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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">cheb</journal-id><journal-title-group><journal-title xml:lang="ru">Чебышевский сборник</journal-title><trans-title-group xml:lang="en"><trans-title>Chebyshevskii Sbornik</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2226-8383</issn><publisher><publisher-name>Tula State Lev Tolstoy  Pedagogical University</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.22405/2226-8383-2024-25-2-67-81</article-id><article-id custom-type="elpub" pub-id-type="custom">cheb-1732</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>Статьи</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>Article</subject></subj-group></article-categories><title-group><article-title>Обобщенное преобразование Данкля на прямой в обратных задачах теории приближений</article-title><trans-title-group xml:lang="en"><trans-title>Generalized Dunkl transform on the line in inverse problems of approximation theory</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>Иванов</surname><given-names>Валерий Иванович</given-names></name><name name-style="western" xml:lang="en"><surname>Ivanov</surname><given-names>Valerii Ivanovich</given-names></name></name-alternatives><bio xml:lang="ru"><p>доктор физико-математических наук, профессор</p></bio><bio xml:lang="en"><p>doctor of physical and mathematical sciences, professor</p></bio><email xlink:type="simple">ivaleryi@mail.ru</email><xref ref-type="aff" rid="aff-1"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>Тульский государственный университет; &#13;
&#13;
Московский государственный университет&#13;
им. М.В. Ломоносова; &#13;
&#13;
Московский центр фундаментальной и прикладной математики</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Tula State University (Tula); &#13;
&#13;
Lomonosov Moscow State University; &#13;
&#13;
Moscow Center for Fundamental and Applied Mathematics</institution><country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2024</year></pub-date><pub-date pub-type="epub"><day>19</day><month>07</month><year>2024</year></pub-date><volume>25</volume><issue>2</issue><fpage>67</fpage><lpage>81</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Иванов В.И., 2024</copyright-statement><copyright-year>2024</copyright-year><copyright-holder xml:lang="ru">Иванов В.И.</copyright-holder><copyright-holder xml:lang="en">Ivanov V.I.</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://www.chebsbornik.ru/jour/article/view/1732">https://www.chebsbornik.ru/jour/article/view/1732</self-uri><abstract><p>Изучается обобщенный гармонический анализ Данкля на прямой, зависящий от параметра 𝑟 ∈ N. Случай 𝑟 = 0 ответствует обычному гармоническому анализу Данкля.Все конструкции зависят от параметра 𝑟 ⩾ 1. С помощью оператора обобщенного сдвигаопределяются разности и модули гладкости. С помощью дифференциально-разностногооператора определяется пространство Соболева. Исследуется приближение функций из пространства 𝐿𝑝(R, 𝑑𝜈𝜆) целыми функциями экспоненциального типа не выше 𝜎 из класса𝑓 ∈ 𝐵𝜎,𝑟 𝑝,𝜆, обладающих свойством 𝑓(2𝑠+1)(0) = 0, 𝑠 = 0, 1, . . . , 𝑟 − 1. Для целых функций из класса 𝑓 ∈ 𝐵𝜎,𝑟 𝑝,𝜆 доказываются неравенства, которые используются в обратных задачах теории приближений. В зависимости от поведения величин наилучшего приближения функции дается оценка модуля гладкости функции, а так же модуля гладкости от степени ее дифференциально-разностного оператора второго порядка. Дается условие асимптотического равенства между наилучшим приближением функции и ее модулем гладкости.