Many natural and artificial systems consist of agents that have ability to show persistent motion. Flock of birds, school of fish, human crowd, bacterial colonies are few of the examples. Agents in such system are called `Self-propelled Particles' (SPPs). Another remarkable property of the agents in such systems is the ability to exhibit collective behavior. The beautiful pattern formation in flock of Starling birds or school of fish is just one of the many outcomes of the collective behavior[1].

There are numerous computational models to understand the collective behavior in such systems. These models aim to understand the formation of such patterns, the mechanism behind the collective behavior. One of the notable model is given by Vicsek et al. now commonly known as the `Vicsek model'. This minimal model assumes that the agent in the system try to behave as it's neighbors do[2]. With this simple but yet effective assumption this model showed some of the prominent features of the collective behavior.

In this session we shall discuss about the systems with SPPs, the Vicsek model and one of the modification to the Vicsek model motivated by the fact that biological agents such as humans, birds, fish etc. have restricted view-angle and hence such agents interact anisotropically with its neighbors if the interaction is via visual clues. We shall discuss the effects on the collective behavior of SPPs due to this modification within the scope of the Vicsek model.
 
Ref.:
[1] T. Vicsek and A. Zafeiris, Phys. Rep. 517, 71 (2012).

[2] T. Vicsek, A. Czir ok, E. Ben-Jacob, I. Cohen, and O. Shochet, Phys. Rev. Lett. 75, 1226 (1995).