<?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">Доклады Академии наук</journal-id><journal-title-group><journal-title xml:lang="en">Доклады Академии наук</journal-title><trans-title-group xml:lang="ru"><trans-title>Доклады Академии наук</trans-title></trans-title-group></journal-title-group><issn publication-format="print">0869-5652</issn><publisher><publisher-name xml:lang="en">The Russian Academy of Sciences</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">14417</article-id><article-id pub-id-type="doi">10.31857/S0869-56524864411-415</article-id><article-categories><subj-group subj-group-type="toc-heading" xml:lang="en"><subject>Mathematics</subject></subj-group><subj-group subj-group-type="toc-heading" xml:lang="ru"><subject>Математика</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">Complexity of discrete Seifert foliations over a graph</article-title><trans-title-group xml:lang="ru"><trans-title>Дискретные расслоения Зейферта над графами и их сложность</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Kwon</surname><given-names>Young Soo</given-names></name><name xml:lang="ru"><surname>Квон</surname><given-names>Йонг Су</given-names></name></name-alternatives><address><country country="KR">Korea, Republic of</country></address><email>smedn@mail.ru</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Mednykh</surname><given-names>A. D.</given-names></name><name xml:lang="ru"><surname>Медных</surname><given-names>А. Д.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>smedn@mail.ru</email><xref ref-type="aff" rid="aff2"/><xref ref-type="aff" rid="aff3"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Mednykh</surname><given-names>I. A.</given-names></name><name xml:lang="ru"><surname>Медных</surname><given-names>И. А.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>smedn@mail.ru</email><xref ref-type="aff" rid="aff2"/><xref ref-type="aff" rid="aff3"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">Yeungnam University</institution></aff><aff><institution xml:lang="ru">Йоннамский университет</institution></aff></aff-alternatives><aff-alternatives id="aff2"><aff><institution xml:lang="en">Sobolev Institute of Mathematics, Siberian Branch of the Russian Academy of Sciences</institution></aff><aff><institution xml:lang="ru">Институт математики имени С.Л. Соболева Сибирского отделения Российской академии наук</institution></aff></aff-alternatives><aff-alternatives id="aff3"><aff><institution xml:lang="en">Novosibirsk State University</institution></aff><aff><institution xml:lang="ru">Новосибирский национальный исследовательский государственный университет</institution></aff></aff-alternatives><pub-date date-type="pub" iso-8601-date="2019-06-10" publication-format="electronic"><day>10</day><month>06</month><year>2019</year></pub-date><volume>486</volume><issue>4</issue><issue-title xml:lang="en"/><issue-title xml:lang="ru"/><fpage>411</fpage><lpage>415</lpage><history><date date-type="received" iso-8601-date="2019-06-26"><day>26</day><month>06</month><year>2019</year></date><date date-type="accepted" iso-8601-date="2019-06-26"><day>26</day><month>06</month><year>2019</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2019, Russian academy of sciences</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2019, Российская академия наук</copyright-statement><copyright-year>2019</copyright-year><copyright-holder xml:lang="en">Russian academy of sciences</copyright-holder><copyright-holder xml:lang="ru">Российская академия наук</copyright-holder></permissions><self-uri xlink:href="https://journals.eco-vector.com/0869-5652/article/view/14417">https://journals.eco-vector.com/0869-5652/article/view/14417</self-uri><abstract xml:lang="en"><p>In the present paper, we study the complexity of an infinite family of graphs <italic>H<sub>n</sub></italic> = <italic>H<sub>n</sub></italic>(<italic>G</italic><sub>1</sub>, <italic>G</italic><sub>2</sub>, ..., <italic>G<sub>m</sub></italic>) that are discrete Seifert foliations over a graph <italic>H</italic> on <italic>m</italic> vertices with fibers <italic>G</italic><sub>1</sub>, <italic>G</italic><sub>2</sub>, ..., <italic>G<sub>m</sub></italic>. Each fiber <italic>G<sub>i</sub></italic> = <italic>C<sub>n</sub></italic>(<italic>s<sub>i</sub></italic><sub>,1</sub>, <italic>s<sub>i</sub></italic><sub>,2</sub>, ..., <italic>s<sub>i</sub></italic><sub>,<italic>k</italic></sub><italic><sub>i</sub></italic>) of this foliation is the circulant graph on <italic>n</italic> vertices with jumps <italic>s<sub>i</sub></italic><sub>,1</sub>, <italic>s<sub>i</sub></italic><sub>,2</sub>, ..., <italic>s<sub>i</sub></italic><sub>,<italic>k</italic></sub><italic><sub>i</sub></italic>. The family of discrete Seifert foliations is sufficiently large. It includes the generalized Petersen graphs, <italic>I</italic>-graphs, <italic>Y</italic>-graphs, <italic>H</italic>-graphs, sandwiches of circulant graphs, discrete torus graph and others. We obtain a closed formula for the number t(<italic>n</italic>) of spanning trees in <italic>H<sub>n</sub></italic> in terms of Chebyshev polynomials, investigate some arithmetical properties of this function and find its asymptotics as <italic>n</italic> → ∞.