Norm-Attainable Operators in Operator Ideals: Characterizations, Properties, and Structural Implications
Wafula A.M
Department of Pure and Applied Mathematics, Jaramogi Oginga Odinga University of Science and Technology, Kenya.
Mogoi N. Evans *
aDepartment of Pure and Applied Mathematics, Jaramogi Oginga Odinga University of Science and Technology, Kenya.
*Author to whom correspondence should be addressed.
Abstract
This paper explores the interplay between norm-attainable operators and operator ideals in the context of Hilbert spaces, providing a comprehensive characterization of their structural and geometric properties. We investigate norm-attainability within common operator classes, including compact operators, Schatten (p)- class, trace-class, and weakly compact operators. Foundational lemmas establish the existence and basic properties of norm-attainable operators, which are extended through propositions detailing their behavior under inclusion in specific operator ideals. Key theorems characterize conditions for norm-attainability, highlighting connections to compactness, spectral properties, and finite-rank approximations. The results elucidate practical implications, such as operator approximations and eigenvalue relationships. These findingshave direct applications in quantum mechanics, signal processing, and numerical analysis, where operator approximations are crucial for efficient computation and system modeling. Furthermore, we outline potential extensions of this work to the more general settings of unbounded operators and Banach spaces, opening avenues for future research and broadening the scope of applicability. This study advances understanding of norm-attainable operators in operator theory, offering new insights into their algebraic and geometric significance within operator ideals.
Keywords: Norm-attainable operator, operator ideals, compact operators, schatten class, weakly compact operators