Spectral Conditions for Norm-Attainment in Bounded Operators on Hilbert Spaces
Mogoi N. Evans *
Department of Pure and Applied Mathematics, Jaramogi Oginga Odinga University of Science and Technology, Kenya.
Wafula A. M.
Department of Pure and Applied Mathematics, Jaramogi Oginga Odinga University of Science and Technology, Kenya.
*Author to whom correspondence should be addressed.
Abstract
On this note, we have investigated the conditions for norm-attainment in bounded operators on Hilbert spaces, focusing on key criteria such as spectral gaps, isolated norms, and nonzero spectral projections. Concrete examples, such as diagonal and weighted shift operators, are used to demonstrate norm-attainment under specific conditions. The impact of compact operator perturbations, essential spectra, and unitary equivalence is also explored. The methodology combines analytical techniques and numerical simulations, and the study concludes by suggesting future research directions, including the exploration of unbounded operators, Banach spaces, and applications in quantum mechanics and signal processing. The findings are situated within the broader context of existing literature on operator theory.
Keywords: Norm-attainment, spectral properties, bounded operators, spectral projections, compact operators