A crossnorm on a pair of
Banach spaces (X,Y ) is a norm, α, on the algebraic tensor product X ⊙ Y
obeying α(x ⊗ y) = ∥x∥∥y∥ for alI x ∈ X,y ∈ Y. When Schatten introduced
crossnorms, he singled out two general classes of crossnorms: the dualizable
crossnorms (called by him “crossnorms whose associates are crossnorms”) and the
uniform crossnorms. These are crossnorms which induce in a natural way other
crossnorms: in the dualizable case, a crossnorm, αd, on X∗⊙ Y ∗, and in the
uniform case, a crossnorm, α, on ℒ(X) ⊙ℒ(Y ) where ℒ(X) is the algebra
of bounded operators on X. Our main new result is a proof that if α is
a uniform crossnorm, then α, the induced crossnorm on ℒ(X) ⊙ℒ(Y ) is
dualizable.
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