536 research outputs found

    Further results on normal families of meromorphic functions concerning shared values

    Full text link
    In this paper, we prove two normality criteria for families of some functions concerning shared values, the results generalize those given by Hu and Meng. Some examples are given to show the sharpness of our results.Comment: 9page

    Normality criteria for a family of meromorphic functions with multiple zeros

    Full text link
    In this article, we prove some normality criteria for a family of meromorphic functions having zeros with some multiplicity. Our main result involves sharing of a holomorphic function by certain differential polynomials. Our results generalize some of the results of Fang and Zalcman and Chen et al to a great extent

    Uniqueness of Some Differential Polynomials of Meromorphic Functions

    Full text link
    In this paper, we prove some uniqueness results which improve and generalize several earlier works. Also, we prove a value distribution result concerning f(k)f^{(k)} which provides a partial answer to a question of Fang and Wang [A note on the conjectures of Hayman, Mues and Gol'dberg, Comp. Methods, Funct. Theory (2013)13, 533-543].Comment: 14 page

    Normality criteria concerning composite meromorphic functions

    Full text link
    In this paper, we prove normality criteria for families of meromorphic functions involving sharing of a holomorphic function by a certain class of differential polynomials. Results in this paper extends the works of different authors carried out in recent years.Comment: 14 page

    Some Normality Criteria

    Full text link
    In this article we prove some normality criteria for a family of meromorphic functions which involves sharing of a non-zero value by certain differential monomials generated by the members of the family. These results generalizes some of the results of Schwick.Comment: 16 Pages. Comments are welcome, Communicate

    Zeros of differential polynomials in real meromorphic functions

    Full text link
    We show that for a real transcendental meromorphic function f, the differential polynomial f'+f^m with m > 4 has infinitely many non-real zeros. Similar results are obtained for differential polynomials f'f^m-1. We specially investigate the case of meromorphic functions with finitely many poles. We show by examples the precision of our results. One of our main tools is the Fatou theorem from complex dynamics.Comment: 18 page

    Bloch's principle

    Full text link
    A heuristic principle attributed to A. Bloch says that a family of holomorphic functions is likely to be normal if there is no nonconstant entire functions with this property. We discuss this principle and survey recent results that have been obtained in connection with it. We pay special attention to properties related to exceptional values of derivatives and existence of fixed points and periodic points, but we also discuss some other instances of the principle.Comment: 30 page

    Dynamics of Generalized Nevanlinna Functions

    Full text link
    In the early 1980's, computers made it possible to observe that in complex dynamics, one often sees dynamical behavior reflected in parameter space and vice versa. This duality was first exploited by Douady, Hubbard and their students in early work on rational maps. See \cite{DH,BH} for example. Here, we continue to study these ideas in the realm of transcendental functions. In \cite{KK1}, it was shown that for the tangent family, λtanz\lambda \tan z, the way the hyperbolic components meet at a point where the asymptotic value eventually lands on infinity reflects the dynamic behavior of the functions at infinity. In the first part of this paper we show that this duality extends to a much more general class of transcendental meromorphic functions that we call {\em generalized Nevanlinna functions} with the additional property that infinity is not an asymptotic value. In particular, we show that in "dynamically natural" one dimensional slices of parameter space, there are "hyperbolic-like" components with a unique distinguished boundary point whose dynamics reflect the behavior inside an asymptotic tract at infinity. Our main result is that {\em every} parameter point in such a slice for which the asymptotic value eventually lands on a pole is such a distinguished boundary point. In the second part of the paper, we apply this result to the families λtanpzq\lambda \tan^p z^q, p,qZ+p,q \in \mathbb Z^+, to prove that all hyperbolic components of period greater than 11 are bounded.Comment: 31 pages, 3 figure

    Group cohomology and the singularities of the Selberg zeta function associated to a Kleinian group

    Full text link
    We prove Patterson's conjecture about the singularities of the Selberg zeta function associated to a convex-cocompact, torsion free group acting on a hyperbolic space.Comment: 63 pages, published versio

    Meromorphic functions of one complex variable. A survey

    Full text link
    This is an appendix to the English translation of the book by A. A. Goldberg and I. V. Ostrovskii, Distribution of values of meromorphic functions, Moscow, Nauka, 1970. An English translation of this book is to be published soon by the AMS. In this appendix we survey the results obtained on the topics of the book after 1970.Comment: 33 page
    corecore