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Related papers: Cosmic Rays Propagation with HelMod: Difference be…

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In this paper, we investigate the heliospheric modulation of cosmic rays in interplanetary space, focusing on their propagation times and energy losses over the solar cycle. To perform the calculations, we employed a data-driven model based…

High Energy Astrophysical Phenomena · Physics 2025-03-20 Nicola Tomassetti , Bruna Bertucci , Emanuele Fiandrini , Behrouz Khiali

A novel hybrid Monte Carlo transport scheme is demonstrated in a scene with solar illumination, scattering and absorbing 2D atmosphere, a textured reflecting mountain, and a small detector located in the sky (mounted on a satellite or a…

Mathematical Physics · Physics 2015-05-28 Guillaume Bal , Anthony Davis , Ian Langmore

Galactic cosmic rays (GCRs) are affected by solar modulation while they propagate through the heliosphere. The study of the time variation of GCR spectra observed at Earth can shed light on the underlying physical processes, specifically…

Space Physics · Physics 2023-09-18 Claudio Corti , Peter Sadowski , Nikolay Nikonov , Marius Potgieter , Veronica Bindi

We present a numerical method and computer code to calculate the radiative transfer and excitation of molecular lines. Formulating the Monte Carlo method from the viewpoint of cells rather than photons allows us to separate local and…

Astrophysics · Physics 2007-05-23 Michiel R. Hogerheijde , Floris F. S. van der Tak

A new Monte-Carlo method for solving linear parabolic partial differential equations is presented. Since, in this new scheme, the particles are followed backward in time, it provides great flexibility in choosing critical points in…

Numerical Analysis · Mathematics 2025-10-20 Johan Carlsson

Indirect imaging problems in biomedical optics generally require repeated evaluation of forward models of radiative transport, for which Monte Carlo is accurate yet computationally costly. We develop a novel approach to reduce this…

Computational Physics · Physics 2020-07-10 Callum M. Macdonald , Simon Arridge , Samuel Powell

Context. The interpretation of polarised radiation emerging from a planetary atmosphere must rely on solutions to the vector Radiative Transport Equation (vRTE). Monte Carlo integration of the vRTE is a valuable approach for its flexible…

Earth and Planetary Astrophysics · Physics 2017-03-15 García Muñoz , A. , Mills , F. P

Kinetic descriptions of runaway electrons (RE) are usually based on Fokker-Planck models that determine the probability distribution function (PDF) of RE in 2-dimensional momentum space. Despite of the simplification involved, the…

Plasma Physics · Physics 2017-09-13 Guannan Zhang , Diego del-Castillo-Negrete

The Hamiltonian Monte Carlo (HMC) method allows sampling from continuous densities. Favorable scaling with dimension has led to wide adoption of HMC by the statistics community. Modern auto-differentiating software should allow more…

Computation · Statistics 2022-08-17 Ian Langmore , Michael Dikovsky , Scott Geraedts , Peter Norgaard , Rob von Behren

The time-dependent modulation of galactic cosmic rays in the heliosphere is studied by computing intensities using a time-dependent modulation model. By introducing recent theoretical advances in the transport coefficients in the model,…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Rex Manuel , Stefan Ferreira , Marius Potgieter

Before being detected at Earth, charged cosmic rays propagate across the Solar System and undergo interactions with the turbulent solar wind and with the heliospheric magnetic field. As a result, they are subject to a series of processes…

High Energy Astrophysical Phenomena · Physics 2018-11-08 Andrea Vittino , Carmelo Evoli , Daniele Gaggero

Anisotropic diffusion is imperative in understanding cosmic ray diffusion across the Galaxy, the heliosphere, and the interplay of cosmic rays with the Galactic magnetic field. This diffusion term contributes to the highly stiff nature of…

High Energy Astrophysical Phenomena · Physics 2023-08-09 Pranab J. Deka , Ralf Kissmann , Lukas Einkemmer

The quantum theory of the Friedmann cosmological model with dust and cosmological constant ($\Lambda$) is not exactly solvable analytically. We apply Path Integral Monte Carlo (PIMC) techniques to study its quantum dynamics using the…

General Relativity and Quantum Cosmology · Physics 2020-09-10 Masooma Ali , Syed Moeez Hassan , Viqar Husain

We calculate cosmic ray transport with a collisional Boltzmann Transport Equation, including E-M forces. We apply the Crank-Nicholson Method to solve this equation. At each time step, the spatial distribution of cosmic rays is applied to…

High Energy Astrophysical Phenomena · Physics 2011-10-17 Paul Rimmer , Eric Herbst

We propose a method of simulation that is based on the averaging of formal solutions of the transfer equation by taking the integral by the Monte Carlo method. This method is used to compute two models, which correspond to the limiting…

Astrophysics · Physics 2007-05-23 Maxim A. Voronkov

We discuss the problem of ultra high energy particles propagation in astrophysical backgrounds. We present two different computational schemes based on both kinetic and Monte Carlo approaches. The kinetic approach is an analytical…

High Energy Astrophysical Phenomena · Physics 2013-12-31 R. Aloisio

A common way to simulate the transport and spread of pollutants in the atmosphere is via stochastic Lagrangian dispersion models. Mathematically, these models describe turbulent transport processes with stochastic differential equations…

We present the stochastic model of the galactic cosmic ray (GCR) particles transport in the heliosphere. Based on the solution of the Parker transport equation we developed models of the short-time variation of the GCR intensity, i.e. the…

Solar and Stellar Astrophysics · Physics 2015-09-23 A. Wawrzynczak , R. Modzelewska , A. Gil

Cosmic ray (CR) transport and acceleration is essential for many astrophysical problems, e.g., CMB foreground, ionization of molecular clouds and all high energy phenomena. Recent advances in MHD turbulence call for revisions in the…

High Energy Astrophysical Phenomena · Physics 2011-12-06 Huirong Yan , A. Lazarian

Thanks to space-borne experiments of cosmic-ray (CR) detection, such as the AMS and PAMELA missions in low-Earth orbit, or the Voyager-1 spacecraft in the interstellar space, a large collection of multi-channel and time-resolved CR data has…

High Energy Astrophysical Phenomena · Physics 2019-07-01 Nicola Tomassetti , Fernando Barão , Bruna Bertucci , Emanuele Fiandrini , Miguel Orcinha