A reprise of the NTV conjecture for the Hilbert transform
Eric T. Sawyer
TL;DR
This work presents a modified, self-contained proof of the two-weight Hilbert transform inequality (the NTV conjecture) for measures $\sigma$ and $\omega$ with hole-based $A_2$ control. It refines the Haar-based decomposition and corona constructions, replacing Poisson-energy arguments with a Sawyer–Wick functional-energy framework and employing an $\mathcal{F}$-Corona/NTV reach structure to control all pieces of the bilinear form: disjoint, comparable, neighbor, diagonal, far, paraproduct, and stopping forms. Central ingredients include a CZ–PE corona with a refined functional-energy bound, the Intertwining Proposition for the far form, the Stopping Child Lemma, and a dual-tree decomposition to handle stopping forms, all tying back to the testing and hole $A_2$ characteristics. Consequently, the Hilbert transform is bounded from $L^2(\sigma)$ to $L^2(\omega)$ with operator norm controlled by $\mathfrak{T}_H^{loc}(\sigma,\omega)$, $\mathcal{A}_2^{hole}(\sigma,\omega)$, and $\mathcal{E}_2(\sigma,\omega)$, plus related constants, matching the two-weight theory in this setting and highlighting a streamlined approach distinct from prior Poisson-based methods.
Abstract
We give a slightly different proof of the NTV conjecture for the Hilbert transform that was proved by T. Hytönen, M. Lacey, E.T. Sawyer, C.-Y. Shen and I. Uriarte-Tuero, building on previous work of F. Nazarov, S. Treil and A. Volberg. After modifying the decomposition of the main bilinear form, we give a new proof of control of functional energy that is based on the potential Theorem 1 of [Saw3], rather than the Poisson Theorem 2 that is used in all other proofs in the literature. This approach was pioneered in the first version of Sawyer and Wick [SaWi] on the ArXiv. Then we alter the bottom-up corona construction, the size functional, the straddling lemmas, and the use of recursion of admissible collections of pairs of intervals, from M. Lacey [Lac]. However, the essence of control of the stopping form remains as in the fundamental work of Lacey.
