1 citations · 5 across the 19 of their papers we have counts for
29 papers
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…
Conditional bases with Property~(A)
Fernando Albiac, Jose L. Ansorena, Pablo Berná +1
Property~(A) is a week symmetry condition that plays a fundamental role in the characterization of greedy-type bases in the isometric case, i.e., when the constants involved in the…
Isomorphisms between vector-valued -spaces for and uniqueness of unconditional structure
Fernando Albiac, Jose L. Ansorena
The aim of this paper is twofold. On the one hand, we manage to identify Banach-valued Hardy spaces of analytic functions over the disc with other classes of Hardy spa…
The structure of greedy-type bases in Tsirelson's space and its convexifications
Fernando Albiac, José L. Ansorena
Tsirelson's space made its appearance in Banach space theory in 1974 soon to become one of the most significant counterexamples in the theory. Its structure broke the…
Elton's near unconditionality of bases as a threshold-free form of greediness
Fernando Albiac, José L. Ansorena, Miguel Berasategui
Elton's near unconditionality and quasi-greediness for largest coefficients are two properties of bases that made their appearance in functional analysis from very different areas…
Sparse approximation using new greedy-like bases in superreflexive spaces
Fernando Albiac, Jose L. Ansorena, Miguel Berasategui
This paper is devoted to theoretical aspects on optimality of sparse approximation. We undertake a quantitative study of new types of greedy-like bases that have recently arisen in…