Let H be a Hilbert space and L(H) be the algebra of all bounded linear operators from H to H. Our goal in this article is to study the set P⋅Lh of operators in L(H) that can be factorized as the product of an orthogonal ...

Let H=H+⊕H− be an orthogonal decomposition of a Hilbert space, with E+, E− the corresponding projections. Let A be a selfadjoint operator in H which is codiagonal with respect to this decomposition (i.e. A(H+)⊂H− and ...

We study the C* -algebra D+K which consists of sums of a diagonal plus a compact operator. We describe the structure of the unitary group, the sets of ideals, automorphisms and projections.

We study the set X of split operators acting in the Hilbert space H: X = {T ∈ B(H) : N(T) ∩ R(T) = {0} and N(T) + R(T) = H}. Inside X , we consider the set Y: Y = {T ∈ X : N(T) ⊥ R(T)}. Several characterizations of these ...

This article is devoted to the study of the set T of all products PA with P an orthogonal projection and A a positive (semidefinite) operator. We describe this set and study optimal factorizations. We also relate this ...

We study the set D of differences D={A=P−Q:P,Q∈P}, where P denotes the set of orthogonal projections in H. We describe models and factorizations for elements in D, which are related to the geometry of P. The study of D ...

We study the behavior of lift-and-project procedures for solving combinatorial optimization problems as described by Lovász and Schrijver (1991) [6] in the context of the stable set problem on graphs. Following the work ...

The purpose of this study is to explore the mechanisms that influence decisions regarding outsourcing competencies in the operation of project management offices (PMOs). The exploratory research described here involves the ...