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Компактная аппроксимация двумерной краевой задачи для эллиптических уравнений второго порядка с разрывным коэффициентом
Математическое моделирование. 2023. Т. 35. № 4. С. 88–119.
Gordin V. A., Шадрин Д. А.
Denis Seliutskii, Russian Journal of Mathematical Physics 2025 Vol. 32 No. 2 P. 399–407
In this paper, we find an upper bound for the first Steklov eigenvalue for a surface of revolution with boundary consisting of two spheres of different radii. Moreover, we prove that, in some cases, this boundary is sharp. ...
Added: May 19, 2026
Жакупов О. Б., European Journal of Mathematics 2025 Vol. 11 Article 84
We provide examples of smooth three-dimensional Fano complete intersections of degree 2, 4, 6, and 8 that have absolute coregularity 0. Considering the main theorem of Avilov, Loginov, and Przyjalkowski (CNTP 18:506–577, 2024) on the remaining 101 families of smooth Fano threefolds, our result implies that each family of smooth Fano threefolds has an element of absolute ...
Added: May 18, 2026
Mkrtchyan N. V., Regional Research of Russia 2026 Vol. 16 No. 1 P. 170–181
The aim of the study is to assess the provision of all settlements in four regions of the Near North of Russia (Vologda, Kostroma, Kirov, and Yaroslavl oblasts) with social infrastructure institutions and to analyze whether the migration balance of settlements is associated with different provision of these institutions. The study was conducted using data ...
Added: May 16, 2026
Lerman L. M., Turaev D. V., Regular and Chaotic Dynamics 2026 Vol. 31 No. 3 P. 349–369
We show that bifurcations of four-dimensional symplectic diffeomorphisms with a quadratic homoclinic tangency to a saddle periodic orbit with real multipliers produce 2-elliptic periodic orbits if the tangency is not partially hyperbolic. We show that a normal form for the rescaled first-return maps near such tangency is given by a four-dimensional symplectic H´enonlike map and study bifurcations of the ...
Added: May 15, 2026
Aleskerov F. T., Yakuba V. I., Khutorskaya O. et al., Springer, 2026.
The book contains new models of bibliometric analysis based on centrality measures in network analysis, pattern analysis and stability analysis. A distinctive feature of these centrality measures is that they account for the parameters of vertices and group influence of vertices to a vertex. This reveals specific groups of publications, authors, terms, journals and affiliations ...
Added: May 15, 2026
Kuptsov P., Panyushev A., Stankevich N., Chaos 2026 Vol. 36 No. 5 Article 053138
We develop a machine-learning approach to reproduce the behavior of two versions of the van der Pol oscillator exhibiting a subcritical Andronov–Hopf bifurcation, with or without a codimension-2 Bautin point. We construct a neural-network model that functions as a recur rent map and train it on short segments of oscillator trajectories. The results show that, ...
Added: May 15, 2026
Dorovskiy A., / Series arXiv "math". 2026.
In this paper the structural stability of generic families of vector fields of the PC-HC class on the two-dimensional sphere is proved. A classification of these families up to moderate equivalence in neighborhoods of their large bifurcation supports is presented, based on such invariants as the configuration and the characteristic set. The realization lemma is proved. ...
Added: May 14, 2026
Lebedev V., Journal of Mathematical Analysis and Applications 2026 Vol. 563 No. 2 Article 130787
It is known that for every continuous real-valued
function $f$ on the circle $\mathbb T=\mathbb R/2\pi\mathbb Z$ there exists a
change of variable, i.e., a self-homeomorphism $h$ of $\mathbb T$, such that
the superposition $f\circ h$ is in the Sobolev space $W_2^{1/2}(\mathbb T)$.
We obtain new results on simultaneous improvement of functions by a single
change of variable in relation ...
Added: May 14, 2026
Gaeva D. V., Barinova G. M., Romanchuk A. Y., Theoretical and Applied Climatology 2026 Vol. 157 Article 302
The objective of the paper was the spatio-temporal analysis of the dynamics of extreme climate indices for the south-eastern coast of the Baltic Sea over the 40-year period 1981–2020, employing 10 extreme indices proposed by Expert Team (ET) on Climate Change Detection and Indices (ETCCDI), characterizing hazardous phenomena as: extremely high temperatures, heat waves and ...
Added: May 13, 2026
Mkrtchyan N. V., Известия РАН. Серия географическая 2026 Т. 90 № 1 С. 231–245
Objective of the study is to assess the provision of all settlements in four regions of the Russian Near
North (Vologda, Kostroma, Kirov, and Yaroslavl oblasts) with social infrastructure facilities and to
analyze whether the migration balance of settlements is associated with varying levels of provision of
these facilities. The study is based on data collected from open ...
Added: May 13, 2026
Blokh A., Oversteegen L., Selinger N. et al., Arnold Mathematical Journal 2025 Vol. 12 No. 1 P. 1–40
We describe a model for the boundary of the connectedness locus of the parameter space of cubic symmetric polynomials. We show that there exists a monotone continuous function from the connectedness locus to the model which is a homeomorphism if the former is locally connected. ...
Added: May 13, 2026
Petrov I., Автоматика и телемеханика 2026 № 6 С. 82–118
Системам связанных агентов и сетевому управлению посвящено большое число отечественных и зарубежных исследований. Исторически, наибольший интерес в теории управления возникал к усредняющим системам и, в частности, к задаче консенсуса. Однако сетевое взаимодействие может характеризоваться более специфическими функциями, отражающими зависимость от действий соседей по сети, что особенно явно проявляется в моделях стратегического взаимодействия на сети, которое ...
