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Projections from onto
Author(s):
Pierre
David
Saphar
Journal:
Proc. Amer. Math. Soc.
127
(1999),
1127-1131.
MSC (1991):
Primary 46B20;
Secondary 46B28
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Abstract:
Let and be two infinite dimensional real Banach spaces. The following question is classical and long-standing. Are the following properties equivalent? a) There exists a projection from the space of continuous linear operators onto the space of compact linear operators. b) . The answer is positive in certain cases, in particular if or has an unconditional basis. It seems that there are few results in the direction of a general solution. For example, suppose that and are reflexive and that or has the approximation property. Then, if , there is no projection of norm 1, from onto . In this paper, one obtains, in particular, the following result: Theorem. Let be a real Banach space which is reflexive (resp. with a separable dual), of infinite dimension, and such that has the approximation property. Let be a real scalar with . Then can be equivalently renormed such that, for any projection from onto , one has . One gives also various results with two spaces and .
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Additional Information:
Pierre
David
Saphar
Affiliation:
Department of Mathematics, Technion--Israel Institute of Technology, Haifa, Israel
Email:
saphar@techunix.technion.ac.il
DOI:
10.1090/S0002-9939-99-04645-6
PII:
S 0002-9939(99)04645-6
Keywords:
Space of continuous linear operators,
space of compact operators,
projection
Received by editor(s):
October 30, 1996
Received by editor(s) in revised form:
July 28, 1997
Additional Notes:
This research was supported by the fund for the promotion of Research at the Technion
Communicated by:
Dale E. Alspach
Copyright of article:
Copyright
1999,
American Mathematical Society
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