Το work with title The complete separation of the two finer asymptotic ℓp structures for 1≤p<∞ by Argyros, Spiros, 1950-, Georgiou Alexandros, Manousakis Antonios, Motakis, Pavlos is licensed under Creative Commons Attribution 4.0 International
Bibliographic Citation
S. A. Argyros, A. Georgiou, A. Manoussakis, and P. Motakis, “The complete separation of the two finer asymptotic ℓp structures for 1≤p<∞,” Forum Math. Sigma, vol. 10, Dec. 2022, doi:10.1017/fms.2022.101.
https://doi.org/10.1017/fms.2022.101
For 1 ≤ 𝑝 < ∞, we present a reflexive Banach space 𝔛( 𝑝)awi , with an unconditional basis, that admits ℓ𝑝 as a unique asymptotic model and does not contain any Asymptotic ℓ𝑝 subspaces. Freeman et al., Trans. AMS. 370 (2018),6933–6953 have shown that whenever a Banach space not containing ℓ1, in particular a reflexive Banach space, admits 𝑐0 as a unique asymptotic model, then it is Asymptotic 𝑐0. These results provide a complete answer to a problem posed by Halbeisen and Odell [Isr. J. Math. 139 (2004), 253–291] and also complete a line of inquiry of the relation between specific asymptotic structures in Banach spaces, initiated in a previous paper by the first and fourth authors. For the definition of 𝔛( 𝑝)awi , we use saturation with asymptotically weakly incomparable constraints,a new method for defining a norm that remains small on a well-founded tree of vectors which penetrates any infinite dimensional closed subspace.