# 30th Marian Smoluchowski Symposium on Statistical Physics

3-8 September 2017
Poland timezone

## Brownian yet non-Gaussian Diffusion

5 Sep 2017, 11:30
30m
Aula ()

oral

### Speaker

Aleksei Chechkin (Akhiezer Institute for Theoretical Physics)

### Description

A growing number of biological, soft, and active matter systems are observed to exhibit normal diffusive dynamics with a linear growth of the mean-squared displacement, yet with a non-Gaussian distribution of increments. Based on the Chubinsky-Slater idea of a diffusing diffusivity, we here establish and analyze a minimal model framework of diffusion processes with fluctuating diffusivity. In particular, we demonstrate the equivalence of the diffusing diffusivity process with a superstatistical approach with a distribution of diffusivities, at times shorter than the diffusivity correlation time. At longer times, a crossover to a Gaussian distribution with an effective diffusivity emerges. Specifically, we establish a subordination picture of Brownian but non-Gaussian diffusion processes, which can be used for a wide class of diffusivity fluctuation statistics. Our results are shown to be in excellent agreement with simulations and numerical evaluations.  Aleksei V. Chechkin, Flavio Seno, Ralf Metzler, and Igor M. Sokolov, PHYSICAL REVIEW X 7, 021002 (2017).

### Primary author

Aleksei Chechkin (Akhiezer Institute for Theoretical Physics)

### Co-authors

Flavio Seno (University of Padova) Igor Sokolov (Humboldt University Berlin) Ralf Metzler (University of Potsdam)

### Presentation Materials

There are no materials yet.
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