10 papers · 1 filter
A characterization of Banach spaces with numerical index one
Subhadip Pal, Saikat Roy, Debmalya Sain
We investigate the extremal properties of the unit ball of , the dual space of bounded linear operators defined on a Banach space equipped with the numerical radius n…
Distance and best approximations in operator norm and trace class norm
Saikat Roy
We study the best approximation and distance problems in the operator space $\B(\HS)$ and in the space of trace class operators $\LS^1(\B(\HS))$. Formulations of distances are obta…
A unified approach to a family of optimization problems in Banach spaces
Kallol Paul, Saikat Roy, Debmalya Sain +1
Our principal aim is to illustrate that the concept Birkhoff-James orthogonality can be applied effectively to obtain a unified approach to a large family of optimization problems…
Birkhoff-James Orthogonality and Its Local Symmetry in Some Sequence Spaces
Babhrubahan Bose, Saikat Roy, Debmalya Sain
We study Birkhoff-James orthogonality and its local symmetry in some sequence spaces namely for , , , and . Using the characte…
Birkhoff-James orthogonality in complex Banach spaces and Bhatia-Šemrl Theorem revisited
Saikat Roy, Satya Bagchi, Debmalya Sain
We explore Birkhoff-James orthogonality of two elements in a complex Banach space by using the directional approach. Our investigation illustrates the geometric distinctions betwee…
Numerical radius and a notion of smoothness in the space of bounded linear operators
Saikat Roy, Debmalya Sain
We observe that the classical notion of numerical radius gives rise to a notion of smoothness in the space of bounded linear operators on certain Banach spaces, whenever the numeri…