In this article, a normalized biholomorphic mapping f defined on bounded starlike circular domain in Cn is considered, where z = 0 is a zero of order k + 1 of f(z) - z. The sharp growth, covering theorems for almos...In this article, a normalized biholomorphic mapping f defined on bounded starlike circular domain in Cn is considered, where z = 0 is a zero of order k + 1 of f(z) - z. The sharp growth, covering theorems for almost starlike mappings of order α and starlike mappings of order α are established. Meanwhile, the construction of the above mappings on bounded starlike circular domain in Cn is also discussed, it provides the extremal mappings for the growth, covering theorems of the above mappings.展开更多
In this paper,we first establish the sharp growth theorem and the distortion theorem of the Frechet derivative for biholomorphic mappings defined on the unit ball of complex Banach spaces and the unit polydisk in C^(n...In this paper,we first establish the sharp growth theorem and the distortion theorem of the Frechet derivative for biholomorphic mappings defined on the unit ball of complex Banach spaces and the unit polydisk in C^(n) with some restricted conditions.We next give the distortion theorem of the Jacobi determinant for biholomorphic mappings defined on the unit ball of C^(n) with an arbitrary norm and the unit polydisk in C^(n) under certain restricted assumptions.Finally we obtain the sharp Goluzin type distortion theorem for biholomorphic mappings defined on the unit ball of complex Banach spaces and the unit polydisk in C^(n) with some additional conditions.The results derived all reduce to the corresponding classical results in one complex variable,and include some known results from the prior literature.展开更多
In this article, the generalized Roper-Suffridge extension operator in Banach spaces for locally biholomorphic mappings is introduced. It is proved that this operator preserves the starlikeness on some domains in Bana...In this article, the generalized Roper-Suffridge extension operator in Banach spaces for locally biholomorphic mappings is introduced. It is proved that this operator preserves the starlikeness on some domains in Banach spaces but does not preserves convexity for some cases. Moreover, the growth theorem, covering theorem, and the radius of starlikeness are discussed. Some results of Roper and Suffridge, Gong and Liu, Graham et al in C^n are extended to Hilbert spaces or Banach spaces.展开更多
In this article,the authors obtain an inequality of homogeneous expansion for f,where f is a quasi-convex mapping(including quasi-convex mapping of type A and quasi-convex mapping of type B)defined on the open unit po...In this article,the authors obtain an inequality of homogeneous expansion for f,where f is a quasi-convex mapping(including quasi-convex mapping of type A and quasi-convex mapping of type B)defined on the open unit polydisk in C n .Meanwhile,the authors also investigate its application.展开更多
Let G_i be a closed Lie subgroup of U(n), ?_i be a bounded Gi-invariant domain in C^n which contains 0, and O(C^n)^(Gi) = C, for i = 1, 2. If f : ?_1→ ?_2 is a biholomorphism, and f(0) = 0, then f is a polynomial map...Let G_i be a closed Lie subgroup of U(n), ?_i be a bounded Gi-invariant domain in C^n which contains 0, and O(C^n)^(Gi) = C, for i = 1, 2. If f : ?_1→ ?_2 is a biholomorphism, and f(0) = 0, then f is a polynomial mapping(see Ning et al.(2017)). In this paper, we provide an upper bound for the degree of such polynomial mappings. It is a natural generalization of the well-known Cartan's theorem.展开更多
In this note, the author introduces some new subcIasses of starlike mappings S^*Ωn1p2,…,pn(β,A,B)={f∈H(Ω):|itanβ+(1-itanβ)2/p(z)аp/аz(z)Jf^-1(z)f(z)-1-AB/1-B^2|〈B-A/1-B^2},on Reinhardt dom...In this note, the author introduces some new subcIasses of starlike mappings S^*Ωn1p2,…,pn(β,A,B)={f∈H(Ω):|itanβ+(1-itanβ)2/p(z)аp/аz(z)Jf^-1(z)f(z)-1-AB/1-B^2|〈B-A/1-B^2},on Reinhardt domains Ωn1p2,…,pn=z∈C^n:|z1|^2+n∑j=2|zj|^pj〈1}where - 1≤A〈B〈1,q=min{p2,…,pn}≥1,l=max{p2,…,pn}≥2 and β ∈(-π/2,π/2).Some different conditions for P are established such that these classes are preserved under the following modified Roper-Suffridge operator F(z)=(f(z1)+f'(z1)Pm(z0),(f'(z1))^1/mz0)'where f is a normalized biholomorphic function on the unit disc D, z = (z1,z0) ∈Ωn1p2,…,pn,z0=(z2,…,zn)∈ C^n-1.Another condition for P is also obtained such that the above generalized Roper-Suffridge operator preserves an almost spirallike function of type/3 and order β These results generalize the modified Roper-Suffridge extension oper-ator from the unit ball to Reinhardt domains. Notice that when p2 = p3 …=pn = 2,our results reduce to the recent results of Feng and Yu.展开更多
