Abstract
We consider a Dirac type operator with matrix coefficients. Estimates for the root vector functions are established, and criteria for the Bessel property and the unconditional basis property of the root vector function systems of this operator in the space \(L_{2}^{2m}(G) \), where \(G=(a,b)\subset \mathbb {R} \) is a finite interval, are obtained.
REFERENCES
Il’in, V.A., On the unconditional basis property on a closed interval for systems of eigenfunctions and associated functions of a second-order differential operator, Dokl. Akad. Nauk SSSR, 1983, vol. 273, no. 5, pp. 1048–1053.
Il’in, V.A., Necessary and sufficient conditions for basis property and equiconvergence with the trigonometric series of spectral expansions. I, Differ. Uravn., 1980, vol. 16, no. 5, pp. 771–794.
Budaev, V.D., Criteria for Bessel and Riesz basis properties of the systems of root functions of differential operators. I, Differ. Equations, 1991, vol. 27, no. 12, pp. 2033–2044.
Lomov, I.S., Estimates for eigenfunctions and associated functions of ordinary differential operators, Differ. Uravn., 1985, vol. 21, no. 5, pp. 903–906.
Kerimov, N.B., Some properties of eigenfunctions and associated functions of ordinary differential operators, Dokl. Akad. Nauk SSSR, 1986, vol. 201, no. 5, pp. 1054–1056.
Kurbanov, V.M., On the distribution of eigenvalues and the Bessel criterion for root functions of a differential operator. I, Differ. Equations, 2005, vol. 41, no. 4, pp. 489–505.
Kritskov, L.V., Uniform estimate of the order of associated functions and distribution of eigenvalues of the one-dimensional Schrödinger operator, Differ. Equations, 1989, vol. 25, no. 7, pp. 784–791.
Tikhomirov, V.V., Sharp estimates for regular solutions of the one-dimensional Schrödinger equation with a spectral parameter, Dokl. Akad. Nauk SSSR, 1983, vol. 273, no. 4, pp. 807–810.
Budaev, V.D., Criteria for Bessel and Riesz basis properties for the systems of root functions of differential operators. II, Differ. Equations, 1992, vol. 28, no. 1, pp. 21–30.
Lomov, I.S., Bessel’s inequality, Riesz theorem, and unconditional basis property for the root vectors of ordinary differential operators, Vestn. Mosk. Univ. Ser. 1. Mat. Mekh., 1992, no. 5, pp. 42–52.
Kerimov, N.B., On the unconditional basis property of the system of eigenfunctions and associated functions of a fourth-order differential operator, Dokl. Akad. Nauk SSSR, 1986, vol. 286, no. 4, pp. 803–806.
Kurbanov, V.M., On the eigenvalue distribution and a Bessel property criterion for root functions of a differential operator: II, Differ. Equations, 2005, vol. 41, no. 5, pp. 649–659.
Kritskov, L.V. and Sarsenbi, A.M., Basicity in \(L_p \) of root functions for differential equations with involution, Electron. J. Differ. Equat., 2015, vol. 278, pp. 1–9.
Kurbanov, V.M., On the Bessel property and unconditional basis property of the systems of root vector functions of the Dirac operator, Differ. Equations, 1996, vol. 32, no. 12, pp. 1601–1610.
Kurbanov, V.M. and Gadzhieva, G.R., Bessel inequality and the basis property for a \( 2m\times 2m\) Dirac type system with an integrable potential, Differ. Equations, 2020, vol. 56, no. 5, pp. 573–584.
Kurbanov, V.M. and Ismailova, A.I., Componentwise uniform equiconvergence of expansions in root vector functions of the Dirac operator with the trigonometric expansion, Differ. Equations, 2012, vol. 48, no. 5, pp. 655–669.
Kurbanov, V.M. and Ismailova, A.I., Absolute and uniform convergence of expansions in root vector functions of the Dirac operator, Dokl. Ross. Akad. Nauk, 2012, vol. 446, no. 4, pp. 380–383.
Kurbanov, V.M. and Ismailova, A.I., Riesz inequality for systems of root vector functions of the Dirac operator, Differ. Equations, 2012, vol. 48, no. 3, pp. 336–342.
Kurbanov, V.M. and Ismailova, A.I., Two-sided estimates for root vector functions of the Dirac operator, Differ. Equations, 2012, vol. 48, no. 4, pp. 494–505.
Kurbanov, V.M. and Abdullayeva, A.M., Bessel property and basicity of the system of root vector-functions of Dirac operator with summable coefficient, Oper. Matrices, 2018, vol. 12, no. 4, pp. 943–954.
Oridoroga, L.L. and Hassi, S., Completeness and Riesz basis property of systems of eigenfunctions and associated functions of Dirac-type operators with boundary conditions depending on the spectral parameter, Math. Notes, 2006, vol. 79, no. 4, pp. 589–593.
Lunev, A.A. and Malamud, M.M., On the basis property of the system of Riesz root vectors for a \(2\times 2\) Dirac type system, Dokl. Ross. Akad. Nauk, 2014, vol. 458, no. 3, pp. 255–260.
Lunyov, A.A. and Malamud, M.M., On the Riesz basis property of the root vector system for Dirac-type systems, J. Math. Anal. Appl., 2016, vol. 441, no. 1, pp. 57–103.
Lunyov, A.A. and Malamud, M.M., On the completeness and Riesz basis property of root supspaces of boundary value problems for first order systems and applications, J. Spectr. Theory, 2015, vol. 5, pp. 17–70.
Lunev, A.A. and Malamud, M.M., On the characteristic determinants of boundary value problems for a Dirac type system, Zap. Nauchn. Semin. POMI, 2022, vol. 516, pp. 69–120.
Savchuk, A.M. and Shkalikov, A.A., The Dirac operator with complex-valued summable potential, Math. Notes, 2014, vol. 96, no. 5, pp. 777–810.
Savchuk, A.M. and Sadovnichaya, I.V., The Riesz basis property with brackets for Dirac systems with summable potentials, J. Math. Sci., 2018, vol. 233, no. 4, pp. 514–540.
Trooshin, I. and Yamamota, M., Riesz basis of root vector of a nonsymmetric system of first-order ordinary differential operators and application to inverse eigenvalue problems, Appl. Anal., 2001, vol. 80, no. 1–2, pp. 19–51.
Djakov, P. and Mityagin, B., Criteria for existence of Riesz basis consisting of root functions of Hill and 1D Dirac operators, J. Func. Anal., 2012, vol. 263, pp. 2300–2332.
Djakov, P. and Mityagin, B., Unconditional convergence of spectral decompositions of 1D Dirac operators with regular boundary conditions, Indiana Univ. Math. J., 2012, vol. 61, no. 1, pp. 359–398.
Mykytnyk, Ya.V. and Puyda, D.V., Bari–Markus property of Dirac operators, Mat. Stud., 2013, vol. 40, no. 2, pp. 165–171.
ACKNOWLEDGMENTS
The author expresses deep gratitude to Prof. V.M. Kurbanov for his constant attention to the work.
Author information
Authors and Affiliations
Corresponding author
Additional information
Translated by V. Potapchouck
Rights and permissions
About this article
Cite this article
Ibadov, E.C. On the Properties of the Root Vector Function Systems of a \(2m \)th-Order Dirac Type Operator with an Integrable Potential. Diff Equat 59, 1295–1314 (2023). https://doi.org/10.1134/S00122661230100014
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S00122661230100014