HILBERT TRANSFORMS ALONG LIPSCHITZ DIRECTION FIELDS: A LACUNARY MODEL

Bilinear Hilbert Transforms along Curves I. the Monomial Case

We establish an L2×L2 to L estimate for the bilinear Hilbert transform along a curve defined by a monomial. Our proof is closely related to multilinear oscillatory integrals.

Double Hilbert Transforms along Polynomial Surfaces in R3

where P(s, t) is a polynomial in s and t with P(0,0)= 0, and ∇P(0,0)= 0. We call H the (local) double Hilbert transform along the surface (s, t,P (s, t)). The operator may be precisely defined for a Schwartz function f by integrating where ≤ |s| ≤ 1 and η ≤ |t | ≤ 1, and then taking the limit as ,η→ 0. The corresponding 1-parameter problem has been extensively studied (see [RS1], [RS2], and [S]...

A Sharp Estimate for the Hilbert Transform along Finite Order Lacunary Sets of Directions

Let D be a nonnegative integer and Θ ⊂ S1 be a lacunary set of directions of order D. We show that the Lp norms, 1 < p < ∞, of the maximal directional Hilbert transform in the plane HΘ f (x ) B sup v ∈Θ p.v. ∫ R f (x + tv ) dt t , x ∈ R 2, are comparable to (log #Θ) 2 . For vector elds vD with range in a lacunary set of of order D and generated using suitable combinations of truncations of Lips...

Classical Wavelet Transforms over Finite Fields

This article introduces a systematic study for computational aspects of classical wavelet transforms over finite fields using tools from computational harmonic analysis and also theoretical linear algebra. We present a concrete formulation for the Frobenius norm of the classical wavelet transforms over finite fields. It is shown that each vector defined over a finite field can be represented as...

Two-dimensional Hilbert Transforms'