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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">Journal of Samara State Technical University, Ser. Physical and Mathematical Sciences</journal-id><journal-title-group><journal-title xml:lang="en">Journal of Samara State Technical University, Ser. Physical and Mathematical Sciences</journal-title><trans-title-group xml:lang="ru"><trans-title>Вестник Самарского государственного технического университета. Серия «Физико-математические науки»</trans-title></trans-title-group></journal-title-group><issn publication-format="print">1991-8615</issn><issn publication-format="electronic">2310-7081</issn><publisher><publisher-name xml:lang="en">Samara State Technical University</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">627028</article-id><article-id pub-id-type="doi">10.14498/vsgtu2083</article-id><article-id pub-id-type="edn">YZQBWZ</article-id><article-categories><subj-group subj-group-type="toc-heading" xml:lang="en"><subject>Differential Equations and Mathematical Physics</subject></subj-group><subj-group subj-group-type="toc-heading" xml:lang="ru"><subject>Дифференциальные уравнения и математическая физика</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">Solvability of a coefficient recovery problem for a time-fractional diffusion equation with periodic boundary and overdetermination conditions</article-title><trans-title-group xml:lang="ru"><trans-title>Разрешимость задачи восстановления коэффициентов в дробно-временном уравнении диффузии с периодическими граничными и переопределенными условиями</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-6054-2827</contrib-id><name-alternatives><name xml:lang="en"><surname>Durdiev</surname><given-names>Durdimurod K.</given-names></name><name xml:lang="ru"><surname>Дурдиев</surname><given-names>Дурдимурод Каландарович</given-names></name></name-alternatives><address><country country="UZ">Uzbekistan</country></address><bio xml:lang="en"><p>Dr. Phys. &amp; Math. Sci., Professor; Head of Branch; Professor, Dept. of Differential Equations</p></bio><bio xml:lang="ru"><p>доктор физико-математических наук, профессор; заведующий отделением; профессор, каф. дифференциальных уравнений</p></bio><email>d.durdiev@mathinst.uz</email><uri>https://www.mathnet.ru/person29112</uri><xref ref-type="aff" rid="aff1"/><xref ref-type="aff" rid="aff2"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-8496-1092</contrib-id><name-alternatives><name xml:lang="en"><surname>Jumaev</surname><given-names>Jonibek J.</given-names></name><name xml:lang="ru"><surname>Жумаев</surname><given-names>Жонибек Жамолович</given-names></name></name-alternatives><address><country country="UZ">Uzbekistan</country></address><bio xml:lang="en"><p>Cand. Phys. &amp; Math. Sci., Associate Professor; Senior Researcher; Associate Professor, Dept. of Differential Equations</p></bio><bio xml:lang="ru"><p>кандидат физико-математических наук, доцент; старший научный сотрудник; доцент, каф. дифференциальных уравнений</p></bio><email>jonibekjj@mail.ru</email><uri>https://www.mathnet.ru/person159031</uri><xref ref-type="aff" rid="aff1"/><xref ref-type="aff" rid="aff2"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">Bukhara Branch of the Institute of Mathematics named after V. I. Romanovskiy at the Academy of Sciences of the Republic of Uzbekistan</institution></aff><aff><institution xml:lang="ru">Бухарское отделение Института математики Академии наук Республики Узбекистан</institution></aff></aff-alternatives><aff-alternatives id="aff2"><aff><institution xml:lang="en">Bukhara State University</institution></aff><aff><institution xml:lang="ru">Бухарский государственный университет</institution></aff></aff-alternatives><pub-date date-type="pub" iso-8601-date="2025-05-20" publication-format="electronic"><day>20</day><month>05</month><year>2025</year></pub-date><volume>29</volume><issue>1</issue><issue-title xml:lang="en"/><issue-title xml:lang="ru"/><fpage>21</fpage><lpage>36</lpage><history><date date-type="received" iso-8601-date="2024-02-15"><day>15</day><month>02</month><year>2024</year></date><date date-type="accepted" iso-8601-date="2024-11-19"><day>19</day><month>11</month><year>2024</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2025, Authors; Samara State Technical University (Compilation, Design, and Layout)</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2025, Авторский коллектив; Самарский государственный технический университет (составление, дизайн, макет)</copyright-statement><copyright-year>2025</copyright-year><copyright-holder xml:lang="en">Authors; Samara State Technical University (Compilation, Design, and Layout)</copyright-holder><copyright-holder xml:lang="ru">Авторский коллектив; Самарский государственный технический университет (составление, дизайн, макет)</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/4.0</ali:license_ref></license></permissions><self-uri xlink:href="https://journals.eco-vector.com/1991-8615/article/view/627028">https://journals.eco-vector.com/1991-8615/article/view/627028</self-uri><abstract xml:lang="en"><p>This article investigates the inverse problem for time-fractional diffusion equations with periodic boundary conditions and integral overdetermination conditions on a rectangular domain. First, the definition of a classical solution to the problem is introduced. Using the Fourier method, the direct problem is reduced to an equivalent integral equation. The existence and uniqueness of the solution to the direct problem are established by employing estimates for the Mittag–Leffler function and generalized singular Gronwall inequalities.In the second part of the work, the inverse problem is examined. This problem is reformulated as an equivalent integral equation, which is then solved using the contraction mapping principle. Local existence and global uniqueness of the solution are rigorously proven. Furthermore, a stability estimate for the solution is derived.The study contributes to the theory of inverse problems for fractional differential equations by providing a framework for analyzing problems with periodic boundary conditions and integral overdetermination. The methods developed in this work can be applied to a wide range of problems in mathematical physics and engineering, where time-fractional diffusion models are increasingly used to describe complex phenomena.</p></abstract><trans-abstract xml:lang="ru"><p>Исследуется обратная задача для уравнений дробно-временной диффузии с периодическими граничными условиями и интегральными условиями переопределения на прямоугольной области. Сначала вводится определение классического решения задачи. Затем с использованием метода Фурье прямая задача сводится к эквивалентному интегральному уравнению. Существование и единственность решения прямой задачи устанавливаются с помощью оценок для функции Миттаг–Леффлера и обобщенных сингулярных неравенств Гронвалля.Во второй части работы рассматривается обратная задача, которая переформулируется в виде эквивалентного интегрального уравнения, а затем решается с использованием принципа сжимающих отображений. Строго доказываются локальное существование и глобальная единственность решения. Кроме того, получена оценка устойчивости решения.Данное исследование вносит вклад в теорию обратных задач для дробных дифференциальных уравнений, предоставляя основу для анализа задач с периодическими граничными условиями и интегральными условиями переопределения. Разработанные методы могут быть применены к широкому кругу задач в математической физике и инженерии, где дробно-временные модели диффузии все чаще используются для описания сложных явлений.</p></trans-abstract><kwd-group xml:lang="en"><kwd>time-fractional diffusion equation</kwd><kwd>periodic boundary conditions</kwd><kwd>inverse problem</kwd><kwd>integral equation</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>уравнение дробно-временной диффузии, периодические граничные условия, обратная задача, интегральное уравнение</kwd></kwd-group><funding-group/></article-meta></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Agarwal R., Sharma U. P., Agarwal R. P. Bicomplex Mittag–Leffler function and associated properties, J. Nonlinear Sci. Appl., 2022, vol. 15, no. 1, pp. 48–60, arXiv: 2103.10324 [math.CV]. DOI: https://doi.org/10.22436/jnsa.015.01.04.</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>Haddouchi F., Guendouz C., Benaicha S. 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