This paper surveys a large class of nonlinear extremal problems in Hardy and Bergman spaces. We discuss the general approach to such problems in Hardy spaces developed by S. Ya. Khavinson in the 1960s, but not well known in the West. We also discuss the major difficulties distinguishing the Bergman space setting and formulate some open problems.

We study the automatic computation of asymptotic expansions of functional inverses. Based on previous work on asymptotic expansions, we give an algorithm which computes Hardy-eld solutions of equations f(y) = x, with f belonging to a large class of functions. D eveloppements asymptotiques d'inverses fonctionnels R esum e Nous etudions le calcul automatique de d eveloppements asymptotiques d'inv...

We study the weighted boundedness of the Cauchy singular integral operator SΓ in Morrey spaces L(Γ) on curves satisfying the arc-chord condition, for a class of ”radial type” almost monotonic weights. The non-weighted boundedness is shown to hold on an arbitrary Carleson curve. We show that the weighted boundedness is reduced to the boundedness of weighted Hardy operators in Morrey spaces L(0, ...

In this paper, we deal with the existence and nonexistence of nonnegative nontrivial weak solutions for a class of degenerate quasilinear elliptic problems with weights and nonlinearity involving the critical Hardy-Sobolev exponent and a sign-changing function. Some existence results are obtained by splitting the Nerahi manifold and by exploring some properties of the best Hardy-Sobolev constan...

This presentation is in two parts. First, we recall the deenition of two types of asymptotic expansions known as nested form and nested expansions. This theory makes it possible to adapt the asymptotic scale to the function under expansion and is based on the theory of Hardy elds 1]. Next, we suggest a reformulation of nested forms in terms of generalized products called star products, and a pr...

In this article we give a unifying approach to the theory of fundamental sequences and their related Hardy hierarchies of number-theoretic functions and we show the equivalence of the new approach with the classical one. Mathematics Subject Classification: 03D20, 03F15, 03E10.