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<article 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" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" article-type="research-article" dtd-version="1.2" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">Contemporary Mathematics. Fundamental Directions</journal-id><journal-title-group><journal-title xml:lang="en">Contemporary Mathematics. Fundamental Directions</journal-title><trans-title-group xml:lang="ru"><trans-title>Современная математика. Фундаментальные направления</trans-title></trans-title-group></journal-title-group><issn publication-format="print">2413-3639</issn><issn publication-format="electronic">2949-0618</issn><publisher><publisher-name xml:lang="en">Peoples’ Friendship University of Russia named after Patrice Lumumba (RUDN University)</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">52763</article-id><article-id pub-id-type="doi">10.22363/2413-3639-2026-72-3-444-453</article-id><article-id pub-id-type="edn">QDITWY</article-id><article-categories><subj-group subj-group-type="toc-heading" xml:lang="en"><subject>Articles</subject></subj-group><subj-group subj-group-type="toc-heading" xml:lang="ru"><subject>Статьи</subject></subj-group><subj-group subj-group-type="article-type"><subject>Research Article</subject></subj-group></article-categories><title-group><article-title xml:lang="en">On solutions of one class of third-order ordinary differential equations with potential operators</article-title><trans-title-group xml:lang="ru"><trans-title>О решениях одного класса обыкновенных дифференциальных уравнений третьего порядка с потенциальными операторами</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-3447-0425</contrib-id><contrib-id contrib-id-type="scopus">6507007003</contrib-id><contrib-id contrib-id-type="researcherid">T-8088-2019</contrib-id><contrib-id contrib-id-type="spin">6087-3245</contrib-id><name-alternatives><name xml:lang="en"><surname>Budochkina</surname><given-names>S. A.</given-names></name><name xml:lang="ru"><surname>Будочкина</surname><given-names>Светлана Александровна</given-names></name></name-alternatives><email>budochkina-sa@rudn.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="scopus">57557881000</contrib-id><name-alternatives><name xml:lang="en"><surname>Luu</surname><given-names>T. H.</given-names></name><name xml:lang="ru"><surname>Лыу</surname><given-names>Тхи Хуен</given-names></name></name-alternatives><email>lyu-t@rudn.ru</email><xref ref-type="aff" rid="aff1"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">RUDN University</institution></aff><aff><institution xml:lang="ru">Российский университет дружбы народов</institution></aff></aff-alternatives><pub-date date-type="pub" iso-8601-date="2026-10-13" publication-format="electronic"><day>13</day><month>10</month><year>2026</year></pub-date><volume>72</volume><issue>3</issue><issue-title xml:lang="en">On the centenary of the birth of Georgii Alexandrovich Kamenskii</issue-title><issue-title xml:lang="ru">К 100-летию со дня рождения Георгия Александровича Каменского</issue-title><fpage>444</fpage><lpage>453</lpage><history><date date-type="received" iso-8601-date="2026-10-13"><day>13</day><month>10</month><year>2026</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2026, Budochkina S.A., Luu T.H.</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2026, Будочкина С.А., Лыу Т.Х.</copyright-statement><copyright-year>2026</copyright-year><copyright-holder xml:lang="en">Budochkina S.A., Luu T.H.</copyright-holder><copyright-holder xml:lang="ru">Будочкина С.А., Лыу Т.Х.