Abstract
We establish the equiconvergence of expansions of an arbitrary function in the class L 2(0, π) in the Fourier series in sines and in the Fourier series in the eigenfunctions of the first boundary value problem for the one-dimensional Schrödinger operator with a nonclassical potential. The equiconvergence is studied in the norm of the Hölder space. The potential is the derivative of a function that belongs to a fractional-order Sobolev space.
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Triebel, H., Interpolation Theory, Function Spaces, Differential Operators, Berlin: Birkhäuser, 1977. Translated under the title Teoriya interpolyatsii, funktsional’nye prostranstva, differentsial’nye operatory, Moscow: Mir, 1980.
Savchuk, A.M. and Shkalikov, A.A., Sturm-Liouville Operators with Distribution Potentials, Tr. Mosk. Mat. Obs., 2003, vol. 64, pp. 159–219.
Savchuk, A.M. and Shkalikov, A.A., Sturm-Liouville Operators with Singular Potentials, Mat. Zametki, 1999, vol. 66, no. 6, pp. 897–912.
Savchuk, A.M. and Shkalikov, A.A., On the Eigenvalues of the Sturm-Liouville Operator with Potentials in Sobolev Spaces, Mat. Zametki, 2006, vol. 80, no. 6, pp. 864–884.
Marchenko, V.A., Operatory Shturma-Liuvillya i ikh prilozheniya (Sturm-Liouville Operators and Their Applications), Kiev: Naukova Dumka, 1977.
Il’in, V.A., Equiconvergence, with the Trigonometric Series, of Expansions in Root Functions of the One-Dimensional Schrödinger Operator with Complex Potential in the Class L 1, Differ. Uravn., 1991, vol. 27, no. 4, pp. 577–597.
Vinokurov, V.A. and Sadovnichii, V.A., Uniform Equiconvergence of a Fourier Series in Eigenfunctions of the First Boundary Value Problem and of a Trigonometric Fourier Series, Dokl. Akad. Nauk, 2001, vol. 380, no. 6, pp. 731–735.
Sadovnichaya, I.V., Equiconvergence of Expansions in Series in Eigenfunctions of Sturm-Liouville Operators with Distribution Potentials, Mat. Sb., 2010, vol. 201, no. 9, pp. 61–76.
Il’in, V.A. and Io, I., Estimation of the Difference of Partial Sums of Expansions Corresponding to Two Arbitrary Nonnegative Self-Adjoint Extensions of Two Sturm-Liouville Operators, Differ. Uravn., 1979, vol. 15, no. 7, pp. 1175–1193.
Rykhlov, V.S., The Rate of Equiconvergence for Differential Operators with Nonzero Coefficient Multiplying the (n − 1)st Derivative, Dokl. Akad. Nauk SSSR, 1984, vol. 279, no. 5, pp. 1053–1056.
Gomilko, A.M. and Radzievskii, G.V., Equiconvergence of Series in Eigenfunctions of Ordinary Functional-Differential Operators, Dokl. Akad. Nauk SSSR, 1991, vol. 316, no. 2, pp. 265–269.
Kurbanov, V.M., Equiconvergence of Biorthogonal Expansions in Root Functions of Differential Operators. I, II, Differ. Uravn., 1999, vol. 35, no. 12, pp. 1597–1609; 2000, vol. 36, no. 3, pp. 319–335.
Lomov, I.S., Convergence of Biorthogonal Expansions of Functions on an Interval for Higher-Order Differential Operators, Differ. Uravn., 2005, vol. 41, no. 5, pp. 632–646.
Lomov, I.S., Dependence of Estimates for the Rate of Local Convergence of Spectral Expansions on the Distance from an Interior Compact Set to the Boundary, Differ. Uravn., 2010, vol. 46, no. 10, pp. 1409–1420.
Sadovnichaya, I.V., On the Rate of Equiconvergence of Expansions in Series in a Trigonometric System and in Eigenfunctions of the Sturm-Liouville Operator with a Distribution Potential, Differ. Uravn., 2008, vol. 44, no. 5, pp. 656–664.
Sadovnichaya, I.V., Equiconvergence Theorems for Sturm-Liouville Operators with Singular Potentials (Rate of Equiconvergence in W θ2 -Norm), Eurasian Math. J., 2010, vol. 1, no. 1, pp. 137–146.
Savchuk, A.M., On Eigenfunctions of the Sturm-Liouville Operator with Potentials in the Sobolev Space, arXiv, 1003.3172, 2010.
Kato, T., Perturbation Theory for Linear Operators, Heidelberg: Springer, 1966. Translated under the title Teoriya vozmushcheniya lineinykh operatorov, Moscow: Mir, 1972.
Savchuk, A.M., Uniform Asymptotic Formulae for Eigenfunctions of Sturm-Liouville Operators with Singular Potentials, arXiv, 0801.1950, 2008.
Samko, S.G., Kilbas, A.A., and Marichev, O.I., Integraly i proizvodnye drobnogo poryadka i nekotorye ikh prilozheniya (Fractional Integrals and Derivatives and Some of Their Applications), Minsk: Nauka i Tekhnika, 1987.
Bari, N.K., Trigonometricheskie ryady (Trigonometric Series), Moscow: Gosudarstv. Izdat. Fiz.-Mat. Lit., 1961.
Hardy, G., Littlewood, J., and Polya, G., Inequalities, Cambridge, 1934. Translated under the title Neravenstva, Moscow, 1948.
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Original Russian Text © I.V. Sadovnichaya, 2012, published in Differentsial’nye Uravneniya, 2012, Vol. 48, No. 5, pp. 674–685.
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Sadovnichaya, I.V. Equiconvergence of expansions in eigenfunctions of Sturm-Liouville operators with distributional potentials in Hölder spaces. Diff Equat 48, 681–692 (2012). https://doi.org/10.1134/S0012266112050060
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DOI: https://doi.org/10.1134/S0012266112050060