[图书][B] Counterexamples in operator theory
MH Mortad - 2022 - Springer
Counterexamples undeniably play an outstanding role in mathematics. As is known,
counterexamples are patently examples but with a different purpose. The commonly agreed …
counterexamples are patently examples but with a different purpose. The commonly agreed …
The Fuglede theorem and some intertwining relations
IFZ Bensaid, S Dehimi, B Fuglede… - Advances in Operator …, 2021 - Springer
In this paper, we show new versions of the Fuglede theorem in an unbounded setting. A
related counterexample is also presented. In the second part of the paper, we give a pair of …
related counterexample is also presented. In the second part of the paper, we give a pair of …
[HTML][HTML] Unbounded products of operators and connections to Dirac-type operators
K Gustafson, MH Mortad - Bulletin des Sciences Mathématiques, 2014 - Elsevier
Let A and B be two densely defined unbounded closeable operators in a Hilbert space such
that their unbounded operator products AB and BA are also densely defined. Then all four …
that their unbounded operator products AB and BA are also densely defined. Then all four …
Commutativity of unbounded normal and self-adjoint operators and applications
MH Mortad - arXiv preprint arXiv:1301.1632, 2013 - arxiv.org
arXiv:1301.1632v1 [math.FA] 8 Jan 2013 Page 1 arXiv:1301.1632v1 [math.FA] 8 Jan 2013
COMMUTATIVITY OF UNBOUNDED NORMAL AND SELF-ADJOINT OPERATORS AND …
COMMUTATIVITY OF UNBOUNDED NORMAL AND SELF-ADJOINT OPERATORS AND …
[PDF][PDF] Class of -power-hyponormal operators in semi-Hilbertian space
C Chellali, A Benali - Func. Anal. Approx. Comput, 2019 - researchgate.net
In this paper, the concept of n-power-hyponormal operators on a Hilbert space defined by
Messaoud Guesba and Mostefa Nadir in [11] is generalized when an additional semi-inner …
Messaoud Guesba and Mostefa Nadir in [11] is generalized when an additional semi-inner …
A criterion for the normality of unbounded operators and applications to self-adjointness
MH Mortad - Rendiconti del Circolo Matematico di Palermo (1952-), 2015 - Springer
In this paper, we give and prove a criterion for the normality of unbounded closed operators,
which is a sort of a maximality result which will be called “double maximality”. As …
which is a sort of a maximality result which will be called “double maximality”. As …
On the closedness of the range of (fractional) powers of certain classes of possibly unbounded operators
In this article, we establish certain identities about the closedness of the range of several
classes of possibly unbounded operators defined on a Hilbert space, such as self-adjoint …
classes of possibly unbounded operators defined on a Hilbert space, such as self-adjoint …
On the closedness, the self-adjointness and the normality of the product of two unbounded operators
MH Mortad - Demonstratio Mathematica, 2012 - degruyter.com
Mohammed Hichem Mortad ON THE CLOSEDNESS, THE SELF-ADJOINTNESS AND THE
NORMALITY OF THE PRODUCT OF TWO UNBOUNDED OPERATORS 1. In Page 1 …
NORMALITY OF THE PRODUCT OF TWO UNBOUNDED OPERATORS 1. In Page 1 …
Similarities involving unbounded normal operators
MH Mortad - Tsukuba Journal of Mathematics, 2010 - JSTOR
SIMILARITIES INVOLVING UNBOUNDED NORMAL OPERATORS Page 1 TSUKUBA J. MATH.
Vol. 34 No. 1 (2010), 129-136 SIMILARITIES INVOLVING UNBOUNDED NORMAL …
Vol. 34 No. 1 (2010), 129-136 SIMILARITIES INVOLVING UNBOUNDED NORMAL …
[PDF][PDF] Products and sums of bounded and unbounded normal operators: Fuglede-Putnam versus Embry
MH Mortad - Rev. Roumaine Math. Pures Appl, 2011 - csm.ro
We start by recalling some notions, definitions and basic results about linear bounded and
unbounded operators. All Hilbert spaces are over C and are separable. All operators …
unbounded operators. All Hilbert spaces are over C and are separable. All operators …