</p></abstract><trans-abstract xml:lang="en"><p>The generalized Dunkl harmonic analysis on the line, depending on the parameter 𝑟 ∈ N, is studied. The case 𝑟 = 0 corresponds to the usual Dunkl harmonic analysis. All designs depend on the parameter 𝑟 ⩾ 1. Using the generalized shift operator, differences and moduli of smoothness are determined. Using the differential-difference operator, the Sobolev space is defined.We study the approximation of functions from space 𝐿𝑝(R, 𝑑𝜈𝜆) by entire functions of exponential type not higher than 𝜎 from the class 𝑓 ∈ 𝐵𝜎,𝑟𝑝,𝜆 that have the property 𝑓(2𝑠+1)(0) = 0, 𝑠 = 0, 1, . . . , 𝑟−1. For entire functions from the class 𝑓 ∈ 𝐵𝜎,𝑟𝑝,𝜆, inequalities are proved that are used in inverseproblems of approximation theory. Depending on the behavior of the values of the function bestapproximation, an estimate is given of the modulus of smoothness of the function, as well as the modulus of smoothness on the degree of its second-order differential-difference operator. A condition is given for asymptotic equality between the best approximation of the function and its modulus of smoothness.</p></trans-abstract><kwd-group xml:lang="ru"><kwd>Обобщенное преобразование Данкля</kwd><kwd>оператор обобщенного сдвига</kwd><kwd>свертка</kwd><kwd>модуль гладкости</kwd><kwd>целые функции экспоненциального типа</kwd><kwd>обратные неравенства теории приближений.</kwd></kwd-group><kwd-group xml:lang="en"><kwd>Generalized Dunkl transform</kwd><kwd>generalized translation operator</kwd><kwd>convolution</kwd><kwd>modulus of smoothness</kwd><kwd>entire functions of exponential type</kwd><kwd>inverse inequalities of approximation theory.</kwd></kwd-group><funding-group><funding-statement xml:lang="ru">Исследование выполнено за счет гранта Российского научного фонда № 23-71-30001, https://rscf.ru/projecs/23-71-30001/, в МГУ им. М.В. Ломоносова.</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">Ben Sa¨ıd S., Kobayashi T., Orsted B. Laguerre semigroup and Dunkl operators // Compos.</mixed-citation><mixed-citation xml:lang="en">Sa¨ıd S., Kobayashi, T., Orsted, B., 2012. “Laguerre semigroup and Dunkl operators” , Compos. Math., vol. 148, no. 4, pp. 1265–1336.</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">Math. 2012. Vol. 148, no. 4. P. 1265–1336.</mixed-citation><mixed-citation xml:lang="en">Dunkl, C. F., 1991. “Integral kernels with reflection group invariance” , Canad. J. Math., vol. 43, pp. 1213–1227.</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Dunkl C. F. Integral kernels with reflection group invariance // Canad. J. Math. 1991. Vol. 43.</mixed-citation><mixed-citation xml:lang="en">R´’osle,r M., 2002. “Dunkl operators. Theory and applications: in Orthogonal Polynomials and</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">P. 1213–1227.</mixed-citation><mixed-citation xml:lang="en">Special Functions” , Lecture Notes in Math. Springer-Verlag, vol. 1817, pp. 93–135.</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">R¨osler M. Dunkl operators. Theory and applications: in Orthogonal Polynomials and Special</mixed-citation><mixed-citation xml:lang="en">Gorbachev, D., Ivanov, V., Tikhonov, S., 2023. “On the kernel of the (𝜅, 𝑎)-Generalized Fourier</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Functions // Lecture Notes in Math. Springer-Verlag, 2002. Vol. 1817. P. 93–135.</mixed-citation><mixed-citation xml:lang="en">transform” , Forum of Mathematics, Sigma, vol. 11: e72 1–25. Published online by Cambridge</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Gorbachev D., Ivanov V., Tikhonov S. On the kernel of the (𝜅, 𝑎)-Generalized Fourier transform // Forum of Mathematics, Sigma. 2023. Vol. 11: e72 1–25. Published online by Cambridge University Press: 14 August 2023. Doi: https://doi.org/10.1017/fms.2023.69.</mixed-citation><mixed-citation xml:lang="en">University Press: 14 August 2023. Doi: https://doi.org/10.1017/fms.2023.69.</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Иванов В. И. Недеформированное обобщенное преобразование Данкля на прямой // Матем. заметки. 2023. Т. 114, № 4. С. 509–524.</mixed-citation><mixed-citation xml:lang="en">Ivanov, V. I., 2023. “Undeformed generalized Dunkl transform on the line” , Math. Notes.,</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Иванов В. И. Оператор сплетения для обобщенного преобразования Данкля на прямой // Чебышевский сборник. 2023. Т. 24, вып. 4. С. 48–62.