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Computation of unsteady electromagnetic scattering about 3D complex bodies in free space with high-order difference potentials
Journal of Computational Physics. 2024. Vol. 498. Article 112705.
We extend the previously developed high-order accurate method for acoustic scattering to electro-magnetic scattering, i.e., from the scalar setting to a vector setting. First, the governing Maxwell’s equations are reduced from their original first-order form to a system of second-order wave equa-tions for the individual Cartesian components of electromagnetic field. In free space, these wave equations are uncoupled. Yet at the boundary of the scatterer, the variables that they govern (i.e., Cartesian field components) remain fully coupled via the boundary conditions that account for the specific scattering mechanism. Next, the wave equations are equivalently replaced with Calderon’s boundary equations with projections obtained using the method of difference poten-tials and a compact high-order accurate scheme. The Calderon’s boundary equations are combined with the boundary conditions and the overall system is solved by least squares. The resulting vec-tor methodology (electromagnetic) inherits many useful properties of the scalar one (acoustic). In particular, it offers sub-linear computational complexity, does not require any special treatment of the artificial outer boundary, and has the capacity to solve multiple similar problems at a low individual cost per problem. We demonstrate the performance of the new method by computing the scattering of a given impinging wave about a double-cone hypersonic shape.
Beck M. E., Seidov S., Mukhin S., Physical Review A: Atomic, Molecular, and Optical physics 2026
Quantum dissipation is studied in the superradiant phase of the extended Dicke model. It is demonstrated analytically by quantum mechanical derivation of the Lindblad equation for the Dicke model in the superradiant state coupled to Caldeira-Leggett thermal bath that the effective viscosity appearing in the semiclassical equations of motion of polaritonic condensate survives in the zero-temperature limit ...
Added: August 13, 2026
Seidov S., Pugach N., Physical Review B: Condensed Matter and Materials Physics 2026
In this manuscript we consider a superconducting film in the vicinity of the critical temperature and presence of the proximity effect. We analytically solve the corresponding linearized Usadel equation and the self-consistency equation, defining the critical temperature. This is a system of coupled differential and integral equations for the anomalous Green's function and the order parameter of ...
Added: August 13, 2026
Yu Z., Wang J., Wang Z. et al., Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 2026 Vol. 384 P. 1–16
The integration of data-driven and knowledge-driven approaches in generative geospatial modelling (GGM) is often hindered by their mathematical incompatibilities. Here, we propose a geometric algebra (GA)-based framework that employs a unified multi-vector representation to fuse heterogeneous data and diverse knowledge. The framework facilitates structured reasoning and hypothesis generation through a task-adaptable, five-stage cycle: representation, reasoning, ...
Added: August 13, 2026
Marshakov A., Yung A, Ievlev E. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2026 Vol. 114 Article 046006
We continue the study of non-Abelian vortex string in 4D N =2 supersymmetric QCD (SQCD) as
critical superstring, and extend this analysis to UðNÞ gauge theory with arbitrary even N and Nf = 2N
number of quarks. We introduce a special mass deformation and show that the SQCD hadron spectrum is
still given by the string spectrum on the ...
Added: August 13, 2026
Ratnikov F., Bocharnikov V., Journal of High Energy Physics 2026 Vol. 2026 P. 1–21
The BM@N experiment (Baryonic Matter at the Nuclotron) is the first fixed-target experiment at the JINR NICA accelerator complex. In this work, data on the interactions of a carbon-ion beam with kinetic energies of 4.0A GeV and 4.5A GeV with C, Al, Cu, and Pb targets are used to measure transverse momentum spectra and rapidity ...
Added: August 12, 2026
Budkov Y., Kalikin N., Journal of Chemical Physics 2026 Vol. 165 Article 064506
A self-consistent statistical-mechanical theory of the Hall effect in electrolyte solutions is developed by extending the self-consistent Debye–Hückel–Onsager (SCDHO) framework to crossed electric and magnetic fields. The theory incorporates non-local ionic charge distributions via Slater-type form factors, regularizing the Coulomb interaction at short range, and accounts for dielectric friction through ion-specific coefficients, employing experimental values ...
