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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">mathematics</journal-id><journal-title-group><journal-title xml:lang="ru">Вестник российских университетов. Математика</journal-title><trans-title-group xml:lang="en"><trans-title>Russian Universities Reports. Mathematics</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2686-9667</issn><issn pub-type="epub">2782-3342</issn><publisher><publisher-name>Тамбовский государственный университет имени Г.Р. Державина</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.20310/2686-9667-2025-30-150-144-159</article-id><article-id custom-type="elpub" pub-id-type="custom">mathematics-96</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>НАУЧНЫЕ СТАТЬИ</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>ORIGINAL ARTICLES</subject></subj-group></article-categories><title-group><article-title>О структуре ядра задачи Шварца в эллипсе в общем случае</article-title><trans-title-group xml:lang="en"><trans-title>On the structure of the kernel of the Schwarz problem in an ellipse in the general case</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-0274-5826</contrib-id><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Николаев</surname><given-names>Владимир Геннадьевич</given-names></name><name name-style="western" xml:lang="en"><surname>Nikolaev</surname><given-names>Vladimir G.</given-names></name></name-alternatives><email xlink:type="simple">vg14@inbox.ru</email><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>ФГБОУ ВО «Новгородский государственный университет им. Ярослава Мудрого</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Novgorod State University</institution><country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2025</year></pub-date><pub-date pub-type="epub"><day>26</day><month>06</month><year>2025</year></pub-date><volume>30</volume><issue>150</issue><fpage>144</fpage><lpage>159</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Николаев В.Г., 2025</copyright-statement><copyright-year>2025</copyright-year><copyright-holder xml:lang="ru">Николаев В.Г.</copyright-holder><copyright-holder xml:lang="en">Nikolaev V.G.</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://mathematics.elpub.ru/jour/article/view/96">https://mathematics.elpub.ru/jour/article/view/96</self-uri><abstract><p>В статье вычислена структура ядра и коядра задачи Шварца для $J$-ана\-ли\-ти\-чес\-ких функций, заданных в эллипсе $D$ с границей $\Gamma.$ Задача Шварца состоит в~нахождении $J$-аналитической в эллипсе $D$ функции по известному значению ее реальной части на $\Gamma. $ В параграфах 1 и 2 приведена постановка задачи, а также изучено ее решение для специальной правой части. В параграфе 3 изложены необходимые сведения из одной работы А.\,П.~Солдатова. В параграфе 4 построено решение союзной задачи Шварца для специальной правой части. На основании этих результатов в параграфе 5 вычислены ядро и коядро задачи Шварца. Схема их вычисления кратко описана в начале пятого параграфа. Затем в теоремах \ref{th5.1}--\ref{th5.6} данная схема реализована. При этом использованы введенные автором понятия теоретической и алгоритмической разрешимости специальной задачи Шварца. Также использован метод математической индукции. Показано, что ядро и коядро задачи Шварца в эллипсе состоят только из вектор-полиномов. Описана структура ядра и коядра в терминах рангов некоторых вещественных матриц, зависящих от матрицы $J$ и эллипса $\Gamma.$ В конце статьи приведен пример вычисления ядра задачи Шварца в эллипсе для двумерной матрицы $J$ с кратным собственным числом.</p></abstract><trans-abstract xml:lang="en"><p>The paper calculates the structure of the kernel and co-kernel of the Schwartz problem for $J$-analytic functions defined in the ellipse $D$ with a boundary $\Gamma.$ The Schwartz problem consists in finding a $J$-analytic function in the ellipse $D$ by the known value of its real part on $\Gamma. $ In paragraphs 1 and 2 the problem is formulated and its solution for a~special right part is studied. Paragraph 3 contains the necessary information from one paper by A.\,P.~Soldatov. Paragraph 4 constructs the solution of the Schwarz union problem for the special right-hand side. On the basis of these results, paragraph 5 calculates the kernel and the co-kernel of the Schwartz problem. The model of their calculation is briefly described at the beginning of the fifth paragraph. Then in the theorems \ref{th5.1}--\ref{th5.6} this scheme is implemented. Here the notions of theoretical and algorithmic solvability of the special Schwarz problem introduced by the author are used. The method of mathematical induction is used as well. It is shown that the kernel and co-kernel of the Schwarz problem in an ellipse consist only of vector polynomials. The paper describes the structure of the kernel and co-kernel in terms of the ranks of some real matrices depending on the matrix $J$ and the ellipse $\Gamma.$ The paper concludes with an example of calculating the kernel of the Schwarz problem in an ellipse for a two-dimensional matrix $J$ with multiple eigenvalue.</p></trans-abstract><kwd-group xml:lang="ru"><kwd>вектор-полином</kwd><kwd>задача Шварца</kwd><kwd>матрица</kwd><kwd>эллипс</kwd><kwd>ядро</kwd><kwd>коядро</kwd><kwd>алгоритмическая разрешимость</kwd><kwd>теоретическая разрешимость</kwd></kwd-group><kwd-group xml:lang="en"><kwd>vector polynomial</kwd><kwd>Schwartz problem</kwd><kwd>matrix</kwd><kwd>ellipse</kwd><kwd>kernel</kwd><kwd>co-kernel</kwd><kwd>algorithmic solvability</kwd><kwd>theoretical solvability</kwd></kwd-group><funding-group><funding-statement xml:lang="ru">Исследование выполнено в ходе реализации НИР «Математическое моделирование природных процессов», выполняемой в рамках государственного задания в сфере научной деятельности (проект № 124111600020-2).</funding-statement><funding-statement xml:lang="en">The study was carried out in the course of implementation of the research work “Mathematical modeling of natural processes”, carried out within the framework of the state assignment in the field of scientific activity (project no. 124111600020-2).</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">Ф.Д. 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