64 citations · 883 across the 94 of their papers we have counts for
11 papers · 1 filter
Orthogonality induced by norm derivatives : A new geometric constant and symmetry
Souvik Ghosh, Kallol Paul, Debmalya Sain
In this article we study the difference between orthogonality induced by the norm derivatives (known as -orthogonality) and Birkhoff-James orthogonality in a normed linear space…
-Davis-Wielandt Radius Bounds of Semi-Hilbertian Space Operators
Messaoud Guesba, Somdatta Barik, Pintu Bhunia +1
Consider is a complex Hilbert space and is a positive operator on The mapping $\langle\cdot,\cdot\rangle_A: \mathcal{H}\times \mathcal{H} \to \math…
On the best coapproximation problem in
Debmalya Sain, Shamim Sohel, Souvik Ghosh +1
We study the best coapproximation problem in the Banach space by using Birkhoff-James orthogonality techniques. Given a subspace of , we comple…
On best coapproximations in subspaces of diagonal matrices
Debmalya Sain, Shamim Sohel, Souvik Ghosh +1
We characterize the best coapproximation(s) to a given matrix out of a given subspace of the space of diagonal matrices , by using Birkhoff-Ja…
On k-smoothness of operators between Banach spaces
Debmalya Sain, Shamim Sohel, Kallol Paul
We explore the -smoothness of bounded linear operators between Banach spaces, using the newly introduced notion of index of smoothness. The characterization of the -smoothnes…
On isosceles orthogonality and some geometric constants in a normed space
Debmalya Sain, Souvik Ghosh, Kallol Paul
We study the James constant , an important geometric quantity associated with a normed space , and explore its connection with isosceles orthogonality…