</copyright-holder><ali:free_to_read xmlns:ali="http://www.niso.org/schemas/ali/1.0/"/><license><ali:license_ref xmlns:ali="http://www.niso.org/schemas/ali/1.0/">https://creativecommons.org/licenses/by-nc/4.0</ali:license_ref></license></permissions><self-uri xlink:href="https://journals.rudn.ru/CMFD/article/view/52763">https://journals.rudn.ru/CMFD/article/view/52763</self-uri><abstract xml:lang="en"><p>In this paper, an analogue of the Bernoulli method for finding solutions of a class of third-order ordinary differential equations with potential operators is developed. Helmholtz potentiality conditions are also derived for this purpose. The theoretical results are illustrated with specific examples.</p></abstract><trans-abstract xml:lang="ru"><p>В настоящей статье разработан аналог метода Бернулли для нахождения решений одного класса обыкновенных дифференциальных уравнений третьего порядка с потенциальными операторами. Для этого также получены условия потенциальности Гельмгольца. Теоретические результаты проиллюстрированы конкретными примерами.</p></trans-abstract><kwd-group xml:lang="en"><kwd>bilinear form</kwd><kwd>potential operator</kwd><kwd>Helmholtz potentiality conditions</kwd><kwd>analogue of the Bernoulli method</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>билинейная форма</kwd><kwd>потенциальный оператор</kwd><kwd>условия потенциальности Гельмгольца</kwd><kwd>аналог метода Бернулли</kwd></kwd-group><funding-group><award-group><funding-source><institution-wrap><institution xml:lang="ru">Работа выполнена при поддержке Министерства науки и высшего образования Российской Федерации (Мегагрант, соглашение № 075-15-2022-1115).</institution></institution-wrap><institution-wrap><institution xml:lang="en">This work was supported by the Ministry of Science and Higher Education of the Russian Federation (Megagrant, Agreement No. 075-15-2022-1115).</institution></institution-wrap></funding-source></award-group></funding-group></article-meta><fn-group/></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Беркович Л.М. О самосопряженных дифференциальных уравнениях и об одном классе уравнений Эйлера//Изв. вузов. Сер. Мат.-1969.-8.-С. 3-9.</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>Будочкина С.А. О представлении одного операторного уравнения с первой производной по времени в форме $B_u$-гамильтонова уравнения//Дифф. уравн.-2013.-49, 2.-С. 175-185.-DOI: 10.1134/S0374064113020052.</mixed-citation></ref><ref id="B3"><label>3.</label><mixed-citation>Будочкина С.А., Лыу Т.Х. О вариационном принципе для одной системы обыкновенных дифференциальных уравнений//Соврем. мат. Фундам. направл.-2025.-71, 1.-С. 71-84.-DOI: 10.22363/2413-3639-2025-71-1-71-84.</mixed-citation></ref><ref id="B4"><label>4.</label><mixed-citation>Галиуллин А.С. Системы Гельмгольца.-М.: РУДН, 1995.</mixed-citation></ref><ref id="B5"><label>5.</label><mixed-citation>Гельмгольц Г. О физическом значении принципа наименьшего действия//В сб.: &lt;&lt;Вариационные принципы механики&gt;&gt;.-М.: Физматгиз, 1959.-С. 430-459.</mixed-citation></ref><ref id="B6"><label>6.</label><mixed-citation>Попов А.М. Обратная задача вариационного исчисления для систем дифференциально-разностных уравнений второго порядка//Мат. заметки.-2002.-72, 5.-С. 745-749.-DOI: 10.4213/mzm464.</mixed-citation></ref><ref id="B7"><label>7.</label><mixed-citation>Савчин В.М. Математические методы механики бесконечномерных непотенциальных систем.-М.: УДН, 1991.</mixed-citation></ref><ref id="B8"><label>8.</label><mixed-citation>Суслов Г.К. О кинетическом потенциале Гельмгольца//Мат. сб.-1896.-19, 1.-С. 197-210.</mixed-citation></ref><ref id="B9"><label>9.