Non-recurrence of exp(z)/z

In this paper, we consider the dynamics of the map z→exp(z)/z on the punctured plane C*=C\{0}. We show that for almost every point z ∈ C*, the ω-limit set of z is equal to {0, ∞}. In particular, the map is not recurrent.     

关于φ（z）f（z）f＇（z）的值分布

本文研究有穷圆内的值分布，其中ｆ（２）为非常数亚纯函数，为非零亚纯函数，并对平面上这样的函数，若，得到     

The rational maps F λ (z) = z m + λ/z d have no Herman rings

It is proved that the rational maps in the family {z → z ^m +λ/z ^d : λ ∈ ?\{0}} for integers m, d ≥ 2 have no Herman rings.     

The Fourier expansion of $$\varvec{\eta (z)\eta (2z)\eta (3z)/\eta (6z)}$$

We compute the Fourier coefficients of the weight one modular form \(\eta (z)\eta (2z)\eta (3z)/\eta (6z)\) in terms of the number of representations of an integer as a sum of two squares. We deduce a relation between this modular form and translates of the modular form \(\eta (z)^4/\eta (2z)^2\). In the last section we use our main result to give an elementary proof of an identity by Victor Kac.     

Regions of Values of the Systems {f(z 1), f(z 2), f'(z 2)} and {f(z 1), f'(z 1), f'(z 1)} on the Class of Typically Real Functions

Let T be the class of functions f(z) = z + a ₂ z ² + . . . that are regular in the unit disk and satisfy the condition Im f(z) Im z > 0 for Im z 0, and let z ₁ and z ₂ be any distinct fixed points in the disk |z| < 1. For the systems of functionals mentioned in the title, the regions of values on T are studied. As a corollary, the regions of values of f'(z ₂) and f'(z ₁) on the subclasses of functions in T with fixed values f (z ₁), f (z ₂) and f (z ₁), f'(z ₁), respectively, are found. Bibliography: 7 titles.     

Positive solutions for singular p(z)$p(z)$-equations

We consider a Dirichlet problem driven by the anisotropic p-Laplacian, with a reaction having the competing effects of a singular term and a parametric superlinear perturbation. We prove a bifurcation-type theorem describing the changes of the set of positive solutions as the parameter varies. We also prove the existence of minimal positive solutions.     

A note on log (f(z)/z) forf inS

We prove that forf a normalized schlicht function in the disk the boundary values of log |f(z)/z| satisfy a growth condition on subarcs of the unit circle .     

z transform theory and applications

Book Reviews

z transform theory and applicationsRobert Vich: D. Reidel, Dordrecht, Boston, Lancaster, Tokyo, 1987, 228 pp.     

Carathéodory balls and norm balls of the domainH={(z1,z2)∈C2∶|z1|+|z2|<1}

LetH be the domain inC ² defined byH={Z=(z ₁,z ₂):║Z║₁=│z║₁│+│z║₂│<1}. LetC _H(z,w) be the Carathéodory distance ofH,z,w∈H. The Carathéodory ballB _C(z_C,α;H) with centerz _C,z_C∈H, and radius α, 0<α<1, is defined byB _c(z_C,α;H)={z∶C_H(z,z_C)<arc tanh α}. The norm ballB _N(z_N,r) with centerz _N,z_N∈H, and radiusr, 0<r<1-‖z _N‖₁, is defined byB _N(z_N,r)={z∶ ‖z−z_N‖₁<r}. Theorem:The only Carathéodory balls of H which are also norm balls are those with their center at the origin.