Spectral properties of unbounded JJ-self-adjoint block operator matrices
نویسندگان
چکیده
We study the spectrum of unbounded J-self-adjoint block operator matrices. In particular, we prove enclosures for the spectrum, provide a sufficient condition for the spectrum being real and derive variational principles for certain real eigenvalues even in the presence of non-real spectrum. The latter lead to lower and upper bounds and asymptotic estimates for eigenvalues. AMS Subject classification 2010: 47B50, 47A10; 47A56, 46C20, 49R05.
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