Strong Partially Greedy Bases with respect to An Arbitrary Sequence

TL;DR

This paper introduces and characterizes the ($ extbf n$, strong partially greedy) property for bases with respect to arbitrary sequences, extending previous concepts and establishing new inequalities and relations.

Contribution

It defines the ($ extbf n$, strong partially greedy) property for bases, provides characterizations, and explores its relations, inequalities, and extensions to weighted and gap bases.

Findings

Characterization of the ($ extbf n$, strong partially greedy) property

Relations among properties for different sequences $ extbf n$

Lebesgue-type inequalities for the ($ extbf n$, strong partially greedy) parameter

Abstract

For Schauder bases, Dilworth et al. introduced and characterized the partially greedy property, which is strictly weaker than the (almost) greedy property. Later, Berasategui et al. defined and studied the strong partially greedy property for general bases. Let $\mathbf n$ be any strictly increasing sequence of positive integers. In this paper, we define the strong partially greedy property with respect to $\mathbf n$, called the ($\mathbf n$, strong partially greedy) property. We give characterizations of this new property, study relations among ($\mathbf n$, strong partially greedy) properties for different sequences $\mathbf n$, establish Lebesgue-type inequalities for the ($\mathbf n$, strong partially greedy) parameter, investigate ($\mathbf n$, strong partially greedy) bases with gaps, and weighted ($\mathbf n$, strong partially greedy) bases, to name a few. Furthermore, we introduce the ($\mathbf n$, almost greedy) property and equate the property to a strengthening of the ($\mathbf n$, strong partially greedy) property. This paper can be viewed both as a survey of recent results regarding strong partially greedy bases and as an extension of these results to an arbitrary sequence instead of $\mathbb{N}$.