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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">48173</article-id><article-id pub-id-type="doi">10.22363/2413-3639-2025-71-4-655-662</article-id><article-id pub-id-type="edn">MIQJVQ</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">Dirac geometric structures</article-title><trans-title-group xml:lang="ru"><trans-title>О геометрических структурах Дирака</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0001-7039-6977</contrib-id><contrib-id contrib-id-type="scopus">36890776900</contrib-id><contrib-id contrib-id-type="researcherid">AAB-1148-2019</contrib-id><contrib-id contrib-id-type="spin">8362-5455</contrib-id><name-alternatives><name xml:lang="en"><surname>Salnikova</surname><given-names>T. V.</given-names></name><name xml:lang="ru"><surname>Сальникова</surname><given-names>Т. В.</given-names></name></name-alternatives><email>tatiana.salnikova@gmail.com</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0003-0066-4168</contrib-id><contrib-id contrib-id-type="scopus">6603260594</contrib-id><contrib-id contrib-id-type="researcherid">Q-5737-2018</contrib-id><name-alternatives><name xml:lang="en"><surname>Kugushev</surname><given-names>E. I.</given-names></name><name xml:lang="ru"><surname>Кугушев</surname><given-names>Е. И.</given-names></name></name-alternatives><email>kugushevei@yandex.ru</email><xref ref-type="aff" rid="aff1"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">Lomonosov Moscow State University</institution></aff><aff><institution xml:lang="ru">Московский государственный университет им. М.В. Ломоносова</institution></aff></aff-alternatives><pub-date date-type="pub" iso-8601-date="2025-12-25" publication-format="electronic"><day>25</day><month>12</month><year>2025</year></pub-date><volume>71</volume><issue>4</issue><issue-title xml:lang="en">VOL 71, NO3 (2025)</issue-title><issue-title xml:lang="ru">ТОМ 71, №4 (2025)</issue-title><fpage>655</fpage><lpage>662</lpage><history><date date-type="received" iso-8601-date="2026-01-21"><day>21</day><month>01</month><year>2026</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2025, Salnikova T.V., Kugushev E.I.</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2025, Сальникова Т.В., Кугушев Е.И.</copyright-statement><copyright-year>2025</copyright-year><copyright-holder xml:lang="en">Salnikova T.V., Kugushev E.I.</copyright-holder><copyright-holder xml:lang="ru">Сальникова Т.В., Кугушев Е.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/48173">https://journals.rudn.ru/CMFD/article/view/48173</self-uri><abstract xml:lang="en"><p>For Hamiltonian systems on symplectic manifolds with constraints in the Dirac model of generalized Hamiltonian dynamics, V. V. Kozlov considered the operation of symplectic projection of a Hamiltonian vector field for the case of generalized nonintegrable differential constraints. This paper considers a constraint regularization method that circumvents the degeneracy of the symplectic projection operation in the case of an odd number of constraints. The method is based on embedding of the original system into an extended system of higher dimension with an increased number of constraints.</p></abstract><trans-abstract xml:lang="ru"><p>Для гамильтоновых систем на симплектических многообразиях со связями в модели обобщенной гамильтоновой динамики Дирака В.В. Козлов рассмотрел операцию симплектического проектирования гамильтонова векторного поля для случая обобщенных неинтегрируемых дифференциальных связей. В данной работе рассматривается метод регуляризации связей, позволяющий обойти вырождение операции симплектического проектирования в случае нечетного количества связей. Он основан на вложении исходной системы в расширенную систему большей размерности с увеличенным количеством связей.</p></trans-abstract><kwd-group xml:lang="en"><kwd>Hamilton’s equations</kwd><kwd>differential constraints</kwd><kwd>symplectic projection</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>уравнения Гамильтона</kwd><kwd>дифференциальные связи</kwd><kwd>симплектическое проектирование</kwd></kwd-group><funding-group/></article-meta><fn-group/></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Борисенко А.А., Ямпольский Л.Я. Риманова геометрия расслоений// Усп. мат. наук.-1991.-46, № 6.-С. 51-95.</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>Козлов В.В. К обобщенной гамильтоновой динамике Дирака// Усп. мат. наук.-2024.- 29, № 4.- С. 95-130.-DOI: 10.4213/rm10183.</mixed-citation></ref><ref id="B3"><label>3.</label><mixed-citation>Сальникова Т.В., Кугушев Е.И. 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