Let C(k,p) denote the smallest real number such that the estimate |ak| ≤C(k,p)‖f‖Hp holds for every f(z) =∑n≥0anzn in the Hp space of the unit disc. We compute C(2,p)for0<p<1andC(3,2/3), and identify the functions attaining ...

We observe that local embedding problems for certain Hardy and Bergman spaces of Dirichlet series are equivalent to boundedness of a class of composition operators. Following this, we perform a careful study of such ...

We consider sharp inequalities for Bergman spaces of the unit disc, establishing analogues of the inequality in Carleman's proof of the isoperimetric inequality and of Weissler's inequality for dilations. By contractivity ...

A sharp version of a recent inequality of Kovalev and Yang on the ratio of the (H1)∗ and H4 norms for certain polynomials is obtained. The inequality is applied to establish a sharp and tractable sufficient condition for ...

For 0<p≤∞, let Hp denote the classical Hardy space of the unit disc. We consider the extremal problem of maximizing the modulus of the kth Taylor coefficient of a function f∈Hp which satisfies ∥f∥Hp≤1 and f(0)=t for some ...

The purpose of this thesis is to explore the relation between the classical Hardy space of analytic functions and the Hardy space of Dirichlet series. Two chapters are devoted to developing the basic properties of these ...

We describe the idempotent Fourier multipliers that act contractively on Hp spaces of the d-dimensional torus Td for d≥1 and 1≤p≤∞. When p is not an even integer, such multipliers are just restrictions of contractive ...

We study H p spaces of Dirichlet series, called H p , for the range 0 < p < ∞. We begin by showing that two natural ways to define H p coincide. We then proceed to study some linear space properties of H p . More specifically, ...

There is a bounded Hankel operator on the Paley–Wiener space of a disc in R2 which does not arise from a bounded symbol.