Abstract:
There are well-known conditions ensuring that a complex n×nn×n matrix AA can be converted by a similarity transformation into a real matrix. Is it possible to realize this conversion via unitary similarity rather than a general one? The following answer to this question is given in this paper: A matrix A∈Mn(C) can be made real by a unitary similarity transformation if and only if A and ¯A are unitarily similar and the matrix P transforming A into ¯A can be chosen unitary and symmetric at the same time. Effective ways for verifying this criterion are discussed.
Citation:
Kh. D. Ikramov, “On Complex Matrices that Are Unitarily Similar to Real Matrices”, Mat. Zametki, 87:6 (2010), 840–847; Math. Notes, 87:6 (2010), 821–827
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\paper On Complex Matrices that Are Unitarily Similar to Real Matrices
\jour Mat. Zametki
\yr 2010
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\pages 840--847
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\jour Math. Notes
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Linking options:
https://www.mathnet.ru/eng/mzm8532
https://doi.org/10.4213/mzm8532
https://www.mathnet.ru/eng/mzm/v87/i6/p840
This publication is cited in the following 9 articles:
Kh. D. Ikramov, “Klassy psevdoperestanovochnosti kompleksnykh matrits i ikh oveschestvlenie”, Sib. zhurn. vychisl. matem., 26:2 (2023), 199–203
Kh. D. Ikramov, “Pseudo-Commutation Classes of Complex Matrices and Their Decomplexification”, Numer. Analys. Appl., 16:2 (2023), 167
Brociek R., Pleszczynski M., Witula R., Lorenc P., “Transformations Preserving Nonsingularity, Trace and Spectrum of Matrices”, Application of Mathematics in Technical and Natural Sciences, AIP Conference Proceedings, 1629, ed. Todorov M., Amer Inst Physics, 2014, 344–348
Kh. D. Ikramov, “Effective Algorithms for Decomplexifying a Matrix by Unitary Similarities or Congruences”, Math. Notes, 92:6 (2012), 767–772
A. K. Abdikalykov, Kh. D. Ikramov, “Simultaneous decomplexification of a pair of complex matrices via a unitary similarity transformation”, J. Math. Sci. (N. Y.), 182:6 (2012), 745–747
Kh. D. Ikramov, “How to distinguish between the latently real matrices and the block quaternions?”, J. Math. Sci. (N. Y.), 182:6 (2012), 779–781
Kh. D. Ikramov, “On latently real matrices and block quaternions”, J. Math. Sci. (N. Y.), 176:1 (2011), 25–28
Kh. D. Ikramov, “Unitary similarity of entrywise conjugate matrices and unitary decomplexification”, J. Math. Sci. (N. Y.), 176:1 (2011), 29–31
Ikramov Kh.D., “Constructive sufficient conditions for the existence of a unitary similarity transformation that converts a given complex matrix into a real one”, Dokl. Math., 82:1 (2010), 563–565