2021/06/23 by Spiros A. Argyros, Argyros, Spiros A., Alexandros Georgiou +5
Mathematics · Computer Science · #Advanced Banach Space Theory #Optimization and Variational Analysis #Advanced Operator Algebra Research
paper · pdf · doi:10.48550/arxiv.2106.12323
For 1≤ p <∞, we present a reflexive Banach space \mathfrakX(p)awi, with an unconditional basis, that admits ℓp as a unique asymptotic model and does not contain any Asymptotic ℓp subspaces. D. Freeman, E. Odell, B. Sari and B. Zheng 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 L. Halbeisen and E. Odell 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 \mathfrakX(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.