4 citations · 7 across the 7 of their papers we have counts for
12 papers
Joint -Numerical Ranges of Operators in Hilbert and Semi-Hilbert Spaces
Kais Feki, Arnab Patra, Jyoti Rani +1
This paper introduces and investigates the concept of the -numerical range for tuples of bounded linear operators in Hilbert spaces. We establish various inequalities concerning…
Further improvements of generalized numerical radius inequalities for Hilbert space operators
Kais Feki
Several new improvements of the -numerical radius inequalities for operators acting on a semi-Hilbert space, i.e., a space generated by a positive operator , are proved. In p…
Numerical radius inequalities for products and sums of semi-Hilbertian space operators
Pintu Bhunia, Kais Feki, Kallol Paul
New inequalities for the -numerical radius of the products and sums of operators acting on a semi-Hilbert space, i.e. a space generated by a positive semidefinite operator ,…
On -parallelism and -Birkhoff-James orthogonality of operators
Tamara Bottazzi, Cristian Conde, Kais Feki
In this paper, we establish several characterizations of the -parallelism of bounded linear operators with respect to the seminorm induced by a positive operator acting on a…
Some bounds for the -numerical radius of certain operator matrices
Kais Feki
For a given bounded positive (semidefinite) linear operator on a complex Hilbert space , we consider the semi-Hilbertian…
Inequalities for the -joint numerical radius of two operators and their applications
Kais Feki
Let be a complex Hilbert space and be a positive (semidefinite) bounded linear operator on . The semi-inne…