889 research outputs found
A note on weighted bounds for rough singular integrals
We show that the operator norm of the composition , where is the maximal operator and is a rough
homogeneous singular integral with angular part , depends quadratically on , and this dependence
is sharp
Sharp weighted norm inequalities for Littlewood-Paley operators and singular integrals
We prove sharp norm inequalities for the intrinsic square function
(introduced recently by M. Wilson) in terms of the characteristic of
for all . This implies the same sharp inequalities for the
classical Lusin area integral , the Littlewood-Paley -function, and
their continuous analogs and . Also, as a corollary, we
obtain sharp weighted inequalities for any convolution Calder\'on-Zygmund
operator for all and , and for its maximal
truncations for
On weighted norm inequalities for the Carleson and Walsh-Carleson operators
We prove bounds for the Carleson operator , its
lacunary version , and its analogue for the Walsh series \W
in terms of the constants for . In particular,
we show that, exactly as for the Hilbert transform,
is bounded linearly by for .
We also obtain bounds in terms of , whose sharpness is
related to certain conjectures (for instance, of Konyagin \cite{K2}) on
pointwise convergence of Fourier series for functions near .
Our approach works in the general context of maximally modulated
Calder\'on-Zygmund operators.Comment: A major revision of arXiv: 1310.3352. In particular, the main result
is proved under a different assumption, and applications to the lacunary
Carleson operator and to the Walsh-Carleson operator are give
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