2024/09/27 by Cheng, Jinhua
#Classical Analysis and ODEs (math.CA) #FOS: Mathematics
paper · doi:10.48550/arxiv.2409.18413
In this paper, we explore a specific class of bi-parameter pseudo-differential operators characterized by symbols σ(x1,x2,ξ1,ξ2) falling within the product-type Hörmander class Smρ, δ. This classification imposes constraints on the behavior of partial derivatives of σ with respect to both spatial and frequency variables. Specifically, we demonstrate that for each multi-index α, β, the inequality | ∂ξα∂xβσ(x1,x2,ξ1,ξ2)| ≤ Cα, β(1+|ξ|)m∏i=12 (1+|ξi|)-ρ|αi|+δ|βi| is satisfied. Our investigation culminates in a rigorous analysis of the Lp-boundedness of such pseudo-differential operators, thereby extending the seminal findings of C. Fefferman from 1973 concerning pseudo-differential operators within the Hörmander class.