Added: August 12, 2026
Speranski S. O., Математические заметки 2026 Т. 120 № 3 С. 470–483
We show that, in terms of closure ordinals, many infinitary calculi for ‘first-order’ logics of probability (i.e., for languages similar to those in [Abadi & Halpern 1994]) are as hard as possible: the corresponding closure ordinals coincide with the least non-constructive ordinal, denoted by $\omega_1^{\mathrm{CK}}$. ...
Added: August 12, 2026
Ali S., Bocharnikov V., Ratnikov F. et al., Sensors 2026 Vol. 26 No. 16 Article 5024
Large distributed sensor arrays require repeated recalibration as radiation damage, material aging, gain variation, and readout drift alter channel responses. We studied a high-granularity calorimeter as a large sensor array and addressed unsupervised recalibration from two unpaired datasets: a nominal reference response and an aged response with attenuated cell-wise signals. Aging was modeled by a ...
Added: August 11, 2026
Kulev Y., Maksaev A., Promyslov V., Linear Algebra and its Applications 2026 Vol. 730 P. 51–72
The notion of λ-th upper scrambling index was introduced by Huang and Liu in 2010, as a generalization of a notion considered by Akelbek and Kirkland in 2009. For a primitive digraph D, it is defined as the smallest positive integer k such that for every λ vertices of D there exist directed paths of lengths k from these vertices to a common vertex. This ...
Added: August 7, 2026
Kanunnikov A., Promyslov V., Vassilieva E., Electronic Journal of Combinatorics 2024 Vol. 31 No. 3 Article P3.6
Introduced by Goulden and Jackson in their 1996 paper, the matchings-Jack conjecture and the hypermap-Jack conjecture (also known as the b-conjecture) are two major open questions relating Jack symmetric functions, the representation theory of the symmetric groups and combinatorial maps. They show that the coefficients in the power sum expansion of some Cauchy sum for ...
Added: August 7, 2026
Ponomarev A., Aleksandrov N., Journal of Physics D: Applied Physics 2026 Vol. 59 Article 315205
Electron attachment and detachment in H2O:O2 and H2O:air mixtures are theoretically studied at moderate (40–100 Td) reduced electric fields. It is shown that there are two synergistic mechanisms of ultra-rapid electron detachment from negative ions in these mixtures, whereas these detachment channels are absent in pure gases. Effective attachment coefficient calculated with consideration for fast ion–molecule ...
Added: August 6, 2026
Khrapai V., Tikhonov E., Nature Physics 2026 P. 1–2
Feng et al.1 presented transport measurements of three-terminal normal–superconductor–normal devices based on topological insulator nanowires. They measured the full differential conductance matrix, defined as Gij = ∂Ii /∂Vj , beyond the linear response regime as a function of various control parameters. Here i, j∈ [1, 2] denote normal terminals biased by the voltages V1 and ...
Added: August 5, 2026
Spiridonov V. P., Belousov N. M., Sarkissian G. A., Analysis and Mathematical Physics 2026 Vol. 16 Article 96
Hyperbolic hypergeometric integrals are defined as Barnes-type integrals of products of hyperbolic gamma functions. Their reduction to ordinary hypergeometric functions is well known. We study in detail their degeneration to complex hypergeometric functions. Namely, using uniform bounds on the integrands, we prove that the univariate hyperbolic beta integral and the conical function degenerate to two-dimensional ...
Added: August 4, 2026
Gayfullin S., Kikteva V., Results in Mathematics 2026 Vol. 81 No. 5 Article 146
In this paper we obtain a criterion of flexibility for an affine complexity-zero horospherical variety. This result generalizes previously known results on flexibility of normal horospherical varieties, horospherical varieties with an action of a semisimple group, and non-normal toric varieties. ...
Added: August 3, 2026
Lunts V., Функциональный анализ и его приложения 2026 Т. 60 № 3 С. 127–129
Доказано, что канонические полуортогональные разложения производной категории диаграммной схемы индуцируют аналогичные разложения подкатегории совершенных комплексов. ...
Added: August 3, 2026
Belomestny D., Gasnikov A., Gladin E. et al., Russian Mathematical Surveys 2026 Vol. 81 No. 4(490) P. 3–90
Reinforcement learning (RL) is increasingly grounded in tools from probability, optimization, and operator theory. This survey organizes the mathematical structures that underpin the design and analysis of modern algorithms in RL. We begin from Markov decision processes (MDPs) and the Bellman operators, emphasizing contraction mappings, monotonicity, and fixed-point theory that yield convergence guarantees and rates ...
