On local preservation of orthogonality and its application to isometries

Autor: Sain, Debmalya, Manna, Jayanta, Paul, Kallol
Rok vydání: 2024
Předmět:
Zdroj: Linear Algebra Appl. 690 (2024), 112-131
Druh dokumentu: Working Paper
DOI: 10.1016/j.laa.2024.03.004
Popis: We investigate the local preservation of Birkhoff-James orthogonality at a point by a linear operator on a finite-dimensional Banach space and illustrate its importance in understanding the action of the operator in terms of the geometry of the concerned spaces. In particular, it is shown that such a study is related to the preservation of k-smoothness and the extremal properties of the unit ball of a Banach space. As an application of the results obtained in this direction, we obtain a refinement of the well-known Blanco-Koldobsky-Turnsek characterization of isometries on some polyhedral Banach spaces, including $ \ell_{\infty}^n, \ell_1^n. $
Databáze: arXiv