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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="en"><front><journal-meta><journal-id journal-id-type="publisher-id">najo</journal-id><journal-title-group><journal-title xml:lang="en">Nanosystems: Physics, Chemistry, Mathematics</journal-title><trans-title-group xml:lang="ru"><trans-title>Наносистемы: физика, химия, математика</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2220-8054</issn><issn pub-type="epub">2305-7971</issn><publisher><publisher-name>Университет ИТМО</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.17586/2220-8054-2021-12-5-549-552</article-id><article-id custom-type="elpub" pub-id-type="custom">najo-507</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="en"><subject>MATHEMATICS</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>МАТЕМАТИКА</subject></subj-group></article-categories><title-group><article-title>Bound states for Laplacian perturbed by varying potential supportedby line in R3</article-title><trans-title-group xml:lang="ru"><trans-title>Связанные состояния лапласиана, возмущенного переменным потенциалом, сосредоточенным на линии в R3</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Bagmutov</surname><given-names>A. S.</given-names></name><name name-style="western" xml:lang="en"><surname>Bagmutov</surname><given-names>A. S.</given-names></name></name-alternatives><bio xml:lang="en"><p>Kronverkskiy, 49, Saint Petersburg, 197101</p></bio><email xlink:type="simple">bagmutov94@mail.ru</email><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="en">ITMO University<country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2021</year></pub-date><pub-date pub-type="epub"><day>05</day><month>08</month><year>2025</year></pub-date><volume>12</volume><issue>5</issue><fpage>549</fpage><lpage>552</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Bagmutov A.S., 2025</copyright-statement><copyright-year>2025</copyright-year><copyright-holder xml:lang="ru">Bagmutov A.S.</copyright-holder><copyright-holder xml:lang="en">Bagmutov A.S.</copyright-holder><license 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://nanojournal.ifmo.ru/jour/article/view/507">https://nanojournal.ifmo.ru/jour/article/view/507</self-uri><abstract><p>We investigate a system with attracting δ-potential located along a straight line in 3D. It has constant intensity, except for a local region. We prove the existence of discrete spectrum and construct an upper bound on the number of bound states, using Birman-Schwinger method.</p></abstract><trans-abstract xml:lang="ru"><p>Мы исследуем систему с притягивающим дельта-потенциалом, сосредоточенным на прямой линии в R3 . Он постоянен, кроме ограниченной области. Мы доказываем существование дискретного спектра и строим верхнюю оценку количества связанных состояний, используя метод Бирмана-Швингера.</p></trans-abstract><kwd-group xml:lang="ru"><kwd>теория расширений операторов</kwd><kwd>сингулярный потенциал</kwd><kwd>спектр</kwd></kwd-group><kwd-group xml:lang="en"><kwd>operator extension theory</kwd><kwd>singular potential</kwd><kwd>spectrum</kwd></kwd-group><funding-group xml:lang="en"><funding-statement>The reported study was funded by RFBR, project number 20-31-90050.</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">Albeverio S., Gesztesy F., Høegh-Krohn R., Holden H. Solvable Models in Quantum Mechanics, Springer, Heidelberg, 1988.</mixed-citation><mixed-citation xml:lang="en">Albeverio S., Gesztesy F., Høegh-Krohn R., Holden H. 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