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Open Access Article
1 - extend numerical radius for adjointable operators on Hilbert C^* -modules
M. Shah Hosseini B. MOOSAVIIn this paper, a new definition of numerical radius for adjointable operators in Hilbert -module space will be introduced. We also give a new proof of numerical radius inequalities for Hilbert space operators.In this paper, a new definition of numerical radius for adjointable operators in Hilbert -module space will be introduced. We also give a new proof of numerical radius inequalities for Hilbert space operators. Manuscript profile -
Open Access Article
2 - Some results on higher numerical ranges and radii of quaternion matrices
Gh. Aghamollaei N. Haj Aboutalebi -
Open Access Article
3 - Some improvements of numerical radius inequalities via Specht’s ratio
Y. Khatib M. Hassani -
Open Access Article
4 - New lower bound for numerical radius for off-diagonal $2\times 2$ matrices
B. Moosavi M. Shah HosseiniNew norm and numerical radius inequalities for operators on Hilbert space are given. Among other inequalities, we prove that if $ A, B \in B(H) $, then \[\Vert A \Vert - \frac{3 \Vert A-B^* \Vert }{2} \leq \omega\left(\left[\begin{array}{cc} 0 & A \\ B & 0 \end{array}\r MoreNew norm and numerical radius inequalities for operators on Hilbert space are given. Among other inequalities, we prove that if $ A, B \in B(H) $, then \[\Vert A \Vert - \frac{3 \Vert A-B^* \Vert }{2} \leq \omega\left(\left[\begin{array}{cc} 0 & A \\ B & 0 \end{array}\right]\right).\] Moreover, $\omega(AB) \leq \frac{3}{2} \Vert Im(A) \Vert \Vert B \Vert + D_{B}\; \omega(A) $. In particular, if $ A $ is self-adjointable, then $\omega(AB) \leq D_{B} \Vert A \Vert$, where $D_{B}=\underset{\lambda \in \mathbb{C}}{\mathop{\inf}}\,\left\| B-\lambda I \right\|$. Manuscript profile -
Open Access Article
5 - Advanced Refinements of Numerical Radius Inequalities
Farzaneh Pouladi Najafabadi Hamid Moradi -
Open Access Article
6 - Norm and Numerical Radius Inequalities for Hilbert Space Operators
Mohsen Omidvar Mahdi Ghasvareh