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<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">kaz29</journal-id><journal-title-group><journal-title xml:lang="ru">Вестник Казахстанско-Британского технического университета</journal-title><trans-title-group xml:lang="en"><trans-title>Herald of the Kazakh-British Technical University</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">1998-6688</issn><issn pub-type="epub">2959-8109</issn><publisher><publisher-name>Казахстанско-Британский Технический Университет</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.55452/1998-6688-2025-22-2-155-164</article-id><article-id custom-type="elpub" pub-id-type="custom">kaz29-1996</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>МАТЕМАТИЧЕСКИЕ НАУКИ</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>MATHEMATICAL SCIENCES</subject></subj-group></article-categories><title-group><article-title>О НЕКОТОРЫХ СПЕКТРАЛЬНЫХ ЗАДАЧАХ ДЛЯ НЕЛОКАЛЬНОГО АНАЛОГА БИГАРМОНИЧЕСКОГО ОПЕРАТОРА</article-title><trans-title-group xml:lang="en"><trans-title>ON SOME SPECTRAL PROBLEMS FOR THE NONLOCAL ANALOGUE OF THE BIHARMONIC OPERATOR</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-1377-4633</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Кошанова</surname><given-names>М. Д.</given-names></name><name name-style="western" xml:lang="en"><surname>Koshanova</surname><given-names>M. D.</given-names></name></name-alternatives><bio xml:lang="ru"><p> к.т.н., доцент </p><p> г. Туркестан </p></bio><bio xml:lang="en"><p> Cand. Tech. Sc., Associate Professor </p><p> Turkistan </p></bio><email xlink:type="simple">maira.koshanova@ayu.edu.kz</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Муратбекова</surname><given-names>М. А.</given-names></name><name name-style="western" xml:lang="en"><surname>Muratbekova</surname><given-names>M. A.</given-names></name></name-alternatives><bio xml:lang="ru"><p> PhD, доцент и.о. </p><p> г. Туркестан </p></bio><bio xml:lang="en"><p> PhD, a.d </p><p> Turkistan </p></bio><email xlink:type="simple">moldir.muratbekova@ayu.edu.kz</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-7735-6484</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Турметов</surname><given-names>Б. Х.</given-names></name><name name-style="western" xml:lang="en"><surname>Turmetov</surname><given-names>B. H.</given-names></name></name-alternatives><bio xml:lang="ru"><p> д.ф.-м.н., профессор </p><p>г. Туркестан</p><p>г. Ташкент</p></bio><bio xml:lang="en"><p> d.f.-m.s., professor </p><p> Turkistan </p><p> Tashkent </p></bio><email xlink:type="simple">batirkhan.turmetov@ayu.edu.kz</email><xref ref-type="aff" rid="aff-2"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru">Международный казахско-турецкий университет А. Ясави<country>Казахстан</country></aff><aff xml:lang="en">Khoja Akhmet Yassawi International Kazakh-Turkish University<country>Kazakhstan</country></aff></aff-alternatives><aff-alternatives id="aff-2"><aff xml:lang="ru">Международный казахско-турецкий университет А. Ясави;&#13;
Университет Альфраганус<country>Казахстан</country></aff><aff xml:lang="en">Khoja Akhmet Yassawi International Kazakh-Turkish University;&#13;
Alfraganus University<country>Kazakhstan</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2025</year></pub-date><pub-date pub-type="epub"><day>06</day><month>07</month><year>2025</year></pub-date><volume>22</volume><issue>2</issue><fpage>155</fpage><lpage>164</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Кошанова М.Д., Муратбекова М.А., Турметов Б.Х., 2025</copyright-statement><copyright-year>2025</copyright-year><copyright-holder xml:lang="ru">Кошанова М.Д., Муратбекова М.А., Турметов Б.Х.</copyright-holder><copyright-holder xml:lang="en">Koshanova M.D., Muratbekova M.A., Turmetov B.H.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://vestnik.kbtu.edu.kz/jour/article/view/1996">https://vestnik.kbtu.edu.kz/jour/article/view/1996</self-uri><abstract><p>Известно, что система собственных функций классического бигармонического оператора с краевым условием Дирихле является полной и ортонормированной в пространстве . Соответствующие этим собственным функциям собственные значения являются положительными, и их можно пронумеровать в порядке возрастания. В некоторых случаях аналогичными свойствами обладают собственные функции и собственные значения краевых задач для возмущенного бигармонического оператора. В данной работе при помощи ортогональных матриц вводится нелокальный аналог возмущенного бигармонического оператора. Для данного