Departamento de Matemáticas, Universidad Pública de Navarra, 31006 Pamplona, Spain
Copyright © 2009 F. Albiac and C. Leránoz. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
For the unit vector basis of has the property of perfect homogeneity: it is equivalent to all its normalized block basic
sequences, that is, perfectly homogeneous bases are a special case of
symmetric bases. For Banach spaces, a classical result of Zippin (1966)
proved that perfectly homogeneous bases are equivalent to either the
canonical -basis or the canonical -basis for some . In this note, we show that (a relaxed form of) perfect homogeneity characterizes
the unit vector bases of for as well amongst bases in nonlocally convex quasi-Banach spaces.