On \(A\)-orthogonally diagonalizable operators on semi-inner product spaces
Authors
R. Respitawulan
- Algebra Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi, Bandung, Indonesia.
F. Yuliawan
- Algebra Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi, Bandung, Indonesia.
H. Garminia
- Algebra Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi, Bandung, Indonesia.
P. Astuti
- Algebra Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi, Bandung, Indonesia.
Abstract
In finite dimensional inner product (IP) spaces, any self-adjoint operator is normal and any normal operator is orthogonally diagonalizable. However, in semi-inner product (SIP) spaces, there exists an \(A\)-self-adjoint operator which is not \(A\)-normal. Therefore, it is interesting to study conditions for an \(A\)-self-adjoint operator on an SIP space to be \(A\)-orthogonally diagonalizable. An SIP is a mapping induced by a positive semi-definite operator on an IP space. In this paper, we study necessary, sufficient, and necessary and sufficient conditions for an \(A\)-self-adjoint operator to be \(A\)-orthogonally diagonalizable.
Share and Cite
ISRP Style
R. Respitawulan, F. Yuliawan, H. Garminia, P. Astuti, On \(A\)-orthogonally diagonalizable operators on semi-inner product spaces, Journal of Mathematics and Computer Science, 36 (2025), no. 3, 290--298
AMA Style
Respitawulan R. , Yuliawan F., Garminia H., Astuti P., On \(A\)-orthogonally diagonalizable operators on semi-inner product spaces. J Math Comput SCI-JM. (2025); 36(3):290--298
Chicago/Turabian Style
Respitawulan, R. , Yuliawan, F., Garminia, H., Astuti, P.. "On \(A\)-orthogonally diagonalizable operators on semi-inner product spaces." Journal of Mathematics and Computer Science, 36, no. 3 (2025): 290--298
Keywords
- Semi-inner product spaces
- spectral decomposition
- \(A\)-self-adjoint operators
MSC
References
-
[1]
O. A. M. S. Ahmed, A. Benali, Hyponormal and k-quasi-hyponormal operators on semi-Hilbertian spaces, Aust. J. Math. Anal. Appl., 13 (2016), 22 pages
-
[2]
O. A. M. S. Ahmed, A. Saddi, A-m-isometric operators in semi-Hilbertian spaces, Linear Algebra Appl., 436 (2012), 3930–3942
-
[3]
M. L. Arias, G. Corach, M. C. Gonzalez, Partial isometries in semi-Hilbertian spaces, Linear Algebra Appl., 428 (2008), 1460–1475
-
[4]
M. L. Arias, G. Corach, M. C. Gonzalez, Metric properties of projections in semi-Hilbertian spaces, Integral Equations Operator Theory, 62 (2008), 11–28
-
[5]
H. Baklouti, S. Namouri, Closed operators in semi-Hilbertian spaces, Linear Multilinear Algebra, 70 (2022), 5847–5858
-
[6]
A. Benali, A. O. M. S. Ahmed, (, )-A-normal operators in semi-Hilbertian spaces, Afr. Mat., 30 (2019), 903–920
-
[7]
V. A. Bovdi, T. Klymchuk, T. Rybalkina, M. A. Salima, V. V. Sergeichuk, Operators on positive semidefinite inner product spaces, Linear Algebra Appl., 596 (2020), 82–105
-
[8]
J. R. Giles, Classes of semi-inner-product spaces, Trans. Amer. Math. Soc., 129 (1967), 436–446
-
[9]
N. Johnston, Advanced Linear and Matrix Algebra, Springer, Cham (2021)
-
[10]
F. Kittaneh, A. Zamani, A refinement of A-Buzano inequality and applications to A-numerical radius inequalities, Linear Algebra Appl., 697 (2024), 32–48
-
[11]
M. G. Krein, Compact linear operators on functional spaces with two norms, Integral Equations Operator Theory, 30 (1998), 140–162
-
[12]
G. Lumer, Semi-inner-product spaces, Trans. Amer. Math. Soc., 100 (1961), 29–43
-
[13]
S. A. O. A. Mahmoud, R. M. Alsharar, A. M. A. Al-Ahmadii, m-quasi-(n,A)-paranormal operators in semi-Hilbertian spaces, Bull. Math. Anal. Appl., 15 (2023), 69–82
-
[14]
R. Respitawulan, Q. Y. Pangestu, E. Kusniyanti, F. Yuliawan, P. Astuti, On the adjoint of bounded operators on a semi-inner product space, J. Indones. Math. Soc., 29 (2023), 311–321
-
[15]
S. Roman, Advanced linear algebra, Springer-Verlag, New York (1992)
-
[16]
A. Saddi, A-normal operators in semi Hilbertian spaces, Aust. J. Math. Anal. Appl., 9 (2012), 12 pages
-
[17]
A. Saddi, F. Mahmoudi, (A,m)-partial isometries in semi-Hilbertian spaces, Linear Multilinear Algebra, 71 (2023), 1640–1656
-
[18]
J. Sen, D. Sain, K. Paul, Orthogonality and norm attainment of operators in semi-Hilbertian spaces, Ann. Funct. Anal., 12 (2021), 12 pages
-
[19]
T.-Y. Tam, P. Zhang, Spectral decomposition of selfadjoint matrices in positive semidefinite inner product spaces and its applications, Linear Multilinear Algebra, 67 (2019), 1829–1838
-
[20]
A. C. Zaanen, Normalisable transformations in Hilbert space and systems of linear integral equations, Acta Math., 83 (1950), 197–248
-
[21]
A. Zamani, Birkhoff-James orthogonality of operators in semi-Hilbertian spaces and its applications, Ann. Funct. Anal., 10 (2019), 433–445