Abstract
A pseudospectral function for a canonical differential system is a nondecreasing function on the real line relative to which the eigentransform for the system is a partial isometry. Pseudospectral functions are constructed by means of eigenfunctions and resolvent operators which depend on boundary conditions for the system. Many results hold for Hamiltonians which have selfadjoint matrix values. The most complete results require the definite case, in which it is assumed that the Hamiltonian is nonnegative.
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This paper is dedicated to the memory of the great mathematician M. G. Krein.
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Rovnyak, J., Sakhnovich, L. (2009). Pseudospectral Functions for Canonical Differential Systems. In: Adamyan, V.M., et al. Modern Analysis and Applications. Operator Theory: Advances and Applications, vol 191. Birkhäuser Basel. https://doi.org/10.1007/978-3-7643-9921-4_12
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DOI: https://doi.org/10.1007/978-3-7643-9921-4_12
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