<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE root>
<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">36489</article-id><article-id pub-id-type="doi">10.22363/2413-3639-2023-69-3-430-444</article-id><article-id pub-id-type="edn">FKQFNA</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">Analytical solution of the space-time fractional reaction-diffusion equation  with variable coefficients</article-title><trans-title-group xml:lang="ru"><trans-title>Аналитическое решение пространственно-временного дробного уравнения реакции-диффузии с переменными коэффициентами</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Mahmoud</surname><given-names>E. I.</given-names></name><name xml:lang="ru"><surname>Махмуд</surname><given-names>Э. И.</given-names></name></name-alternatives><email>ei_abdelgalil@yahoo.com</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="2023-10-15" publication-format="electronic"><day>15</day><month>10</month><year>2023</year></pub-date><volume>69</volume><issue>3</issue><issue-title xml:lang="en">VOL 69, NO3 (2023)</issue-title><issue-title xml:lang="ru">ТОМ 69, №3 (2023)</issue-title><fpage>430</fpage><lpage>444</lpage><history><date date-type="received" iso-8601-date="2023-10-24"><day>24</day><month>10</month><year>2023</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2023, Mahmoud E.I.</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2023, Махмуд Э.И.</copyright-statement><copyright-year>2023</copyright-year><copyright-holder xml:lang="en">Mahmoud E.I.</copyright-holder><copyright-holder xml:lang="ru">Махмуд Э.И.</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/36489">https://journals.rudn.ru/CMFD/article/view/36489</self-uri><abstract xml:lang="en"><p style="text-align: justify;">In this paper, we solve the problem of an inhomogeneous one-dimensional fractional differential reaction-diffusion equation with variable coefficients (1.1)-(1.2) by the method of separation of variables (the Fourier method). The Caputo derivative and the Riemann-Liouville derivative are considered in the time and space directions, respectively. We prove that the obtained solution of the boundary-value problem satisfies the given boundary conditions. We discuss the convergence of the series defining the proposed solution.</p></abstract><trans-abstract xml:lang="ru"><p style="text-align: justify;">В статье решена задача неоднородного одномерного дробного дифференциального уравнения реакции-диффузии с переменными коэффициентами (1.1)-(1.2) методом разделения переменных (метод Фурье). Производная Капуто и производная Римана-Лиувилля рассматриваются во временном и пространственном направлениях соответственно. Приведено доказательство того, что найденное решение краевой задачи удовлетворяет заданным краевым условиям, и обсуждается сходимость рядов, определяющих предложенное решение.</p></trans-abstract><kwd-group xml:lang="en"><kwd>reaction-diffusion equation</kwd><kwd>advective diffusion</kwd><kwd>boundary-value problem</kwd><kwd>fractional derivative</kwd><kwd>Caputo derivative</kwd><kwd>Riemann-Liouville derivative</kwd><kwd>separation of variables method</kwd><kwd>Fourier method</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>уравнение реакции-диффузии</kwd><kwd>адвективная диффузия</kwd><kwd>краевая задача</kwd><kwd>дробная производная</kwd><kwd>производная Капуто</kwd><kwd>производная Римана-Лиувилля</kwd><kwd>метод разделения переменных</kwd><kwd>метод Фурье</kwd></kwd-group><funding-group/></article-meta></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Алероев Т.С., Алероева Х.Т. Об одном классе несамосопряженных операторов, сопутствующих дифференциальным уравнениям дробного порядка// Укр. мат. вiсн.- 2015.- 12, № 3.-С. 293-310.</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>Нахушев А.М. Дробное исчисление и его применение. -М.: Физматлит, 2003.</mixed-citation></ref><ref id="B3"><label>3.</label><mixed-citation>Aleroev T.S. Solving the boundary value problems for differential equations with fractional derivatives by the method of separation of variables// Mathematics.- 2020.- 8.- 1877.</mixed-citation></ref><ref id="B4"><label>4.</label><mixed-citation>Aleroev T.S., Elsayed A.M., Mahmoud E.I. Solving one dimensional time-space fractional vibration string equation// Conf. Ser. Mater. Sci. Eng.- 2021.-1129.-С. 20-30.</mixed-citation></ref><ref id="B5"><label>5.</label><mixed-citation>Aleroev T.S., Kirane M., Malik S.A. Determination of a source term for a time fractional diffusion equation with an integral type over-determining condition// Electron. J. Differ. Equ. -2013.-270.- С. 1-16.</mixed-citation></ref><ref id="B6"><label>6.</label><mixed-citation>Curtiss D.R. Recent extensions of Descartes’ rule of signs// Ann. Math.- 1918.- 19, № 4.- С. 251-278.</mixed-citation></ref><ref id="B7"><label>7.</label><mixed-citation>Gorenflo R., Kilbas A.A., Mainardi F., Rogosin S.V. Mittag-Leffler Functions Related Topics and Applications.- New York: Springer, 2014.</mixed-citation></ref><ref id="B8"><label>8.</label><mixed-citation>Gorenflo R., Mainardi F. Random walk models for space fractional diffusion processes// Fract. Calc. Appl. Anal. -1998.-1.- С. 167-191.</mixed-citation></ref><ref id="B9"><label>9.</label><mixed-citation>Hu Z., Liu W., Liu J. Boundary value problems for fractional differential equations// Tijdschrift voor Urologie.-2014.- 2014, № 1.-С. 1-11.</mixed-citation></ref><ref id="B10"><label>10.</label><mixed-citation>Luchko Y., Gorenflo R. An operational method for solving fractional differential equations// Acta Math.- 1999.-24.-С. 207-234.</mixed-citation></ref><ref id="B11"><label>11.</label><mixed-citation>Plociniczak L. Eigenvalue asymptotics for a fractional boundary-value problem// Appl. Math. Comput.- 2014.-241.- С. 125-128.</mixed-citation></ref><ref id="B12"><label>12.</label><mixed-citation>Samko S.G., Kilbas A.A., Marichev O.I. Fractional Integrals and Derivatives. Theory and Applications.- New York: Gordon and Breach, 1993.</mixed-citation></ref></ref-list></back></article>
