© 2001 by London Mathematical Society
© The London Mathematical Society
Direct Sums of Operator Spaces
Department of Mathematics, University of Texas Austin, TX 78712, USA, timur{at}math.utexas.edu
Received 10 July 2000.
It is proved that if X and Y are operator spaces such that every completely bounded operator from X into Y is completely compact and Z is a completely complemented subspace of X
Y, then there exists a completely bounded automorphism
: X
Y
X
Y with completely bounded inverse such that
Z = X0
Y0, where X0 and Y0 are completely complemented subspaces of X and Y, respectively. If X and Y are homogeneous, the existence is proved of such a
under a weaker assumption that any operator from X to Y is strictly singular. An upper estimate is obtained for ||
||cb||
1||cb if X and Y are separable homogeneous Hilbertian operator spaces. Also proved is the uniqueness of a completely unconditional basis in X
Y if X and Y satisfy certain conditions.