Regensburg 2007 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
DY: Fachverband Dynamik und Statistische Physik
DY 9: Statistical physics in biological systems
DY 9.4: Vortrag
Montag, 26. März 2007, 17:15–17:30, H3
Non-equilibrium phenomena in rod-shaped self-propelled particles — •Fernando Peruani1,2, Andreas Deutsch1, and Markus Baer3 — 1Technische Universitaet Dresden, Dresden, Germany — 2Max Planck for the Physics of Complex Systems, Dresden, Germany — 3Physikalisch-Technische Bundesanstalt, Berlin, Germany
Motivated by orientation and aggregation phenomena in gliding bacteria, we study collective motion in a twodimensional model of active, self-propelled rods interacting through volume exclusion. In simulations with individual particles, we find that particle clustering is facilitated by a sufficiently large packing fraction or length-to-width ratio. The transition to clustering in simulations is well captured by a mean-field model for the cluster size distribution, which predicts that critical value of the aspect ratio is given by C/Eta - 1 where C is a constant and Eta is the packing fraction [1].
In order to study orientational order in more detail, we simplify the above model by considering self-propelled point-like particles interacting through a liquid crystal-based alignment mechanism. We provide numerical evidence that such a system exhibits a continuous phase transition and long-range orientation order. The results are qualitative in line with prediction of a simple mean-field theory.
[1] F. Peruani, A. Deutsch and M. Bär, Phys. Rev. E, 74, 030904 (2006) (R)