出版社:The Editorial Committee of the Interdisciplinary Information Sciences
摘要:Given a sequence { φ j } of bounded functions on the dual group Γ of a locally compact abelian group G , we have a family of Fourier multiplier operators each element of which is made from a component φ j of the given sequence. On the other hand, the restrictions φ j | Λ of φ j to a subgroup Λ of Γ build Fourier multiplier operators on G ⁄ Λ ⊥. We are interested in the transference of continuity from the maximal operator constructed by the family of Fourier multiplier operators composed of { φ j } to the counterpart maximal operator corresponding to { φ j | Λ }. For the study, it is a powerful tool that, if k ∈ L 1( Γ ), then the maximal operator corresponding to { k *φ j } inherits the strong or weak typeness ( p , q ) from the one associated with { φ j }. First we give a method of showing it. Our result contains the case p = q =1 and our proof is simpler and more straightforward than the one in [2]. Next we consider the case of G = R n and Λ = Z n , and develop arguments over Lorentz spaces and Hardy spaces.
关键词:Fourier multiplier;maximal operator;weak type (p,q);Lorentz space;Hardy space