Diffusive anomalies in a long-range Hamiltonian system
We scrutinize the anomalies in diffusion observed in an extended long-range system of classical rotors, the HMF model. Under suitable preparation, the system falls into long-lived quasi-stationary states for which superdiffusion of rotor phases has been reported. In the present work, we investigate...
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| Published in: | Physical review. E, Statistical, nonlinear, and soft matter physics Vol. 74; no. 2 Pt 1; p. 021118 |
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| Main Authors: | , |
| Format: | Journal Article |
| Language: | English |
| Published: |
United States
01-08-2006
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| Online Access: | Get full text |
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| Summary: | We scrutinize the anomalies in diffusion observed in an extended long-range system of classical rotors, the HMF model. Under suitable preparation, the system falls into long-lived quasi-stationary states for which superdiffusion of rotor phases has been reported. In the present work, we investigate diffusive motion by monitoring the evolution of full distributions of unfolded phases. After a transient, numerical histograms can be fitted by the q -Gaussian form P(x) proportional to {1+(q-1)[x/beta]2}(1/(1-q)) , with parameter q increasing with time before reaching a steady value q approximately 32 (squared Lorentzian). From the analysis of the second moment of numerical distributions, we also discuss the relaxation to equilibrium and show that diffusive motion in quasistationary trajectories depends strongly on system size. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
| ISSN: | 1539-3755 1550-2376 |
| DOI: | 10.1103/PhysRevE.74.021118 |