导数具有相同1值点的亚纯函数的唯一性定理

本文给出了一个导数具有相同1值点的亚纯函数唯一性定理,回答了C.C.Yang的一个问题,纠正了K.Shibazaki的一个结果.例子表明本文结果是精确的.     

与其导数分担一个值的整函数(英文)

主要得到与其导数分担一个值的整函数的一个唯一性定理，推广并改进了Gundersen与杨连中的有关结果．     

涉及例外函数的正规定则

讨论了一个涉及例外函数的亚纯函数正规定则,一定程度上推广和改进了方明亮~([2])等人的相关结果.     

与分担函数相关的正规定则

本文研究了与分担函数相关的亚纯函数族的正规性的问题.利用Nevanlinna理论的方法,得到了一个正规定则,推广了庞学诚和Zalcman~[3]的一个结果.     

导数具有k阶分担小函数的亚纯函数

主要讨论亚纯函数的导数具有某些k阶分担小函数时的唯一性问题,得到一个有趣的结果,推广了作者近期的一个结果..     

具两个公共小函数的整函数的唯一性

主要得到整函数与其导函数具两个公共小函数时的一个唯一性定理,改进了Rubel-Yang及郑稼华等人的某些结果。     

CM分担三个公共小函数对的亚纯函数的惟一性

研究了具有三个CM公共小函数对，一个IM公共小函数对的亚纯函数的惟一性，改进了李平与杨重骏，Brosch等人的有关结果，用例子说明本文的结果是最佳的.     

两类解析函数族的一些性质

研究两类解析函数族的性质，推广了Chichra[4]、Mocanu[5]和Obradovic[6]的一些结果。另外，也指出了S.Owa[8]的一个错误。     

单个函数平移和伸缩的叠加在L^p（R^d）中的逼近

本文主要讨论单个函数平移和伸缩的线性组合对Ｌ＾ｐ（Ｒ＾ｎ）中一紧集内函数的逼近，给出一个很强的逼近结果，这在神经网络应用研究中具有重要意义。     

β级α型Bazilevi?函数的对数系数

利用从属关系给出|(g(z)/f(z))~α|的估计.运用构造一个非负函数和对复变函数模的积分进行估计的方法,对β级α型Bazilevi函数类Bα(β)的对数系数bn进行研究.所得结果推广了一些作者的相关结果.     

Coefficient estimates for bi-univalent Ma-Minda starlike and convex functions

Estimates on the initial coefficients are obtained for normalized analytic functions f in the open unit disk with f and its inverse g=f⁻¹ satisfying the conditions that zf^′(z)/f(z) and zg^′(z)/g(z) are both subordinate to a univalent function whose range is symmetric with respect to the real axis. Several related classes of functions are also considered, and connections to earlier known results are made.     

Dirichlet problem for pluriholomorphic functions of two complex variables

In this paper the Dirichlet problem for pluriholomorphic functions of two complex variables is investigated. The key point is the relation between pluriholomorphic functions and pluriharmonic functions. The link is constituted by the Fueter-regular functions of one quaternionic variable. Previous results about the boundary values of pluriharmonic functions and new results on L² traces of regular functions are applied to obtain a characterization of the traces of pluriholomorphic functions.     

On a conjecture of D. Styer regarding univalent geometric and annular starlike functions

The aim of this paper is two-fold. First, to give a direct proof for the already established result of Styer which states that a univalent geometrically starlike function is a univalent annular starlike function if is bounded. Second, to show that the boundedness condition of is necessary, thus disproving a conjecture of Styer.

     

Functional inequalities involving special functions

Let up(x) be the generalized and normalized Bessel function depending on parameters b,c,p and let σ(r)=up(1−r²)/up(r²), r∈(0,1). Motivated by an open problem of Anderson, Vamanamurthy, and Vuorinen we prove that for all r₁,r₂∈(0,1) for certain conditions on the parameters b,c,p.     

On the Characterization of Preinvex Functions

In Refs. [J. Math. Anal. Appl. 258:287–308, [2001]; J. Math. Anal. Appl. 256:229–241, [2001]], Yang and Li presented a characterization of preinvex functions and semistrictly preinvex functions under a certain set of conditions. In this note, we show that the same results or even more general ones can be obtained under weaker assumptions; we also give a characterization of strictly preinvex functions under mild conditions. This research was supported by the National Natural Science Foundation of China under Grants 70671064 and 60673177, and the Education Department Foundation of Zhejiang Province Grant 20070306. The authors thank Professor F. Giannessi for valuable comments on the original version of this paper.     

Solving in the affirmative a conjecture about a limit of gradients

In this journal, Giannessi (Ref. 1) conjectured the existence of a convex function on , wheren 2, such that f(te) exists fort>0,e = (1, 0, ..., 0), but lim _t0 f(te) does not exist. Furthermore, he generalized the question by substituting the aforesaid ray with a curve having an endpoint at 0 (the origin) and by asking the question for the infinite-dimensional case. With the example in Section 1, we answer in the affirmative all parts of the conjecture. Section 2 (concerning curves) and Section 3 indicate conditions (asked in Ref. 1) under which the limit exists. In Section 4, an example peculiar to the infinite-dimensional case is given.This work is dedicated to the memory of Gianfranco Cimmino.     

A note on hyperharmonic and polyharmonic functions

We show that the spaces of harmonic functions with respect to the Poincaré metric in the unit ball B^N in have many different properties depending upon whether N is even or odd.     

On the structure of homothetic functions

Summary Homothetic function is a term which refers to some extension of the concept of a homogeneous function. We study different hierarchies of generalized homogeneous functions. The main result is a general classification of those functions.     

Double piling structure of matrix monotone functions and of matrix convex functions

There are basic equivalent assertions known for operator monotone functions and operator convex functions in two papers by Hansen and Pedersen. In this note we consider their results as correlation problem between two sequences of matrix n-monotone functions and matrix n-convex functions, and we focus the following three assertions at each label n among them:

(i) f(0)0 and f is n-convex in [0,α),

(ii) For each matrix a with its spectrum in [0,α) and a contraction c in the matrix algebra M_n,

f(cac)cf(a)c,