Abstract
A linear operator in a separable Hilbert space is called a quasinormal one if it is a sum of a normal operator and a compact one. In the paper, bounds for the spectrum of quasinormal operators are established. In addition, the lower estimate for the spectral radius is derived. Under some restrictions, that estimate improves the well-known results. Applications to integral operators and matrices are discussed. Our results are new even in the finite-dimensional case.
Original language | English |
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Pages (from-to) | 3737-3746 |
Number of pages | 10 |
Journal | Proceedings of the American Mathematical Society |
Volume | 131 |
Issue number | 12 |
DOIs | |
State | Published - 1 Dec 2003 |
Keywords
- Finite and infinite matrices
- Integral operators
- Linear operators
- Spectral radius
- Spectrum
ASJC Scopus subject areas
- General Mathematics
- Applied Mathematics