Abstract
This chapter is about approximation of positive operators by operators that in some sense preserve size: by—in ascending order of generality—unitaries, isometries and partial isometries.
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Bibliography
J.G. Aiken, J.A. Erdos, J.A. Goldstein, Unitary approximation of positive operators. Ill. J. Math. 24, 61–72 (1980)
J.G. Aikten, J.A. Erdos, J.A. Goldstein, On Lowdin orthogonalization. Int. J. Quantum Chem. 18, 1101–1108 (1980)
J.A. Goldstein, M. Levy, Linear algebra and quantum chemistry. Am. Math. Mon. 98, 710–718 (1991)
P.R. Halmos, A Hilbert Space Problem Book, 2nd edn. (Springer, New York, 1974)
P.J. Maher, Partially isometric approximation of positive operators. Ill. J. Math. 33, 227–243 (1989)
P.J. Maher, Spectral approximants concerning balanced and convex sets. Ann. Univ. Sci. Budapest. 46, 177–181 (2003)
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Maher, P.J. (2017). Unitary, Isometric and Partially Isometric Approximation of Positive Operators. In: Operator Approximant Problems Arising from Quantum Theory. Birkhäuser, Cham. https://doi.org/10.1007/978-3-319-61170-9_6
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DOI: https://doi.org/10.1007/978-3-319-61170-9_6
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Publisher Name: Birkhäuser, Cham
Print ISBN: 978-3-319-61169-3
Online ISBN: 978-3-319-61170-9
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