Coarsening of topological defects in 2D polar active matter

TL;DR

This study investigates how topological defects in 2D polar active matter evolve over time, revealing unique non-equilibrium behaviors such as persistent defect density and power-law coarsening.

Contribution

It provides new insights into defect dynamics in active matter, highlighting emergent screening and nontrivial steady states not predicted by existing theories.

Findings

Persistent defect density at long times

Power law decay of defect coarsening

Emergent screening of topological charges

Abstract

We numerically study the coarsening of topological defects in 2D polar active matter and make several interesting observations and predictions. (i) The long time state is characterized by nonzero density of defects, in stark contrast to theoretical expectations. (ii) The kinetics of defect coarsening shows power law decay to steady state, as opposed to exponential decay in thermal equilibrium. (iii) Observations (i) and (ii) together suggest emergent screening of topological charges due to activity. (iv) Nontrivial defect coarsening in the active model leads to nontrivial steady state patterns. We investigate, characterize, and validate these patterns and discuss their biological significance.