English
Related papers

Related papers: Strong partially greedy bases and Lebesgue-type in…

200 papers

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…

Functional Analysis · Mathematics 2024-05-14 Hung Viet Chu

We continue the study of Lebesgue-type parameters for various greedy algorithms in quasi-Banach spaces. First, we introduce a parameter that can be used with the quasi-greedy parameter to obtain the exact growth of the Lebesgue parameter…

Functional Analysis · Mathematics 2025-08-28 Miguel Berasategui , Pablo M. Berná , Hung Viet Chu , Andrea García

We introduce and study the notion of weak weight-semi-greedy Markushevich bases - which extends the concepts of weight semi-greedy and weak semi-greedy Markushevich bases. In particular, we study conditions under which such bases are weight…

Functional Analysis · Mathematics 2024-11-20 Miguel Berasategui , Silvia Lassalle

We establish estimates for the Lebesgue parameters of the Chebyshev Weak Thresholding Greedy Algorithm in the case of general bases in Banach spaces. These generalize and slightly improve earlier results in [9], and are complemented with…

Functional Analysis · Mathematics 2018-11-13 Pablo M. Berná , Oscar Blasco , Gustavo Garrigós , Eugenio Hernández , Timur Oikhberg

We introduce and study the notion of weak semi-greedy systems -which is inspired in the concepts of semi-greedy and Branch semi-greedy systems and weak thresholding sets-, and prove that in the context Markushevich bases in infinite…

Functional Analysis · Mathematics 2021-10-15 Miguel Berasategui , Silvia Lassalle

We present various estimates for the Lebesgue constants of the thresholding greedy algorithm, in the case of general bases in Banach spaces. We show the optimality of these estimates in some situations. Our results recover and slightly…

Functional Analysis · Mathematics 2016-06-22 Pablo M. Berná , Gustavo Garrigós , Óscar Blasco

In [25], T. Oikhberg introduced and studied variants of the greedy and weak greedy algorithms for sequences with gaps, with a focus on the $\mathbf n$-$t$-quasi-greedy property that is based on them. Building upon this foundation, our…

Functional Analysis · Mathematics 2023-09-04 Miguel Berasategui , Pablo M. Berná

We continue with the study of greedy-type bases in quasi-Banach spaces started in [3]. In this paper, we study partially-greedy bases focusing our attention in two main results: -Characterization of partially-greedy bases in quasi-Banach…

Functional Analysis · Mathematics 2020-04-03 Pablo M. Berná

We obtain Lebesgue-type inequalities for the greedy algorithm for arbitrary complete seminormalized biorthogonal systems in Banach spaces. The bounds are given only in terms of the upper democracy functions of the basis and its dual. We…

Functional Analysis · Mathematics 2017-09-18 P. M. Berná , O. Blasco , G. Garrigós , E. Hernández , T. Oikhberg

We continue our study of the Thresholding Greedy Algorithm when we restrict the vectors involved in our approximations so that they either are supported on intervals of $\mathbb N$ or have constant coefficients. We introduce and…

Functional Analysis · Mathematics 2023-02-14 Miguel Berasategui , Pablo M. Berná , Hung Viet Chu

Partially greedy bases in Banach spaces were introduced by Dilworth et al. as a strictly weaker notion than the (almost) greedy bases. In this paper, we study two natural ways to strengthen the definition of partial greediness. The first…

Functional Analysis · Mathematics 2023-02-07 Miguel Berasategui , Pablo M. Berná , Hung Viet Chu

We investigate various aspects of the "weighted" greedy algorithm with respect to a Schauder basis. For a weight w, we describe w-greedy, w-almost-greedy and w-partially-greedy bases, and show some properties of w-semi-greedy bases. To…

Functional Analysis · Mathematics 2018-06-19 P. M. Berná , S. J. Dilworth , D. Kutzarova , T. Oikhberg , B. Wallis

The purpose of this paper is to quantify the size of the Lebesgue constants $(L_m)_{m=1}^{\infty}$ associated with the thresholding greedy algorithm in terms of a new generation of parameters that modulate accurately some features of a…

Functional Analysis · Mathematics 2021-04-23 Fernando Albiac , Jose L. Ansorena , Pablo M. Berna

The general problem addressed in this work is the development of a systematic study of the thresholding greedy algorithm for general biorthogonal systems (also known as Markushevich bases) in quasi-Banach spaces from a functional-analytic…

Functional Analysis · Mathematics 2019-03-29 Fernando Albiac , Jose L. Ansorena , Pablo M. Berna , Przemyslaw Wojtaszczyk

The purpose of this paper is to introduce $\omega$-Chebyshev-greedy and $\omega$-partially greedy approximation classes and to study their relation with $\omega$-approximation spaces, where the latter are a generalization of the classical…

Functional Analysis · Mathematics 2023-03-17 Pablo M. Berná , Hung Viet Chu , Eugenio Hernández

In this paper we study a new class of bases, weaker than quasi-greedy bases, which retain their unconditionality properties and can provide the same optimality for the thresholding greedy algorithm. We measure how far these bases are from…

Functional Analysis · Mathematics 2021-06-03 Fernando Albiac , Jose L. Ansorena , Miguel Berasategui , Pablo M. Berna , Silvia Lassalle

We shall present new characterizations of partially greedy and almost greedy bases. A new class of basis (which we call reverse partially greedy basis) arises naturally from these characterizations of partially greedy bases. We also give…

Functional Analysis · Mathematics 2018-05-18 S. J. Dilworth , Divya Khurana

In 2003, S. J. Dilworth et al. ([8]) introduced the notion of almost-greedy (resp. partially-greedy) bases. These bases were characterized in terms of quasi-greediness and democracy (resp. conservativeness). In this paper we will show a new…

Functional Analysis · Mathematics 2021-08-04 Pablo M. Berná , Diego Mondéjar

This article closes the cycle of characterizations of greedy-like bases in the isometric case initiated in [F. Albiac and P. Wojtaszczyk, Characterization of $1$-greedy bases, J. Approx. Theory 138 (2006)] with the characterization of…

Functional Analysis · Mathematics 2015-08-18 F. Albiac , J. L. Ansorena

We show that for quasi-greedy bases in real Banach spaces the error of the thresholding greedy algorithm of order N is bounded by the best N-term error of approximation times a constant which depends on the democracy functions and the…

Functional Analysis · Mathematics 2011-11-17 Eugenio Hernández
‹ Prev 1 2 3 10 Next ›