2024/12/09 by Petr Honzík, Honzík, Petr, Stefanos Lappas +3 · 2 citations
Mathematics · #Advanced Harmonic Analysis Research #Differential Equations and Boundary Problems #Numerical methods in inverse problems
paper · pdf · doi:10.48550/arxiv.2412.07014
We establish the full quasi-Banach range of Lp1(\mathbb R) × Lp2(\mathbb R) → Lp(\mathbb R) bounds for one-dimensional bilinear singular integral operators with homogeneous kernels whose restriction Ω to the unit sphere \mathbb S1 is supported away from the degenerate line θ1=θ2, belongs to Lq(\mathbb S1) for some q>1 and has vanishing integral. In fact, a more general result is obtained by dropping the support condition on Ω and requiring that Ω∈ Lq(\mathbb S1,uq), where u(θ1,θ2)=|θ1-θ2|-1 for (θ1,θ2)∈ \mathbb S1. In addition, we provide counterexamples that show the failure of the n-dimensional version of the previous result when n≥ 2, as well as the failure of its m-linear variant in dimension one when m≥ 3. The relationship of these results to (un)boundedness properties of higher-dimensional multilinear Hilbert transforms is also discussed.