On the Essential Spectrum of Operator Pencils
ABSTRACT For a closed densely defined linear operator A$A$ and a bounded linear operator B$B$ on a Banach space X$X$ whose essential spectrums are contained in disjoint sectors, we show that the essential spectrum of the associated operator pencil λA+B$\lambda A+ B$ is contained in a sector of the c...
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Published in | Proceedings in applied mathematics and mechanics Vol. 24; no. 4 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
01.12.2024
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Online Access | Get full text |
ISSN | 1617-7061 1617-7061 |
DOI | 10.1002/pamm.202400095 |
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Summary: | ABSTRACT
For a closed densely defined linear operator A$A$ and a bounded linear operator B$B$ on a Banach space X$X$ whose essential spectrums are contained in disjoint sectors, we show that the essential spectrum of the associated operator pencil λA+B$\lambda A+ B$ is contained in a sector of the complex plane whose boundaries are determined purely by the angles that define the two sectors, which contain the essential spectrums of A$A$ and B$B$. |
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ISSN: | 1617-7061 1617-7061 |
DOI: | 10.1002/pamm.202400095 |