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1.
We studied the normality conditions in families of meromorphic functions, improved the results of Fang and Zalcman [Fang ML, Zalcman L, Normal families and shared values of meromorphic functions, Computational Methods and Function Theory, 2001, 1 (1): 289-299], and generalized two new normality criterions. Let F be a family of meromorphic functions in a domain D, a a non-zero finite complex number, B a positive real number, and k and m two positive integers satisfying m>2k 4. If every function denoted by f belonging to F has only zeros with multiplicity at least k and satisfies f m(z)f (k)(z)=a??f (k)(z)?≤B or f m(z)f (k)(z)=a??f (z)?≥B, then F is normal in D.  相似文献   

2.
We studied the normality criterion for families of meromorphic functions related to shared sets. Let F be a family of meromorphic functions on the unit disc △, a and b be distinct non-zero values, S={a,b}, and k be a positive integer. If for every f∈ F, i) the zeros of f(z) have a multiplicity of at least k+ 1, and ii) E^-f(k)(S) lohtain in E^-f(S), then F is normal on .4. At the same time, the corresponding results of normal function are also proved.  相似文献   

3.
The uniqueness of meromorphic fuctions sharing one value was studied. Using the concept of weighted sharing, we proved the following theorem. For two meromorphic functions f and g which are not polynominals of degree less than a positive integer k, if f nf (k) and g ng (k) share (1,2), where n is another positive integer not less than k 10, then f nf (k) identically equals g ng (k) or f nf (k)g ng (k) identically equals 1. Particularly for k =1, we improved the results of Yang [Yang CC, Hua XH, Uniqueness and value-sharing of meromorphic functions, Annales Academi? Scientiarum Fennic? Mathematica, 1997, 22: 395-406], and Fang [Fang ML, Hua XH, Entire function that share one value, Journal of Nanjing University, 1996, 13(1): 44-48. (In Chinese)].  相似文献   

4.
设(F)为定义在区域D内的一族亚纯函数,a(z)和b(z)为两个在D满足a(z)≠b(z)和a(z)≠b(k)(z)以及a(z)(≠)a'(z)的全纯函数,若对于任意的f∈(F),f(z)-a(z)的零点重级至少是k,f(z)和f(k)(z)分担a(z),且当f(z)=b(z)时,f(k)(z)=b(z),那么(F)在...  相似文献   

5.
研究了关于分担一个值的亚纯函数的正规族问题,证明了:设F为区域D上的亚纯函数族,k是正整数,如果对任意的f∈F.f-a的零点重数至少为k,f(z)=a■f(k)(z)=a■f(k+1)(z)=a,则F在D上正规.  相似文献   

6.
The uniqueness problem of entire functions concerning weighted sharing was discussed, and the following theorem was proved. Let f and 8 be two non-constant entire functions, m, n and k three positive integers, and n〉2k+4. If Em(1,(f^n)^(k))= Em(1,(g^n)^(k)), then either f(z)=c1c^cz and 8(z)= c2c^cz or f=ts, where c, c1 and c2 are three constants satisfying (-1)^k(c1c2)^n(nc)^2k=], and t is a constant satisfying t^n=1. The theorem generalizes the result of Fang [Fang ML, Uniqueness and value sharing of entire functions, Computer & Mathematics with Applications, 2002, 44: 823-831].  相似文献   

7.
研究了一类微分方程f(k)+A(z)f*+B(z)f=0亚纯解的增长性,其中A(z),B(z)为有限级的超越亚纯函数,F为有限级亚纯函数.研究了微分方程亚纯解的不动点与超级,得到了进一步的结果.  相似文献   

8.
Based on a unicity theorem for entire funcitions concerning differential polynomials proposed by M. L. Fang and W. Hong, we studied the uniqueness problem of two meromorphic functions whose differential polynomials share the same 1- point by proving two theorems and their related lemmas. The results extend and improve given by Fang and Hong’s theorem.  相似文献   

