7 papers
Some refinements of numerical radius inequalities
Zahra Heydarbeygi, Maryam Amyari, Mahnaz Khanehgir
In this paper, we give some refinements for the second inequality in , where . In particular, if is hyponormal by refining the…
Approximate numerical radius orthogonality
Maryam Amyari, Marzieh Moradian Khibary
We introduce the notion of approximate numerical radius (Birkhoff) orthogonality and investigate its significant properties. Let and $\varepsilon…
More on -orthogonality and -parallelism
Maryam Torabian, Maryam Amyari, Marzieh Moradian Khibary
We investigate some aspects of various numerical radius orthogonalities and numerical radius parallelism for bounded linear operators on a Hilbert space . Among severa…
The operator--valued parallelism and norm-parallelism in matrices
M. Mohammadi Gohari, M. Amyari
Let be a Hilbert space, and let be the -algebra of compact operators on . In this paper, we present some characterizations of the n…
Parallelism in Hilbert -modules
M. Mohammadi Gohari, M. Amyari
Let be a Hilbert space and be the -algebra of compact operators on . In this paper, we present some characteriza…
A new type of Numerical radius of operators on Hilbert -module
Marzieh Mehrazin, Maryam Amyari, Mohsen Erfanian Omidvar
In this paper, we define a new concept of numerical range and prove its basic results. We also define the numerical radius and prove that $$ω_{o}(T)\l…