β（ f ,·） and Lα,β（ f ,·） of the mixed area （πr2）-βA（ f ,r） and the mixed length （2πr）-βL（ f ,r） （0≤β≤1 and 0〈r〈1） of f （rD） and？f （rD） under a holomorphic map f from the unit disk D into the finite complex plane C.
文摘设f(z)=h(z)+g(z)=z+sum (a_nz_n) from n=2 to +∞+sum(b_nz^n)from n=1 to +∞为定义在单位圆盘U上的调和映照,满足条件sum(np) from n=2 to +∞(|an|+|bn|)≤1-|b1|,证明当0<p≤1时,f(z)在圆盘|z|<r0=1/(21-p)内单叶;当1<p≤2时,(z)在圆盘|z|<R=1/(22-p)内为凸像函数.所得结果推广了M.Jahangiri等和M.ztürk等的结论.
