English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

This paper is devoted to theoretical aspects on optimality of sparseapproximation. We undertake a quantitative study of new types of greedy-likebases that have recently arisen in the context of nonlinear $m$-termapproximation in Banach spaces as a generalization of the properties thatcharacterize almost greedy bases, i.e., quasi-greediness and democracy. As ameans to compare the efficiency of these new bases with already existing onesin regards to the implementation of the Thresholding Greedy Algorithm, we placeemphasis on obtaining estimates for their sequence of unconditionalityparameters. Using an enhanced version of the original method from [S. J.Dilworth, N. J. Kalton, and D. Kutzarova, On the existence of almost greedybases in Banach spaces, Studia Math. 159 (2003), no. 1, 67-101] for buildingalmost greedy bases, we manage to construct bidemocratic bases whoseunconditionality parameters satisfy significantly worse estimates than almostgreedy bases even in Hilbert spaces.

Sparse approximation using new greedy-like bases in superreflexive spaces