Теоретическая и математическая физика
RUS  ENG    ЖУРНАЛЫ   ПЕРСОНАЛИИ   ОРГАНИЗАЦИИ   КОНФЕРЕНЦИИ   СЕМИНАРЫ   ВИДЕОТЕКА   ПАКЕТ AMSBIB  
Общая информация
Последний выпуск
Архив
Импакт-фактор
Правила для авторов
Лицензионный договор
Загрузить рукопись

Поиск публикаций
Поиск ссылок

RSS
Последний выпуск
Текущие выпуски
Архивные выпуски
Что такое RSS



ТМФ:
Год:
Том:
Выпуск:
Страница:
Найти






Персональный вход:
Логин:
Пароль:
Запомнить пароль
Войти
Забыли пароль?
Регистрация


Теоретическая и математическая физика, 2009, том 158, номер 3, страницы 419–424
DOI: https://doi.org/10.4213/tmf6324
(Mi tmf6324)
 

Эта публикация цитируется в 79 научных статьях (всего в 79 статьях)

Дробные интегро-дифференциальные уравнения для электромагнитных волн в диэлектрических средах

В. Е. Тарасов

Научно-исследовательский институт ядерной физики им. Д. В. Скобельцына, МГУ им. М. В. Ломоносова
Список литературы:
Аннотация: Доказано, что электромагнитные поля в диэлектрических средах, восприимчивость которых в широком частотном диапазоне подчиняется дробно-степенной зависимости, описываются дифференциальными уравнениями с производными нецелого порядка по времени. Получены дробные интегро-дифференциальные уравнения для электромагнитных волн в диэлектрике. Электромагнитные поля в диэлектриках демонстрируют дробно-степенную релаксацию. Дробные интегро-дифференциальные уравнения для электромагнитных волн являются общими для широкого класса диэлектрических сред независимо от физической структуры, химического состава или природы поляризации (дипольная, электронная или ионная).
Ключевые слова: дробное интегро-дифференцирование, дробное затухание, универсальный ответ, электромагнитное поле, диэлектрические среды.
Поступило в редакцию: 18.12.2007
После доработки: 24.06.2008
Англоязычная версия:
Theoretical and Mathematical Physics, 2009, Volume 158, Issue 3, Pages 355–359
DOI: https://doi.org/10.1007/s11232-009-0029-z
Реферативные базы данных:
Образец цитирования: В. Е. Тарасов, “Дробные интегро-дифференциальные уравнения для электромагнитных волн в диэлектрических средах”, ТМФ, 158:3 (2009), 419–424; Theoret. and Math. Phys., 158:3 (2009), 355–359
Цитирование в формате AMSBIB
\RBibitem{Tar09}
\by В.~Е.~Тарасов
\paper Дробные интегро-дифференциальные уравнения для электромагнитных волн в~диэлектрических средах
\jour ТМФ
\yr 2009
\vol 158
\issue 3
\pages 419--424
\mathnet{http://mi.mathnet.ru/tmf6324}
\crossref{https://doi.org/10.4213/tmf6324}
\mathscinet{http://mathscinet.ams.org/mathscinet-getitem?mr=2547451}
\zmath{https://zbmath.org/?q=an:1177.78020}
\adsnasa{https://adsabs.harvard.edu/cgi-bin/bib_query?2009TMP...158..355T}
\transl
\jour Theoret. and Math. Phys.
