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Related papers: Do we observe L\'evy flights in cosmic rays?

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The propagation of light that undergoes multiple-scattering by resonant atomic vapor can be described as a L\'evy flight. L\'evy flight is a random walk with heavy tailed step-size (r) distribution, decaying asymptotically as $P(r)\sim…

The enigma of cosmic ray origin and propagation stands as a key question in particle astrophysics. The precise spatial and spectral measurements of diffuse Galactic gamma-ray emission provide new avenues for unraveling this mystery. Based…

High Energy Astrophysical Phenomena · Physics 2025-10-01 Qi-Ling Chen , Qiang Yuan , Yi-Qing Guo , Ming-Ming Kang , Chao-Wen Yang

L\'evy Flights are paradigmatic generalised random walk processes, in which the independent stationary increments---the "jump lengths"---are drawn from an $\alpha$-stable jump length distribution with long-tailed, power-law asymptote. As a…

Statistical Mechanics · Physics 2020-08-26 A. Padash , A. V. Chechkin , B. Dybiec , I. Pavlyukevich , B. Shokri , R. Metzler

Multiple scattering of light by resonant vapor is characterized by L\'evy-type superdiffusion with a single-step size distribution $p(x)\propto 1/x^{1+\alpha}$. We investigate L\'evy flight of light in a hot rubidium vapor…

In the Heliosphere, power-law particle distributions are observed e.g. upstream of interplanetary shocks, which can result from superdiffusive transport. This non-Gaussian transport regime may result from intermittent magnetic field…

High Energy Astrophysical Phenomena · Physics 2024-12-25 Sophie Aerdker , Lukas Merten , Frederic Effenberger , Horst Fichtner , Julia Becker Tjus

Levy flights, characterized by the microscopic step index f, are for f<2 (the case of rare events) considered in short range and long range quenched random force fields with arbitrary vector character to first loop order in an expansion…

Statistical Mechanics · Physics 2009-10-31 Hans C. Fogedby

In this paper we review the hypothesis that a considerable part of the cosmic ray flux observed above about $10^{19}\eV$ may be produced by decaying or annihilating topological defects left over from phase transitions in the early universe…

Astrophysics · Physics 2010-11-01 G. Sigl

We investigate multiple scattering of near-resonant light in a Doppler-broadened atomic vapor. We experimentally characterize the length distribution of the steps between successive scattering events. The obtained power law is…

Atomic Physics · Physics 2013-06-26 Nicolas Mercadier , Martine Chevrollier , William Guerin , Robin Kaiser

We discuss diffusion properties of a dynamical system, which is characterised by long-tail distributions and finite correlations. The particle velocity has the stable L\'evy distribution; it is assumed as a jumping process (the kangaroo…

Statistical Mechanics · Physics 2011-06-21 Tomasz Srokowski

One of the most striking astrophysical phenomena today is the existence of cosmic ray particles with energies in excess of 10^20 eV. While their presence has been confirmed by a number of experiments, it is not clear where and how these…

High Energy Physics - Experiment · Physics 2009-11-11 Stefan Westerhoff

Anomalous diffusion processes, in particular superdiffusive ones, are known to be efficient strategies for searching and navigation by animals and also in human mobility. One way to create such regimes are L\'evy flights, where the walkers…

Physics and Society · Physics 2017-02-22 Sarah de Nigris , Timoteo Carletti , Renaud Lambiotte

The L\'evy-Lorentz gas describes the motion of a particle on the real line in the presence of a random array of scattering points, whose distances between neighboring points are heavy-tailed i.i.d. random variables with finite mean. The…

Probability · Mathematics 2023-04-24 Marco Zamparo

We investigate the first-passage dynamics of symmetric and asymmetric L\'evy flights in a semi-infinite and bounded intervals. By solving the space-fractional diffusion equation, we analyse the fractional-order moments of the first-passage…

Statistical Mechanics · Physics 2020-08-26 Amin Padash , Aleksei V. Chechkin , Bartłomiej Dybiec , Marcin Magdziarz , Babak Shokri , Ralf Metzler

We consider the combined effects of a power law L\'{e}vy step distribution characterized by the step index $f$ and a power law waiting time distribution characterized by the time index $g$ on the long time behavior of a random walker. The…

Condensed Matter · Physics 2009-10-22 Hans C. Fogedby

Anomalous diffusion and L\'evy flights, which are characterized by the occurrence of random discrete jumps of all scales, have been observed in a plethora of natural and engineered systems, ranging from the motion of molecules to climate…

Dynamical Systems · Mathematics 2023-09-04 Chunxi Jiao , Georg A. Gottwald

This article considers the statistical properties of L\'evy walks possessing a regular long-term linear scaling of the mean square displacement with time, for which the conditions of the classical Central Limit Theorem apply.…

Statistical Mechanics · Physics 2022-12-07 Massimiliano Giona , Andrea Cairoli , Rainer Klages

The transport of platelets in blood is commonly assumed to obey an advection-diffusion equation. Here we propose a disruptive view, by showing that the random part of their velocity is governed by a fat-tailed probability distribution,…

Computational Physics · Physics 2021-09-17 Christos Kotsalos , Karim Zouaoui Boudjeltia , Ritabrata Dutta , Jonas Latt , Bastien Chopard

Among Markovian processes, the hallmark of L\'evy flights is superdiffusion, or faster-than-Brownian dynamics. Here we show that L\'evy laws, as well as Gaussians, can also be the limit distributions of processes with long range memory that…

Statistical Mechanics · Physics 2016-02-10 Denis Boyer , Inti Pineda

The non-Markovian continuous-time random walk model, featuring fat-tailed waiting times and narrow distributed displacements with a non-zero mean, is a well studied model for anomalous diffusion. Using an analytical approach, we recently…

Statistical Mechanics · Physics 2023-09-18 Wanli Wang , Eli Barkai

The origin of the highest energy cosmic rays is still unknown. The discovery of their sources will reveal the workings of the most energetic astrophysical accelerators in the universe. Current observations show a spectrum consistent with an…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Kumiko Kotera , Angela V. Olinto