English
Related papers

Related papers: Generalized diffusion theory for radiative transfe…

200 papers

We theoretically analyze diffusion trajectories of an anisotropic object moving on a two dimensional space in the absence of an external field. In determining diffusion parameters associated with the shape anisotropy, we devise a measure…

Statistical Mechanics · Physics 2015-08-31 Sunghan Roh , Juyeon Yi , Yong Woon Kim

Galactic transport models for cosmic rays involve the diffusive motion of these particles in the interstellar medium. Due to the large-scale structured galactic magnetic field this diffusion is anisotropic with respect to the local field…

High Energy Astrophysical Phenomena · Physics 2013-06-07 Frederic Effenberger , Horst Fichtner , Klaus Scherer , Ingo Büsching

We generalize classical dispersion theory for a passive scalar to derive an asymptotic long-time convection-diffusion equation for a solute suspended in a wide, structured channel and subject to a steady low-Reynolds-number shear flow. Our…

Fluid Dynamics · Physics 2023-05-03 James V. Roggeveen , Howard A. Stone , Christina Kurzthaler

We resolve a long standing question regarding the suitable effective diffusion coefficient of the spherically-symmetric transport equation, which is valid at long times. To that end, we generalize a transport solution in three dimensions…

Statistical Mechanics · Physics 2024-02-01 Shay I. Heizler , Menahem Krief , Michael Assaf

Enhanced diffusion, which describes the accelerated spread of passive scalars due to the interaction between advection and molecular diffusion, has been extensively studied in simplified geometries, such as uniform shear and radial flows.…

Analysis of PDEs · Mathematics 2024-11-04 Rômulo Damasclin Chaves dos Santos , Jorge Henrique de Oliveira Sales

The spatial diffusion of energetic particles in a magnetic field composed of a large-scale background and a small-scale turbulent component should be expected to be anisotropic. While such anisotropic diffusion has been known for quite a…

High Energy Astrophysical Phenomena · Physics 2025-07-17 Julien Dörner , Jonas Hellrung , Julia Becker Tjus , Horst Fichtner

We derive new diffusion solutions to the monoenergetic generalized linear Boltzmann transport equation (GLBE) for the stationary collision density and scalar flux about an isotropic point source in an infinite $d$-dimensional absorbing…

Graphics · Computer Science 2014-07-02 Eugene d'Eon

Numerical transfer matrices have been widely used in the study of wave propagation and scattering. These may be viewed as descretizations of a recently introduced fundamental notion of transfer matrix which admits a representation in terms…

Classical Physics · Physics 2023-10-03 Farhang Loran , Ali Mostafazadeh

The electromagnetic wave propagation in an anisotropic dielectric media with two generic matrices $\epsilon^{ij}$ and $\mu^{ij}$ of permittivity and permeability is studied. These matrices are not required to be symmetric, positive…

Classical Physics · Physics 2013-03-08 Yakov Itin

We develop a transfer-matrix formulation of the scattering of electromagnetic waves by a general isotropic medium which makes use of a notion of electromagnetic transfer matrix $\mathbf{M}$ that does not involve slicing of the scattering…

Quantum Physics · Physics 2020-09-24 Farhang Loran , Ali Mostafazadeh

In seismic imaging, understanding the relationship between wavefront-propagation velocity and time-interval velocity is crucial for achieving optimal resolution. However, this task becomes even more challenging when considering anisotropic…

Geophysics · Physics 2025-04-28 Tiago A. Coimbra , Rodrigo Bloot , Jorge H. Faccipieri

We study the propagation of radio waves through a medium possessing density fluctuations that are elongated along the ambient magnetic field and described by an anisotropic Goldreich-Sridhar power spectrum. We derive general formulas for…

Astrophysics · Physics 2009-11-07 B. D. G. Chandran , D. C. Backer

When lifting the assumption of spatially-independent scattering centers in classical linear transport theory, collision rate is no longer proportional to angular flux / radiance because the macroscopic cross-section $\Sigma_t(s)$ depends on…

Statistical Mechanics · Physics 2019-11-12 Eugene d'Eon

We develop a model based on a multiple scattering theory to describe the diffusion of polarized light in disordered media exhibiting short-range structural correlations. Starting from exact expressions of the average field and the field…

Optics · Physics 2016-10-03 Kevin Vynck , Romain Pierrat , Rémi Carminati

This is the second paper in a series on light scattering from optically anisotropic scatterers embedded in an isotropic medium. The apparently complex T-matrix theory involving mixing of angular momentum components turns out to be an…

Optics · Physics 2007-05-23 A. D. Kiselev , V. Yu. Reshetnyak , T. J. Sluckin

Light diffusion is usually associated with thick, opaque media. Indeed, multiple scattering is necessary for the onset of the diffusive regime and such condition is generally not met in almost transparent media. Nonetheless, at long enough…

We introduce the concept of Randomly Modulated Gaussian Processes as a unifying framework for modeling, analyzing and classifying anomalous diffusion models in heterogeneous media. This formulation incorporates correlations in the…

Biological Physics · Physics 2026-03-16 Yann Lanoiselée , Denis S. Grebenkov , Gianni Pagnini

Scattering on a resonance state coupled to a complicated background is a typical problem for mesoscopic quantum many-body systems as well as for wave propagation in the presence of a complex environment. On average, such a simple mode…

Mesoscale and Nanoscale Physics · Physics 2020-03-09 Dmitry V. Savin

We introduce a non-exponential radiative framework that takes into account the local spatial correlation of scattering particles in a medium. Most previous works in graphics have ignored this, assuming uncorrelated media with a uniform,…

Graphics · Computer Science 2018-05-14 Adrian Jarabo , Carlos Aliaga , Diego Gutierrez

Scattering problems are important in describing light propagation in wide ranging media such as the atmosphere, colloidal solutions, metamaterials, glass ceramic composites, transparent polycrystalline ceramics, and surfaces. The Rayleigh…

Optics · Physics 2023-05-03 M. H. Shachar , J. E. Garay