Local spectral theory for2×2operator matrices
2003 ◽
Vol 2003
(42)
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pp. 2667-2672
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Keyword(s):
Sigma B
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We discuss the spectral properties of the operatorMC∈ℒ(X⊕Y)defined byMC:=(AC0B), whereA∈ℒ(X),B∈ℒ(Y),C∈ℒ(Y,X), andX,Yare complex Banach spaces. We prove that(SA∗∩SB)∪σ(MC)=σ(A)∪σ(B)for allC∈ℒ(Y,X). This allows us to give a partial positive answer to Question 3 of Du and Jin (1994) and generalizations of some results of Houimdi and Zguitti (2000). Some applications to the similarity problem are also given.
Keyword(s):
1972 ◽
Vol 168
◽
pp. 133
◽
2005 ◽
Vol 305
(1)
◽
pp. 175-182
2007 ◽
Vol 57
(3)
◽
pp. 831-842
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