</mixed-citation><mixed-citation xml:lang="en">vol. 114, no. 4, pp. 509–524.</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Иванов В. И. Обобщенное одномерное преобразование Данкля в прямых теоремах теории приближений // Матем. заметки. 2024. Т. 116, № 2. С. 269–284.</mixed-citation><mixed-citation xml:lang="en">Ivanov, V. I., 2023. “The intertwining operator for the generalized Dunkl transform on the line” ,</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">Платонов С. С. Гармонический анализ Бесселя и приближение функций на полупрямой</mixed-citation><mixed-citation xml:lang="en">Chebyshevskii sbornik, vol. 24, no. 4, pp. 48–62.</mixed-citation></citation-alternatives></ref><ref id="cit12"><label>12</label><citation-alternatives><mixed-citation xml:lang="ru">// Изв. РАН. Сер. матем. 2007. Т. 71, № 5. С. 149-196.</mixed-citation><mixed-citation xml:lang="en">Ivanov, V. I., 2024. “Generalized one-dimensional Dunkl transform in direct problems of</mixed-citation></citation-alternatives></ref><ref id="cit13"><label>13</label><citation-alternatives><mixed-citation xml:lang="ru">Платонов С. С. Обобщенные сдвиги Бесселя и некоторые задачи теории приближений</mixed-citation><mixed-citation xml:lang="en">approximation theory” , Math. Notes., vol. 116, no. 2, pp. 269–284.</mixed-citation></citation-alternatives></ref><ref id="cit14"><label>14</label><citation-alternatives><mixed-citation xml:lang="ru">функций на полупрямой // Сиб. матем. журн. 2009. Т. 50, № 1. С. 154-174.</mixed-citation><mixed-citation xml:lang="en">Platonov, S. S., 2007. “Bessel harmonic analysis and approximation of functions on the halfline”, Izv. Math., vol. 71, no. 5, pp. 1001–1048.</mixed-citation></citation-alternatives></ref><ref id="cit15"><label>15</label><citation-alternatives><mixed-citation xml:lang="ru">Gorbachev D. V., Ivanov V. I., Tikhonov SYu. Positive Lp-Bounded Dunkl-Type Generalized</mixed-citation><mixed-citation xml:lang="en">Platonov, S. S., 2009. “Bessel generalized translations and some problems of approximation</mixed-citation></citation-alternatives></ref><ref id="cit16"><label>16</label><citation-alternatives><mixed-citation xml:lang="ru">Translation Operator and Its Applications // Constr. Approx. 2023. Vol. 49, no. 3. P. 555–605.</mixed-citation><mixed-citation xml:lang="en">theory for functions on the half-line” , Siberian Math. J., vol. 50, no. 1, pp. 123–140.</mixed-citation></citation-alternatives></ref><ref id="cit17"><label>17</label><citation-alternatives><mixed-citation xml:lang="ru">Gorbachev D. V., Ivanov V. I. Fractional Smoothness in Lp with Dunkl Weight and Its</mixed-citation><mixed-citation xml:lang="en">Gorbachev, D. V., Ivanov, V. I., Tikhonov, SYu., 2019. “Positive Lp-Bounded Dunkl-Type</mixed-citation></citation-alternatives></ref><ref id="cit18"><label>18</label><citation-alternatives><mixed-citation xml:lang="ru">Applications // Math. Notes. 2019. Vol. 106, no. 4. P. 537–561.</mixed-citation><mixed-citation xml:lang="en">Generalized Translation Operator and Its Applications” , Constr. Approx., vol. 49, no. 3,</mixed-citation></citation-alternatives></ref><ref id="cit19"><label>19</label><citation-alternatives><mixed-citation xml:lang="ru">pp. 555–605.</mixed-citation><mixed-citation xml:lang="en">pp. 555–605.</mixed-citation></citation-alternatives></ref><ref id="cit20"><label>20</label><citation-alternatives><mixed-citation xml:lang="ru">Gorbachev, D. V., Ivanov, V. I., 2019. “Fractional Smoothness in Lp with Dunkl Weight and Its</mixed-citation><mixed-citation xml:lang="en">Gorbachev, D. V., Ivanov, V. I., 2019. “Fractional Smoothness in Lp with Dunkl Weight and Its</mixed-citation></citation-alternatives></ref><ref id="cit21"><label>21</label><citation-alternatives><mixed-citation xml:lang="ru">Applications” , Math. Notes., vol. 106, no. 4, pp. 537–561.</mixed-citation><mixed-citation xml:lang="en">Applications” , Math. Notes., vol. 106, no. 4, pp. 537–561.</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
