Showing 2025Show all
3 papers · 1 filter
math.FA2025
When Greedy Approximation Breaks: Counterexamples in Quasi-Banach Spaces
Fernando Albiac, José L. Ansorena, Miguel Berasategui +1
We construct two counterexamples that resolve long-standing open problems on greedy approximation theory with respect to bases, posed in [F. Albiac et al., Dissertationes Math. 560…
math.FA2025
Lebesgue-type estimates for greedy algorithms in quasi-Banach spaces
Miguel Berasategui, Pablo M. Berná, Hung Viet Chu +1
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 param…
math.FA2025
Summability Methods for the Greedy Algorithm in Banach spaces
Miguel Berasategui, Pablo M. Berná, Stephen J. Dilworth +1
For the past 25 years, one of the most studied algorithms in the field of Nonlinear Approximation Theory has been the Thresholding Greedy Algorithm. In this paper, we propose new s…