оператора исследуются спектральные вопросы двух краевых задач. В первой задаче рассматриваются краевые условия Дирихле, во второй – условия типа Дирихле. При исследовании первой задачи мы используем полноту системы собственных функций задачи Дирихле для возмущенного бигармонического оператора. Используя свойства данных систем, а также свойства отображений с ортогональными матрицами, находим собственные функции и собственные значения основной задачи. Во второй задаче используем собственные функции и собственные значения задачи Дирихле для оператора Лапласа. При использовании явного вида, а также свойств этих систем строятся собственные функции и собственные значения второй задачи. Доказаны теоремы о полноте систем собственных функций, рассматриваемых задач в пространстве L2.</p></abstract><trans-abstract xml:lang="en"><p>It is known that the system of eigenfunctions of the classical biharmonic operator with the Dirichlet boundary condition is complete and orthonormal in space. The eigenvalues corresponding to these eigenfunctions are positive and can be numbered in ascending order. In some cases, eigenfunctions and eigenvalues of boundary value problems for a perturbed biharmonic operator have similar properties. In this work, a nonlocal analogue of the perturbed biharmonic operator is introduced using orthogonal matrices. Spectral problems of two boundary value problems are studied for this operator. Dirichlet boundary conditions are considered in the first problem, and Dirichlet-type conditions in the second. When studying the first problem, we use the complete system of eigenfunctions of the Dirichlet problem for the perturbed biharmonic operator. Using the properties of these systems, as well as the properties of the image with orthogonal matrices, we find the eigenfunctions and eigenvalues of the main problem. In the second task, we use the eigenfunctions and eigenvalues of the Dirichlet problem for the Laplace operator. Using the explicit form, as well as the properties of these systems, we construct the eigenfunctions and eigenvalues of the second task. The proof of the theorem on the completeness of the system of eigenfunctions of the considered tasks in space is provided.</p></trans-abstract><kwd-group xml:lang="ru"><kwd>ортогональная матрица</kwd><kwd>нелокальный бигармонический оператор</kwd><kwd>задача Дирихле</kwd><kwd>задача типа Дирихле</kwd><kwd>собственные значения</kwd><kwd>собственные функции</kwd><kwd>полнота системы</kwd></kwd-group><kwd-group xml:lang="en"><kwd>Orthogonal matrix</kwd><kwd>nonlocal biharmonic operator</kwd><kwd>Dirichlet problem</kwd><kwd>Dirichlet-type problem</kwd><kwd>eigenvalues</kwd><kwd>eigenfunctions</kwd><kwd>system completeness</kwd></kwd-group><funding-group xml:lang="ru"><funding-statement>Бұл жұмыс Қазақстан Республикасы Ғылым және жоғары білім министрлігінің Ғылым комитетінің гранты аясында (грант № AP19677926) қаржыландырылды.</funding-statement></funding-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Kirane M., Sadybekov M.A., Sarsenbi A.A. On an inverse problem of reconstructing a subdiffusion process from nonlocal data // Mathematical Methods in the Applied Sciences. – 2019. – Vol. 42. – No. 6. – P. 2043–2052. https://doi.org/10.1002/mma.5498.</mixed-citation><mixed-citation xml:lang="en">Kirane M., Sadybekov M.A., Sarsenbi A.A. On an inverse problem of reconstructing a subdiffusion process from nonlocal data // Mathematical Methods in the Applied Sciences. – 2019. – Vol. 42. – No. 6. – P. 2043–2052. https://doi.org/10.1002/mma.5498.</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Torebek B.T, Tapdigoglu R. Some inverse problems for the nonlocal heat equation with Caputo fractional derivative // Mathematical Methods in the Applied Sciences. – 2017. – Vol. 40. – No. 18. – P. 6468–6479. https://doi.org/10.1002/mma.4468.</mixed-citation><mixed-citation xml:lang="en">Torebek B.T, Tapdigoglu R. Some inverse problems for the nonlocal heat equation with Caputo fractional derivative // Mathematical Methods in the Applied Sciences. – 2017. – Vol. 40. – No. 18. – P. 6468–6479. https://doi.org/10.1002/mma.4468.</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Kornuta A.A., Lukianenko V.A. Stable structures of nonlinear parabolic equations with transformation of spatial variables // Lobachevskii Journal of Mathematics. – 2021. – Vol. 42. – No. 5. – P. 911–930. https://doi.org/10.1134/S1995080221050073.