Full paper in PDF:
$% E. Martín, E. Indurain, A. Plans, and A. Rodes, Two geometric constants for operators acting on a separable Banach space, Rev. Mat. Univ. Complut. Madrid 1 (1988), no. 1, 2, 3, 2330.%$

Two Geometric Constants for Operators Acting on a Separable Banach Space

Elena MARTíN, Esteban INDURAIN,
Antonio PLANS, and Álvaro RODES
Departamento de Matemáticas
Facultad de Ciencias
Zaragoza 50009 -- Spain


Recibido: March 3, 1988
Revisado: June 24, 1988

The main result of this paper is the following: A separable Banach space X  is reflexive if and only if the infimum of the Gelfand numbers of any bounded linear operator defined on X  can be computed by means of just one sequence on nested, closed, finite codimensional subspaces with null intersection.

1980 Mathematics Subject Classification (1985 revision): 47A10, 47A53, 46B10, 40A05.