54 citations · 332 across the 64 of their papers we have counts for
14 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…
Gateaux differentiability in the Banach space of meromorphic functions
Sanjay Mallick, Debmalya Sain
We study the Gateaux differentiability in the Banach space of meromorphic functions and obtain a complete characterization of the same, by using Birkhoff-James orthogonality techni…
Orthogonality and smoothness induced by the norm derivatives
Debmalya Sain
We study the concepts of orthogonality and smoothness in normed linear spaces, induced by the derivatives of the norm function. We obtain analytic characterizations of the said ort…
On norm derivatives and the ball-covering property of Banach spaces
Debmalya Sain
We study a local version of the ball-covering problem in Banach spaces, and obtain a complete solution to it in terms of the norm derivatives. We illustrate the advantage of the lo…
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…