J. Ansorena

collaborators

11 papers

math.FA2026

Boundedness of the averaging projections in nonlocally convex Lorentz sequence spaces and applications to basis theory

Fernando Albiac, JosÃ© L. Ansorena, Miguel Berasategui

We study the boundedness of averaging projections associated with symmetric Schauder bases in quasi-Banach spaces. Although this property is standard in the Banach setting, it is f…

math.FA2026

Lipschitz extensions into $p$ -Banach spaces, and canonical embeddings of Lipschitz-free $p$ -spaces for $0 < p < 1$

Fernando Albiac, JosÃ© L. Ansorena

We show that inclusions of $p$ -metric spaces always produce genuine linear embeddings at the level of Lipschitz-free $p$ -spaces. More precisely, for every $0 < p < 1$ and every inclusi…

math.FA2026

Isometric renormings for greedy bases in Banach spaces, with applications to the Haar System in $L_{p} [0, 1]$ , $1 < p < \infty$

Fernando Albiac, JosÃ© L. Ansorena, Miguel Berasategui +1

We investigate the problem of improving the greedy-type constant of a basis by means of an equivalent renorming of the ambient Banach space. Our main result shows that if a Banach…

math.FA2026

Unconditional structure of Banach spaces with few operators

Fernando Albiac, Jose L. Ansorena

This article was initially motivated by our goal to show that the Banach space $G$ constructed by Gowers in [W. T. Gowers, A solution to Banach's hyperplane problem, Bull.…

math.FA2026

Remarks about symmetry-type conditions of conditional bases of Banach spaces

We investigate the existence of equivalent p-norms, 0< p 1, under which conditional symmetric or spreading bases in quasi-Banach spaces become isometric. For spreading bases (which…

math.FA2025

Mutually non isomorphic mixed-norm Lebesgue spaces

We prove that for $1 \leq p, q \leq \infty$ the mixed-norm spaces $L_{q} (L_{p})$ are mutually non-isomorphic, with the only exception that $L_{q} (L_{2})$ is isomorphic to $L_{q} (L_{q})$ for all $1<q…

Boundedness of the averaging projections in nonlocally convex Lorentz sequence spaces and applications to basis theory

Lipschitz extensions into p-Banach spaces, and canonical embeddings of Lipschitz-free p-spaces for 0<p<1

Isometric renormings for greedy bases in Banach spaces, with applications to the Haar System in Lp​[0,1], 1<p<∞

Unconditional structure of Banach spaces with few operators

Remarks about symmetry-type conditions of conditional bases of Banach spaces

Mutually non isomorphic mixed-norm Lebesgue spaces

Lipschitz extensions into $p$ -Banach spaces, and canonical embeddings of Lipschitz-free $p$ -spaces for $0 < p < 1$

Isometric renormings for greedy bases in Banach spaces, with applications to the Haar System in $L_{p} [0, 1]$ , $1 < p < \infty$