This article is devoted to a deep study of the Roper-Suffridge extension operator with special geometric properties.First,we prove that the Roper-Suffridge extension operator preservesϵstarlikeness on the open unit ba...This article is devoted to a deep study of the Roper-Suffridge extension operator with special geometric properties.First,we prove that the Roper-Suffridge extension operator preservesϵstarlikeness on the open unit ball of a complex Banach space C×X,where X is a complex Banach space.This result includes many known results.Secondly,by introducing a new class of almost boundary starlike mappings of orderαon the unit ball B n of C n,we prove that the Roper-Suffridge extension operator preserves almost boundary starlikeness of orderαon B n.Finally,we propose some problems.展开更多
In this article, first, a sufficient condition for a starlike mapping of order a f(x) defined on the unit ball in a complex Banach space is given. Second, the sharp estimate of the third homogeneous expansion for f ...In this article, first, a sufficient condition for a starlike mapping of order a f(x) defined on the unit ball in a complex Banach space is given. Second, the sharp estimate of the third homogeneous expansion for f is established as well, where f(z) = (f1(z), f2(z),..., fn(z))' is a starlike mapping of order a or a normalized biholomorphic starlike mapping defined on the unit polydisk in Cn, and D2fk(0)(z2) /2i= zk(∑l=1^b akzzl), k = 2t l=1 k = 1, 2,..., n. Our result states that the Bieberbaeh conjecture in several complex variables (the case of the third homogeneous expansion for starlike mappings of order α and biholomorphic starlike mappings) is partly proved.展开更多
In this paper, we construct a new Roper-Suffridge extension operator Φn^r,β1,,βn(f)(z) = F(z) = ((rf(z1/r)/z1)^β1z1,(rf(z1/r)/z1)^β2z2,...,(rf(z1/r)/z1)^βnzn)',where f is a normalized locall...In this paper, we construct a new Roper-Suffridge extension operator Φn^r,β1,,βn(f)(z) = F(z) = ((rf(z1/r)/z1)^β1z1,(rf(z1/r)/z1)^β2z2,...,(rf(z1/r)/z1)^βnzn)',where f is a normalized locally biholomorphic function on the unit disc D, r = sup{|z1| : z =(z1, ···, zn) ∈Ω}, β1∈ [0, 1], 0 ≤βk≤β1, k = 2, ···, n, then we prove it can preserve the property of spirallikeness of type β, almost starlikeness of order α and starlikeness of orderα on bounded complete Reinhardt domain Ω, respectively.展开更多
This note is devoted to applying the principle of subordination in order to explore the Roper-Suffridge extension operator and the Pfaltzgraff-Suffridge extension operator with special analytic properties.First,we pro...This note is devoted to applying the principle of subordination in order to explore the Roper-Suffridge extension operator and the Pfaltzgraff-Suffridge extension operator with special analytic properties.First,we prove that both the Roper-Suffridge extension operator and the Pfaltzgraff-Suffridge extension operator preserve subordination.As applications,we obtain that if β∈[0,1],γ∈[0,1/r]and β+γ≤1,then the Roper-Suffridge extension operator Φ_(β+γ)(f)(z)=(f(z_(1)),(f(z_(1))/z_(1))^(β)(f’(z_(1)))^(γ)w),z∈Ω_(p,r) preserves an almost starlike mapping of complex order λ on Ω_(p,r)={z=(z_(1),w)∈C×X:|z_(1)|^(p)+‖w‖_(X)^(r)<1},where 1≤p≤2,r≥1 and X is a complex Banach space.Second,by applying the principle of subordination,we will prove that the Pfaltzgraff-Suffridge extension operator preserves an almost starlike mapping of complex order λ.Finally,we will obtain the lower bound of distortion theorems associated with the Roper-Suffridge extension operator.This subordination principle seems to be a new idea for dealing with the Loewner chain associated with the Roper-Suffridge extension operator,and enables us to generalize many known results from p=2 to 1≤p≤2.展开更多
In this paper, we consider the following Reinhardt domains. Let M = (M1, M2,..., Mn) : [0,1] → [0,1]^n be a C2-function and Mj(0) = 0, Mj(1) = 1, Mj″ 〉 0, C1jr^pj-1 〈 Mj′(r) 〈 C2jr^pj-1, r∈ (0, 1), ...In this paper, we consider the following Reinhardt domains. Let M = (M1, M2,..., Mn) : [0,1] → [0,1]^n be a C2-function and Mj(0) = 0, Mj(1) = 1, Mj″ 〉 0, C1jr^pj-1 〈 Mj′(r) 〈 C2jr^pj-1, r∈ (0, 1), pj 〉 2, 1 ≤ j ≤ n, 0 〈 C1j 〈 C2j be constants. Define DM={z=(z1,z2,…,Zn)^T∈C^n:n∑j=1 Mj(|zj|)〈1}Then DM C^n is a convex Reinhardt domain. We give an extension theorem for a normalized biholomorphic convex mapping f : DM -→ C^n.展开更多
基金The research was supported by the National Nat ural Science Foundation of China(10571164)Specialized Research Fund for the Doctoral Program of Higher Education(20050358052)+1 种基金Guangdong Natural Science Foundation(06301315)the Doctoral Foundation of Zhanjiang Normal University(Z0420)
文摘In this article, a normalized biholomorphic mapping f defined on bounded starlike circular domain in Cn is considered, where z = 0 is a zero of order k + 1 of f(z) - z. The sharp growth, covering theorems for almost starlike mappings of order α and starlike mappings of order α are established. Meanwhile, the construction of the above mappings on bounded starlike circular domain in Cn is also discussed, it provides the extremal mappings for the growth, covering theorems of the above mappings.
