The uniqueness of an entire function sharing a small entire function with its derivatives

In this paper, we prove a theorem on the growth of a solution of a linear differential equation. From this we obtain some uniqueness theorems concerning that a nonconstant entire function and its derivatives sharing a small entire function. The results in this paper improve many known results. Some examples are provided to show that the results in this paper are the best possible.     

An entire function and its derivatives sharing a polynomial

In this paper, we study the growth of solutions of a first-order linear differential equation and that of a second-order linear differential equation. From this we obtain some uniqueness theorems of a nonconstant entire function and its first derivative having the same fixed points with the same multiplicities. The results in this paper also improve some known results. Some examples show that the results in this paper are best possible.     

On uniqueness of an entire function and its derivatives

In this paper, we study the growth of solutions of a first order linear differential equation. From this we verify that a conjecture given by Brück is true under the restriction of the hyper order less than 1/2, and obtain some uniqueness theorems of a nonconstant entire function and its first derivative sharing a nonzero constant CM. The results in this paper also improve some known results. Some examples show that the results in this paper are best possible. Project supported by the NSFC (NO. A0324617) and the RFDP (NO. 20060422049). Received: 20 April 2006 Revised: 4 February 2007     

Entire functions sharing one polynomial with their derivatives

In this paper, we study the growth of solutions of ak-th order linear differential equation and that of a k + 1-th order linear differential equation. From this we affirmatively answer a uniqueness question concerning a conjecture given by Brück in 1996 under the restriction of the hyper order less than 1/2, and obtain some uniqueness theorems of a nonconstant entire function and its derivative sharing a finite nonzero complex number CM. The results in this paper also improve some known results. Some examples are provided to show that the results in this paper are best possible.     

整函数与其微分多项式IM分担两个值

设 f(Z)为非常数整函数 ,L (f )为 f (Z)的具有小函数系数的线性微分多项式 ,本文研究当 f(Z)与 L (f ) IM分担两个有穷复数时的唯一性问题 ,给出了 f (Z)与L (f )完全确定的表达式 ,改进了李平、杨重骏最近获得的一个结果 ,从而也改进了先前的一些结果 .     

Value sharing and differential equations

Suppose that f is a nonconstant entire function and L[f] a linear differential polynomial in f with constant coefficients. In this paper, by considering the existence of the solutions of some differential equations, we find all the forms of entire functions f in most cases when f and L[f] share two values counting multiplicities jointly. This result generalize some known results due to Rubel–Yang and Li–Yang.     

Uniqueness of entire functions sharing an entire function of smaller order with their derivatives

In this paper, we prove some uniqueness theorems of entire functions and their derivatives that share an entire of function whose order is less than their order. The results in this paper improve those given by G. G. Gundersen and L. Z. Yang, J. P. Wang, J. M. Chang, and Y. Z. Zhu, X. M. Li and H. X. Yi, and others. Some examples are provided to show that the results in this paper are the best possible.     

On solutions of linear differential equations with entire coefficients

The first result of the paper concerns the effect of perturbation of the entire coefficients of certain linear differential equations on the oscillation of the solutions. Subsequent results involve the separation of the zeros of a Bank-Laine function.     

On universal entire functions with zero-free derivatives

We prove in this note a generalization of a theorem due to G. Herzog on zero-free universal entire functions. Specifically, it is shown that, if a nonnegative integer q and a nonconstant entire function φ of subexponential type are given, then there is a residual set in the class of entire functions with zero-free derivatives of orders q and q + 1, such that every member of that set is universal with respect to φ (D), where D is the differentiation operator. This work is supported in part by DGICYT grant PB93-0926.     

Entire functions sharing an entire function of smaller order with their difference operators

We study a uniqueness question of entire functions order with their difference operators, and deal with a question in this paper extend the corresponding results obtained by Liu Examples are provided to show that the results in this paper, in sharing an entire function of smaller posed by Liu and Yang. The results -Yang and by Liu-Laine respectively. a sense, are the best possible.     

