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Related papers: Memory-Controlled Diffusion

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We consider a reaction-diffusion process with retardation. The particles, immersed in traps initially, remain inactive until another particle is annihilated spontaneously with a rate $\lambda$ at a certain point $\vec x$. In that case the…

Statistical Mechanics · Physics 2015-06-25 Michael Schulz , Steffen Trimper , Knud Zabrocki

This work collects some methodological insights for numerical solution of a "minimum-dispersion" control problem for nonlinear stochastic differential equations, a particular relaxation of the covariance steering task. The main ingredient…

Optimization and Control · Mathematics 2025-10-16 Roman Chertovskih , Nikolay Pogodaev , Maxim Staritsyn , A. Pedro Aguiar

In this work, the motion of a dust particle under the influence of the random force due to dust charge fluctuations is considered as a non-Markovian stochastic process. Memory effects in the velocity process of the dust particle are…

Plasma Physics · Physics 2017-10-26 Zahra Ghannad , Hossein Hakimi Pajouh

Fractional Brownian motion (FBM), a non-Markovian self-similar Gaussian stochastic process with long-ranged correlations, represents a widely applied, paradigmatic mathematical model of anomalous diffusion. We report the results of…

There are many fields where the transition from diffusive to ballistic motion is important. Here we deal with relaxation processes in nmr in gases. Correlation functions for trajectory variables (position and velocity) valid across this…

Statistical Mechanics · Physics 2010-12-21 R. Golub , C. M. Swank

Score-based generative models (SGMs) learn a family of noise-conditional score functions corresponding to the data density perturbed with increasingly large amounts of noise. These perturbed data densities are linked together by the…

Machine Learning · Computer Science 2023-06-16 Chieh-Hsin Lai , Yuhta Takida , Naoki Murata , Toshimitsu Uesaka , Yuki Mitsufuji , Stefano Ermon

We study the transport of high-energy particles in pulsar wind nebulae (PWN) using three-dimensional MHD (see Porth et al. (2014) for details) and test-particle simulations, as well as a Fokker-Planck particle transport model. The latter…

High Energy Astrophysical Phenomena · Physics 2016-07-27 O. Porth , M. J. Vorster , M. Lyutikov , N. E. Engelbrecht

We derive an analytical expression for the transition path time (TPT) distribution for a one-dimensional particle crossing a parabolic barrier. The solution is expressed in terms of the eigenfunctions and eigenvalues of the associated…

Statistical Mechanics · Physics 2018-12-10 Michele Caraglio , Stefanie Put , Enrico Carlon , Carlo Vanderzande

Representations based on random walks can exploit discrete data distributions for clustering and classification. We extend such representations from discrete to continuous distributions. Transition probabilities are now calculated using a…

Machine Learning · Computer Science 2012-12-12 Chen-Hsiang Yeang , Martin Szummer

We study generalized diffusion-wave equation in which the second order time derivative is replaced by integro-differential operator. It yields time fractional and distributed order time fractional diffusion-wave equations as particular…

Statistical Mechanics · Physics 2019-05-02 Trifce Sandev , Zivorad Tomovski , Johan Dubbeldam , Aleksei Chechkin

Diffusion in nonhomogeneous media is described by a dynamical process driven by a general Levy noise and subordinated to a random time; the subordinator depends on the position. This problem is approximated by a multiplicative process…

Statistical Mechanics · Physics 2015-06-18 Tomasz Srokowski

The Poisson-Nernst-Planck (PNP) diffusional model for the immittance or impedance spectroscopy response of an electrolytic cell in a finite-length situation is extended to a general framework. In this new formalism, the bulk behavior of the…

A non--linear diffusion equation is derived by taking into account hopping rates depending on the occupation of next neighbouring sites. There appears additonal repulsive and attractive forces leading to a changed local mobiltiy. The…

Statistical Mechanics · Physics 2009-10-31 S. Artz , M. Schulz , S. Trimper

We introduced simple microscopic non-Markovian walk models which describe underlying mechanism of anomalous diffusions. In the models, we considered the competitions between randomness and memory effects of previous history by introducing…

Statistical Mechanics · Physics 2015-06-19 Hyun-Joo Kim

Local diffusivity of a protein depends crucially on the conformation, and the conformational fluctuations are often non-Markovian. Here, we investigate the Langevin equation with non-Markovian fluctuating diffusivity, where the fluctuating…

Statistical Mechanics · Physics 2023-04-26 Mutsumi Kimura , Takuma Akimoto

It is proved that the distributions of scaling limits of Continuous Time Random Walks (CTRWs) solve integro-differential equations akin to Fokker-Planck Equations for diffusion processes. In contrast to previous such results, it is not…

Probability · Mathematics 2016-07-20 Boris Baeumer , Peter Straka

Stochastic reaction-diffusion equations are a popular modelling approach for studying interacting populations in a heterogeneous environment under the influence of environmental fluctuations. Although the theoretical basis of alternative…

Populations and Evolution · Quantitative Biology 2017-02-16 Ivo Siekmann , Michael Bengfort , Horst Malchow

Evidence accumulation models of simple decision-making have long assumed that the brain estimates a scalar decision variable corresponding to the log-likelihood ratio of the two alternatives. Typical neural implementations of this…

Neurons and Cognition · Quantitative Biology 2018-10-24 Marc W. Howard , Andre Luzardo , Zoran Tiganj

Strong interaction with other particles or feedback from the medium on a Brownian particle entail memory effects in the effective dynamics. We discuss the extension of the fluctuation-dissipation theorem to nonequilibrium Langevin systems…

Statistical Mechanics · Physics 2013-09-23 C. Maes , S. Safaverdi , P. Visco , F. van Wijland

The Ornstein--Uhlenbeck Particle (OUP) model imagines a microscopic swimmer propelled by an active force which is correlated with itself on a finite time-scale. Here we investigate the influence of external potentials on an ideal suspension…

Soft Condensed Matter · Physics 2018-04-09 Cato Sandford , Alexander Y. Grosberg