基金Supported by National Natural Science Foundation of China(11871257,12071130)。
文摘In this paper,we first establish the sharp growth theorem and the distortion theorem of the Frechet derivative for biholomorphic mappings defined on the unit ball of complex Banach spaces and the unit polydisk in C^(n) with some restricted conditions.We next give the distortion theorem of the Jacobi determinant for biholomorphic mappings defined on the unit ball of C^(n) with an arbitrary norm and the unit polydisk in C^(n) under certain restricted assumptions.Finally we obtain the sharp Goluzin type distortion theorem for biholomorphic mappings defined on the unit ball of complex Banach spaces and the unit polydisk in C^(n) with some additional conditions.The results derived all reduce to the corresponding classical results in one complex variable,and include some known results from the prior literature.
基金This research is partly supported by the National Natural Science Foundation of China (10471048) the Doctoral Foundation of the Education Committee of China(20050574002)+1 种基金 the Natural Science Foundation of Fujian Province, China (Z0511013)the Education Commission Foundation of Fujian Province, China (JB04038)
文摘In this article, the generalized Roper-Suffridge extension operator in Banach spaces for locally biholomorphic mappings is introduced. It is proved that this operator preserves the starlikeness on some domains in Banach spaces but does not preserves convexity for some cases. Moreover, the growth theorem, covering theorem, and the radius of starlikeness are discussed. Some results of Roper and Suffridge, Gong and Liu, Graham et al in C^n are extended to Hilbert spaces or Banach spaces.
基金Sponsored by National Natural Science Foundation of China under grant No.10571164Specialized Research Fund for the Doctoral Program of Higher Education under grant No.20050358052Guangdong Natural Science Foundation under grant No.06301315
文摘In this article,the authors obtain an inequality of homogeneous expansion for f,where f is a quasi-convex mapping(including quasi-convex mapping of type A and quasi-convex mapping of type B)defined on the open unit polydisk in C n .Meanwhile,the authors also investigate its application.
基金supported by National Natural Science Foundation of China(Grant Nos.11501058 and 11431013)the Fundamental Research Funds for the Central Universities(Grant No.0208005202035)Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant No.QYZDY-SSW-SYS001)
文摘Let G_i be a closed Lie subgroup of U(n), ?_i be a bounded Gi-invariant domain in C^n which contains 0, and O(C^n)^(Gi) = C, for i = 1, 2. If f : ?_1→ ?_2 is a biholomorphism, and f(0) = 0, then f is a polynomial mapping(see Ning et al.(2017)). In this paper, we provide an upper bound for the degree of such polynomial mappings. It is a natural generalization of the well-known Cartan's theorem.
基金supported by the National Natural Science Foundation of China(11001246,11101139)Zhejiang Innovation Project(T200905)
文摘In this note, the author introduces some new subcIasses of starlike mappings S^*Ωn1p2,…,pn(β,A,B)={f∈H(Ω):|itanβ+(1-itanβ)2/p(z)аp/аz(z)Jf^-1(z)f(z)-1-AB/1-B^2|〈B-A/1-B^2},on Reinhardt domains Ωn1p2,…,pn=z∈C^n:|z1|^2+n∑j=2|zj|^pj〈1}where - 1≤A〈B〈1,q=min{p2,…,pn}≥1,l=max{p2,…,pn}≥2 and β ∈(-π/2,π/2).Some different conditions for P are established such that these classes are preserved under the following modified Roper-Suffridge operator F(z)=(f(z1)+f'(z1)Pm(z0),(f'(z1))^1/mz0)'where f is a normalized biholomorphic function on the unit disc D, z = (z1,z0) ∈Ωn1p2,…,pn,z0=(z2,…,zn)∈ C^n-1.Another condition for P is also obtained such that the above generalized Roper-Suffridge operator preserves an almost spirallike function of type/3 and order β These results generalize the modified Roper-Suffridge extension oper-ator from the unit ball to Reinhardt domains. Notice that when p2 = p3 …=pn = 2,our results reduce to the recent results of Feng and Yu.
