The dynamical collision network in granular gases
| dc.creator | Alvarez-Hamelin, José Ignacio | |
| dc.creator | Puglisi, Andrea | |
| dc.date | 2006-09-14 | |
| dc.date | 2007-05-12 | |
| dc.date.accessioned | 2026-07-07T08:00:49Z | |
| dc.date.available | 2026-07-07T08:00:49Z | |
| dc.description | We dynamically construct the interaction network in a granular gas, using the sequence of collisions collected in an MD event driven simulation of inelastic hard disks from time 0 till time t. The network is decomposed into its k-core structure: particles in a core of index k have collided at least k times with other particles in the same core. The difference between cores k+1 and k is the so-called k-shell, and the set of all shells is a complete and on-overlapping decomposition of the system. Because of energy dissipation, the gas cools down: its initial spatially homogeneous dynamics, characterized by the Haff law, i.e. a t^{-2} energy decay, is unstable towards a strongly inhomogeneous phase with clusters and vortices, where energy decays as t^{-1}. The clear transition between those two phases appears in the evolution of the k-shells structure in the collision network. In the homogeneous regime the k-shell structure evolves as in a growing network with fixed number of vertices and randomly added links: the shell distribution is strongly peaked around the most populated shell, which has an index k_{max} ~ 0.9 <d> with <d> the average number of collisions experienced by a particle. During the final non-homogeneous regime a growing fraction of collisions is concentrated in small, almost closed, 'communities' of particles: k_{max} is no more linear in <d> and the distribution of shells becomes extremely large developing a power-law tail ~ k^{-3} for high shell indexes. We propose the k-shell decomposition as a quantitative characterization of Molecular Chaos violation. | |
| dc.identifier | https://arxiv.org/abs/cond-mat/0609341 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/0609341 | |
| dc.identifier | Physical Review E: Statistical, Nonlinear, and Soft Matter Physics 75, 5 (02/05/2007) 051302 | |
| dc.identifier | doi:10.1103/PhysRevE.75.051302 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/128766 | |
| dc.subject | Statistical Mechanics | |
| dc.title | The dynamical collision network in granular gases | |
| dc.type | text |