Nayak's theorem for compact operators
Functional Analysis
2024-09-10 v2
Abstract
Let be an complex matrix and let be the eigenvalues of arranged such that and for let be the singular values of . Then a famous theorem of Yamamoto (1967) states that Recently S. Nayak strengthened this result very significantly by showing that the sequence of matrices itself converges to a positive matrix whose eigenvalues are Here this theorem has been extended to arbitrary compact operators on infinite dimensional complex separable Hilbert spaces. The proof makes use of Nayak's theorem, Stone-Weirstrass theorem, Borel-Caratheodory theorem and some technical results of Anselone and Palmer on collectively compact operators. Simple examples show that the result does not hold for general bounded operators.
Keywords
Cite
@article{arxiv.2408.16994,
title = {Nayak's theorem for compact operators},
author = {B V Rajarama Bhat and Neeru Bala},
journal= {arXiv preprint arXiv:2408.16994},
year = {2024}
}
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14 Pages