Added: August 3, 2026
G. G. Bondarenko, Kristya V. I., Savichkin D. O. et al., Journal of Surface Investigation: X-Ray, Synchrotron and Neutron Techniques 2026 Vol. 20 No. 2 P. 417–423
A model of a glow gas discharge in a mixture of argon and mercury vapor is formulated in the presence
of a thin insulating film on the cathode surface. Dependences of the discharge characteristics on the
mixture temperature are calculated in the range of its variation, in which a noticeable contribution to ionization
of the working gas is ...
Added: August 1, 2026
Касимов Р. Х., Аржанов А. И., Седых К. О. et al., Оптический журнал 2026 Т. 93 № 1 С. 80–86
Предмет исследования. Использование метода капельного нанесения для изготовления источника одиночных фотонов. Цель работы. Разработка технологического процесса изготовления источника одиночных фотонов на коллоидных квантовых точках для использования их в фотон- ных интегральных схемах. Метод. На первом этапе в программе ANSYS Lumerical рассчитыва- ются период и фактор заполнения фокусирующих элементов связи на длинах волн 545 и 600 ...
Added: July 31, 2026
Nevzorov A., Golikov A., Gneushev D. et al., JETP Letters 2026 Vol. 147–151 No. 3 P. 147–151
This paper demonstrates a special stochastic operation mode of a photonic element with a thin GeTe film deposited at a silicon nitride waveguide. As opposed to traditional deterministic switching between stable states, it has been shown that identical pump laser pulses cause a stochastic change in the transmission coefficient. The discovered effect opens up new ...
Added: July 31, 2026
A. Radomskii, Mathematical notes 2026 Vol. 119 No. 6 P. 1136–1147
We obtain an upper bound for the sum $\sum_{n\leq N} (a_{n}/\varphi (a_{n}))^{s}$, where $\varphi$ is Euler's totient function, $s\in\mathbb{N}$, and $a_{1},\ldots, a_{N}$ are positive integers (not necessarily distinct) with some restrictions. As applications, for any $t>0$, we obtain an upper bound for the number of $n\in [1,N]$ such that $a_{n}/ \varphi (a_{n})> t$. ...
Added: July 31, 2026
Dual-mode infrared detection via photovoltaic and barrier pyroelectric effects in PbTe p–n junctions
Jarashneli A., Кобцев Д. М., Upcher A. et al., Journal of Applied Physics 2026 Vol. 140 No. 2 Article 024501
In the work, two effects appeared in PbTe p–n junctions under mid-wavelength infrared (2 − 5 μm) and long-wavelength infrared irradiation (≈10.6 μm). The first effect was created by the optical absorption of lR-photons in PbTe and caused by its photovoltage effect. The second novel effect is related to the heating process and the formation ...
Added: July 31, 2026
Petropavlovsky S., Turkel E., Journal of Computational Physics 2026 Vol. 558 Article 114880
We propose a method for the numerical computation of the 3D time-harmonic scattering about objects of complex shape. Our approach relies on the method of difference potentials combined with the lacunae-based integration of the Helmholtz equation. The former allows to handle curvilinear boundaries of scattering shapes on regular Cartesian grids with no loss of accuracy. ...
Added: April 6, 2026
Смирнов И. А., Черкесова Л. В., Поркшеян В. М. et al., IEEE, 2019.
Development of informational-communicative technologies and radioelectronics of XXI century is related to transmission more and more incrementing data volumes at all, and is oriented on application not only microwave frequencies (SHF), but also subTHz and THz (EHF and HHF) ranges - from 0,1 to 10 THz. Arrangements of these bands are divided into 2 levels: ...
Added: May 10, 2023
Petropavlovsky S., Tsynkov S., Turkel E., Journal of Computational Physics 2022 Vol. 471 Article 111632
We compute the scattering of unsteady acoustic waves about complex three-dimensional
bodies with high order accuracy. The geometry of a scattering body is defined with
the help of CAD. Its surface is represented as a collection of non-overlapping patches,
each parameterized independently by means of high order splines (NURBS). As a specific
example, we consider a submarine-like scatterer constructed ...
Added: September 28, 2022