基金the NNSF of China(11671362,11971165)Beijing Municipal Natural Science Foundation(1182008)the Scientific Research Funds of Huaqiao University.
文摘This article is devoted to a deep study of the Roper-Suffridge extension operator with special geometric properties.First,we prove that the Roper-Suffridge extension operator preservesϵstarlikeness on the open unit ball of a complex Banach space C×X,where X is a complex Banach space.This result includes many known results.Secondly,by introducing a new class of almost boundary starlike mappings of orderαon the unit ball B n of C n,we prove that the Roper-Suffridge extension operator preserves almost boundary starlikeness of orderαon B n.Finally,we propose some problems.
基金Project supported by National Natural Science Foundation of China(10971063,11061015)Major Program of Zhejiang Provincial Natural Science Foundation of China(D7080080)Guangdong Natural Science Foundation(06301315)
文摘In this article, first, a sufficient condition for a starlike mapping of order a f(x) defined on the unit ball in a complex Banach space is given. Second, the sharp estimate of the third homogeneous expansion for f is established as well, where f(z) = (f1(z), f2(z),..., fn(z))' is a starlike mapping of order a or a normalized biholomorphic starlike mapping defined on the unit polydisk in Cn, and D2fk(0)(z2) /2i= zk(∑l=1^b akzzl), k = 2t l=1 k = 1, 2,..., n. Our result states that the Bieberbaeh conjecture in several complex variables (the case of the third homogeneous expansion for starlike mappings of order α and biholomorphic starlike mappings) is partly proved.
文摘In this paper, we construct a new Roper-Suffridge extension operator Φn^r,β1,,βn(f)(z) = F(z) = ((rf(z1/r)/z1)^β1z1,(rf(z1/r)/z1)^β2z2,...,(rf(z1/r)/z1)^βnzn)',where f is a normalized locally biholomorphic function on the unit disc D, r = sup{|z1| : z =(z1, ···, zn) ∈Ω}, β1∈ [0, 1], 0 ≤βk≤β1, k = 2, ···, n, then we prove it can preserve the property of spirallikeness of type β, almost starlikeness of order α and starlikeness of orderα on bounded complete Reinhardt domain Ω, respectively.
基金partially supported by the NationalNatural Science Foundation of China(12071161,11971165,11701307)the Natural Science Foundation of Fujian Province(2020J01073)。
文摘This note is devoted to applying the principle of subordination in order to explore the Roper-Suffridge extension operator and the Pfaltzgraff-Suffridge extension operator with special analytic properties.First,we prove that both the Roper-Suffridge extension operator and the Pfaltzgraff-Suffridge extension operator preserve subordination.As applications,we obtain that if β∈[0,1],γ∈[0,1/r]and β+γ≤1,then the Roper-Suffridge extension operator Φ_(β+γ)(f)(z)=(f(z_(1)),(f(z_(1))/z_(1))^(β)(f’(z_(1)))^(γ)w),z∈Ω_(p,r) preserves an almost starlike mapping of complex order λ on Ω_(p,r)={z=(z_(1),w)∈C×X:|z_(1)|^(p)+‖w‖_(X)^(r)<1},where 1≤p≤2,r≥1 and X is a complex Banach space.Second,by applying the principle of subordination,we will prove that the Pfaltzgraff-Suffridge extension operator preserves an almost starlike mapping of complex order λ.Finally,we will obtain the lower bound of distortion theorems associated with the Roper-Suffridge extension operator.This subordination principle seems to be a new idea for dealing with the Loewner chain associated with the Roper-Suffridge extension operator,and enables us to generalize many known results from p=2 to 1≤p≤2.
基金the Natural Science Foundation of China (Grant No.10671194 and 10731080/A01010501)
文摘In this paper, we consider the following Reinhardt domains. Let M = (M1, M2,..., Mn) : [0,1] → [0,1]^n be a C2-function and Mj(0) = 0, Mj(1) = 1, Mj″ 〉 0, C1jr^pj-1 〈 Mj′(r) 〈 C2jr^pj-1, r∈ (0, 1), pj 〉 2, 1 ≤ j ≤ n, 0 〈 C1j 〈 C2j be constants. Define DM={z=(z1,z2,…,Zn)^T∈C^n:n∑j=1 Mj(|zj|)〈1}Then DM C^n is a convex Reinhardt domain. We give an extension theorem for a normalized biholomorphic convex mapping f : DM -→ C^n.