Variants of the James tree space
摘要
We introduce and study two variant JT2,p and JTG of James Tree space JT. Both spaces are non-Hilbertian, they contain subspaces isomorphic to ℓ2, and all such subspaces are complemented. The space JT2,p is reflexive with an unconditional basis and its non-Hilbertian subspaces contain ℓp. The space JTG is non-reflexive and its non-Hilbertian subspaces contain c0. These examples form the semiclassical basis for an exotic forthcoming construction related to a question of W. Cuellar Carrera, N. de Rancourt and V. Ferenczi.