Interacting Random Walkers and Non-Equilibrium Fluctuations
| dc.creator | Agliari, E. | |
| dc.creator | Casartelli, M. | |
| dc.creator | Vezzani, A. | |
| dc.date | 2008-09-30 | |
| dc.date.accessioned | 2026-07-07T10:06:27Z | |
| dc.date.available | 2026-07-07T10:06:27Z | |
| dc.description | We introduce a model of interacting Random Walk, whose hopping amplitude depends on the number of walkers/particles on the link. The mesoscopic counterpart of such a microscopic dynamics is a diffusing system whose diffusivity depends on the particle density. A non-equilibrium stationary flux can be induced by suitable boundary conditions, and we show indeed that it is mesoscopically described by a Fourier equation with a density dependent diffusivity. A simple mean-field description predicts a critical diffusivity if the hopping amplitude vanishes for a certain walker density. Actually, we evidence that, even if the density equals this pseudo-critical value, the system does not present any criticality but only a dynamical slowing down. This property is confirmed by the fact that, in spite of interaction, the particle distribution at equilibrium is simply described in terms of a product of Poissonians. For mesoscopic systems with a stationary flux, a very effect of interaction among particles consists in the amplification of fluctuations, which is especially relevant close to the pseudo-critical density. This agrees with analogous results obtained for Ising models, clarifying that larger fluctuations are induced by the dynamical slowing down and not by a genuine criticality. The consistency of this amplification effect with altered coloured noise in time series is also proved. | |
| dc.description | 8 pages, 7 figures | |
| dc.identifier | https://arxiv.org/abs/0809.5244 | |
| dc.identifier | http://arxiv.org/abs/0809.5244 | |
| dc.identifier | The European Physical Journal B 65 2 (2008) 257-264 | |
| dc.identifier | doi:10.1140/epjb/e2008-00330-7 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/170330 | |
| dc.subject | Statistical Mechanics | |
| dc.title | Interacting Random Walkers and Non-Equilibrium Fluctuations | |
| dc.type | text |