2017 Fiscal Year Final Research Report
Fluctuating diffusivity and intermittent search in crowded environment
| Project/Area Number |
15K17590
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Foundations of mathematics/Applied mathematics
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| Research Institution | Naruto University of Education |
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Principal Investigator |
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| Project Period (FY) |
2015-04-01 – 2018-03-31
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| Keywords | ブラウン運動 / 拡散性の揺らぎ / 混み合い |
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| Outline of Final Research Achievements |
The main results consist of four points. (1) The time averaged mean square displacement (TMSD), which is frequently used in single-particle-tracking experiments, is generalized into a second-order tensor (a TMSD tensor). Using correlation functions of this TMSD tensor, a novel method to detect "magnitude" and "orientation" fluctuations of diffusivity from trajectory data is proposed. (2) This TMSD tensor analysis is applied to four fundamental polymer models, and it is found that these models exhibit qualitatively different types of the fluctuating diffusivity. (3) A Langevin equation with diffusivity fluctuating between a fast and a slow diffusive state is analytically studied, and it is shown that the TMSD analysis can be used to detect the fluctuating diffusivity. (4) A coarse-grained model of a bacterial cytoplasm (a poly-disperse colloidal suspension with and without hydrodynamic interaction) are studied, and a theoretical prediction for reduction of diffusivity is derived.
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| Free Research Field |
統計物理学
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