Notes on entire functions sharing an entire function of a smaller order with their difference operators

In this paper, we study a uniqueness question of entire functions sharing an entire function of smaller order with their difference operators. The results in this paper extend Theorem 1.1 in [19] by Liu and Yang and deal with Question 1 in [19], where the entire functions are of finite order. Moreover, we repair certain statements in [21] by Li et al., which in turn had depended on questionable assertions of Lemma 2.6 in [20]. Examples are provided to show that the results in this paper are best possible.     

An entire function that shares a small function with a homogeneous differential polynomial

In connection to a result of R. Brück,we study the uniqueness of an entire function when it shares a small function with a homogeneous differential polynomial.     

On a theorem of A. and C. Rényi and a conjecture of C. C. Yang concerning periodicity of entire functions

Analysis Mathematica - A theorem of A. and C. Rényi on periodic entire functions states that an entire function f(z) must be periodic if P(f(z)) is periodic, where P(z) is a nonconstant...     

An entire space polynomial-time algorithm for linear programming

We propose an entire space polynomial-time algorithm for linear programming. First, we give a class of penalty functions on entire space for linear programming by which the dual of a linear program of standard form can be converted into an unconstrained optimization problem. The relevant properties on the unconstrained optimization problem such as the duality, the boundedness of the solution and the path-following lemma, etc, are proved. Second, a self-concordant function on entire space which can be used as penalty for linear programming is constructed. For this specific function, more results are obtained. In particular, we show that, by taking a parameter large enough, the optimal solution for the unconstrained optimization problem is located in the increasing interval of the self-concordant function, which ensures the feasibility of solutions. Then by means of the self-concordant penalty function on entire space, a path-following algorithm on entire space for linear programming is presented. The number of Newton steps of the algorithm is no more than $O(nL\log (nL/ {\varepsilon }))$ , and moreover, in short step, it is no more than $O(\sqrt{n}\log (nL/{\varepsilon }))$ .     

Unicity of entire functions and their linear differential polynomials

We study the relationship between an entire function f and its certain type of linear differential polynomial L when f and L share one finite nonzero value under some additional conditions. The results improve and generalize some previous results obtained by C.C. Yang and some other authors.     

Uniqueness of entire function sharing a small function with its derivative

This paper is devoted to studying the relationship between an entire function and its derivative when they share one small function. We generalize some previous results of Gundersen and Yang [G. Gundersen, L.Z. Yang, Entire functions that share one value with one or two of their derivatives, J. Math. Anal. Appl. 223 (1998) 85–95], Chang and Zhu [J. Chang, Y. Zhu, Entire functions that share a small function with their derivatives, J. Math. Anal. Appl. 351 (2009) 491–496].     

关于亚纯函数的分解

讨论了一类亚纯函数的分解 ,推广了整函数的相关结果 .证明了有理函数与超越整函数的复合不可能为具有非常数多项式为模的拟周期函数 .     

整代数体函数与其导函数的增长级

对整代数体函数与其导函数的增长性进行了研究,得到了整代数体函数与其导函数的特征函数之间关系式,并证明了它们具有相同的级和下级,从而将亚纯函数的相应结果推广到了整代数体函数.     

Optimal uniform approximation on angles by entire functions

The paper discusses the best or optimal uniform approximation problem by entire functions on a closed angle Δ. This problem has been studied by M.V. Keldysch in [4], under the assumption that the functions ? subject to approximation are holomorphic in a larger angle containing Δ and there is no restriction on the growth of ? at infinity. In [8], the problem was investigated for a wider class of functions ? continuously complex differentiable on Δ, with sharper estimates on the growth of approximating entire functions, linked with the growth of ? on Δ and the differential properties of ? on the boundary of Δ. In this paper, we improve some of the results on entire approximation on angles, using new approximation ideas partially presented in [9] and [10].