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A qubit lattice algorithm (QLA) is developed for Maxwell equations in a two-dimensional Cartesian geometry. In particular, the initial value problem of electromagnetic pulse scattering off a localized 2D dielectric object is considered. A…

Optics · Physics 2022-11-09 G. Vahala , M. Soe , L. Vahala , A. K. Ram

Multi-layered structures are widely used in the construction of metamaterial devices to realize various cutting-edge waveguide applications. This paper makes several contributions to the mathematical analysis of subwavelength resonances in…

Analysis of PDEs · Mathematics 2025-04-09 Youjun Deng , Lingzheng Kong , Yongjian Liu , Liyan Zhu

The scattering of quasiperiodic waves for a two-dimensional Helmholtz equation with a constant refractive index perturbed by a function which is periodic in one direction and of finite support in the other is considered. The scattering…

Mathematical Physics · Physics 2019-10-23 P. Zhevandrov , A. Merzon , M. I. Romero Rodríguez , J. E. de la Paz Méndez

Due to its accuracy and generality, Monte Carlo radiative transfer (MCRT) has emerged as the prevalent method for Ly$\alpha$ radiative transfer in arbitrary geometries. The standard MCRT encounters a significant efficiency barrier in the…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-13 Aaron Smith , Benny T. -H. Tsang , Volker Bromm , Milos Milosavljevic

Inverse scattering problem is discussed for the Maxwell's equations. A reduction of the Maxwell's system to a new Fredholm second-kind integral equation with a {\it scalar weakly singular kernel} is given for electromagnetic (EM) wave…

Analysis of PDEs · Mathematics 2012-06-27 A. G. Ramm

We present a novel generalization of the two-stream method of radiative transfer, which allows for the accurate treatment of radiative transfer in the presence of strong infrared scattering by aerosols. We prove that this generalization…

Earth and Planetary Astrophysics · Physics 2017-10-04 Kevin Heng , Daniel Kitzmann

We extend the T-matrix approach to light scattering by spherical particles to some simple cases in which the scatterers are optically anisotropic. Specifically we consider cases in which the spherical particles include radially and…

Optics · Physics 2009-11-07 A. D. Kiselev , V. Yu Reshetnyak , T. J. Sluckin

Computer simulations of radio energy transfer in the ionospheric layer with random small-scale irregularities for the case of a point ground-based source and total reflection have been carried out using specially designed algorithm based on…

Astrophysics · Physics 2009-10-31 N. A. Zabotin , E. S. Kovalenko

The inverse radiative transfer problem finds broad applications in medical imaging, atmospheric science, astronomy, and many other areas. This problem intends to recover the optical properties, denoted as absorption and scattering…

Numerical Analysis · Mathematics 2017-08-08 Qin Li , Ruiwen Shu , Li Wang

Radiative transfer is essential in astronomy, both for interpreting observations and simulating various astrophysical phenomena. However, self-consistent line radiative transfer is computationally expensive, especially in 3D. To reduce the…

Instrumentation and Methods for Astrophysics · Physics 2025-05-14 Thomas Ceulemans , Frederik De Ceuster , Leen Decin

In this paper we introduce a method for solving linear and nonlinear scattering problems for wave equations using a new hybrid approach. This new approach consists of a reformulation of the governing equations into a form that can be solved…

Numerical Analysis · Mathematics 2018-07-04 Aihua Lin , Anastasiia Kuzmina , Per Kristen Jakobsen

We present and analyze a multiscale method for wave propagation problems, posed on spatial networks. By introducing a coarse scale, using a finite element space interpolated onto the network, we construct a discrete multiscale space using…

Numerical Analysis · Mathematics 2023-04-12 Morgan Görtz , Per Ljung , Axel Målqvist

Scalar wave scattering by many small particles of arbitrary shapes with impedance boundary condition is studied. The problem is solved asymptotically and numerically under the assumptions a << d << lambda, where k = 2pi/lambda is the wave…

Numerical Analysis · Mathematics 2016-02-16 Alexander Ramm , Nhan Tran

In this paper we discuss numerical methods and algorithms for the solution of NLTE stellar atmosphere problems involving expanding atmospheres, e.g., found in novae, supernovae and stellar winds. We show how a scheme of nested iterations…

Astrophysics · Physics 2011-06-02 P. H. Hauschildt , E. Baron

Efficient numerical methods are required for the design of optimised devices. In magnonics, the primary computational tool is micromagnetic simulations, which solve the Landau-Lifshitz equation discretised in time and space. However, their…

Mesoscale and Nanoscale Physics · Physics 2023-07-26 Wojciech Śmigaj , Krzysztof Sobucki , Paweł Gruszecki , Maciej Krawczyk

The radiation transfer equation is widely used for simulating such as heat transfer in engineering, diffuse optical tomography in healthcare, and radiation hydrodynamics in astrophysics. By combining the lattice Boltzmann method, we propose…

Quantum Physics · Physics 2024-03-11 Asuka Igarashi , Tadashi Kadowaki , Shiro Kawabata

The transition-matrix ($T$-matrix) approach provides a general formalism to study scattering problems in various areas of physics, including acoustics (scalar fields) and electromagnetics (vector fields), and is related to the theory of the…

Optics · Physics 2016-02-08 Eric C. Le Ru , Walter R. C. Somerville , Baptiste Auguié

We describe two separate wavelength discretization schemes that can be used in the numerical solution of the comoving frame radiative transfer equation. We present an improved second order discretization scheme and show that it leads to…

Astrophysics · Physics 2009-11-10 Peter H. Hauschildt , E. Baron

This work presents efficient solution techniques for radiative transfer in the smoothed particle hydrodynamics discretization. Two choices that impact efficiency are how the material and radiation energy are coupled, which determines the…

Computational Physics · Physics 2021-03-17 Brody R. Bassett , J. Michael Owen , Thomas A. Brunner

We present a new Lattice Boltzmann (LB) formulation to solve the Maxwell equations for electromagnetic (EM) waves propagating in a heterogeneous medium. By using a pseudo-vector discrete Boltzmann distribution, the scheme is shown to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Shravan M. Hanasoge , Sauro Succi , Steven A. Orszag