</mixed-citation><mixed-citation xml:lang="en">Kornuta A.A., Lukianenko V.A. Stable structures of nonlinear parabolic equations with transformation of spatial variables // Lobachevskii Journal of Mathematics. – 2021. – Vol. 42. – No. 5. – P. 911–930. https://doi.org/10.1134/S1995080221050073.</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">Kornuta A. A., Lukianenko V. A. Nonlinear optics problem with transformation of a spatial variable and an oblique derivative // Contemporary Mathematics. Fundamental Directions. – 2023. – Vol. 69. – No. 2. – P. 276–288. https://doi.org/10.22363/2413-3639-2023-69-2-276-288.</mixed-citation><mixed-citation xml:lang="en">Kornuta A. A., Lukianenko V. A. Nonlinear optics problem with transformation of a spatial variable and an oblique derivative // Contemporary Mathematics. Fundamental Directions. – 2023. – Vol. 69. – No. 2. – P. 276–288. https://doi.org/10.22363/2413-3639-2023-69-2-276-288.</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">Baskakov A.G., Krishtal I.A., Uskova N.B. On the spectral analysis of a differential operator with an involution and general boundary conditions // Eurasian Mathematical Journal. – 2020. – Vol. 11. – No. 2. – P. 30–39. https://doi.org/10.32523/2077-9879-2020-11-2-30-39.</mixed-citation><mixed-citation xml:lang="en">Baskakov A.G., Krishtal I.A., Uskova N.B. On the spectral analysis of a differential operator with an involution and general boundary conditions // Eurasian Mathematical Journal. – 2020. – Vol. 11. – No. 2. – P. 30–39. https://doi.org/10.32523/2077-9879-2020-11-2-30-39.</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Bondarenko N.P. Inverse spectral problems for functional-differential operators with involution // Journal of Differential Equations. – 2022. – Vol. 318. – No. 5. – P. 169–186. https: //doi.org/10.1016/j.jde.2022.02.027.</mixed-citation><mixed-citation xml:lang="en">Bondarenko N.P. Inverse spectral problems for functional-differential operators with involution // Journal of Differential Equations. – 2022. – Vol. 318. – No. 5. – P. 169–186. https: //doi.org/10.1016/j.jde.2022.02.027.</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Granilshchikova Y.A., Shkalikov A.A. Spectral Properties of a Differential Operator with Involution // Moscow Univ. Math. Bull. – 2022. – Vol.77. – No .4. – P. 204–208. https://doi.org/10.3103/S0027132222040040.</mixed-citation><mixed-citation xml:lang="en">Granilshchikova Y.A., Shkalikov A.A. Spectral Properties of a Differential Operator with Involution // Moscow Univ. Math. Bull. – 2022. – Vol.77. – No .4. – P. 204–208. https://doi.org/10.3103/S0027132222040040.</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Kritskov L.V., Ioffe V.L. Spectral Properties of the Cauchy Problem for a Second-Order Operator with Involution//Differential Equations. – 2021. – Vol. 57. –No. 2. – P. 1–10. https: //doi.org/10.1134/S0012266121010018.</mixed-citation><mixed-citation xml:lang="en">Kritskov L.V., Ioffe V.L. Spectral Properties of the Cauchy Problem for a Second-Order Operator with Involution//Differential Equations. – 2021. – Vol. 57. –No. 2. – P. 1–10. https: //doi.org/10.1134/S0012266121010018.</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Kritskov L., Sadybekov M., Sarsenbi A. Properties in pL of root functions for a nonlocal problem with involution // Turkish Journal of Mathematics. – 2019. – Vol. 43. – No. 1. – P. 393– 401. https://doi.org/10.3906/mat-1809-12.</mixed-citation><mixed-citation xml:lang="en">Kritskov L., Sadybekov M., Sarsenbi A. Properties in pL of root functions for a nonlocal problem with involution // Turkish Journal of Mathematics. – 2019. – Vol. 43. – No. 1. – P. 393– 401. https://doi.org/10.3906/mat-1809-12.</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Sarsenbi A.A., Sarsenbi A.M. On eigenfunctions of the boundary value problems for second order differential equations with involution//Symmetry. – 2021. – Vol. 13. – No. 1972. – P. 1–9. https://doi.org/10.3390/sym13101972.</mixed-citation><mixed-citation xml:lang="en">Sarsenbi A.A., Sarsenbi A.M. On eigenfunctions of the boundary value problems for second order differential equations with involution//Symmetry. – 2021. – Vol. 13. – No. 1972. – P. 1–9. https://doi.org/10.3390/sym13101972.</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">Sarsenbi A.A., Sarsenbi A.M. Boundary value problems for a second-order differential equation with involution in the second derivative and their solvability // AIMS Mathematics. – 2023. – Vol. 8. – No. 11. – P. 26275–26289. https://doi.org/10.3934/math.20231340.