Added: May 12, 2026
М.: ООО «Макс Пресс», 2026.
В настоящем сборнике представлены тезисы докладов участников семинара "Интеграция основного и дополнительного физико-математического образования", проходившего 11 февраля 2026 года в ГБОУ Школа №2007 ФМШ г. москвы, а также другие публикации, посвящённые вопросам дополнительного физико-математического образования. ...
Added: May 11, 2026
Magnus J. R., Peresetsky A., Frontiers in Psychology 2022 Vol. 13 Article 840180
An explanation of the Dunning–Kruger effect is provided which does not require any psychological explanation, because it is derived as a statistical artifact. This is achieved by specifying a simple statistical model which explicitly takes the (random) boundary constraints into account. The model fits the data almost perfectly ...
Added: March 25, 2022
Magnus J. R., Peresetsky A., / Series TI "Tinbergen Institute Discussion Paper". 2021. No. 2021-092/III.
Added: November 3, 2021
Gordin V. A., Океанологические исследования 2019 Т. 47 № 1 С. 32–37
Compact difference schemes are well known and demonstrate a high order of accuracy for differential equations with constant coefficients.
Algorithms for constructing compact schemes of the 4-th order for boundary value problems with variable (smooth and with a jump) coefficient have been developed. For the diffusion equations with a smooth variable coefficient and the Levin - ...
Added: June 15, 2021
Kurakin D., Социологическое обозрение 2020 Т. 19 № 3 С. 167–231
Inequality is amongst the most fundamental and formidable social problems of modernity. It thus does not come as a surprise that it is a major theme that cuts through multiple areas of sociology. However, the major limitation of most social research on inequality is that its focus is often limited to the redistribution of resources, ...
Added: October 16, 2020
Gordin V. A., Shemendyuk A., / Series arXiv "math". 2018. No. 1811.05311.
Local perturbations of an infinitely long rod go away to infinity. On the contrary, in the case of a finite length of the rod the perturbations reach its boundary and are reflected from them. The boundary conditions constructed here for the implicit difference scheme imitate the Cauchy problem and provide almost no reflection. These boundary ...
Added: January 13, 2020
Gordin V. A., В кн.: Современные проблемы математического моделирования: сборник трудов XVIII Всероссийской конференции-школы молодых исследователей (пос. Абрау-Дюрсо, 16–20 сентября 2019 г.).: Ростов н/Д: Издательство ЮФУ, 2019. Гл. 9 С. 40–52.
When solving boundary value problems of mathematical physics, compact schemes allow increasing (in comparison with classical ones) the solution accuracy order with a slight increase in the number of arithmetic operations. An indispensable condition of the algorithm is the use of the double-sweep approach. A method for calculating the coefficients of schemes is shown both ...
Added: December 30, 2019
Ростов н/Д: Издательство ЮФУ, 2019.
В сборнике представлены доклады участников XVIII Всероссийской конференции-школы молодых исследователей ”СОВРЕМЕННЫЕ ПРОБЛЕМЫ МАТЕМАТИЧЕСКОГО МОДЕЛИРОВАНИЯ”, организованной Институтом прикладной математики им. М.В. Келдыша РАН и Институтом математики, механики и компьютерных наук им. И.И. Воровича Южного федерального университета, проходившей с 16 по 21 сентября
2019 года в поселке Абрау-Дюрсо, Новороссийск, Россия. В работе школы приняли участие представители научных центров ...
Added: December 29, 2019
Kurakin D., American Journal of Cultural Sociology 2020 Vol. 8 No. 1 P. 63–89
Cultural sociology must catch up in taking seriously recent initiatives in the sociology of culture and cognition, represented by the works of Omar Lizardo, John Levi Martin, Stephen Vaisey, and others. However, aiming at progress in cultural analysis, these theories are partly driven by an epistemic logic alien to cultural theorizing, making the very concept ...
Added: October 14, 2019
Gordin V. A., Tsymbalov E. A., Математическое моделирование 2017 Т. 29 № 12 С. 16–28
We present compact difference approximation on equidistant grid for the Dirichlet problem for
the second order divergent type linear differential equation with piecewise-constant coefficient
and discontinuous right hand side. Our numerical experiments demonstrate essential advantage of
the scheme in comparison with the classic divergence scheme. We obtain same results for the
Sturm – Liouville problem. The Richardson extrapolation method ...
Added: December 15, 2016
Gordin V. A., Tsymbalov E. A., Mathematical Models and Computer Simulations, 10(1), 79-88 2017 Т. 29 № 7 С. 3–14
We present compact difference scheme on three-point stencil for unknown function. The scheme approximates linear second order differential equation with variable smooth coefficient. Our numerical experiments confirmed 4-th accuracy order of solutions of the difference scheme and of eigenvalues’ approximation for the boundary problem. The difference operator is almost self-conjugate, and its spectrum is real. ...
Added: December 15, 2016
Lavrinenko Y. S., Morozov I.V., Valuev I. A., Contributions to Plasma Physics 2016 Vol. 56 P. 448–458
The influence of boundary conditions for the classical and wave packet molecular dynamics (MD) simulations of nonideal electron-ion plasma is studied. We start with the classical MD and perform a comprehensive study of convergence of the per-particle potential energy and pressure with the number of particles using both the nearest image method (periodic boundaries) and ...
Added: June 28, 2016