Increasing sequences of contractive projections on a reflexive LP space share an unconditionality property similar to that exhibited sequences of self-adjoint projections on a Hilbert space. A slight variation of this property is shown to be precisely the correct condition on a reflexive Banach space to ensure that every operator with a contractive AC-functional calculus is scalar-type spectraL

We give the weakest constraint qualification known to us that ensures the maximal monotonicity of the operator A∗ ◦ T ◦A when A is a linear continuous mapping between two reflexive Banach spaces and T is a maximal monotone operator. As a special case we get the weakest constraint qualification that ensures the maximal monotonicity of the sum of two maximal monotone operators on a reflexive Bana...

The hyperbolic algebra A h , studied recently by Katavolos and Power [5], is the weak star closed operator algebra on L 2 (R) generated by H ∞ (R), as multiplication operators, and by the dilation operators V t , t ≥ 0, given by V t f (x) = e t/2 f (e t x). We show that A h is a reflexive operator algebra and that the four dimensional manifold Lat A h (with the natural topology) is the reflexiv...

We prove that for every bounded linear operator T : X → X, where X is a non-reflexive quotient of a von Neumann algebra, the point spectrum of T ∗ is non-empty (i.e. for some λ ∈ C the operator λI − T fails to have dense range.) In particular, and as an application, we obtain that such a space cannot support a topologically transitive operator.