</mixed-citation><mixed-citation xml:lang="en">Sarsenbi A.A., Sarsenbi A.M. Boundary value problems for a second-order differential equation with involution in the second derivative and their solvability // AIMS Mathematics. – 2023. – Vol. 8. – No. 11. – P. 26275–26289. https://doi.org/10.3934/math.20231340.</mixed-citation></citation-alternatives></ref><ref id="cit12"><label>12</label><citation-alternatives><mixed-citation xml:lang="ru">Vladykina V.E., Shkalikov A.A. Regular Ordinary Differential Operators with Involution//Math Notes. – 2019. – Vol. 106. – P. 674–687. https://doi.org/10.1134/S0001434619110026.</mixed-citation><mixed-citation xml:lang="en">Vladykina V.E., Shkalikov A.A. Regular Ordinary Differential Operators with Involution//Math Notes. – 2019. – Vol. 106. – P. 674–687. https://doi.org/10.1134/S0001434619110026.</mixed-citation></citation-alternatives></ref><ref id="cit13"><label>13</label><citation-alternatives><mixed-citation xml:lang="ru">Kirane M., Sarsenbi A.A. Solvability of Mixed Problems for a Fourth-Order Equation with Involution and Fractional Derivative//Fractal and Fractional. – 2023. – Vol. 7. – No. 131. – P. 1–12. https://doi.org/10.3390/fractalfract7020131.</mixed-citation><mixed-citation xml:lang="en">Kirane M., Sarsenbi A.A. Solvability of Mixed Problems for a Fourth-Order Equation with Involution and Fractional Derivative//Fractal and Fractional. – 2023. – Vol. 7. – No. 131. – P. 1–12. https://doi.org/10.3390/fractalfract7020131.</mixed-citation></citation-alternatives></ref><ref id="cit14"><label>14</label><citation-alternatives><mixed-citation xml:lang="ru">Polyakov D.M. On the Bari basis property for even-orderdifferential operators with involution//Tamkang journal of mathematics. – 2023. – Vol. 54. – No. 4. – P. 339 – 351. http://dx.doi.org/10.5556/j.tkjm.54.2023.4899.</mixed-citation><mixed-citation xml:lang="en">Polyakov D.M. On the Bari basis property for even-orderdifferential operators with involution//Tamkang journal of mathematics. – 2023. – Vol. 54. – No. 4. – P. 339 – 351. http://dx.doi.org/10.5556/j.tkjm.54.2023.4899.</mixed-citation></citation-alternatives></ref><ref id="cit15"><label>15</label><citation-alternatives><mixed-citation xml:lang="ru">Turmetov B. Kh., Karachik V.V. Solvability of nonlocal Dirichlet problem for generalized Helmholtz equation in a unit ball // Complex Variables and Elliptic Equations. – 2023. – Vol. 68. – No. 7. – P. 1204–1218. https://doi.org/10.1080/17476933.2022.2040021.</mixed-citation><mixed-citation xml:lang="en">Turmetov B. Kh., Karachik V.V. Solvability of nonlocal Dirichlet problem for generalized Helmholtz equation in a unit ball // Complex Variables and Elliptic Equations. – 2023. – Vol. 68. – No. 7. – P. 1204–1218. https://doi.org/10.1080/17476933.2022.2040021.</mixed-citation></citation-alternatives></ref><ref id="cit16"><label>16</label><citation-alternatives><mixed-citation xml:lang="ru">Turmetov B., Karacik V.V. On eigenfunctions and eigenvalues of a nonlocal Laplace operator with involution in a parallelepiped // AIP Conference Proceedings. – 2023. – Vol. 2879. – No. 1. – P. 1–4. https://doi.org/10.1063/5.0175246.</mixed-citation><mixed-citation xml:lang="en">Turmetov B., Karacik V.V. On eigenfunctions and eigenvalues of a nonlocal Laplace operator with involution in a parallelepiped // AIP Conference Proceedings. – 2023. – Vol. 2879. – No. 1. – P. 1–4. https://doi.org/10.1063/5.0175246.</mixed-citation></citation-alternatives></ref><ref id="cit17"><label>17</label><citation-alternatives><mixed-citation xml:lang="ru">Rektorys K., Variational methods in mathematics, science and engineering. – Dordrecht: Springer, 1977. https://doi.org/10.1007/978-94-011-6450-4.</mixed-citation><mixed-citation xml:lang="en">Rektorys K., Variational methods in mathematics, science and engineering. – Dordrecht: Springer, 1977. https://doi.org/10.1007/978-94-011-6450-4.</mixed-citation></citation-alternatives></ref><ref id="cit18"><label>18</label><citation-alternatives><mixed-citation xml:lang="ru">Karachik V.V., Sarsenbi A., Turmetov B.Kh. On solvability of the main boundary value problems for a non-local Poisson equation // Turkish journal of mathematics. – 2019. – Vol. 43. – No. 3. – P. 1604–1625. https://doi.org/10.3906/mat-1901-71.</mixed-citation><mixed-citation xml:lang="en">Karachik V.V., Sarsenbi A., Turmetov B.Kh. On solvability of the main boundary value problems for a non-local Poisson equation // Turkish journal of mathematics. – 2019. – Vol. 43. – No. 3. – P. 1604–1625. https://doi.org/10.3906/mat-1901-71.</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