\yr 2009
\vol 158
\issue 3
\pages 355--359
\crossref{https://doi.org/10.1007/s11232-009-0029-z}
\isi{https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=Publons&SrcAuth=Publons_CEL&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=000264844000008}
\scopus{https://www.scopus.com/record/display.url?origin=inward&eid=2-s2.0-63849151360}
Образцы ссылок на эту страницу:
  • https://www.mathnet.ru/rus/tmf6324
  • https://doi.org/10.4213/tmf6324
  • https://www.mathnet.ru/rus/tmf/v158/i3/p419
  • Эта публикация цитируется в следующих статьяx:
    1. Preda L., Mihailescu M., Preda A., “Application of fractional derivative to the relaxation of laser target”, University Politehnica of Bucharest Scientific Bulletin Ser. A Appl. Math. Phys., 71:4 (2009), 11–20  isi
    2. Elwakil A.S., “Fractional-Order Circuits and Systems: An Emerging Interdisciplinary Research Area”, IEEE Circuits and Systems Magazine, 10:4 (2010), 40–50  crossref  isi  scopus
    3. Calcagni G., “Geometry of Fractional Spaces”, Adv. Theor. Math. Phys., 16:2 (2012), 549–644  crossref  mathscinet  zmath  isi  elib  scopus
    4. Hussain A., Naqvi S.A., Illahi A., Syed A.A., Naqvi Q.A., “Fields in Fractional Parallel Plate Db Waveguides”, Prog. Electromagn. Res., 125 (2012), 273–294  crossref  isi  elib  scopus  scopus
    5. Edelman M., “Universal Fractional Map and Cascade of Bifurcations Type Attractors”, Chaos, 23:3 (2013), 033127  crossref  mathscinet  zmath  adsnasa  isi  elib  scopus  scopus
    6. Alikhani R., Bahrami F., “Global Solutions for Nonlinear Fuzzy Fractional Integral and Integrodifferential Equations”, Commun. Nonlinear Sci. Numer. Simul., 18:8 (2013), 2007–2017  crossref  mathscinet  zmath  adsnasa  isi  elib  scopus
    7. Tarasov V.E., “Lattice Model of Fractional Gradient and Integral Elasticity: Long-Range Interaction of Grunwald-Letnikov-Riesz Type”, Mech. Mater., 70 (2014), 106–114  crossref  isi  scopus  scopus
    8. Calcagni G., Magueijo J., Rodriguez Fernandez D., “Varying Electric Charge in Multiscale Spacetimes”, Phys. Rev. D, 89:2 (2014), 024021  crossref  mathscinet  adsnasa  isi  scopus  scopus
    9. Gulistan S., Abbas M., Syed A.A., “Fractional Dual Fields For a Slab Placed in Unbounded Dielectric Magnetic Medium”, Int. J. Appl. Electromagn. Mech., 46:1 (2014), 11–21  crossref  isi
    10. Tarasov V.E., “Fractal Electrodynamics Via Non-Integer Dimensional Space Approach”, Phys. Lett. A, 379:36 (2015), 2055–2061  crossref  mathscinet  zmath  adsnasa  isi  elib  scopus  scopus
    11. Edelman M., “on the Fractional Eulerian Numbers and Equivalence of Maps With Long Term Power-Law Memory (Integral Volterra Equations of the Second Kind) To Grunvald-Letnikov Fractional Difference (Differential) Equations”, Chaos, 25:7 (2015), 073103  crossref  mathscinet  zmath  adsnasa  isi
    12. Hu J.-B., Zhao L.-D., Lu G.-P., Zhang Sh.-B., “the Stability and Control of Fractional Nonlinear System With Distributed Time Delay”, Appl. Math. Model., 40:4 (2016), 3257–3263  crossref  mathscinet  isi  scopus  scopus
    13. Cherif M.H., Belghaba K., Ziane D., “Homotopy Perturbation Method For Solving the Fractional Fisher'S Equation”, Int. J. Anal. Appl., 10:1 (2016), 9–16  mathscinet  zmath  isi
    14. Hu J.-B., Lu G.-P., Zhao L.-D., “Synchronization of Fractional Chaotic Complex Networks With Distributed Delays”, Nonlinear Dyn., 83:1-2 (2016), 1101–1108  crossref  mathscinet  zmath  isi  scopus  scopus
    15. Singh Ch.Sh., Singh H., Singh V.K., Singh O.P., “Fractional order operational matrix methods for fractional singular integro-differential equation”, Appl. Math. Model., 40:23-24 (2016), 10705–10718  crossref  mathscinet  isi  scopus