</p></abstract><trans-abstract xml:lang="ru"><p>В настоящей работе мы рассматриваем бесконечное семейство графов <italic>H<sub>n</sub></italic> = <italic>H<sub>n</sub></italic>(<italic>G</italic><sub>1</sub>, <italic>G</italic><sub>2</sub>, ..., <italic>G<sub>m</sub></italic>), представляющих из себя дискретные расслоения Зейферта над заданным графом <italic>H</italic> на <italic>m</italic> вершинах с особыми слоями <italic>G</italic><sub>1</sub>, <italic>G</italic><sub>2</sub>, ..., <italic>G<sub>m</sub></italic>. Каждый слой <italic>G<sub>i</sub></italic> = <italic>C<sub>n</sub></italic>(<italic>s<sub>i</sub></italic><sub>,1</sub>, <italic>s<sub>i</sub></italic><sub>,2</sub>, ..., <italic>s<sub>i</sub></italic><sub>,<italic>k</italic></sub><italic><sub>i</sub></italic>) такого расслоения является циркулянтным графом на <italic>n</italic> вершинах со скачками <italic>s<sub>i</sub></italic><sub>,1</sub>, <italic>s<sub>i</sub></italic><sub>,2</sub>, ..., <italic>s<sub>i</sub></italic><sub>,<italic>k</italic></sub><italic><sub>i</sub></italic>. Семей-ство дискретных расслоений Зейферта достаточно обширно. Оно включает обобщённые графы Петерсена, <italic>I</italic>-графы, <italic>Y</italic>-графы, <italic>H</italic>-графы, сандвичи циркулянтных графов, дискретные торы и др. В работе получены формулы для числа порождающих деревьев t(<italic>n</italic>) графа <italic>H<sub>n</sub></italic> в терминах полиномов Чебышева, изучены аналитические и арифметические свойства этой функции и найдена её асимптотика при <italic>n</italic> → ∞.</p></trans-abstract><kwd-group xml:lang="en"><kwd>complexity of graph</kwd><kwd>circulant graph</kwd><kwd>cyclic covering</kwd><kwd>spanning tree</kwd><kwd>graph spectrum</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>сложность графа</kwd><kwd>циркулянтный граф</kwd><kwd>циклическое накрытие</kwd><kwd>остовное дерево</kwd><kwd>спектр граф</kwd></kwd-group><funding-group><award-group><funding-source><institution-wrap><institution xml:lang="en">Russian Foundation for Basic Research</institution></institution-wrap><institution-wrap><institution xml:lang="ru">Российский фонд фундаментальных исследований</institution></institution-wrap></funding-source><award-id></award-id></award-group><award-group><funding-source><institution-wrap><institution xml:lang="en">Russian Foundation for Basic Research</institution></institution-wrap><institution-wrap><institution xml:lang="ru">Российский фонд фундаментальных исследований</institution></institution-wrap></funding-source><award-id></award-id></award-group><award-group><funding-source><institution-wrap><institution xml:lang="en">Government of the Russian Federation</institution></institution-wrap><institution-wrap><institution xml:lang="ru">Правительство РФ</institution></institution-wrap></funding-source><award-id></award-id></award-group></funding-group></article-meta></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Boesch F.T., Prodinger H. // Graphs and Combin. 1986. V. 2. 1. P. 191-200.</mixed-citation></ref><ref id="B2"><label>2.</label><mixed-citation>Golin M.J., Xuerong Yong, Yuanping Zhang // Discrete Math. 2010. V. 310. P. 792-803.</mixed-citation></ref><ref id="B3"><label>3.</label><mixed-citation>Sun W., Wang S., Zhang J. // J. Appl. Anal. Comput. 2016. V. 6. 1. P. 65-75.</mixed-citation></ref><ref id="B4"><label>4.</label><mixed-citation>Wu F.Y. // J. Phys. A: Math. Gen. 1977. V. 10. P. L113-115.</mixed-citation></ref><ref id="B5"><label>5.</label><mixed-citation>Shrock R., Wu F.Y. // J. Phys. A: Math. Gen. 2000. V. 33. P. 3881-3902.</mixed-citation></ref><ref id="B6"><label>6.</label><mixed-citation>Guttmann A.J., Rogers M.D. // J. Phys. A: Math. Theor. 2012. V. 45. 49. 494001.</mixed-citation></ref><ref id="B7"><label>7.</label><mixed-citation>Louis J. //Bull. Aust. Math. Soc. 2015. V. 92, 3. P. 365-373.</mixed-citation></ref><ref id="B8"><label>8.</label><mixed-citation>Abrosimov N.V., Baigonakova G.A., Mednykh I.A. // Sib. Electronic Math. Rep. 2018. V. 15. P. 1145-1157.</mixed-citation></ref><ref id="B9"><label>9.</label><mixed-citation>Kwon Y.S., Mednykh A.D., Mednykh I.A. // Linear Algebra Appl. 2017, V. 529, P. 355-373.</mixed-citation></ref><ref id="B10"><label>10.</label><mixed-citation>Медных А.Д., Медных И.А. // ДАН. 2018. Т. 479. № 4. С. 363-367.</mixed-citation></ref><ref id="B11"><label>11.</label><mixed-citation>Mednykh I.A. // Ars Math. Contemp. 2018. V. 15. P. 467-485.</mixed-citation></ref><ref id="B12"><label>12.</label><mixed-citation>Horton J.D., Bouwer I.Z. // J. Combin. Theory. Ser. B. 1991. V. 53. P. 114-129.</mixed-citation></ref><ref id="B13"><label>13.</label><mixed-citation>Kwon Y.S., Mednykh A.D., Mednykh I.A. // arXiv: 1811.03801v1 [math.CO] 09 Nov 2018.</mixed-citation></ref><ref id="B14"><label>14.</label><mixed-citation>Lorenzini D. // J. Combin. Theory Ser. B. 2008. V. 98. 6. P. 1271-1300.</mixed-citation></ref></ref-list></back></article>