</label><mixed-citation>Филиппов В.М. Вариационные принципы для непотенциальных операторов.-М.: УДН, 1985.</mixed-citation></ref><ref id="B10"><label>10.</label><mixed-citation>Филиппов В.М. О вариационном принципе для гипоэллиптических уравнений с постоянными коэффициентами//Дифф. уравн.-1986.-22, 2.-С. 338-343.</mixed-citation></ref><ref id="B11"><label>11.</label><mixed-citation>Филиппов В.М., Савчин В.М., Шорохов С.Г. Вариационные принципы для непотенциальных операторов//Итоги науки и техн. Сер. Соврем. пробл. мат. Нов. достиж.-1992.-40.-С. 3-176.</mixed-citation></ref><ref id="B12"><label>12.</label><mixed-citation>Agrawal O.P. Formulation of Euler-Lagrange equations for fractional variational problems//J. Math. Anal. Appl.-2002.-272, 1.-С. 368-379.-DOI: 10.1016/S0022-247X(02)00180-4.</mixed-citation></ref><ref id="B13"><label>13.</label><mixed-citation>Beccar-Varela M.P., Bhuiyan M.A.M., Mariani M.C., Tweneboah O.K. Analytic methods for solving higher order ordinary differential equations//Mathematics.-2019.-7.-826.-DOI: 10.3390/math7090826.</mixed-citation></ref><ref id="B14"><label>14.</label><mixed-citation>Budochkina S.A. Symmetries and first integrals of a second order evolutionary operator equation//Eurasian Math. J.-2012.-3, 1.-С. 18-28.</mixed-citation></ref><ref id="B15"><label>15.</label><mixed-citation>Budochkina S.A., Dekhanova E.S. On the potentiality of a class of operators relative to local bilinear forms//Ural Math. J.-2021.-7, 1.-С. 26-37.-DOI: 10.15826/umj.2021.1.003.</mixed-citation></ref><ref id="B16"><label>16.</label><mixed-citation>Budochkina S.A., Luu T.H. On connection between variationality of a six-order ordinary differential equation and Hamilton-Ostrogradskii equations//Lobachevskii J. Math.-2021.-42, 15.-С. 3594-3605.-DOI: 10.1134/S1995080222030052.</mixed-citation></ref><ref id="B17"><label>17.</label><mixed-citation>Budochkina S.A., Luu T.H. On variational symmetries and conservation laws of a fifth-order partial differential equation//Lobachevskii J. Math.-2024.-45, 6.-С. 2466-2477.-DOI: 10.1134/S1995080224602765.</mixed-citation></ref><ref id="B18"><label>18.</label><mixed-citation>Budochkina S.A., Luu T.H., Shokarev V.A. On indirect representability of fourth order ordinary differential equation in form of Hamilton-Ostrogradsky equations//Уфимск. мат. ж.-2023.-15, 3.-С. 121-131.-DOI: 10.13108/2023-15-3-118.</mixed-citation></ref><ref id="B19"><label>19.</label><mixed-citation>Budochkina S.A., Vu H.P. On an indirect representation of evolutionary equations in the form of Birkhoff's equations//Eurasian Math. J.-2022.-13, 3.-С. 23-32.-DOI: 10.32523/2077-9879-2022-13-3-23-32.</mixed-citation></ref><ref id="B20"><label>20.</label><mixed-citation>Kalpakides V.K., Charalambopoulos A. On Hamilton's principle for discrete and continuous systems: a convolved action principle//Rep. Math. Phys.-2021.-87, 2.-С. 225-248.-DOI: 10.1016/S0034-4877(21)00027-6.</mixed-citation></ref><ref id="B21"><label>21.</label><mixed-citation>Mayer A. Die Existenzbedingungen eines kinetischen Potentiales//S\"achsischen Acad. Wiss. Phys.-Math. Kl.-1896.-48.-С. 519-529.</mixed-citation></ref><ref id="B22"><label>22.</label><mixed-citation>Tleubergenov M.I., Ibraeva G.T. On the solvability of the main inverse problem for stochastic differential systems//Ukr. Math. J.-2019.-71, 1.-С. 157-165.-DOI: 10.1007/s11253-019-01631-w.</mixed-citation></ref><ref id="B23"><label>23.</label><mixed-citation>Tonti E. Variational formulation for every nonlinear problem//Int. J. Engrg. Sci.-1984.-22, 11-12.-С. 1343-1371.-DOI: 10.1016/0020-7225(84)90026-0.</mixed-citation></ref></ref-list></back></article>
