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Published on: February 22, 2018

Fluctuations and pattern formation in self-propelled particles.

Shradha Mishra1, Aparna Baskaran, M Cristina Marchetti

  • 1Physics Department, Syracuse University, Syracuse, New York 13244, USA.

Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|September 28, 2010
PubMed
Summary
This summary is machine-generated.

The flocking state of self-propelled particles becomes unstable, forming dynamic stripes and disordered regions. Even stable flocking states show significant density and order fluctuations.

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Area of Science:

  • Physics
  • Statistical Mechanics
  • Soft Matter Physics

Background:

  • Self-propelled particles exhibit collective behaviors like flocking.
  • Hydrodynamic descriptions capture large-scale properties of such systems.

Purpose of the Study:

  • Investigate the stability of the flocking state in self-propelled particle systems.
  • Characterize the emergent patterns and fluctuations.

Main Methods:

  • Coarse-grained hydrodynamic equations for density and polarization fields.
  • Analytical and numerical studies of the governing equations.

Main Results:

  • The flocking state is unstable beyond a self-propulsion velocity threshold.
  • An inhomogeneous state with propagating stripes and disordered regions emerges.
  • Large fluctuations in density and orientational order are observed even in stable flocking regimes.

Conclusions:

  • The transition from ordered flocking to inhomogeneous states is driven by spatial fluctuations.
  • Hydrodynamic descriptions are crucial for understanding emergent collective behaviors and fluctuations in active matter systems.