A VARIATION NORM CARLESON THEOREM FOR VECTOR-VALUED WALSH-FOURIER SERIES
A VARIATION NORM CARLESON THEOREM FOR VECTOR-VALUED WALSH-FOURIER SERIES
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DOI:
10.4171/rmi/804
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发表时间:
2012-09
影响因子:
1.2
通讯作者:
T. Hytonen;M. Lacey;I. Parissis
中科院分区:
文献类型:
--
作者:
T. Hytonen;M. Lacey;I. Parissis
We prove a variation norm Carleson theorem for Walsh-Fourier series of func- tions with values in a UMD Banach space. Our only hypothesis on the Banach space is that it has finite tile-type, a notion introduced by Hytonen and Lacey. Given q ∈ (2,∞) we show that, if the space X has tile-typeτ for allτ ∈ (q,∞) then the r-variation of the Walsh-Fourier sums of any function f ∈ L p ((0,1);X) belongs to L p , whenever q q. For intermediatespaces, i.e. spacesX = (Y,H)θ which arecomplex interpolation spaces between some UMD space Y and a Hilbert space H, the tile-type is q = 2/θ. We show that in this case the variationnorm Carleson theoremremains true for allr> q in the largerrangep> (2r/q) ' .