English
Related papers

Related papers: Birkhoff-James orthogonality of linear operators o…

200 papers

We characterize left symmetric linear operators on a finite dimensional strictly convex and smooth real normed linear space $ \mathbb{X},$ which answers a question raised recently by one of the authors in \cite{S} [D. Sain,…

Functional Analysis · Mathematics 2024-07-30 Debmalya Sain , Puja Ghosh , Kallol Paul

We study Birkhoff-James orthogonality of bounded linear operators on complex Banach spaces and obtain a complete characterization of the same. By means of introducing new definitions, we illustrate that it is possible in the complex case,…

Functional Analysis · Mathematics 2024-07-30 Kallol Paul , Debmalya Sain , Arpita Mal , Kalidas Mandal

We study left symmetric bounded linear operators in the sense of Birkhoff-James orthogonality defined between infinite dimensional Banach spaces. We prove that a bounded linear operator defined between two strictly convex Banach spaces is…

Functional Analysis · Mathematics 2024-08-13 Kallol Paul , Arpita Mal , Pawel Wójcik

In this paper, we study Birkhoff-James orthogonality of bounded linear operators and give a complete characterization of Birkhoff-James orthogonality of bounded linear operators on infinite dimensional real normed linear spaces. As an…

Functional Analysis · Mathematics 2024-08-13 Debmalya Sain , Kallol Paul , Arpita Mal

This paper deals with study of Birkhoff-James orthogonality of a linear operator to a subspace of operators defined between arbitrary Banach spaces. In case the domain space is reflexive and the subspace is finite dimensional we obtain a…

Functional Analysis · Mathematics 2019-12-10 Arpita Mal , Kallol Paul

We study Birkhoff-James orthogonality and isosceles orthogonality of bounded linear operators between Hilbert spaces and Banach spaces. We explore Birkhoff-James orthogonality of bounded linear operators in light of a new notion introduced…

Functional Analysis · Mathematics 2020-04-28 Tamara Bottazzi , Cristian Conde , Debmalya Sain

We study Birkhoff-James orthogonality and its local symmetry in some sequence spaces namely $\ell_p,$ for $1\leq p\leq\infty$, $p\neq2$, $c$, $c_0$ and $c_{00}$. Using the characterization of the local symmetry of Birkhoff-James…

Functional Analysis · Mathematics 2022-05-25 Babhrubahan Bose , Saikat Roy , Debmalya Sain

We study the norm derivatives in the context of Birkhoff-James orthogonality in real Banach spaces. As an application of this, we obtain a complete characterization of the left-symmetric points and the right-symmetric points in a real…

Functional Analysis · Mathematics 2020-09-25 Divya Khurana , Debmalya Sain

We study approximate Birkhoff-James orthogonality of bounded linear operators defined between normed linear spaces $\mathbb{X}$ and $\mathbb{Y}.$ As an application of the results obtained, we characterize smoothness of a bounded linear…

Functional Analysis · Mathematics 2024-08-13 Arpita Mal , Kallol Paul , T. S. S. R. K. Rao , Debmalya Sain

We study Birkhoff-James orthogonality of compact (bounded) linear operators between Hilbert spaces and Banach spaces. Applying the notion of semi-inner-products in normed linear spaces and some related geometric ideas, we generalize and…

Functional Analysis · Mathematics 2018-10-12 Debmalya Sain , Kallol Paul , Arpita Mal

There are two notions of approximate Birkhoff-James orthogonality in a normed space. We characterize both the notions of approximate Birkhoff-James orthogonality in the space of bounded linear operators defined on a normed space. A complete…

Functional Analysis · Mathematics 2024-08-13 Kallol Paul , Debmalya Sain , Arpita Mal

We present a sufficient condition for smoothness of bounded linear operators on Banach spaces for the first time. Let $T, A \in B(\mathbb{X}, \mathbb{Y}),$ where $\mathbb{X}$ is a real Banach space and $\mathbb{Y}$ is a real normed linear…

Functional Analysis · Mathematics 2024-07-30 Kallol Paul , Debmalya Sain , Puja Ghosh

In this paper we explore the properties of a bounded linear operator defined on a Banach space, in light of operator norm attainment. Using Birkhoff-James orthogonality techniques, we give a necessary condition for a bounded linear operator…

Functional Analysis · Mathematics 2016-08-03 Debmalya Sain

Let $\mathbb{X}$ be a Banach space and let $\mathbb{X}^*$ be the dual space of $\mathbb{X}.$ For $x,y \in \mathbb{X},$ $ x$ is said to be $T$-orthogonal to $y$ if $Tx(y) =0,$ where $T$ is a bounded linear operator from $\mathbb{X}$ to…

Functional Analysis · Mathematics 2024-08-14 Debmalya Sain , Souvik Ghosh , Kallol Paul

We explore Birkhoff-James orthogonality of two elements in a complex Banach space by using the directional approach. Our investigation illustrates the geometric distinctions between a smooth point and a non-smooth point in a complex Banach…

Functional Analysis · Mathematics 2021-09-28 Saikat Roy , Satya Bagchi , Debmalya Sain

In this article, we discuss the relationship between Birkhoff-James orthogonality of elementary tensors in the space $L^{p}(\mu)\otimes^{\Delta_{p}}X,\; (1\leq p<\infty)$ with the individual elements in their respective spaces, where $X$ is…

Functional Analysis · Mathematics 2023-10-31 Mohit , Ranjana Jain

Let $X$ be a complex Banach space and $x,y\in X$. By definition, we say that $x$ is Birkhoff-James orthogonal to $y$ if $ \|x+\lambda y\|_{X} \geq \|x\|_{X}$ for all $\lambda \in \mathbb{C}$. We prove that $x$ is Birkhoff-James orthogonal…

Functional Analysis · Mathematics 2020-10-05 Kousik Dhara , Narayan Rakshit , Jaydeb Sarkar , Aryaman Sensarma

We study the smoothness and the norm attainment of bounded bilinear operators between Banach spaces, using the concepts of Birkhoff-James orthogonality and semi-inner-products. In the finite-dimensional case, we characterize Birkhoff-James…

Functional Analysis · Mathematics 2019-07-04 Debmalya Sain

We completely characterize smoothness of bounded linear operators between infinite dimensional real normed linear spaces, probably for the very first time, by applying the concepts of Birkhoff-James orthogonality and semi-inner-products in…

Functional Analysis · Mathematics 2024-08-13 Debmalya Sain , Kallol Paul , Arpita Mal , Anubhab Ray

We study the relationship between the point-wise symmetry of Birkhoff-James orthogonality and the geometry of the space of operators $\mathbb{B}(\ell_\infty^n,\ell_1^m)$. We show that any non-zero left-symmetric point in this space is a…

Functional Analysis · Mathematics 2022-11-17 Babhrubahan Bose
‹ Prev 1 2 3 10 Next ›