We study the solvability of the Sylvester equation AX + YB = C and the operator equation AXD + FYB = C in the general setting of adjointable operators between Hilbert C*-modules. On the basis of the Moore–Penrose inverses of the associated operators, we establish necessary and sufficient conditions for the existence of solutions to these equations and obtain general expressions for the solutions in the solvable cases. We also propose an approach to the investigation of positive solutions for a special case of Lyapunov equation.
Similar content being viewed by others
References
A. A. Boichuk and A. A. Pokutnyi, “Perturbation theory of operator equations in the Fréchet and Hilbert spaces,” Ukr. Math. Zh., 67, No. 9, 1181–1188 (2016); English translation: Ukr. Math. J., 67, No. 9, 1327–1335 (2016).
A. A. Boichuk and A. M. Samoilenko, Generalized Inverse Operators and Fredholm Boundary-Value Problems, 2nd ed., Ser. Inverse and Ill-posed Problems , 59, De Gruyter, Berlin (2016).
H. Braden, “The equations ATX ± XTA = B,” SIAM J. Matrix Anal. Appl., 20, 295–302 (1998).
D. S. Cvetković-Ilić and J. J. Kohila, “Positive and real-positive solutions to the equation axa* = c in C*-algebras,” Lin. Multilin. Alg., 55, 535–543 (2007).
A. Dajić and J. J. Koliha, “Positive solutions to the equations AX = C and XB = D for Hilbert space operators,” J. Math. Anal. Appl., 333, 567–576 (2007).
D. S. Djordjevic, “Explicit solution of the operator equation A*X + X*A = B,” J. Comput. Appl. Math., 200, 701–704 (2007).
G. R. Duan, “The solution to the matrix equation AV +BW = EV J + R,” Appl. Math. Lett., 17, 1197–1202 (2004).
G. R. Duan and R. J. Patton, “Robust fault detection using Luenberger-type unknown input observers—a parametric approach,” Int. J. Syst. Sci., 32, No. 4, 533–540 (2001).
X. Fang and J. Yu, “Solutions to operator equations on Hilbert C*-modules, II,” Integr. Equat. Operat. Theory, 68, 23–60 (2010).
R. E. Harte and M. Mbekhta, “On generalized inverses in C*-algebras,” Studia Math., 103, 71–77 (1992).
C. G. Khatri and S. K. Mitra, “Hermitian and nonnegative definite solutions of linear matrix equations,” SIAM J. Appl. Math., 31, 579–585 (1976).
P. Kirrinnis, “Fast algorithms for the Sylvester equation AX − XBT = C,” Theor. Comput. Sci., 259, 623–638 (2001).
E. C. Lance, “Hilbert C*-modules. A toolkit for operator algebraists,” London Math. Soc. Lecture Note Ser., 210, Cambridge Univ. Press, Cambridge (1995).
M. Mohammadzadeh Karizaki, M. Hassani, M. Amyari, and M. Khosravi, “Operator matrix of Moore–Penrose inverse operators on Hilbert C*-modules,” Colloq. Math., 140, 171–182 (2015).
M. Mohammadzadeh Karizaki, M. Hassani, and S. S. Dragomir, “Explicit solution to modular operator equation TXS*−SX*T*=A,” Kragujevac J. Math., 40, No. 2, 280–289 (2016).
T. Mor, N. Fukuma, and M. Kuwahara, “Explicit solution and eigenvalue bounds in the Lyapunov matrix equation,” IEEE Trans. Automat. Control, 31, 656–658 (1986).
Z. Mousavi, R. Eskandari, M. S. Moslehian, and F. Mirzapour, “Operator equations AX + YB = C and AX A* + BY B* = C in Hilbert C*-modules,” Lin. Algebra Appl., 517, 85–98 (2017).
F. Piao, Q. Zhanga, and Z. Wang, “The solution to matrix equation AX + XTC = B,” J. Franklin Inst., 344, 1056–1062 (2007).
M. Wang, X. Cheng, and M. Wei, “Iterative algorithms for solving the matrix equation AXB +CXTD = E,” Appl. Math. Comput., 187, No. 2, 622–629 (2007).
Q. Xu, “Common Hermitian and positive solutions to the adjointable operator equations AX = C, XB = D,” Lin. Algebra Appl., 429, 1–11 (2008).
Q. Xu and L. Sheng, “Positive semi-definite matrices of adjointable operators on Hilbert C*-modules,” Lin. Algebra Appl., 428, 992–1000 (2008).
Q. Xu, L. Sheng, and Y. Gu, “The solutions to some operator equations,” Lin. Algebra Appl., 429, 1997–2024 (2008).
X. Zhang, “Hermitian nonnegative-definite and positive-definite solutions of the matrix equation AXB = C,” Appl. Math. E-Notes, 4, 40–47 (2004).
B. Zhou and G. R. Duan, “An explicit solution to the matrix equation AX − XF = BY,” Lin. Algebra Appl., 402, 345–366 (2005).
Author information
Authors and Affiliations
Corresponding author
Additional information
Published in Ukrains’kyi Matematychnyi Zhurnal, Vol. 73, No. 3, pp. 354–369, March, 2021. Ukrainian DOI: 10.37863/umzh.v73i3.152.
Rights and permissions
About this article
Cite this article
Moghani, Z.N., Karizaki, M.M. & Khanehgir, M. Solutions of the Sylvester Equation in C*-Modular Operators. Ukr Math J 73, 414–432 (2021). https://doi.org/10.1007/s11253-021-01933-y
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11253-021-01933-y