Uniqueness of unconditional basis of ℓ2⊕T(2)

We provide a new extension of Pitt’s theorem for compact operators between quasi-Banach lattices which permits to describe unconditional bases of finite direct sums of Banach spaces X1 · · · Xn as direct sums of unconditional bases of their summands. The general splitting principle we obtain yields,...

Descripción completa

Detalles Bibliográficos
Autores: Albiac Alesanco, Fernando José, Ansorena, José L.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2022
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/42790
Acceso en línea:https://hdl.handle.net/2454/42790
Access Level:acceso abierto
Palabra clave:Banach lattice
Equivalence of bases
Hardy spaces
Quasi-Banach space
Tsirelson space
Unconditional basis
Uniqueness of structure
Descripción
Sumario:We provide a new extension of Pitt’s theorem for compact operators between quasi-Banach lattices which permits to describe unconditional bases of finite direct sums of Banach spaces X1 · · · Xn as direct sums of unconditional bases of their summands. The general splitting principle we obtain yields, in particular, that if each Xi has a unique unconditional basis (up to equivalence and permutation), then X1 · · · Xn has a unique unconditional basis too. Among the novel applications of our techniques to the structure of Banach and quasi-Banach spaces we have that the space ℓ2⊕T(2) has a unique unconditional basis.