Discrete Double Hilbert Transforms Along Polynomial Surfaces

Abstract

We obtain a necessary and sufficient condition on a polynomial $P(t_1,t_2)$ for the ${\ell }^p$ boundedness of the discrete double Hilbert transforms associated with $P(t)$ for $1<p<\infty$. The proof is based on the multi-parameter circle method treating the cases of $|t_1|\not\approx |t_2|$ arising from $1/t_1$ and $1/t_2$.

In this revised version, we have carefully rewritten the main theorems to ensure full accuracy, and we have provided complete and detailed proofs for clarity