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

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The propagation of charged cosmic rays through the Galactic environment influences all aspects of the observation at Earth. Energy spectrum, composition and arrival directions are changed due to deflections in magnetic fields and…

Instrumentation and Methods for Astrophysics · Physics 2017-07-26 Lukas Merten , Julia Becker Tjus , Horst Fichtner , Björn Eichmann , Günter Sigl

We study the time-dependent modulation effect and derive the local interstellar spectra (LIS) for the cosmic ray (CR) proton, helium, boron and carbon. A two-dimensional modulation model including the variation of the interplanetary…

High Energy Astrophysical Phenomena · Physics 2019-09-25 Bing-Bing Wang , Xiao-Jun Bi , Kung Fang , Su-Jie Lin , Peng-Fei Yin

Light propagation in turbid media is driven by the equation of radiative transfer. We give a formal probabilistic representation of its solution in the framework of biological tissues and we implement algorithms based on Monte Carlo methods…

Computation · Statistics 2014-10-16 Laura Vinckenbosch , Céline Lacaux , Samy Tindel , Magalie Thomassin , Tiphaine Obara

The ACE-CRIS collaboration has recently released the measurement of radioactive $^{60}$Fe nuclei abundance in Galactic Cosmic Rays, in the energy range $\sim 195-500$ MeV per nucleon. We model Cosmic Ray propagation and derive from this…

High Energy Astrophysical Phenomena · Physics 2020-04-29 Giovanni Morlino , Elena Amato

Numerical solutions of the cosmic-ray (CR) magneto-hydrodynamic equations are dogged by a powerful numerical instability, which arises from the constraint that CRs can only stream down their gradient. The standard cure is to regularize by…

High Energy Astrophysical Phenomena · Physics 2018-03-16 Yan-Fei Jiang , Peng Oh

We introduce Preconditioned Monte Carlo (PMC), a novel Monte Carlo method for Bayesian inference that facilitates efficient sampling of probability distributions with non-trivial geometry. PMC utilises a Normalising Flow (NF) in order to…

Instrumentation and Methods for Astrophysics · Physics 2022-08-24 Minas Karamanis , Florian Beutler , John A. Peacock , David Nabergoj , Uros Seljak

An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time and…

Solar and Stellar Astrophysics · Physics 2016-11-28 Ilias Cholis , Dan Hooper , Tim Linden

We present a Monte-Carlo (MC) calculation of the propagation of cosmic ray protons in the Galaxy for energies above 1 PeV. We discuss the relative strengths of competing effects such as parallel/perpendicular diffusion and drifts in toy…

Astrophysics · Physics 2007-05-23 Daniel De Marco , Pasquale Blasi , Todor Stanev

The Diffusion Monte Carlo method is devoted to the computation of electronic ground-state energies of molecules. In this paper, we focus on implementations of this method which consist in exploring the configuration space with a {\bf fixed}…

Numerical Analysis · Mathematics 2007-05-23 Tony Lelievre , Mohamed El Makrini , Benjamin Jourdain

We introduce a new Monte Carlo method by incorporating a guided distribution function to the conventional Monte Carlo method. In this way, the efficiency of Monte Carlo methods is drastically improved. To further speed up the algorithm, we…

Computational Physics · Physics 2009-11-07 S. P. Li

We present a new model of the heliospheric interface - the region of the solar wind interaction with the local interstellar medium. This new model performs a multi-component treatment of charged particles in the heliosphere. All charged…

Astrophysics · Physics 2009-11-11 Yury G. Malama , Vlad V. Izmodenov , Sergey V. Chalov

Radiative transfer in curved spacetimes has become increasingly important to understanding high-energy astrophysical phenomena and testing general relativity in the strong field limit. The equations of radiative transfer are physically…

Astrophysics · Physics 2009-11-13 Avery E. Broderick

We use cosmography to present constraints on the kinematics of the Universe, without postulating any underlying theoretical model. To this end, we use a Monte Carlo Markov Chain analysis to perform comparisons to the supernova Ia Union 2…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

We discuss the efficiency of Monte Carlo methods in solving continuum radiative transfer problems. The sampling of the radiation field and convergence of dust temperature calculations in the case of optically thick clouds are both studied.…

Astrophysics · Physics 2009-11-10 M. Juvela

Particle methods based on evolving the spatial derivatives of the solution were originally introduced to simulate reaction-diffusion processes, inspired by vortex methods for the Navier--Stokes equations. Such methods, referred to as…

Numerical Analysis · Mathematics 2025-01-24 Giulia Bertaglia , Lorenzo Pareschi , Russel E. Caflisch

We consider an alternative to the Monte Carlo method for dust continuous radiative transfer simulations: the Quasi-Monte Carlo method. We briefly discuss what it is, its history, and possible implementations. We compare the Monte Carlo…

Solar and Stellar Astrophysics · Physics 2024-06-25 S. G. Shulman

In this paper, we propose and analyze a new stochastic homogenization method for diffusion equations with random and fast oscillatory coefficients. In the proposed method, the homogenized solutions are sought through a two-stage procedure.…

Numerical Analysis · Mathematics 2022-03-14 Zihao Yang , Jizu Huang , Xiaobing Feng , Xiaofei Guan

During the past years several variance reduction techniques for Monte Carlo electron transport have been developed in order to reduce the electron computation time transport for absorbed dose distribution. We have implemented the Macro…

Medical Physics · Physics 2009-11-13 L. A. Perles , A. de Almeida

We solve numerically exactly a simple toy model to quantum general relativity or more properly to path integral on a curved space. We consider the thermal equilibrium of a quantum many body problem on the sphere, the surface of constant…

Quantum Gases · Physics 2026-03-25 Riccardo Fantoni

Solving the continuum radiative transfer equation in high opacity media requires sophisticated numerical tools. In order to test the reliability of such tools, we present a benchmark of radiative transfer codes in a 2D disc configuration.…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. Pinte , T. J. Harries , M. Min , A. M. Watson , C. P. Dullemond , P. Woitke , F. Menard , M. C. Duran-Rojas
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