Abstract
It is shown that the unitary similarity of two matrix algebras generated by pairs of orthoprojectors { P1, Q1} and {P2,Q2} can be verified by comparing the traces of P1, Q1, and (P1Q1)i, i = 1, 2, …, n, with those of P2, Q2, and (P2Q2)i. The conditions of the unitary similarity of two matrices with quadratic minimal polynomials presented in [A. George and Kh. D. Ikramov, Unitary similarity of matrices with quadratic minimal polynomials, Linear Algebra Appl., 349, 11–16 (2002)] are refined. Bibliography: 10 titles.
Similar content being viewed by others
References
W. Specht, “Zur Theorie der Matrizen. II,” Jahresber. Deutsch. Math.-Verein., 50, 19–23 (1940).
C. A. Pearcy, “A complete set of unitary invariants for operators generating finite W*-algebras of type I,” Pacific J. Math., 12, 1405–1416 (1962).
R. A. Horn and C. R. Johnson, Matrix Analysis, Cambridge University Press (1985).
C. Pappacena, “An upper bound for the length of a finite-dimensional algebra,” J. Algebra, 197, 535–545 (1997).
Yu. A. Al’pin and Kh. D. Ikramov, “On the unitary similarity of matrix families,” Matem. Zametki, 74, 772–782 (2003).
F. T. Gaines, T. J. Laffey, and H. M. Shapiro, “Pairs of matrices with quadratic minimal polynomials,” Linear Algebra Appl., 52/53, 289–292 (1983).
A. George and Kh. D. Ikramov, “Unitary similarity of matrices with quadratic minimal polynomials, ” Linear Algebra Appl., 349, 11–16 (2002).
D. Z. Djoković, “Unitary similarity of projectors,” Aeq. Math., 42, 220–224 (1991).
Kh. D. Ikramov, “The canonical Schur form of a unitarily quasidiagonalizable matrix,” Comput. Math. Math. Phys., 37, 1367–1371 (1997).
A. George and Kh. D. Ikramov, “A note on the canonical form of a pair of orthoprojectors,” Zap. Nauchn. Semin. POMI, 309, 17–22 (2003).
Author information
Authors and Affiliations
Additional information
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 323, 2005, pp. 5–14.
Rights and permissions
About this article
Cite this article
Al’pin, Y.A., Ikramov, K.D. Unitary similarity of algebras generated by pairs of orthoprojectors. J Math Sci 137, 4763–4768 (2006). https://doi.org/10.1007/s10958-006-0272-x
Received:
Issue Date:
DOI: https://doi.org/10.1007/s10958-006-0272-x