In this paper we determine the distributional behavior of sums of free (in the sense of Voiculescu) identically distributed, infinitesimal random variables. The theory is shown to parallel theâ€¦ (More)

We provide a characterization of the possible eigenvalues of the sum of two selfadjoint elements of a II1 factor which can be embedded in the ultrapower RÏ‰ of the hyperfinite II1 factor.

1. This note is a continuation of our earlier paper [-3], in which we developed a dilation theory for a certain class of contraction operators acting on a separable, infinite dimensional, complexâ€¦ (More)

The commutant lifting theorem of [24] may be regarded as a very general interpolation theorem from which a number of classical interpolation results may be deduced. In this paper we prove a spectralâ€¦ (More)

In this paper, we employ a lifting method introduced by the authors in order to study the structured singular value applied to input/output operators of control systems. We moreover give a newâ€¦ (More)

A genericity condition is removed from a result of Agler and Young which reduces the spectral Nevanlinna-Pick problem in two dimensions to a family of classical Nevanlinna-Pick problems. Unlike theâ€¦ (More)

If z1, z2, . . . , zn are complex numbers in the open unit disk D and A1, A2, . . . , An are N Ã—N matrices, let F denote the family of analytic functions, bounded in D, such that for each F âˆˆ F , Fâ€¦ (More)

The main purpose of this article is to give an approach to the recent invariant subspace theorem of Brown, Chevreau and Pearcy: Every contraction on a Hubert space, whose spectrum contains the unitâ€¦ (More)

Certain operator algebras A on a Hilbert space have the property that every densely defined linear transformation commuting with A is closable. Such algebras are said to have the closabilityâ€¦ (More)

It was proved in [4] that the ultraweakly closed algebras generated by certain contractions on Hubert space have a remarkable property. This property, in conjunction with the fact that these algebrasâ€¦ (More)