9.
本文主要得到亚纯函数与其k阶导数具1IM公共值的唯一性定理,推广了某些已知的结果  相似文献   

10.
证明了非常数的亚纯函数的一类非线性微分多项式具有一个非零公共值的亚纯函数的唯一性,其文结果改进了杨重骏和华歆厚的结果,扩充了方明亮的结果。  相似文献   

11.
利用NevanLinna的亚纯函数的值分布理论,研究了超越亚纯函数微分多项式的值分布理论,取得以下主要结果:若f(z)是复平面上超越严亚纯函数,m、n和k都是正整数,且n≥2,Qj[f](j=1,2…,m)为f(z)的微分单项式,Q[f]=sum from j=1 to m ()aj(z)Qj[f]为f(z)的拟微分多项式,aj(z)是f(z)的小函数,令F(z)=Q[f](f(k)(z))n-c,则T(T,f(k)≤k+1/n(k=1)/(R,1/Q[F]+(r,1/F)+S(r,f))  相似文献   

12.
通过研究亚纯函数的Nevanlinna值分布理论问题,并结合亚纯函数的小函数,及其微分单项式和微分多项式,得到一比较有趣的关于亚纯函数的计数函数密指量和微分多项式的不等式,此不等式改进了Fang,Yang及I Lahiri和S.Dewan等学者的结果。  相似文献   

13.
讨论了一般微分单项式的值分布 ,得到定理 :设 f 是平面上的超越亚纯函数 .F=fn0 (f( i) ) ni… (f( k) ) nk-c,ni≥ 1,c≠ 0是常数 ,那么 (n0 -2 ) T(r,f )≤ N(r,1F ) S(r,f )  n0 >2T(r,f )≤ 7(i 1)i (Ni) (r,1f ) N(r,1F) ) S(r,f )  n0 =1T(r,f )≤ 7(N (r,1f ) N(r,1F) ) S(r,f )  n0 =0 .  相似文献   

14.
刘克笑 《安康学院学报》2010,22(5):94-96,99
研究全纯函数与其微分多项式分担函数,得到了如下的正规定则:设F是区域D内的全纯函数族,k是一正整数,h1(z),h2(z)在区域D内的解析,满足|h1(z)|2+|h2(z)|2≠0。若f∈F,f的零点重级至少为k,且f(z)=0|f(k)(z)|≤M(常数M〉0),(z)=αi(z)L(Z)=αi(z),i=1,2,其中L(z)=f∞(z)+α1(z)f(k-1)(z)+…+αk(z)f(z)为f的微分多项式,αi(z)(i=1,2,…,k,k≥1)在D内解析,那么F在D内正规。  相似文献   

15.
文章研究了亚纯函数的唯一性,得到了关于亚纯函数f(z)和g(z)分担5个小函数的一个唯一性定理.  相似文献   

16.
从分担值以及分担集合角度出发,研究亚纯函数与其高阶导数分担集合的正规性及亚纯函数与其一阶导数在分担集合情况下的正规定则,结果改正推广了前人的结果.  相似文献   

17.
主要研究亚纯函数的导数分担公共值的情形,对于两个亚纯函数的k阶导数在涉及截断分担一个公共值的情况进行了详细讨论。证明过程中通过对函数重级零点、极点的分类讨论并进行了详细计算,得到一个亚纯函数唯一性问题的结果。  相似文献   

18.
The uniqueness problem of entire functions sharing one small function was studied. By Picard’s Theorem, we proved that for two transcendental entire functions f (z) and g(z), a positive integer n≥9, and a(z) (not identically eaqual to zero) being a common small function related to f (z) and g(z), if f n(z)(f(z)-1)f′(z) and gn(z)(g(z)-1)g′(z) share a(z) CM, where CM is counting multiplicity, then g(z) ≡ f (z). This is an extended version of Fang and Hong’s theorem [ Fang ML, Hong W, A unicity theorem for entire functions concerning differential polynomials, Journal of Indian Pure Applied Mathematics, 2001, 32 (9): 1343-1348].  相似文献   

19.
从权弱分担的角度分析亚纯函数(或整函数)fn与其k阶导数[fn](k)的唯一性问题,得到f(n)=[fn](k)且f=cexp((λ/n)z)(c为非需常数,λk=1)的充分条件.  相似文献   

20.
设p是素数,对于非负整数k,设F(k)=22k 1是第k个Fermat数,本文证明了:方程x y xy=2p-1没有正整数解(x,y)的充要条件是P=2或者P=F(k)且F(2k)也是素数.  相似文献   

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