Brownian yet Non-Gaussian Diffusion: From Superstatistics to Subordination of Diffusing Diffusivities
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 establis...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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American Physical Society
2017-04-01
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| Series: | Physical Review X |
| Online Access: | http://doi.org/10.1103/PhysRevX.7.021002 |
| _version_ | 1818826396470870016 |
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| author | Aleksei V. Chechkin Flavio Seno Ralf Metzler Igor M. Sokolov |
| author_facet | Aleksei V. Chechkin Flavio Seno Ralf Metzler Igor M. Sokolov |
| author_sort | Aleksei V. Chechkin |
| collection | DOAJ |
| 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. |
| first_indexed | 2024-12-19T00:27:00Z |
| format | Article |
| id | doaj.art-68c63a7434ea473fba0493574ffd51f7 |
| institution | Directory Open Access Journal |
| issn | 2160-3308 |
| language | English |
| last_indexed | 2024-12-19T00:27:00Z |
| publishDate | 2017-04-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review X |
| spelling | doaj.art-68c63a7434ea473fba0493574ffd51f72022-12-21T20:45:14ZengAmerican Physical SocietyPhysical Review X2160-33082017-04-017202100210.1103/PhysRevX.7.021002Brownian yet Non-Gaussian Diffusion: From Superstatistics to Subordination of Diffusing DiffusivitiesAleksei V. ChechkinFlavio SenoRalf MetzlerIgor M. SokolovA 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.http://doi.org/10.1103/PhysRevX.7.021002 |
| spellingShingle | Aleksei V. Chechkin Flavio Seno Ralf Metzler Igor M. Sokolov Brownian yet Non-Gaussian Diffusion: From Superstatistics to Subordination of Diffusing Diffusivities Physical Review X |
| title | Brownian yet Non-Gaussian Diffusion: From Superstatistics to Subordination of Diffusing Diffusivities |
| title_full | Brownian yet Non-Gaussian Diffusion: From Superstatistics to Subordination of Diffusing Diffusivities |
| title_fullStr | Brownian yet Non-Gaussian Diffusion: From Superstatistics to Subordination of Diffusing Diffusivities |
| title_full_unstemmed | Brownian yet Non-Gaussian Diffusion: From Superstatistics to Subordination of Diffusing Diffusivities |
| title_short | Brownian yet Non-Gaussian Diffusion: From Superstatistics to Subordination of Diffusing Diffusivities |
| title_sort | brownian yet non gaussian diffusion from superstatistics to subordination of diffusing diffusivities |
| url | http://doi.org/10.1103/PhysRevX.7.021002 |
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