    16. Garrappa R., Mainardi F., Maione G., “Models of dielectric relaxation based on completely monotone functions”, Fract. Calc. Appl. Anal., 19:5 (2016), 1105–1160  crossref  mathscinet  zmath  isi  elib  scopus
    17. Bouzid N., Merad M., Baleanu D., “On Fractional Duffin?Kemmer?Petiau Equation”, Few-Body Syst., 57:4 (2016), 265–273  crossref  isi  elib  scopus
    18. Gomez-Aguilar J.F., Yepez-Martinez H., Calderon-Ramon C., Benavidez-Cruz M., Morales-Mendoza L.J., “Fractional electromagnetic waves in conducting media”, J. Electromagn. Waves Appl., 30:2 (2016), 259–271  crossref  mathscinet  isi  elib  scopus
    19. Patel V.K., Singh S., Singh V.K., “Two-dimensional wavelets collocation method for electromagnetic waves in dielectric media”, J. Comput. Appl. Math., 317 (2017), 307–330  crossref  mathscinet  zmath  isi  elib  scopus
    20. Kumar K., Pandey R.K., Sharma Sh., “Comparative study of three numerical schemes for fractional integro-differential equations”, J. Comput. Appl. Math., 315 (2017), 287–302  crossref  mathscinet  zmath  isi  elib  scopus
    21. Zhao F., Xie J., Huang Q., “Numerical Simulation of One-Dimensional Fractional Nonsteady Heat Transfer Model Based on the Second Kind Chebyshev Wavelet”, Discrete Dyn. Nat. Soc., 2017, 2658124  crossref  mathscinet  isi
    22. Patel V.K., Singh S., Singh V.K., “Two-Dimensional Shifted Legendre Polynomial Collocation Method For Electromagnetic Waves in Dielectric Media Via Almost Operational Matrices”, Math. Meth. Appl. Sci., 40:10 (2017), 3698–3717  crossref  mathscinet  zmath  isi  scopus  scopus
    23. Si G., Diao L., Zhu J., Lei Yu., Zhang Ya., “Attempt to Generalize Fractional-Order Electric Elements to Complex-Order Ones”, Chin. Phys. B, 26:6 (2017), 060503  crossref  isi  scopus  scopus
    24. Bouzid N., Merad M., “Space-Time Fractional DKP Equation and Its Solution”, Few-Body Syst., 58:3 (2017), UNSP 131  crossref  isi  scopus  scopus
    25. Zheng R., Jiang X., Zhang H., “L1 Fourier Spectral Methods For a Class of Generalized Two-Dimensional Time Fractional Nonlinear Anomalous Diffusion Equations”, Comput. Math. Appl., 75:5 (2018), 1515–1530  crossref  mathscinet  isi  scopus
    26. Sharma Sh., Pandey R.K., Kumar K., “Collocation Method With Convergence For Generalized Fractional Integro-Differential Equations”, J. Comput. Appl. Math., 342 (2018), 419–430  crossref  mathscinet  zmath  isi  scopus  scopus
    27. Abd El-Maksoud A.J., Abd El-Kader A.A., Hassan B.G., Abdelhamed M.A., Rihan N.G., Tolba M.F., Said L.A., Radwan A.G., Abu-Elyazeed M.F., “Fpga Implementation of Fractional-Order Chua'S Chaotic System”, 2018 7Th International Conference on Modern Circuits and Systems Technologies (Mocast), IEEE, 2018  isi
    28. Tarasov V.E., Tarasova V.V., “Criterion of Existence of Power-Law Memory For Economic Processes”, Entropy, 20:6 (2018), 414  crossref  mathscinet  isi  scopus
    29. Burgos C., Calatayud J., Cortes J.-C., Navarro-Quiles A., “A Full Probabilistic Solution of the Random Linear Fractional Differential Equation Via the Random Variable Transformation Technique”, Math. Meth. Appl. Sci., 41:18, SI (2018), 9037–9047  crossref  mathscinet  zmath  isi  scopus
    30. Dai X., Bu W., Xiao A., “Well-Posedness and Em Approximations For Non-Lipschitz Stochastic Fractional Integro-Differential Equations”, J. Comput. Appl. Math., 356 (2019), 377–390  crossref  mathscinet  isi  scopus
    31. Jamil M., Khan R.A., Shah K., “Existence Theory to a Class of Boundary Value Problems of Hybrid Fractional Sequential Integro-Differential Equations”, Bound. Value Probl., 2019, 77  crossref  mathscinet  isi  scopus
