We deal with the problem of uniqueness of meromorphic functions sharing three values, and obtain several results which improve and extend some theorems of M. Ozawa, H. Ueda, H. X. Yi and other authors. We provide examples to show that results are sharp.

Dati due elementi $f$ e $g$ in un'algebra uniforme $A$, sia $G=f(M_A/f({\partial }_A)$. Nella presente Nota si danno, fra l’altro, due nuove dimostrazioni elementari del fatto che la funzione $\lambda \to \log \max g(f^{-1}(\lambda ))$ è subarmonica su $G$ e che l’applicazione $\lambda \to g(f^{-1}(\lambda ))$ è analitica nel senso di Oka.

This paper is devoted to studying the effects of a vanishing structural damping on the controllability properties of the one dimensional linear beam equation. The vanishing term depends on a small parameter $\epsilon \in (0,1)$. We study the boundary controllability properties of this perturbed equation and the behavior of its boundary controls $v_{\epsilon }$ as $\epsilon$ goes to zero. It is shown that for any time $T$ sufficiently large but independent of $\epsilon$ and for each initial data in a suitable space there exists a uniformly bounded...

This article considers the linear 1-d Schrödinger equation in (0,π) perturbed by a vanishing viscosity term depending on a small parameter ε > 0. We study the boundary controllability properties of this perturbed equation and the behavior of its boundary controls vε as ε goes to zero. It is shown that, for any time T sufficiently large but independent of ε and for each initial datum in H−1(0,π), there exists a uniformly...

This article considers the linear 1-d Schrödinger equation in (0,π) perturbed by a vanishing viscosity term depending on a small parameter ε > 0. We study the boundary controllability properties of this perturbed equation and the behavior of its boundary controls vε as ε goes to zero. It is shown that, for any time T sufficiently large but independent of ε and for each initial datum in H−1(0,π), there exists a uniformly...

Let $C$ be the extended complex plane; $G\subset C$ a finite Jordan with $0\in G$; $w=\varphi \left(z\right)$ the conformal mapping of $G$ onto the disk $B\left(0;{\rho }_0\right):=\left\}w\left|w\right|<{\rho }_0\right\{$ normalized by $\varphi \left(0\right)=0$ and ${\varphi }^{\text{'}}\left(0\right)=1$. Let us set ${\varphi }_p\left(z\right):={\int }_0^z{\left[{\varphi }^{\text{'}}\left(\zeta \right)\right]}^{2/p}\mathrm{d}\zeta$, and let ${\pi }_{n,p}\left(z\right)$ be the generalized Bieberbach polynomial of degree $n$ for the pair $(G,0)$, which minimizes the integral $\underset{G}{\int \int }{\left|{\varphi }_p^{\text{'}}\left(z\right)-P_n^{\text{'}}\left(z\right)\right|}^p\mathrm{d}{\sigma }_z$ in the class of all polynomials of degree not exceeding $\le n$ with $P_n\left(0\right)=0$, $P_n^{\text{'}}\left(0\right)=1$. In this paper we study the uniform convergence of the generalized Bieberbach polynomials ${\pi }_{n,p}\left(z\right)$ to ${\varphi }_p\left(z\right)$ on $\overline{G}$ with interior and exterior zero angles and determine its dependence on the...