A lot is known about the forward iterates of an analytic function which is bounded by 1 in modulus on the unit disk D. The Denjoy-Wolff Theorem describes their convergence properties and several authors, from the 1880's to the 1980's, have provided conjugations which yield very precise descriptions of the dynamics. Backward-iteration sequences are of a different nature because a point could have infinitely many preimages as well as none. However, if we insist in choosing preimages that are at a...

For an entire function $f$ let $N\left(z\right)=z-f\left(z\right)/f^{\prime }\left(z\right)$ be the Newton function associated to $f$. Each zero $\xi$ of $f$ is an attractive fixed point of $N$ and is contained in an invariant component of the Fatou set of the meromorphic function $N$ in which the iterates of $N$ converge to $\xi$. If $f$ has an asymptotic representation $f\left(z\right)\sim exp(-z^n),n\in \mathbb{N}$, in a sector $|argz|\<\epsilon$, then there exists an invariant component of the Fatou set where the iterates of $N$ tend to infinity. Such a component is called an invariant Baker domain.A question in the opposite direction...

Some basic theorems and formulae (equations and inequalities) of several areas of mathematics that hold in Bernstein spaces $B_{\sigma }^p$ are no longer valid in larger spaces. However, when a function f is in some sense close to a Bernstein space, then the corresponding relation holds with a remainder or error term. This paper presents a new, unified approach to these errors in terms of the distance of f from $B_{\sigma }^p$. The difficult situation of derivative-free error estimates is also covered.

Let $H^{\infty }$ be the class of bounded analytic functions on $D:\left|z\right|\<1$, and let $\bar{D}$ be the set of maximal ideals of the algebra $H^{\infty }$, a compactification of $D$. The relations between functions in $H^{\infty }$ and their cluster values on $\bar{D}-D$ are studied. Let $D_1$ be the subset of $\bar{D}$ over the point 1. A subset $A$ of $D_1$ is a “Fatou set” if every $f$ in $H^{\infty }$ has a limit at $e^{i\theta }A$ for almost every $\theta$. The nontangential subset of $D_1$ is a Fatou set according to the Fatou theorem. There are many larger Fatou sets, for example the fine topology subset of $D_1$ but...

We study boundary properties of universal Taylor series. We prove that if f is a universal Taylor series on the open unit disk, then there exists a residual subset G of the unit circle such that f is unbounded on all radii with endpoints in G. We also study the effect of summability methods on universal Taylor series. In particular, we show that a Taylor series is universal if and only if its Cesàro means are universal.

Let $u$ be harmonic in the half-space $R_{+}^{n+1}$, $n\ge 2$. We show that $u$ can have a fine limit at almost every point of the unit cubs in $R^n=\partial R_{+}^{n+1}$ but fail to have a nontangential limit at any point of the cube. The method is probabilistic and utilizes the equivalence between conditional Brownian motion limits and fine limits at the boundary.In $R_{+}^2$ it is known that the Hardy classes $H^p$, $0\<p\<\infty$, may be described in terms of the integrability of the nontangential maximal function, or, alternatively, in terms of the integrability...

We solve the following Dirichlet problem on the bounded balanced domain $\Omega$ with some additional properties: For $p>0$ and a positive lower semi-continuous function $u$ on $\partial \Omega$ with $u\left(z\right)=u\left(\lambda z\right)$ for $\left|\lambda \right|=1$, $z\in \partial \Omega$ we construct a holomorphic function $f\in 𝕆\left(\Omega \right)$ such that $u\left(z\right)={\int }_{𝔻z}{\left|f\right|}^{p}d{𝔏}_{𝔻z}^2$ for $z\in \partial \Omega$, where $𝔻=\{\lambda \in ℂ|\lambda |<1\}$.