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...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)=α→ |^f(k)(z)| ≤B or f^m(z)f^(k)(z)=α→|f(z)| ≥, then F is normal in D.展开更多
This paper presents an inequality, by use of which some results about the value distribution of f nf (k) are proved, where n and k are two positive integers.
A normal theorem concerning meromorphic functions sharing values was proved with the method of Zalcman- Pang.The theorem is as follows. If for each f in F, all zeros of f-a have multiplicity at least k (k≥2), f and i...A normal theorem concerning meromorphic functions sharing values was proved with the method of Zalcman- Pang.The theorem is as follows. If for each f in F, all zeros of f-a have multiplicity at least k (k≥2), f and its k-th derivative function share a, and if f=b whenever its k-th derivative equal b, then F is normal in D. This theorem improved the result of Chen and Fang [Chen HH, Fang ML, Shared values and normal families of meromorphic functions, Journal of Mathematical Analysis and Applications, 2001, 260: 124-132].展开更多
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 [ and g which are not polynominals of degree ...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 [ 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 Academiae Scientiarum Fennicae 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)].展开更多
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...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.展开更多
In this paper, we obtain the following normal criterion: Let F be a family of mero-morphic functions in domain D belong to C, all of whose zeros have multiplicity k + 1 at least. If there exist holomorphic functio...In this paper, we obtain the following normal criterion: Let F be a family of mero-morphic functions in domain D belong to C, all of whose zeros have multiplicity k + 1 at least. If there exist holomorphic functions α(z) not vanishing on D, such that for every function f(z) ∈F, f(z) shares α(z) IM with L(f) on D, then F is normal on D, where L(f) is linear differential polynomials of f(z) with holomorphic coefficients, and k is some positive numbers. We also proved coressponding results on normal functions.展开更多
文摘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)=α→ |^f(k)(z)| ≤B or f^m(z)f^(k)(z)=α→|f(z)| ≥, then F is normal in D.
文摘This paper presents an inequality, by use of which some results about the value distribution of f nf (k) are proved, where n and k are two positive integers.
文摘A normal theorem concerning meromorphic functions sharing values was proved with the method of Zalcman- Pang.The theorem is as follows. If for each f in F, all zeros of f-a have multiplicity at least k (k≥2), f and its k-th derivative function share a, and if f=b whenever its k-th derivative equal b, then F is normal in D. This theorem improved the result of Chen and Fang [Chen HH, Fang ML, Shared values and normal families of meromorphic functions, Journal of Mathematical Analysis and Applications, 2001, 260: 124-132].
文摘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 [ 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 Academiae Scientiarum Fennicae 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)].
文摘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.
基金the"11.5"Research & Study Programe of SWUST(No.06zx2116)
文摘In this paper, we obtain the following normal criterion: Let F be a family of mero-morphic functions in domain D belong to C, all of whose zeros have multiplicity k + 1 at least. If there exist holomorphic functions α(z) not vanishing on D, such that for every function f(z) ∈F, f(z) shares α(z) IM with L(f) on D, then F is normal on D, where L(f) is linear differential polynomials of f(z) with holomorphic coefficients, and k is some positive numbers. We also proved coressponding results on normal functions.