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Related papers: Asymptotic Radiative Transfer

200 papers

The distribution function for the intensity of radiation propagating in a random medium is analyzed for arbitrary multiplicity of scattering (for arbitrary relation between the distance of propagation and mean free path), including as…

Condensed Matter · Physics 2007-05-23 Eugene Kogan , Moshe Kaveh

Motivated by practical applications in heat conduction and contaminant transport, we consider heat and mass diffusion across a perturbed interface separating two finite regions of distinct diffusivity. Under the assumption of continuity of…

Biological Physics · Physics 2022-01-12 Elliot J. Carr , Dylan J. Oliver , Matthew J. Simpson

We present a general method to calculate radiative transfer including scattering in the continuum as well as in lines in spherically symmetric systems that are influenced by the effects of general relativity (GR). We utilize a comoving…

Astrophysics · Physics 2009-11-11 S. Knop , P. H. Hauschildt , E. Baron

We study various combinations of active diffusion with branching, as an extension of standard reaction-diffusion processes. We concentrate on the selection of the asymptotic wavefront speed for thermal run-and-tumble and for thermal active…

Statistical Mechanics · Physics 2020-05-22 Thibaut Demaerel , Christian Maes

The asymptotics of a singularly perturbed problem is constructed. describing the transport of a polydisperse impurity in the atmosphere, taking into account the processes of precipitation and wind pick-up, as well as the processes of…

Analysis of PDEs · Mathematics 2024-12-30 A. V. Nesterov

Anomalous transport processes in which the variance of the distance travelled does not necessarily increase linearly with time are modelled using the formalism of continuous time random walks. We compute particle propagators which have the…

Astrophysics · Physics 2011-05-23 B. R. Ragot , J. G. Kirk

The emission of electromagnetic waves from a source within or near a non-trivial medium (with or without boundaries, crystalline or amorphous, with inhomogeneities, absorption and so on) is sometimes studied using the reciprocity principle.…

Classical Physics · Physics 2016-09-08 Ariel Caticha

The long-time behavior of a reaction-diffusion front between one static (e.g. porous solid) reactant A and one initially separated diffusing reactant B is analyzed for the mean-field reaction-rate density R(\rho_A,\rho_B) =…

Chemical Physics · Physics 2009-10-31 Martin Z. Bazant , Howard A. Stone

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 study the validity of the time-dependent asymptotic $P_N$ approximation in radiative transfer of photons. The time-dependent asymptotic $P_N$ is an approximation which uses the standard $P_N$ equations with a closure that is based on the…

Computational Physics · Physics 2021-08-26 Re'em Harel , Stanislav Burov , Shay I. Heizler

Previous proposals to permit non-exponential free-path statistics in radiative transfer have not included support for volume and boundary sources that are spatially uncorrelated from the scattering events in the medium. Birth-collision free…

Computational Physics · Physics 2021-02-19 Eugene d'Eon

We present an asymptotic-preserving (AP) numerical method for solving the three-temperature radiative transfer model, which holds significant importance in inertial confinement fusion. A carefully designedsplitting method is developed that…

Numerical Analysis · Mathematics 2024-03-01 Ruo Li , Weiming Li , Shengtong Liang , Yuehan Shao , Min Tang , Yanli Wang

Our theory relates the secondary spectrum, the 2D power spectrum of the radio dynamic spectrum, to the scattered pulsar image in a thin scattering screen geometry. Recently discovered parabolic arcs in secondary spectra are generic features…

Astrophysics · Physics 2009-11-10 James M. Cordes , Barney J. Rickett , Daniel R. Stinebring , William A. Coles

Using distribution theory we present the moment asymptotic expansion of continuous wavelet transform in different distributional spaces for large and small values of dilation parameter $a$. We also obtain asymptotic expansions for certain…

Functional Analysis · Mathematics 2014-05-02 R S Pathak , Ashish Pathak

We suggest the azimuthal distribution of mean transverse (radial) rapidity of the final state particles as a more direct measure of the transverse motion of the source than the standard azimuthal multiplicity distribution. Using a sample…

Nuclear Theory · Physics 2015-06-11 Lin Li , Na Li , Yuanfang Wu

We point out that particles accelerated in a non-relativistic shock of compression ratio $r$ attain the standard, $p=(r+2)/(r-1)$ spectral index only under certain conditions. Previous derivations of the spectrum, based on the…

High Energy Astrophysical Phenomena · Physics 2020-07-07 Uri Keshet , Ofir Arad , Yuri Lyubarski

We develop a theory for waveform-diverse moving-target synthetic-aperture radar, in the case in which a single moving antenna is used for both transmitting and receiving. We assume that the targets (scattering objects) are moving linearly,…

Classical Physics · Physics 2011-05-17 Margaret Cheney , Brett Borden

We discuss the radiative transfer theory for translucent clouds illuminated by an extended background source. First we derive a rigorous solution based on the assumption that multiple scattering produce an isotropic flux. Then we derive a…

Solar and Stellar Astrophysics · Physics 2017-05-10 Davide Biganzoli , Marco Potenza , Massimo Robberto

Transfer learning is an essential tool for improving the performance of primary tasks by leveraging information from auxiliary data resources. In this work, we propose Adaptive Robust Transfer Learning (ART), a flexible pipeline of…

Machine Learning · Statistics 2023-05-02 Boxiang Wang , Yunan Wu , Chenglong Ye

We suggest a rigorous definition of the pathwise flux across the boundary of a bounded open set for transient finite energy diffusion processes. The expectation of such a flux has the property of depending only on the current velocity $v$,…

Probability · Mathematics 2007-05-23 Andrea Posilicano , Stefania Ugolini