    32. Zeid S.S., “Approximation Methods For Solving Fractional Equations”, Chaos Solitons Fractals, 125 (2019), 171–193  crossref  mathscinet  isi
    33. Hendi F.A., Shammakh W., Al-badrani H., “Existence Result and Approximate Solutions For Quadratic Integro-Differential Equations of Fractional Order”, J. King Saud Univ. Sci., 31:3 (2019), 314–321  crossref  isi
    34. Jonnalagadda J.M., “Fractional Difference Equations of Volterra Type”, Kragujev. J. Math., 43:2 (2019), 219–237  mathscinet  isi
    35. Ali A., Shah K., Li Y., Khan R.A., “Numerical Treatment of Coupled System of Fractional Order Partial Differential Equations”, J. Math. Comput. Sci.-JMCS, 19:2 (2019), 74–85  crossref  isi  scopus
    36. Stefanski T.R., Gulgowski J., “Electromagnetic-Based Derivation of Fractional-Order Circuit Theory”, Commun. Nonlinear Sci. Numer. Simul., 79 (2019), UNSP 104897  crossref  mathscinet  isi
    37. Sultana F., Singh D., Pandey R.K., Zeidan D., “Numerical Schemes For a Class of Tempered Fractional Integro-Differential Equations”, Appl. Numer. Math., 157 (2020), 110–134  crossref  mathscinet  isi
    38. Pskhu A.V., Rekhviashvili S.Sh., “Retarded Potentials in Fractional Electrodynamics”, Mosc. Univ. Phys. Bull., 75:4 (2020), 316–319  crossref  isi  scopus
    39. Alsaedi A., Broom A., Ntouyas S.K., Ahmad B., “Existence Results and the Dimension of the Solution Set For a Nonlocal Inclusions Problem With Mixed Fractional Derivatives and Integrals”, J. Nonlinear Funct. Anal., 2020, 28  crossref  mathscinet  isi
    40. Ahmad B., Broom A., Alsaedi A., Ntouyas S.K., “Nonlinear Integro-Differential Equations Involving Mixed Right and Left Fractional Derivatives and Integrals With Nonlocal Boundary Data”, Mathematics, 8:3 (2020)  crossref  isi
    41. Maurya R.K., Devi V., Singh V.K., “Multistep Schemes For One and Two Dimensional Electromagnetic Wave Models Based on Fractional Derivative Approximation”, J. Comput. Appl. Math., 380 (2020), 112985  crossref  mathscinet  isi  scopus
    42. Nasrolahpour H., “Fractional Electromagnetic Metamaterials”, Optik, 203 (2020), UNSP 163969  crossref  isi
    43. Zhou X. Shan W. Niu Zh. Xiao P. Wang Y., “Lie Symmetry Analysis, Explicit Solutions and Conservation Laws For the Time Fractional Kolmogorov-Petrovskii-Piskunov Equation”, Waves Random Complex Media, 30:3 (2020), 514–529  crossref  mathscinet  isi
    44. Gupta A., Pandey R.K., “Adaptive Huber Scheme For Weakly Singular Fractional Integro-Differential Equations”, Differ. Equat. Dyn. Syst., 28:3, SI (2020), 527–538  crossref  mathscinet  isi
    45. Alsaedi A., Broom A., Ntouyas S.K., Ahmad B., “Nonlocal Fractional Boundary Value Problems Involving Mixed Right and Left Fractional Derivatives and Integrals”, Axioms, 9:2 (2020), 50  crossref  isi
    46. Persechino A., “An Introduction to Fractional Calculus Numerical Methods and Application to Hf Dielectric Response”, Adv. Electromagn., 9:1 (2020), 19–30  crossref  isi
    47. Alsaedi A., Albideewi A.F., Ntouyas S.K., Ahmad B., “On Caputo-Riemann-Liouville Type Fractional Integro-Differential Equations With Multi-Point Sub-Strip Boundary Conditions”, Mathematics, 8:11 (2020), 1899  crossref  mathscinet  isi
    48. Qiang X., Kamran, Mahboob A., Chu Yu.-M., “Numerical Approximation of Fractional-Order Volterra Integrodifferential Equation”, J. Funct. space, 2020 (2020), 8875792  crossref  mathscinet  isi  scopus
    49. Stefanski T.P., Gulgowski J., “Signal Propagation in Electromagnetic Media Described By Fractional-Order Models”, Commun. Nonlinear Sci. Numer. Simul., 82 (2020), UNSP 105029  crossref  mathscinet  isi
