8 papers
On the commutativity of closed symmetric operators
Souheyb Dehimi, Mohammed Hichem Mortad, Ahmed Bachir
In this article, we give conditions guaranteeing the commutativity of a bounded self-adjoint operator with an unbounded closed symmetric operator.
Unbounded generalizations of the Fuglede-Putnam theorem
Souheyb Dehimi, Mohammed Hichem Mortad, Ahmed Bachir
In this paper, we prove and disprove several generalizations of unbounded versions of the Fuglede-Putnam theorem.
Unbounded generalizations of the Fuglede-Putnam theorem and applications to the commutativity of self-adjoint operators
Souheyb Dehimi, Mohammed Hichem Mortad, Ahmed Bachir
In this article, we prove and disprove several generalizations of unbounded versions of the Fuglede-Putnam theorem. As applications, we give conditions guaranteeing the commutativi…
On the Operator Equations
Souheyb Dehimi, Mohammed Hichem Mortad, Zsigmond Tarcsay
Let and let be a closed linear operator (everywhere bounded or unbounded). In this paper, we study (among others) equations of the type where $n\geq…
The Fuglede Theorem and Some Intertwining Relations
Ikram Fatima Zohra Bensaid, Souheyb Dehimi, Bent Fuglede +1
In this paper, we show a new and classic version of the celebrated Fuglede Theorem in an unbounded setting. A related counterexample is equally presented. In the second strand of t…
Chernoff Like Counterexamples Related to Unbounded Operators
Souheyb Dehimi, Mohammed Hichem Mortad
In this paper, we give an example of a closed unbounded operator whose square's domain and adjoint's square domain are equal and trivial. Then, we come up with an essentially self-…