?
О пространственной дискретизации одномерной квазигазодинамической системы уравнений с общими уравнениями состояния и балансе энтропии
Журнал вычислительной математики и математической физики. 2015. Т. 55. № 2. С. 267–284.
Gavrilin V. A., Zlotnik A.
Piontkovski D., / Series arXiv "math". 2026.
A noncommutative projective variety is defined, following Artin and Zhang, by a graded coherent algebra 𝐴. The category of coherent sheaves is then the quotient qgr(𝐴) of the category of finitely presented graded modules by the subcategory of torsion modules. We consider the categorical and polynomial entropies of the Serre twist, that is, of the ...
Added: June 23, 2026
Piontkovski D., / Series arXiv "math". 2025.
If a symmetric multilinear algebra is weakly nil, then it is Engel. This result may be regarded as an infinite-dimensional analogue of the well-known Jacobian theorem, which states that if a polynomial mapping has a polynomial inverse, then its Jacobian matrix is invertible. This refines a theorem of Gerstenhaber and partially answers a question posed ...
Added: June 23, 2026
Shipilov F., Barnyakov A., Ivanov A. et al., / Series Physics "arxiv.org". 2026.
A fast simulation of the detector response is a vital task in high-energy physics (HEP). Traditional Monte-Carlo methods form the backbone of modern particle physics simulation software but are computationally expensive. We present a machine-learning-based approach to fast simulation of the Focusing Aerogel Ring Imaging Cherenkov (FARICH) detector response. Given a particle track and momentum, ...
Added: May 19, 2026
Derkacheva A., Sakirkina M., Kraev G. et al., /. 2026.
Comprehensive data on natural hazards and their consequences are crucial for effective for risk assessment, adaptation planning, and emergency response. However, many countries face challenges with fragmented, inconsistent, and inaccessible data, particularly regarding local-scale events. To address this data gap in Russia, we developed an end-to-end processing pipeline that scrapes news from various online sources, ...
Added: April 28, 2026
Pilé I., Deng Y., Shchur L., / Series arXiv "math". 2026. No. 2604.10254.
We investigate the spatial overlap of successive spin configurations in Markov chain Monte Carlo simulations using the local Metropolis algorithm and the Svendsen-Wang and Wolff cluster algorithms. We examine the dynamics of these algorithms for two models in different universality classes: the Ising model and the Potts model with three components. The overlap of two ...
Added: April 20, 2026
Gabdullin N., Androsov I., / Series Computer Science "arxiv.org". 2026.
Label prediction in neural networks (NNs) has O(n) complexity proportional to the number of classes. This holds true for classification using fully connected layers and cosine similarity with some set of class prototypes. In this paper we show that if NN latent space (LS) geometry is known and possesses specific properties, label prediction complexity can ...
Added: April 2, 2026
Sorokin K., Beketov M., Онучин А. et al., / arxiv.org. Серия cs.SI "Social and Information Networks ". 2025.
Community detection in complex networks is a fundamental problem, open to new approaches in various scientific settings. We introduce a novel community detection method, based on Ricci flow on graphs. Our technique iteratively updates edge weights (their metric lengths) according to their (combinatorial) Foster version of Ricci curvature computed from effective resistance distance between the ...
Added: January 15, 2026
Petrovanov I., Sergeev A., / Series Computer Science "arxiv.org". 2025. No. 2512.18332.
Transport coding reduces message delay in packet-switched networks by introducing controlled redundancy at the transport layer: original packets are encoded into coded packets, and the message is reconstructed after the first successful deliveries, effectively shifting latency from the maximum packet delay to the -th order statistic. We present a concise, reproducible discrete-event implementation of transport coding in OMNeT++, including ...
Added: December 24, 2025
Hessian-based lightweight neural network for brain vessel segmentation on a minimal training dataset
Меньшиков И. А., Бернадотт А. К., Elvimov N. S., / Series arXie "Statistical mechanics". 2025.
