Weighted Bergman spaces induced by rapidly incresing weights

TL;DR

This paper investigates weighted Bergman spaces induced by rapidly increasing weights, characterizing measures, operator boundedness, and function properties, revealing new insights into their structure and applications to differential equations.

Contribution

It introduces new concepts and approaches for analyzing weighted Bergman spaces with rapidly increasing weights, including measure characterization, operator theory, and function decomposition.

Findings

Weighted Bergman spaces lie closer to Hardy space than classical weighted spaces.

Characterization of measures for embedding into L^q spaces involves geometric conditions.

Boundedness of integral operators depends on non-conformally invariant function spaces.

Abstract

This monograph is devoted to the study of the weighted Bergman space $A^p_\om$ of the unit disc $\D$ that is induced by a radial continuous weight $\om$ satisfying {equation}\label{absteq} \lim_{r\to 1^-}\frac{\int_r^1\om(s)\,ds}{\om(r)(1-r)}=\infty.\tag{\dag} {equation} Every such $A^p_\om$ lies between the Hardy space $H^p$ and every classical weighted Bergman space $A^p_\a$. Even if it is well known that $H^p$ is the limit of $A^p_\a$, as $\a\to-1$, in many respects, it is shown that $A^p_\om$ lies "closer" to $H^p$ than any $A^p_\a$, and that several finer function-theoretic properties of $A^p_\a$ do not carry over to $A^p_\om$. As to concrete objects to be studied, positive Borel measures $\mu$ on $\D$ such that $A^p_\om\subset L^q(\mu)$, $0<p\le q<\infty $, are characterized in terms of a neat geometric condition involving Carleson squares. It is also proved that each $f\in A^p_\om$ can be represented in the form $f=f_1\cdot f_2$, where $f_1\in A^{p_1}_\om$, $f_2\in A^{p_2}_\om$ and $\frac{1}{p_1}+ \frac{1}{p_2}=\frac{1}{p}$. Because of the tricky nature of $A^p_\om$ several new concepts are introduced. It gives raise to a some what new approach to the study of the integral operator $$ T_g(f)(z)=\int_{0}^{z}f(\zeta)\,g'(\zeta)\,d\zeta. $$ This study reveals the fact that $T_g:A^p_\om\to A^p_\om$ is bounded if and only if $g$ belongs to a certain space of analytic functions that is not conformally invariant. The symbols $g$ for which $T_g$ belongs to the Schatten $p$-class $\SSS_p(A^2_\om)$ are also described. Furthermore, techniques developed are applied to the study of the growth and the oscillation of analytic solutions of (linear) differential equations.