    50. Gulgowski J., Stefanski T.P., “On Applications of Fractional Derivatives in Electromagnetic Theory”, 2020 23Rd International Microwave and Radar Conference (Mikon 2020), IEEE, 2020, 13–17  isi
    51. Maurya R.K., Devi V., Singh V.K., “Stability and Convergence of Multistep Schemes For 1D and 2D Fractional Model With Nonlinear Source Term”, Appl. Math. Model., 89:2 (2021), 1721–1746  crossref  mathscinet  isi  scopus
    52. Kumar K., Pandey R.K., Sultana F., “Numerical Schemes With Convergence For Generalized Fractional Integro-Differential Equations”, J. Comput. Appl. Math., 388 (2021), 113318  crossref  mathscinet  isi
    53. Sylvere A.S., Justin M., David V., Joseph M., Betchewe G., “Impact of Fractional Effects on Modulational Instability and Bright Soliton in Fractional Optical Metamaterials”, Waves Random Complex Media, 2021  crossref  mathscinet  isi
    54. Patel V.K., Bahuguna D., “An Efficient Matrix Approach For the Numerical Solutions of Electromagnetic Wave Model Based on Fractional Partial Derivative”, Appl. Numer. Math., 169 (2021), 1–20  crossref  mathscinet  isi
    55. Stefanski T.P., Gulgowski J., “Formulation of Time-Fractional Electrodynamics Based on Riemann-Silberstein Vector”, Entropy, 23:8 (2021), 987  crossref  mathscinet  isi
    56. Stefanski T.P., “On Possible Applications of Media Described By Fractional-Order Models in Electromagnetic Cloaking”, Commun. Nonlinear Sci. Numer. Simul., 99 (2021), 105827  crossref  mathscinet  isi
    57. Mustafa S., Hajira, Khan H., Shah R., Masood S., “A Novel Analytical Approach For the Solution of Fractional-Order Diffusion-Wave Equations”, Fractal Fract., 5:4 (2021), 206  crossref  isi
    58. Pleumpreedaporn S., Sudsutad W., Thaiprayoon Ch., Napoles J.E., Kongson J., “A Study of Psi-Hilfer Fractional Boundary Value Problem Via Nonlinear Integral Conditions Describing Navier Model”, Mathematics, 9:24 (2021), 3292  crossref  isi
    59. Gulgowski J., Stefanski T.P., “Generalization of Kramers-Kronig Relations For Evaluation of Causality in Power-Law Media”, Commun. Nonlinear Sci. Numer. Simul., 95 (2021), 105664  crossref  mathscinet  isi  scopus
    60. Ziane D., Hamdi Cherif M., “A New Analytical Solution of Klein-Gordon Equation With Local Fractional Derivative”, Asian-Eur. J. Math., 14:3 (2021), 2150029  crossref  mathscinet  isi
    61. Abdelhakem M., Mahmoud D., Baleanu D., El-kady M., “Shifted Ultraspherical Pseudo-Galerkin Method For Approximating the Solutions of Some Types of Ordinary Fractional Problems”, Adv. Differ. Equ., 2021:1 (2021), 110  crossref  mathscinet  isi
    62. Wang J., Kamran, Jamal A., Li X., “Numerical Solution of Fractional-Order Fredholm Integrodifferential Equation in the Sense of Atangana-Baleanu Derivative”, Math. Probl. Eng., 2021 (2021), 6662808  crossref  mathscinet  isi
    63. Thaiprayoon Ch., Sudsutad W., Alzabut J., Etemad S., Rezapour Sh., “On the Qualitative Analysis of the Fractional Boundary Value Problem Describing Thermostat Control Model Via Psi-Hilfer Fractional Operator”, Adv. Differ. Equ., 2021:1 (2021), 201  crossref  mathscinet  isi
    64. Ali A., Khan N., Israr S., “On Establishing Qualitative Theory to Nonlinear Boundary Value Problem of Fractional Differential Equations”, Math. Sci., 15:4 (2021), 395–403  crossref  mathscinet  isi
    65. Zheng B., Hu Ch., Yu J., Jiang H., “Synchronization Analysis For Delayed Spatio-Temporal Neural Networks With Fractional-Order”, Neurocomputing, 441 (2021), 226–236  crossref  isi
