School of Mathematics, Georgia Institute of Technology, Atlanta, Georgia 30332 ; Department of Mathematics, University of California--Los Angeles, Los Angeles, California 90055-1555
Abstract:
For a Schwartz function on the plane and a non-zero define the Hilbert transform of in the direction to be
p.v.
Let be a Schwartz function with frequency support in the annulus , and . We prove that the maximal operator maps into weak , and into for . The estimate is sharp. The method of proof is based upon techniques related to the pointwise convergence of Fourier series. Indeed, our main theorem implies this result on Fourier series.