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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…

On the base of Diffusion Monte-Carlo method it is developed a new Complex Diffusion Monte-Carlo (CDMC) method allowing to simulate the quantum systems with complex wave function. There are no approximations on the calculation of modulus and…

Condensed Matter · Physics 2007-05-23 B. Abdullaev , M. Musakhanov , A. Nakamura

Quantum diffusion is studied via dissipative Madelung hydrodynamics. Initially the wave packet spreads ballistically, than passes for an instant through normal diffusion and later tends asymptotically to a sub-diffusive law. It is shown…

Quantum Physics · Physics 2011-04-21 Roumen Tsekov

The disturbance of the transmission of light through a diffusive medium due to an object hidden in it can be expressed in terms of an effective charge and dipole moment. In the mesoscopic regime, beyond the diffusion approximation, we…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 David Lancaster , Theo Nieuwenhuizen

A phenomenological model for the dissipation of scalar fluctuations due to the straining by the fluid motion is proposed in this letter. An explicit equation is obtained for the time evolution of the probability distribution function of a…

Fluid Dynamics · Physics 2015-06-26 Antoine Venaille , Joel Sommeria

The relation of particle transport of relativistic particles in plasmas with high-amplitude isotropic sub-Larmor-scale magnetic turbulence to the spectra of radiation simultaneously produced by these particles is investigated both…

High Energy Astrophysical Phenomena · Physics 2013-07-16 Brett D. Keenan , Mikhail V. Medvedev

The bulk nuclear matter produced in heavy ion collisions carries a multitude of conserved quantum numbers: electric charge, baryon number, and strangeness. Therefore, the diffusion processes associated to these conserved charges cannot…

High Energy Physics - Phenomenology · Physics 2020-04-15 Jan A. Fotakis , Moritz Greif , Gabriel Denicol , Harri Niemi , Carsten Greiner

As a fundamental astrophysical process, the scattering of particles by turbulent magnetic fields has its physical foundation laid by the magnetohydrodynamic (MHD) turbulence theory. In the framework of the modern theory of MHD turbulence,…

High Energy Astrophysical Phenomena · Physics 2018-11-28 Siyao Xu , Alex Lazarian

The propagation of high-energy cosmic rays through giant molecular clouds constitutes a fundamental process in astronomy and astrophysics. The diffusion of cosmic-rays through these magnetically turbulent environments is often studied…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Marco Fatuzzo , Fulvio Melia , Elizabeth Todd , Fred Adams

In order to understand how the chemical and isotopic compositions of dust grains in a gaseous turbulent protoplanetary disk are altered during their journey in the disk, it is important to determine their individual trajectories. We study…

Earth and Planetary Astrophysics · Physics 2015-05-28 Sebastien Charnoz , Laure Fouchet , Jérôme Aleon , Manuel Moreira

A diffusion process for charge distributions in a phase space is examined. The corresponding charge moves in a force field and under an action of a random field. There are the diffusion motions for coordinates and for momenta. In our model,…

Mathematical Physics · Physics 2008-03-19 E. M. Beniaminov

Being able to accurately model and predict the dynamics of dispersed inclusions transported by a turbulent flow, remains a challenge with important scientific, environmental and economical issues. One critical and difficult point is to…

We study numerically the evolution of the velocity distribution of atoms under the action of the bichromatic force. The comparison of the time dependencies of the distribution width and the average acceleration of atoms reveal the…

Optics · Physics 2021-04-14 V. I. Romanenko , L. P. Yatsenko

The probability of a quantum particle being detected in a given solid angle is determined by the $S$-matrix. The explanation of this fact in time dependent scattering theory is often linked to the quantum flux, since the quantum flux…

Mathematical Physics · Physics 2010-08-20 Detlef Dürr , Martin Kolb , Tilo Moser , Sarah Römer

We report simulations of diffusive particle acceleration in oblique magnetohydrodynamical (MHD) shocks. These calculations are based on extension to oblique shocks of a numerical model for ``thermal leakage'' injection of particles at low…

Astrophysics · Physics 2009-10-28 Hyesung Kang , T. W. Jones

We report studies on first-order Fermi acceleration in parallel modified shock waves with a large scattering center compression ratio expected from turbulence transmission models. Using a Monte Carlo technique we have modeled particle…

Astrophysics · Physics 2009-11-11 Joni J. P. Virtanen , Rami Vainio

Recently a model for noisy reduced magnetohydrodynamic turbulence was proposed. The latter model was already used to study the random walk of magnetic field lines. In the current article we use the same model to investigate the diffusion of…

Solar and Stellar Astrophysics · Physics 2015-06-22 Andreas Shalchi , Mohammad Hussein

The experiments of Leptos et al. [Phys. Rev. Lett. 103, 198103 (2009)] show that the displacements of small particles affected by swimming microorganisms achieve a non-Gaussian distribution, which nevertheless scales diffusively -- the…

Soft Condensed Matter · Physics 2017-10-26 Jean-Luc Thiffeault

Excluded-volume effects can play an important role in determining transport properties in diffusion of particles. Here, the diffusion of finite-sized hard-core interacting particles in two or three dimensions is considered systematically…

Analysis of PDEs · Mathematics 2012-01-06 Maria Bruna , S. Jonathan Chapman

In surface diffusion, one of the key observables is the so-called intermediate scattering function which is measured directly from the surface technique called Helium spin echo. In this work, we show that this function can be seen as a…

Statistical Mechanics · Physics 2026-04-17 E. E. Torres-Miyares , S. Miret-Artés