Displaying similar documents to “An abstract approach to some spectral problems of direct sum differential operators.”

On unbounded hyponormal operators III

J. Janas (1994)

Studia Mathematica


The paper deals mostly with spectral properties of unbounded hyponormal operators. Some nontrivial examples of such operators are given.

The Positive Supercyclicity Theorem.

F. León Saavedra (2004)

Extracta Mathematicae


We present some recent results related with supercyclic operators, also some of its consequences. We will finalize with new related questions.

On the spectral properties of translation operators in one-dimensional tubes

Wojciech Hyb (1991)

Annales Polonici Mathematici


We study the spectral properties of some group of unitary operators in the Hilbert space of square Lebesgue integrable holomorphic functions on a one-dimensional tube (see formula (1)). Applying the Genchev transform ([2], [5]) we prove that this group has continuous simple spectrum (Theorem 4) and that the projection-valued measure for this group has a very explicit form (Theorem 5).