CONICET | Buscador de Institutos y Recursos Humanos

POSTERIntroduction The study of flocking behavior has attracted interdisciplinary interest due not only to their fascinating characteristics and their ubiquity in all scales, but also for their complex nature. Modeling of swarming and flocking contributes to the understanding of natural phenomena and becomes relevant for many practical and technological applications, e.g. collective robotic motion, design and control of artificial micro swimmers, etc. [1-7]. Within this broad context, the Vicsek Model (VM) [2], which considers individuals that try to adopt the direction of movement of their interacting neighbors, under the influence of some noise, e.g. due to the environment, has gained large popularity becoming an archetypical model for the study of the onset of order upon the interactive displacement of self-driven individuals. The simple rules of the VM guarantee the observation of a rather complex and interesting critical behavior: an ordered phase of collective motion is found for low enough levels of noise, while a disordered phase is observed at high noise. However, the nature of the phase transition between tose phases could be of first-or second-order, depending on the type of considered noise [4,5,7]. The aim of this paper is to investigate the structural characteristics of the networks forme among the self-driven individuals during the farm-from equilibrium stationary states of the VM. We expect that the proposed study will shed some light on some poorly understood characteristics of the VM, Duch as the origin of ordering, as well as on the nature of the order-disorder observed phase transition, i.e. first- versus second-order. Results The collective motion of self-driven individuals leads to the formation of complex spatial- temporal patterns. We performed extensive numerical simulations of the VM showing that the structure of the clusters formed upon flocking strongly depends on the nature of the noise. By evaluating relevant network properties such as the average path length, the average degree, the clustering coefficient, etc.. We give evidence on the formation of complex structures with an effective dimension higher than the dimensionality of the space where the actual displacements take place. Furthermore, these structures are capable to sustain orientationally ordered states when the displacements are suppressed. Conclusions. The structural properties of the clusters formed upon flocking strongly depend on the type of noise affecting the interactions between individuals. The relevance of our findings to the understanding of the onset of long-range order upon flocking is also discussed. References [1] J. L. Deneubourg and S. Goss, Ethology, Ecology, Evolution 1989, 1: 295. [2] T. Vicsek, et al., Phys. Rev. Lett. 1995, 75: 1226-1229. [3] G. Theraulaz, et al., Proc. Nat. Acad. Sci. 2002, 99: 645. [4] C. Huepe and M. Aldana, Phys. Rev. Lett. 2004, 92: 168701. [5] G. Grégoire, and H. Chaté, Phys. Rev. Lett. 2004, 92: 025702. [6] T. Feder, Phys Today 2007, 60: 28. [7] G. Baglietto and E.V. Albano, Phys. Rev. E 2009, 80: 050103(R), 4pp.