    66. Kumar S., Pandey R.K., Srivastava H.M., Singh G.N., “A Convergent Collocation Approach For Generalized Fractional Integro-Differential Equations Using Jacobi Poly-Fractonomials”, Mathematics, 9:9 (2021), 979  crossref  isi
    67. Beybalaev V.D., Abduragimov I E., Yakubov A.Z., Meilanov R.R., Aliverdiev A.A., “Numerical Research of Non-Isothermal Filtration Process in Fractal Medium With Non-Locality in Time”, Therm. Sci., 25:1, B (2021), 465–475  crossref  isi
    68. Karpinski K. Zielinska-Raczynska S. Ziemkiewicz D., “Fractional Derivative Modification of Drude Model”, Sensors, 21:15 (2021), 4974  crossref  isi  scopus
    69. Timofejeva I., Navickas Z., Telksnys T., Marcinkevicius R., Yang X.-J., Ragulskis M., “The Extension of Analytic Solutions to Fdes to the Negative Half-Line”, AIMS Math., 6:4 (2021), 3257–3271  crossref  mathscinet  isi
    70. Singh D., Sultana F., Pandey R.K., Atangana A., “A Comparative Study of Three Numerical Schemes For Solving Atangana-Baleanu Fractional Integro-Differential Equation Defined in Caputo Sense”, Eng. Comput., 38:S1 (2022), 149–168  crossref  isi
    71. Mendiola-Fuentes J., Melchor-Aguilar D., “A Note on Stability of Fractional Logistic Maps”, Appl. Math. Lett., 125 (2022), 107787  crossref  mathscinet  isi
    72. Dai X., Xiao A., Bu W., “Stochastic Fractional Integro-Differential Equations With Weakly Singular Kernels: Well-Posedness and Euler-Maruyama Approximation”, Discrete Contin. Dyn. Syst.-Ser. B, 27:8 (2022), 4231  crossref  isi
    73. Wang X., Xu B., Shi P., Li Sh., “Efficient Learning Control of Uncertain Fractional-Order Chaotic Systems With Disturbance”, IEEE Trans. Neural Netw. Learn. Syst., 33:1 (2022), 445–450  crossref  mathscinet  isi
    74. Behera S., Ray S.S., “A Wavelet-Based Novel Technique For Linear and Nonlinear Fractional Volterra-Fredholm Integro-Differential Equations”, Comput. Appl. Math., 41:2 (2022), 77  crossref  mathscinet  isi
    75. Wu L., Chen Zh., Ding X., “A Minimal Search Method For Solving Fractional Integro-Differential Equations Based on Modified Legendre Multiwavelets”, J. Appl. Math. Comput., 68:2 (2022), 1467–1483  crossref  mathscinet  isi
    76. Abdelhakem M., Abdelhamied D., Alshehri M.G., El-Kady M., “Shifted Legendre Fractional Pseudospectral Differentiation Matrices For Solving Fractional Differential Problems”, Fractals-Complex Geom. Patterns Scaling Nat. Soc., 30:01 (2022), 2240038  crossref  isi
    77. Jan M.N., Zaman G., Ahmad I., Ali N., Nisar K.S., Abdel-Aty A.-H., Zakarya M., “Existence Theory to a Class of Fractional Order Hybrid Differential Equations”, Fractals-Complex Geom. Patterns Scaling Nat. Soc., 30:01 (2022), 2240022  crossref  isi
    78. Stefanski T.P., Gulgowski J., Tsakmakidis K.L., “Analytical Methods For Causality Evaluation of Photonic Materials”, Materials, 15:4 (2022), 1536  crossref  isi
    79. Khaminsou B., Sudsutad W., Kongson J., Nontasawatsri S., Vajrapatkul A., Thaiprayoon Ch., “Investigation of Caputo Proportional Fractional Integro-Differential Equation With Mixed Nonlocal Conditions With Respect to Another Function”, AIMS Math., 7:6 (2022), 9549–9576  crossref  mathscinet  isi
    Citing articles in Google Scholar: Russian citations, English citations
    Related articles in Google Scholar: Russian articles, English articles
    Теоретическая и математическая физика Theoretical and Mathematical Physics
    Статистика просмотров:
    Страница аннотации:1273
    PDF полного текста:309
    Список литературы:73
    Первая страница:42
     
      Обратная связь:
     Пользовательское соглашение  Регистрация посетителей портала  Логотипы © Математический институт им. В. А. Стеклова РАН, 2024