Trace ideal criteria for generalized integration operators
Georgios Nikolaidis
TL;DR
This work characterizes when the generalized Volterra operator $T_{g,a}$ lies in the Schatten classes $S^p(A^2_\alpha)$ on Hardy and Bergman spaces. By introducing the index $\lambda$ from the order-$n$ operator and employing hyperbolic geometry, Littlewood–Paley theory, and a Luecking-type framework, the authors prove that $T_{g,a}\in S^p(A^2_\alpha)$ if and only if the symbol $g$ belongs to the Besov space $\mathcal{B}_p$ whenever $p>\frac{1}{n-\lambda}$; for $0<p\le\frac{1}{n-\lambda}$, the operator is zero. The argument carefully handles term cancellations and reduces Schatten-norm estimates to Besov regularity of $g$, extending the classical $T_g$ results (the case $\lambda=n-1$) to the broader family $T_{g,a}$ on both Hardy and Bergman spaces. The results sharpen the understanding of factorization-type operators in spaces of analytic functions and provide explicit, sharp criteria for Schatten-class membership in terms of symbol smoothness.
Abstract
For $g \in \operatorname{Hol}(\mathbb D)$, we study the class of generalized integration operators $T_{g,a}$, acting on Hardy and Bergman spaces of the unit disc in the complex plane. This class of integral operators were introduced to study factorization theorems in the Hardy spaces of the unit disc. We completely characterize the space of symbols g, for which $T_{g,a}$ belongs to the Schatten-von Neumann ideals of the Hardy and Bergman spaces.
