高维Hausdorff算子在Hp(Rn)上的有界性

本文主要研究以下形式的Hausdorff算子H_Φf(x)=∫_RⁿΦ(u₁….,u_n)f(u₁x₁,…,u_nx_n)du₁…du_n,其中Φ是Rⁿ上的缓增分布.当n≥2,0Φ在H^p(Rⁿ)上有界当且仅当Φ≡0.进一步,当n≥2,n/n+1Φ有合适定义,那么H_Φ在H^p(Rⁿ)上有界当且仅当Φ是常数.这些结果都表明Hausdorff算子H_Φ在H^p(Rⁿ)上的有界性很复杂.此外,我们将H_Φ转化成卷积型算子,得到H_Φ在Lebesgue空间上有界的一些新的结果.     

MIXED LIPSCHITZ SPACES AND THEIR APPLICATIONS

The purpose of this paper is to introduce bi-parameter mixed Lipschitz spaces and characterize them via the Littlewood-Paley theory.As an application,we derive a boundedness criterion for singular integral operators in a mixed Journé class on mixed Lipschitz spaces.Key elements of the paper are the development of the Littlewood-Paley theory for a special mixed Besov spaces,and a density argument for the mixed Lipschitz spaces in the weak sense.