Modeling Flocks and Prices: Jumping Particles with an Attractive Interaction (shortened version)

TL;DR

This paper introduces a finite particle jump model with attractive interactions based on relative positions, deriving a mean field equation in the large system limit that exhibits traveling wave solutions and links to extreme value statistics.

Contribution

It presents a novel particle model with position-dependent jump rates and establishes a mean field limit with traveling wave solutions, connecting microscopic dynamics to macroscopic behavior.

Findings

Mean field limit described by a new PDE with traveling wave solutions

Attractive interaction mechanism keeps particles clustered

Connection established between particle dynamics and extreme value statistics

Abstract

We introduce and investigate a new model of a finite number of particles jumping forward on the real line. The jump lengths are independent of everything, but the jump rate of each particle depends on the relative position of the particle compared to the center of mass of the system. The rates are higher for those left behind, and lower for those ahead of the center of mass, providing an attractive interaction keeping the particles together. We prove that in the fluid limit, as the number of particles goes to infinity, the evolution of the system is described by a mean field equation that exhibits traveling wave solutions. A connection to extreme value statistics is also provided.