On the Geometry of Positive Maps in Matrix Algebras.
On the operator equation .
Operators preserving ideals in C*-algebras
The aim of this paper is to prove that derivations of a C*-algebra A can be characterized in the space of all linear continuous operators T : A → A by the conditions T(1) = 0, T(L∩R) ⊂ L + R for any closed left ideal L and right ideal R. As a corollary we get an extension of the result of Kadison [5] on local derivations in W*-algebras. Stronger results of this kind are proved under some additional conditions on the cohomologies of A.
Remarks on the order for quantum observables
Rieffel’s pseudodifferential calculus and spectral analysis of quantum Hamiltonians
We use the functorial properties of Rieffel’s pseudodifferential calculus to study families of operators associated to topological dynamical systems acted by a symplectic space. Information about the spectra and the essential spectra are extracted from the quasi-orbit structure of the dynamical system. The semi-classical behavior of the families of spectra is also studied.
Stabilität starkstetiger, positiver Operatorhalbgruppen auf C*-Algebren.
Sur les sous-espaces spectraux d'un opérateur compact relativement à une algèbre de von Neumann
Soit un opérateur compact dans une algèbre de Von Neumann. On montre que le sous-espace sup ker est relativement fini.
The von Neumann algebra associated with an infinite number of t-free noncommutative gaussian random variables
We show that the von Neumann algebras generated by an infinite number of t-deformed free gaussian operators are factors of type .
Über die Zerlegung von Operatoren in topologischen direkten Integralen von Hilberträumen.
О двух методах исследования обратимости операторов из -алгебр, порожденных динамическими системами