The thresholding greedy algorithm, greedy bases, and duality

SJ Dilworth, NJ Kalton, D Kutzarova… - Constructive …, 2003 - Springer
Some new conditions that arise naturally in the study of the Thresholding Greedy Algorithm
are introduced for bases of8 anach spaces. We relate these conditions to best n-term …

Lebesgue inequalities for the greedy algorithm in general bases

PM Berná, Ó Blasco, G Garrigós - Revista matemática complutense, 2017 - Springer
We present various estimates for the Lebesgue type inequalities associated with the
thresholding greedy algorithm, in the case of general bases in Banach spaces. We show the …

Lebesgue-type inequalities for quasi-greedy bases

G Garrigós, E Hernández, T Oikhberg - Constructive Approximation, 2013 - Springer
We show that, for quasi-greedy bases in real or complex Banach spaces, an optimal bound
for the ratio between greedy N-term approximation∥ x− GN x∥ and the best N-term …

[ΒΙΒΛΙΟ][B] Sparse approximation with bases

V Temlyakov, S Tikhonov - 2015 - Springer
The last decade has seen great progress in the study of nonlinear approximation, which was
motivated by numerous applications. Nonlinear approximation is important in applications …

[PDF][PDF] Quasi-greedy bases and Lebesgue-type inequalities

SJ Dilworth, M Soto-Bajo, VN Temlyakov - Studia Math, 2012 - researchgate.net
We study Lebesgue-type inequalities for greedy approximation with respect to quasi-greedy
bases. We mostly concentrate on this study in the Lp spaces. The novelty of the paper is in …

Building highly conditional almost greedy and quasi-greedy bases in Banach spaces

F Albiac, JL Ansorena, SJ Dilworth… - Journal of Functional …, 2019 - Elsevier
It is known that for a conditional quasi-greedy basis B in a Banach space X, the associated
sequence (km [B]) m= 1∞ of its conditionality constants verifies the estimate km [B]= O (log⁡ …

Embeddings and Lebesgue-type inequalities for the greedy algorithm in Banach spaces

PM Berná, O Blasco, G Garrigós, E Hernández… - Constructive …, 2018 - Springer
We obtain Lebesgue-type inequalities for the greedy algorithm for arbitrary complete
seminormalized biorthogonal systems in Banach spaces. The bounds are given only in …

Conditional quasi-greedy bases in Hilbert and Banach spaces

G Garrigós, P Wojtaszczyk - Indiana University Mathematics Journal, 2014 - JSTOR
For quasi-greedy bases 𝓑 in Hilbert spaces, we give—answering a question by Temlyakov—
an improved bound of the associated conditionality constants kN (𝓑)= O (logN) 1–ε, for some …

New parameters and Lebesgue-type estimates in greedy approximation

F Albiac, JL Ansorena, PM Berná - Forum of Mathematics, Sigma, 2022 - cambridge.org
The purpose of this paper is to quantify the size of the Lebesgue constants associated with
the thresholding greedy algorithm in terms of a new generation of parameters that modulate …

Lebesgue constants for the weak greedy algorithm

SJ Dilworth, D Kutzarova, T Oikhberg - Revista Matemática Complutense, 2015 - Springer
We estimate the Lebesgue constants for the weak thresholding greedy algorithm in a
Banach space relative to a biorthogonal system. The estimates involve the weakness …