APPROXIMATION PROPERTIES AP_s AND p-NUCLEAR OPERATORS (the case 1 ≤ s ≤ ∞)

摘要

It is shown that there exist Banach spaces Z and W such that Z~(**) and W have bases and for every p ∈ (2, +∞] there is an operator T : W → Z that is not p-nuclear but T~(**) is p-nuclear.