Abstract
Let \(\varphi \) be a linear functional of rank one acting on an irreducible semigroup \(\mathcal {S}\) of operators on a finite- or infinite-dimensional Hilbert space. It is a well-known and simple fact that the range of \(\varphi \) cannot be a singleton. We start a study of possible finite ranges for such functionals. In particular, we prove that in certain cases, the existence of a single such functional \(\varphi \) with a two-element range yields valuable information on the structure of \(\mathcal {S}\).
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Omladič, M., Radjabalipour, M., Radjavi, H.: On semigroups of matrices with traces in a subfield. Linear Algebra Appl. 208(209), 419–424 (1994)
Popov, A.I., Radjavi, H.: Semigroups of partial isometries. Semigroup Forum 87, 663–678 (2013). Erratum: Semigroups of partial isometries. Semigroup Forum 87, 679–680 (2013)
Popov, A.I., Radjavi, H., Williamson, P.: Nonnegative matrix semigroups with finite diagonals. Linear Algebra Appl. 434, 1409–1424 (2011)
Radjabalipour, M., Radjavi, H.: A finiteness lemma, Brauer’s theorem and other irreducibility results. Commun. Algebra 27, 301–319 (1999)
Radjavi, H., Rosenthal, P.: Simultaneous Triangularization Universitext. Springer, New York (2000)
Radjavi, H., Rosenthal, P.: Limitations on the size of semigroups of matrices. Semigroup Forum 76, 25–31 (2008)
Yahaghi, B.R.: On irreducible semigroups of matrices with traces in a subfield. Linear Algebra Appl. 383, 17–28 (2004)
Acknowledgments
L.W. Marcoux was research supported in part by NSERC (Canada). M. Omladič was research supported in part by the Slovenian Research Agency – ARRS (Slovenia).
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Communicated by Anthony Lau.
This paper was submitted while the fifth name author was on sabbatical leave at the University of Waterloo. He would like to thank Department of Pure Mathematics of the University of Waterloo, and in particular L.W. Marcoux and H. Radjavi, for their support.
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Marcoux, L.W., Omladič, M., Popov, A.I. et al. Ranges of vector states on irreducible operator semigroups. Semigroup Forum 93, 264–304 (2016). https://doi.org/10.1007/s00233-015-9772-7
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DOI: https://doi.org/10.1007/s00233-015-9772-7