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Related papers: Equilibrium-diffusion limit of the radiation model

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We prove the existence of a traveling wave solution for a boundary reaction diffusion equation when the reaction term is the combustion nonlinearity with ignition temperature. A key role in the proof is plaid by an explicit formula for…

Analysis of PDEs · Mathematics 2011-01-25 L. Caffarelli , A. Mellet , Y. Sire

Conditions are obtained for the existence of a warm inflationary attractor in the system of equations describing an inflaton coupled to radiation. These conditions restrict the temperature dependence of the dissipative terms and the size of…

Astrophysics · Physics 2011-07-13 Ian G Moss , Chun Xiong

We introduce closed-form transition density expansions for multivariate affine jump-diffusion processes. The expansions rely on a general approximation theory which we develop in weighted Hilbert spaces for random variables which possess…

Statistics Theory · Mathematics 2016-01-07 Damir Filipović , Eberhard Mayerhofer , Paul Schneider

Accurate prediction of electron temperature ($T_{\rm e}$) is critical for non-equilibrium plasma applications ranging from hypersonic flight to plasma-assisted combustion. We recently proposed a thermodynamically consistent model for…

Plasma Physics · Physics 2026-03-13 Bernard Parent , Felipe Martin Rodriguez Fuentes

We present a comprehensive analytical study of radiative transfer using the method of moments and include the effects of non-isotropic scattering in the coherent limit. Within this unified formalism, we derive the governing equations and…

Earth and Planetary Astrophysics · Physics 2015-06-19 Kevin Heng , João M. Mendonça , Jae-Min Lee

We obtained a new representation of a solution of the heat conduction equation with boundary condition of the third kind for a layer. The result is presented as a superposition of fundamental solutions for an unbounded system with variable…

Mathematical Physics · Physics 2007-05-23 A. S. Usenko

The laws of thermodynamics provide a clear concept of the temperature for an equilibrium system in the continuum limit. Meanwhile, the equipartition theorem allows one to make a connection between the ensemble average of the kinetic energy…

Statistical Mechanics · Physics 2009-11-13 Alex V. Popov , Rigoberto Hernandez

The paper presents an analytical theory quantitatively describing the heterogeneous combustion of nonvolatile (metal) particles in the diffusion-limited regime. It is assumed that the particle is suspended in an unconfined, isobaric,…

Fluid Dynamics · Physics 2025-02-11 Daoguan Ning , Andreas Dreizler

We consider the numerical approximation of boundary conditions in radiative transfer problems by a perfectly matched layer approach. The main idea is to extend the computational domain by an absorbing layer and to use an appropriate…

Numerical Analysis · Mathematics 2018-02-26 Herbert Egger , Matthias Schlottbom

We derive a diffusion approximation for the kinetic Vlasov-Fokker-Planck equation in bounded spatial domains with specular reflection type boundary conditions. The method of proof involves the construction of a particular class of test…

Analysis of PDEs · Mathematics 2017-01-06 Ludovic Cesbron , Harsha Hutridurga

This paper presents the set of plane-parallel model atmosphere equations for a very hot neutron star (X-ray burst source). The model equations assume both hydrostatic and radiative equilibrium, and the equation of state of an ideal gas in…

Astrophysics · Physics 2009-11-10 A. Majczyna , J. Madej , P. C. Joss , A. Rozanska

This paper focuses on a drift-diffusion system subjected to boundedly non dissipative Robin boundary conditions. A general existence result with large initial conditions is established by using suitable L1, L2 and trace estimates. Finally,…

Analysis of PDEs · Mathematics 2018-10-02 Arnaud Heibig , Adrien Petrov , Christian Reichert

The close-to-equilibrium regularity of solutions to a class of reaction-diffusion systems is investigated. The considered systems typically arise from chemical reaction networks and satisfy a complex balanced condition. Under some…

Analysis of PDEs · Mathematics 2017-11-29 Bao Quoc Tang

We investigate a temperature-based model, called extended two-temperature model (eTTM), that describes the electronic non-equilibrium and its effect on energy dissipation in metals after ultrashort laser excitation. We derive and discuss…

Materials Science · Physics 2023-08-03 Markus Uehlein , Sebastian T. Weber , Baerbel Rethfeld

This paper investigates solutions of hyperbolic diffusion equations in $\mathbb{R}^3$ with random initial conditions. The solutions are given as spatial-temporal random fields. Their restrictions to the unit sphere $S^2$ are studied. All…

We consider in this contribution a simplified idealized one-dimensional model in a nuclear core reactor coupling the diffusion equation on the neutron flux withthe enthalpy equation for the water which collects the heat produced by this…

Numerical Analysis · Mathematics 2025-03-11 Olivier Lafitte , François Dubois

This paper deals with the optimal synthesis of aperture fields for (radiating) near-field communications in obstructed environments. A physically consistent model based on knife-edge diffraction is used to formulate the problem as a…

Signal Processing · Electrical Eng. & Systems 2025-10-31 Francesco Verde , Donatella Darsena , Marco Di Renzo , Vincenzo Galdi

We discuss metric perturbations of the relativistic diffusion equation around the homogeneous Juttner equilibrium of massless particles in a homogeneous expanding universe. The metric perturbation describes matter distribution and the…

General Relativity and Quantum Cosmology · Physics 2015-02-27 Z. Haba

We consider non-reversible perturbations of reversible diffusions that do not alter the invariant distribution and we ask whether there exists an optimal perturbation such that the rate of convergence to equilibrium is maximized. We solve…

Numerical Analysis · Mathematics 2015-06-12 Tony Lelièvre , Francis Nier , Grigorios A. Pavliotis

A cold electron beam propagating through a background plasma is subject to filamentation process due to theWeibel instability. If the initial beam radius is large compared with the electron skin depth and the beam density is much smaller…

Plasma Physics · Physics 2011-09-05 Vladimir Khudik , Igor Kaganovich , Gennady Shvets