Point-wise Symmetry of Birkhoff-James Orthogonality and Geometry of $\mathbb{B}(\ell_\infty^n,\ell_1^m)$

Abstract

We study the relationship between the point-wise symmetry of Birkhoff-James orthogonality and the geometry of the space of operators B(ℓ n ∞ , ℓ m 1 ). We show that any non-zero left-symmetric point in this space is a smooth point. We also show that for n ≥ 4, any unit norm right-symmetric point of this space is an extreme point of the closed unit ball. This marks the first step towards characterizing the extreme points of these unit balls and finding the Grothendieck constants G(m, n) using Birkhoff-James orthogonality techniques.