Accurate segmentation of blood vessels in brain magnetic resonance angiography (MRA) is essential for successful surgical procedures, such as aneurysm repair or bypass surgery. Currently, annotation is primarily performed through manual segmentation or classical methods, such as the Frangi filter, which often lack sufficient accuracy. Neural networks have emerged as powerful tools for medical image ...
Added: December 1, 2025
Rubchinskiy A., Chubarova D., / Series WP7 "Математические методы анализа решений в экономике, бизнесе и политике". 2025. No. WP7/2025/01.
The article examines one of the most famous examples of socio-economic systems, characterized by significant uncertainty – the S&P-500 stock market, where shares of 500 largest US companies are traded. No assumptions are made about the probabilistic characteristics of the stock market. A flexible algorithm for daily trading has been developed, based on both known fixed data ...
Added: November 9, 2025
Zlotnik A., Lomonosov T., Математическое моделирование 2025 Т. 37 № 1 С. 151–170
A system of four balance differential equations is used to describe dynamics of heterogeneous compressible binary mixtures with stiffened gas equations of state for mixture components, including gas and liquid ones. The main points are its quasi-homogeneous form that arises as a result of eliminating volume fractions of components from the collection of sought functions ...
Added: October 6, 2024
Zlotnik A., Lomonosov T., Doklady Mathematics 2023 Vol. 108 No. 3 P. 443–449
We consider the so-called four-equation model for dynamics of the heterogeneous compressible binary mixtures with the Noble-Abel stiffened-gas equations of state. We exploit its quasi-homogeneous form that arises after excluding the volume concentrations from the sought functions and is based on a quadratic equation for the common pressure of the components. We present new properties ...
Added: March 1, 2024
А. А. Злотник, Т. А. Ломоносов, Доклады Российской академии наук. Математика, информатика, процессы управления (ранее - Доклады Академии Наук. Математика) 2023 Т. 514 № 1 С. 26–33
Рассматривается так называемая модель из четырех уравнений динамики гетерогенных сжимаемых бинарных смесей при уравнениях состояния “сжатого” газа Ноубла-Абеля. Используется ее квазигомогенная форма, возникающая после исключения объемных концентраций из искомых функций и основанная на квадратном уравнении для общего давления компонент. Приводятся новые свойства этого уравнения и простая формула для квадрата скорости звука, предлагается альтернативный вывод формулы, ...
Added: December 23, 2023
Zlotnik A., Applied Mathematics Letters 2023 Vol. 146 Article 108801
We deal with the so-called four-equation model for dynamics of the heterogeneous binary mixtures of the Noble-Abel stiffened-gases (NASGes). In relation to the quasi-homogeneous form of the model, we suggest a new insight on a quadratic equation for the pressure, give a simple formula for the squared speed of sound and present a new proof ...
Added: August 4, 2023
I. A. Kondratyev, S. G. Moiseenko, Lobachevskii Journal of Mathematics 2023 Vol. 44 No. 1 P. 44–56
In astrophysical fluid dynamics, some types of flows, like e.g., magnetorotational super- nova explosions, deal with a highly variable Mach number (from M ≪ 1 in the protoneutron star region to M ≫ 1 near the shock wave expelling from the stellar envelope) in presence of a strong differential rotation. The Courant–Friedrichs–Lewy (CFL) stability condition ...
Added: May 22, 2023
Fedchenko A., Journal of Mathematical Sciences 2023 Vol. 270 No. 6 P. 815–826
We consider regularizations of systems of equations for a multicomponent gas mixture dynamics in the barotropic multi-velocity and one-velocity cases. Energy balance equations are derived for them.
For the system of equations in the one-velocity case, the system linearized on a constant solution is studied, and, for the weak solutions to the initial-boundary value problem with ...
Added: May 11, 2023
A. N. Krenke, R. B. Sandlersky, A. S. Baybar et al., Известия РАН. Серия биологическая. 2023 Vol. 50 No. 1 P. S85–S99
Four main models of the appearance of boundaries (in a particular case, integrity), arising from the theory of nonlinear dynamic systems, are considered briefly. On the basis of Kotelnikov’s fundamental sampling theorem and, accordingly, general information theory, the character of a distinguished boundary as a function of the sampling frequency in a spatial series with a ...
