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Extreme power law in a driven many-particle system without threshold dynamics.
Roman Mani1, Lucas Böttcher2, Hans J Herrmann1
1Computational Physics, Institut für Baustoffe, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|November 7, 2014
Summary
High-density particle interactions can cause avalanche-like energy transfers, leading to extreme power laws. Crowd disasters may result from passive momentum transfers, not active pushing.
Area of Science:
- Physics
- Complex Systems
- Statistical Mechanics
Background:
- Individual particles exhibit well-behaved Gaussian velocity distributions.
- Particle interactions at high densities can lead to complex emergent behaviors.
Purpose of the Study:
- To investigate the dynamics of a one-dimensional driven many-particle system.
- To understand the mechanisms behind avalanche-like momentum and energy transfer.
- To explore the relevance of these dynamics to crowd disasters.
Main Methods:
- Simulating a one-dimensional system of particles connected by elastic springs.
- Modeling particle interactions as dissipative, energy-conserving, or antidissipative (pinball-like) at critical densities.
- Analyzing particle behavior under Gaussian noise driving.
Main Results:
- High-density interactions generate avalanche-like momentum and energy transfer.
- Extreme power laws emerge, lacking well-defined mean and variance.
- Velocity variance significantly increases towards the system's free boundaries.
Conclusions:
- Avalanche effects in dense particle systems are driven by passive momentum transfer.
- The model provides insights into crowd disaster dynamics, suggesting passive transfer as a primary cause over active pushing.
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