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We investigate the relativistic generalization of the classical St\"{o}rmer problem, which describes the motion of charged particles in a purely magnetic dipole field. By incorporating special relativistic effects, the particle dynamics is…

High Energy Astrophysical Phenomena · Physics 2026-05-07 Tiberiu Harko , Francisco S. N. Lobo

In a recent article the authors showed that the radiative Transfer equations with multiple frequencies and scattering can be formulated as a nonlinear integral system. In the present article, the formulation is extended to handle reflective…

Numerical Analysis · Mathematics 2023-06-12 Olivier Pironneau , Pierre-Henri Tournier

Relativistic thermal electrons moving in a large-scale magnetic field can produce synchrotron radiation. Linear synchrotron polarization can also be produced by the relativistic thermal electrons. In this paper, we utilize a hybrid…

High Energy Astrophysical Phenomena · Physics 2018-07-11 Jirong Mao , Stefano Covino , Jiancheng Wang

We develop the 3-dimensional general relativistic radiative transfer code: CARTOON (Calculation code of Authentic Radiative Transfer based On phOton Number conservation in curved space-time) which is improved from the 2-dimensional code:…

High Energy Astrophysical Phenomena · Physics 2022-10-12 Mikiya M. Takahashi , Ken Ohsuga , Rohta Takahashi , Takumi Ogawa , Masayuki Umemura , Yuta Asahina

GYOTO, a general relativistic ray-tracing code, is presented. It aims at computing images of astronomical bodies in the vicinity of compact objects, as well as trajectories of massive bodies in relativistic environments. This code is…

General Relativity and Quantum Cosmology · Physics 2012-03-15 Frederic H. Vincent , Thibaut Paumard , Eric Gourgoulhon , Guy Perrin

This Thesis describes the basic framework and applications of a relativistic ray-tracing code for analyzing accretion processes around Kerr black holes. We begin in Chapter 1 with a brief historical summary of the major advances in black…

Astrophysics · Physics 2009-09-29 Jeremy D. Schnittman

We expand on our previous study of the impact of atmospheric seeing on polarization cross-talk, and show how the formalism that was developed in that work can be applied to treat the case of spatial modulators of polarization. Beside…

Instrumentation and Methods for Astrophysics · Physics 2026-02-17 Roberto Casini , Alfred G. de Wijn

The estimation of molecular abundances in interstellar clouds from spectroscopic observations requires radiative transfer calculations, which depend on basic molecular input data. This paper reviews recent developments in the fields of…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Floris van der Tak

This paper discusses the problem of gravitational perturbations of radiating spacetimes. We lay out the theoretical framework for describing the interaction of external gravitational fields with a radiating spacetime. This is done by…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Manasse R. Mbonye , Ronald L. Mallett

Numerical modeling of galactic cosmic rays (GCRs) penetration through the heliosphere to the vicinity of the Sun is considered. Galactic cosmic rays are charged particles with energies exceeding 10 MeV/nucl., originating from far beyond the…

High Energy Astrophysical Phenomena · Physics 2025-09-04 D. A. Shestakov , V. V. Izmodenov

We adapt the transfer matrix ($\T$-matrix) method originally designed for one-dimensional quantum mechanical problems to solve the circularly symmetric two-dimensional problem of graphene quantum dots. In similarity to one-dimensional…

Mesoscale and Nanoscale Physics · Physics 2016-05-25 H. Chau Nguyen , Nhung T. T. Nguyen , V. Lien Nguyen

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

We show the necessity for a new approach towards comprehensive and consistent simulations of the propagation of galactic cosmic rays. Our developments are optimised for addressing the spatially 3-dimensional inhomogeneous diffusion problem…

Instrumentation and Methods for Astrophysics · Physics 2013-08-14 M. Werner , R. Kissmann , A. W. Strong , O. Reimer

We present spectral methods developed in our group to solve three-dimensional partial differential equations. The emphasis is put on equations arising from astrophysical problems in the framework of general relativity.

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. Bonazzola , E. Gourgoulhon , J. -A. Marck

Relativistic radiative transfer problems require the calculation of photon trajectories in curved spacetime. We present a novel technique for rapid and accurate calculation of null geodesics in the Kerr metric. The equations of motion from…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Jason Dexter , Eric Agol

It is shown that polar coding schemes achieve the known achievable rate regions for several multi-terminal communications problems including lossy distributed source coding, multiple access channels and multiple descriptions coding. The…

Information Theory · Computer Science 2014-04-29 Aria G. Sahebi , S. Sandeep Pradhan

The development of radiation hydrodynamical methods that are able to follow gas dynamics and radiative transfer self-consistently is key to the solution of many problems in numerical astrophysics. Such fluid flows are highly complex, rarely…

Scattering of light from an anisotropic source produces linear polarization in spectral lines and the continuum. In the outer layers of a stellar atmosphere the anisotropy of the radiation field is typically dominated by the radiation…

Solar and Stellar Astrophysics · Physics 2015-05-30 Rafael Manso Sainz , Javier Trujillo Bueno

Radiative transfer and radiation hydrodynamics use the relativistic Boltzmann equation to describe the kinetics of photons. It is difficult to solve the six-dimensional time-dependent transfer equation unless the problem is highly symmetric…

Instrumentation and Methods for Astrophysics · Physics 2011-02-09 Chi-kwan Chan

We present an updated version of POLARIS, a well established code designated for dust polarisation and line radiative transfer (RT) in arbitrary astrophysical environments. We extend the already available capabilities with a synchrotron…

Astrophysics of Galaxies · Physics 2019-11-06 Stefan Reissl , Robert Brauer , Ralf S. Klessen , Eric W. Pellegrini