Issue
EPL
Volume 86, Number 4, May 2009
Article Number 48004
Number of page(s) 5
Section Interdisciplinary Physics and Related Areas of Science and Technology
DOI http://dx.doi.org/10.1209/0295-5075/86/48004
Published online 03 June 2009
EPL, 86 (2009) 48004
DOI: 10.1209/0295-5075/86/48004

Self-organized pattern formation in a diverse attractive-repulsive swarm

D. E. O. Juanico

National Institute of Physics University of the Philippines - Diliman, Quezon City 1101, Philippines

djuanico@gmail.com

received 28 December 2008; accepted in final form 30 April 2009; published May 2009
published online 3 June 2009

Abstract
A diverse, asynchronous swarm consisting of N mobile, attractive-repulsive particles evolves inside a two-dimensional confinement. Each particle k is characterized by a preferred neighboring distance $\rho _{k}$ determined from a truncated normal distribution of mean $\overline{\rho} $ and standard deviation $\sigma _{\rho}$, for $0\leqslant \rho < \infty $. Pairwise particle interaction is either attractive or repulsive depending on whether the distance between two particles is greater or less than $\rho _{k}$. The swarm forms self-organized metastable patterns as particles adjust their positions via random asynchronous evolution. An order parameter U is defined as a measure for pattern metastability, which is found to exhibit a first-order phase transition at $\sigma _{\rho c}$ = 0.606. For $\sigma _{\rho} < \sigma _{\rho c}$ tetrapolar patterns are formed, whereas for $\sigma _{\rho } > \sigma _{\rho c}$ stellate patterns are formed. This work explores the role of diversity in self-organized pattern formation in an attractive-repulsive swarm system.

PACS
87.23.Cc - Population dynamics and ecological pattern formation.
05.65.+b - Self-organized systems.
87.18.Hf - Spatiotemporal pattern formation in cellular populations.

© EPLA 2009