论文标题
在近似空间和贪婪型基地上
On Approximation Spaces and Greedy-type Bases
论文作者
论文摘要
本文的目的是引入$ω$ -CHEBYSHEV-GREDY和$ω$ - 部分在贪婪的近似类中,并使用$ω$ -Approximation Spaces研究它们的关系,其中后者是经典近似空间的概括。这种关系为我们提供了足够的条件,即某些连续嵌入意味着不同的贪婪型特性。在此过程中,我们概括了P. wojtaszczyk的结果,并表征了准巴纳奇空间中的半怪异Schauder基地,从而概括了第一作者的先前结果。
The purpose of this paper is to introduce $ω$-Chebyshev-greedy and $ω$-partially greedy approximation classes and to study their relation with $ω$-approximation spaces, where the latter are a generalization of the classical approximation spaces. The relation gives us sufficient conditions of when certain continuous embeddings imply different greedy-type properties. Along the way, we generalize a result by P. Wojtaszczyk as well as characterize semi-greedy Schauder bases in quasi-Banach spaces, generalizing a previous result by the first author.