Added: December 2, 2022
А. А. Злотник, Доклады Российской академии наук. Математика, информатика, процессы управления (ранее - Доклады Академии Наук. Математика) 2022 Т. 505 № 1 С. 30–36
Изучается явная двухслойная разностная схема для линеаризованной многомерной квазигазодинамической системы уравнений. Для начально-краевой задачи на неравномерной прямоугольной сетке впервые даются достаточные условия $L^2$-диссипативности типа Куранта энергетическим методом. Для задачи Коши на равномерной сетке усовершенствуются как необходимые, так и достаточные условия $L^2$-диссипативности в спектральном методе. Указывается новая форма задания параметра релаксации, гарантирующая равномерную ограниченность сверху и снизу числа ...
Added: June 20, 2022
Zlotnik A., Fedchenko A., Дифференциальные уравнения 2022 Т. 58 № 3 С. 346–360
Изучается квазигидродинамическая система уравнений гомогенной (с общими скоростью и температурой) многокомпонентной газовой смеси в отсутствие химических реакций, с общей регуляризующей скоростью.
Для нее выводится уравнение баланса энтропии с неотрицательным производством энтропии при наличии потоков диффузии компонент смеси. В отсутствие потоков диффузии новым способом строится линеаризованная на постоянном решении система уравнений, выполняется ее приведение к симметричному виду и ...
Added: March 23, 2022
Zlotnik A.A., Fedchenko A.S., Doklady Mathematics 2021 Vol. 104 No. 3 P. 340–346
For an aggregated quasi-gasdynamic system of equations for a homogeneous gas mixture, we give an entropy balance equation with a nonnegative entropy production in the presence of diffusion fluxes. We also derive the existence, uniqueness, and L^2 -dissipativity of weak solutions to an initial-boundary value problem for the system linearized at a constant solution. Additionally, the Petrovskii parabolicity ...
Added: February 17, 2022
Zlotnik A., Fedchenko A., / Институт прикладной математики им. М.В. Келдыша Российской академии наук. Серия "Препринты ИПМ им. М.В. Келдыша". 2021. № 77.
Added: November 11, 2021
Злотник А.А., Федченко А.С., Доклады Российской академии наук. Математика, информатика, процессы управления (ранее - Доклады Академии Наук. Математика) 2021 Т. 501 № 1 С. 31–37
For an aggregated quasi-gasdynamic system of equations for a homogeneous gas mixture, we give the entropy balance equation with a nonnegative entropy production in the presence of diffusion fluxes. We also derive the existence, uniqueness and $L^2$-dissipativity of weak solutions to an initial-boundary value problem for a system linearized at a constant solution as well as ...
Added: September 28, 2021
А. А. Злотник, Т. А. Ломоносов, Доклады Российской академии наук. Математика, информатика, процессы управления (ранее - Доклады Академии Наук. Математика) 2020 Т. 492 № 1 С. 31–37
We study an explicit two-level symmetric in space finite-difference scheme for the multi\-di\-men\-si\-onal barotropic gas dynamics system of equations with quasi-gasdynamic regulari\-za\-tion linearized at a constant solution (with arbitrary velocity). A criterion and both necessary and sufficient conditions for the $L^2$-dissipativity of the solutions to the Cauchy problem for the scheme are derived by the spectral ...
Added: March 4, 2020
Lomonosov T., В кн.: Межвузовская научно-техническая конференция студентов, аспирантов и молодых специалистов им. Е.В. Арменского.: М.: МИЭМ НИУ ВШЭ, 2019.
В работе приводятся критерии (необходимые и достаточные условия) $L^2$-устойчивости для линеаризованных на постоянном решении разностных схем, основанных на некоторой регуляризации 1D баротропных и полных уравнений газовой динамики. Техника вывода основана на спектральном подходе. ...
Added: December 11, 2019