Orthogonality in Banach Spaces via projective tensor product

Kousik Dhara, Narayan Rakshit, Jaydeb Sarkar +1

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 $\Vert x+\lambda y{\Vert }_X\ge \Vert x{\Vert }_X$ for all $\lambda \in \mathbb{C}$. We…