Semi-inner product and angles in Schatten ideals

TL;DR

This paper explores the geometric structure of Schatten p-class ideals for p > 1 by interpreting them as semi-inner product spaces, introducing a new angle concept and analyzing properties like orthogonality and parallelism.

Contribution

It introduces a novel notion of angle in Schatten ideals and investigates geometric properties within the semi-inner product framework, advancing understanding of operator geometry.

Findings

Defined a new angle concept in Schatten p-classes

Analyzed Birkhoff-James orthogonality and p-parallelism in this context

Provided insights into the geometry of operator spaces

Abstract

In this paper, we investigate the Schatten $p$-class ideals for $p >1$ as semi-inner product spaces in the sense of Giles and Lumer. Within this framework, we explore several geometric and analytic notions such as Birkhoff-James orthogonality, $p$-parallelism, and related properties that naturally arise when these structures are interpreted through the lens of the associated semi-inner product. Furthermore, we introduce a novel notion of angle adapted to this context, which generalizes and unifies existing angle definitions in normed spaces. Our results contribute to a deeper understanding of the geometry of the $p$-Schatten class and offer new perspectives on operator behavior in semi-inner product spaces.