We construct an operator
from L1[0,1] to C[0,1] which may not be approximated by norm attaining
operators with respect to the operator norm. This solves a question raised by J.
Johnson and J. Wolfe and furnishes the first example of a pair of classical
Banach spaces such that the norm attaining operators are not dense. C[0,1] is
the first example of a classical Banach space which does not have property
B.
On the other hand, we show that a weakly compact operator from C(K) into a
Banach space X may be approximated in norm by norm attaining operators.
This shows in particular that the norm attaining operators are dense in
B(C(K),L1[0,1]) and B(C(K),l2), thus solving two questions raised by Johnson and
Wolfe.
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