We present an example of linear differential operator in a Hilbert space, which has no eigenfunctions but has, in a certain sense, some generalized eigenfunctions. It is proved that this operator is formally adjoint to Bessel-type differential operators for which the systems of canonical eigenfunctions are over-complete. We also analyze the completeness of the system of generalized eigenfunctions for this differential operator.
Similar content being viewed by others
References
G. N. Watson, A Treatise on the Theory of Bessel Functions, Cambridge Univ. Press, Cambridge, The Macmillan Company, New York (1944).
V. S. Vladimirov, Equations of Mathematical Physics [in Russian], Nauka, Moscow (1981).
A. M. Sedletskii, “Analytic Fourier transforms and exponential approximations. I,” J. Math. Sci. (N.Y.), 129, No. 6, 4251–4408 (2005).
B. Ya. Levin, Distribution of Zeros of Entire Functions, Vol. 5, American Mathematical Society, Providence, RI (1980).
Yu. M. Berezanskii, Expansions in Eigenfunctions of Self-Adjoint Operators, Vol. 17, American Mathematical Society, Providence, RI (1968).
N. Dunford and J. T. Schwartz, Linear Operators. Spectral Operators, Part III, Interscience Publ., New York (1971).
B. M. Levitan, “Expansion in Fourier series and integrals with Bessel functions,” Usp. Mat. Nauk, 6, No. 2(42), 102–143 (1951).
V. A. Marchenko, Sturm–Liouville Operators and Applications, American Mathematical Society, Providence, RI (2011).
M. A. Naimark, Linear Differential Operators, Ungar, New York (1968).
E. C. Titchmarsh, Eigenfunction Expansions Associated with Second Order Differential Equations, Part I, Clarendon Press, Oxford (1946).
F. S. Rofe-Beketov and A. M. Khol’kin, Spectral Analysis of Differential Operators: Interplay Between Spectral and Oscillatory Properties, World Scientific Publ. Co., Hackensack (2005).
H. Hochstadt, “The mean convergence of Fourier–Bessel series,” SIAM Rev., 9, 211–218 (1967).
J. R. Higgins, Completeness and Basis Properties of Sets of Special Functions, Cambridge Univ. Press, Cambridge (1977).
R. Carlson, “A Borg–Levinson theorem for Bessel operators,” Pacific J. Math., 177, No. 1, 1–26 (1997).
M. Reed and B. Simon, Methods of Modern Mathematical Physics, Vol. 2, Academic Press, New (1975).
V. Guillemin, “Spectral theory on S2: Some open questions,” Adv. Math., 42, No. 3, 283–298 (1981).
D. Gurarie, “Zonal Schrödinger operators on the n-sphere: inverse spectral problem and rigidity,” Comm. Math. Phys., 131, 571–603 (1990).
B. V. Vynnyts’kyi and O. V. Shavala, “Some properties of boundary value problems for Bessel’s equation,” Math. Bull. Shevchenko Sci. Soc., 10, 169–172 (2013).
R. V. Khats’, “Generalized eigenvectors of linear operators and biorthogonal systems,” Constr. Math. Anal., 5, No. 2, 60–71 (2022).
A. M. Perelomov, “On the completeness of a system of coherent states,” Teor. Mat. Fiz., 6, No. 2, 213–224 (1971).
A. A. Shkalikov, “Boundary problems for ordinary differential equations with parameter in the boundary conditions,” J. Math. Sci., 33, No. 6, 1311–1342 (1986).
B. V. Vynnyts’kyi and O. V. Shavala, “Boundedness of solutions of a linear differential equation of the second order and one boundary-value problem for the Bessel equation,” Mat. Stud., 30, No. 1, 31–41 (2008).
O. V. Shavala, “On some approximating properties of Bessel functions with index –5=2;” Mat. Stud., 43, No. 2, 180–184 (2015).
O. V. Shavala, “On the completeness of the system of functions generated by the Bessel function,” Bukov. Mat. Zh., 5, No. 3–4, 168–171 (2017).
B. V. Vynnyts’kyi and R. V. Khats’, “Some approximation properties of the systems of Bessel functions of index –3/2;” Mat. Stud., 34, No. 2, 152–159 (2010).
B. V. Vynnyts’kyi and V. M. Dilnyi, “On approximation properties of one trigonometric system,” Russ. Math., 58, No. 11, 10–21 (2014).
B. V. Vynnyts’kyi and R. V. Khats’, “A remark on basis property of systems of Bessel and Mittag–Leffler type functions,” J. Contemp. Math. Anal., 50, No. 6, 300–305 (2015).
B. V. Vynnyts’kyi, R. V. Khats’, and I. B. Sheparovych, “Unconditional bases of systems of Bessel functions,” Eurasian Math. J., 11, No. 4, 76–86 (2020).
B. V. Vynnyts’kyi and R. V. Khats’, “On the completeness and minimality of sets of Bessel functions in weighted L2-spaces,” Eurasian Math. J., 6, No. 1, 123–131 (2015).
B. V. Vynnyts’kyi and R. V. Khats’, “Completeness and minimality of systems of Bessel functions,” Ufa Math. J., 5, No. 2, 131–141 (2013).
B. V. Vynnyts’kyi and R. V. Khats’, “Complete biorthogonal systems of Bessel functions,” Mat. Stud., 48, No. 2, 150–155 (2017).
R. V. Khats’, “On conditions of the completeness of some systems of Bessel functions in the space L2((0; 1)); x2pdx),” Azerb. J. Math., 11, No. 1, 3–10 (2021).
R. V. Khats’, “Completeness conditions of systems of Bessel functions in weighted L2-spaces in terms of entire functions,” Turkish J. Math., 45, No. 2, 890–895 (2021).
R. V. Khats’, “Integral representation of one class of entire functions,” Armen. J. Math., 14, Paper No. 1, 1–9 (2022).
Author information
Authors and Affiliations
Corresponding author
Additional information
Translated from Neliniini Kolyvannya, Vol. 25, No. 2-3, pp. 242–252, April–September, 2022.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Khats’, R.V. Completeness of the System of Generalized Eigenfunctions for a Bessel-Type Differential Operator. J Math Sci 274, 898–911 (2023). https://doi.org/10.1007/s10958-023-06652-2
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10958-023-06652-2