$L^{\vec{p}}-L^{\vec{q}}$ Boundedness of Multiparameter Forelli-Rudin Type Operators on Tube Domains Over The Forward Light Cones
Xin Xia, Guan Tie Deng
TL;DR
This paper analyzes when multiparameter Forelli-Rudin type operators on tubular domains $T_{\Lambda_n}$ over the forward light cone are bounded between weighted mixed-norm Lebesgue spaces. Using Schur-type testing for product kernels and adjoint-duality arguments, it derives sharp parameter relations and explicit coupling conditions, notably $c_i = n + a_i + b_i + \frac{n + \beta_i}{q_i} - \frac{n + \alpha_i}{p_i}$ and the bounds $-q_i a_i < \beta_i + 1$, $\alpha_i + 1 < p_i(b_i + 1)$. The main results (Theorems 1–5) provide complete necessary and sufficient characterizations for two operator classes, covering general and endpoint mixed-norm regimes, with important implications for Bergman projections in this geometry. The work extends classical Forelli-Rudin theory to a multiparameter, tube-domain setting, offering a rigorous framework for weighted Bergman-type operators on domains tied to the forward light cone.
Abstract
This study investigates necessary and sufficient conditions for the boundedness of Forelli-Rudin type operators on weighted Lebesgue spaces associated with tubular domains over the forward light cone. We establish a complete characterization of the boundedness for two classes of multiparameter Forelli-Rudin type operators from the mixed-norm Lebesgue space $L^{\vec{p}}$ to $L^{\vec{q}}$, in the range $1 \leq \vec{p} \leq \vec{q} < \infty$. The findings contribute significantly to the analysis of Bergman projection operators in this setting.
