In a recent paper, a new method was proposed to find the common invariant subspaces of a set of matrices. This paper investigates the more general problem of putting a set of matrices into block triangular or block-diagonal form simultaneously. Based on common invariant subspaces, two algorithms for simultaneous block triangularization and block diagonalization of sets of matrices are presented. As an alternate approach for simultaneous block diagonalization of sets of matrices by an invertible matrix, a new algorithm is developed based on the generalized eigenvectors of a commuting matrix. Moreover, a new characterization for the simultaneous block diagonalization by an invertible matrix is provided. The algorithms are applied to concrete examples using the symbolic manipulation system Maple.
Citation: Ahmad Y. Al-Dweik, Ryad Ghanam, Gerard Thompson, M. T. Mustafa. Algorithms for simultaneous block triangularization and block diagonalization of sets of matrices[J]. AIMS Mathematics, 2023, 8(8): 19757-19772. doi: 10.3934/math.20231007
In a recent paper, a new method was proposed to find the common invariant subspaces of a set of matrices. This paper investigates the more general problem of putting a set of matrices into block triangular or block-diagonal form simultaneously. Based on common invariant subspaces, two algorithms for simultaneous block triangularization and block diagonalization of sets of matrices are presented. As an alternate approach for simultaneous block diagonalization of sets of matrices by an invertible matrix, a new algorithm is developed based on the generalized eigenvectors of a commuting matrix. Moreover, a new characterization for the simultaneous block diagonalization by an invertible matrix is provided. The algorithms are applied to concrete examples using the symbolic manipulation system Maple.
[1] | A. Y. Al-Dweik, R. Ghanam, G. Thompson, H. Azad, A novel procedure for constructing invariant subspaces of a set of matrices, Annali di Matematica, 202 (2022), 77–93. https://doi.org/10.1007/s10231-022-01233-7 doi: 10.1007/s10231-022-01233-7 |
[2] | I. Bischer, C. Döring, A. Trautner, Simultaneous block diagonalization of matrices of finite order, J. Phys. A Math. Theor., 54 (2021), 085203. https://doi.org/10.1088/1751-8121/abd979 doi: 10.1088/1751-8121/abd979 |
[3] | G. Pastuszak, T. Kamizawa, A. Jamiołkowski, On a criterion for simultaneous block-diagonalization of normal matrices, Open Syst. Inf. Dyn., 23 (2016), 1650003. https://doi.org/10.1142/S1230161216500037 doi: 10.1142/S1230161216500037 |
[4] | R. S. Dummit, R. M. Foote, Abstract Algebra, New York: Wiley, 2004. |
[5] | N. Jacobson, Lectures in Abstract Algebra. Vol. II. Linear Algebra, Princeton: Van Nostrand, 1953. |
[6] | C. Dubi, An algorithmic approach to simultaneous triangularization, Linear Algebra Appl., 430 (2009), 2975–2981. https://doi.org/10.1016/j.laa.2008.05.037 doi: 10.1016/j.laa.2008.05.037 |
[7] | H. Specht, Zur theorie der gruppen linearer substitutionen. Ⅱ, Jahresbericht der Deutschen Mathematiker-Vereinigung, 49 (1939), 207–215. |
[8] | H. Shapiro, Simultaneous block triangularization and block diagonalization of sets of matrices, Linear Algebra Appl., 25 (1979), 129–137. https://doi.org/10.1016/0024-3795(79)90012-0 doi: 10.1016/0024-3795(79)90012-0 |
[9] | T. Maehara, K. Murota, Algorithm for error-controlled simultaneous block-diagonalization of matrices, SIAM J. Matrix Anal. Appl., 32 (2011), 605–620. https://doi.org/10.1137/090779966 doi: 10.1137/090779966 |