# Clustering and anisotropic correlated percolation in polar flocks

## TL;DR

This paper investigates clustering and anisotropic percolation in the Vicsek model of active matter, revealing that the order-disorder transition is unrelated to percolation and identifying a novel anisotropic percolation transition in the ordered phase.

## Contribution

It demonstrates that the order-disorder transition in the Vicsek model is not linked to percolation and uncovers a new anisotropic percolation transition in the ordered phase.

## Key findings

- Order-disorder transition is not related to percolation.
- Geometric percolation occurs in different phases.
- Anisotropic percolation transition is found in the ordered phase.

## Abstract

We study clustering and percolation phenomena in the Vicsek model, taken here in its capacity of prototypical model for dry aligning active matter. Our results show that the order-disorder transition is not related in any way to a percolation transition, contrary to some earlier claims. We study geometric percolation in each of the phases at play, but we mostly focus on the ordered Toner-Tu phase, where we find that the long-range correlations of density fluctuations give rise to a novel anisotropic percolation transition.