Effective temperature of active matter.

@article{Loi2008EffectiveTO,
  title={Effective temperature of active matter.},
  author={Davide Loi and Stefano Mossa and Leticia F. Cugliandolo},
  journal={Physical review. E, Statistical, nonlinear, and soft matter physics},
  year={2008},
  volume={77 5 Pt 1},
  pages={
          051111
        }
}
We follow the dynamics of an ensemble of interacting self-propelled motorized particles in contact with an equilibrated thermal bath. We find that the fluctuation-dissipation relation allows for the definition of an effective temperature that is compatible with the results obtained using a tracer particle as a thermometer. The effective temperature takes a value which is higher than the temperature of the bath, and it is continuously controlled by the motor intensity. 
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112 Citations

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References

SHOWING 1-10 OF 56 REFERENCES
Thermal properties of slow dynamics
A fluctuation theorem for non-equilibrium relaxational systems driven by external forces
We discuss an extension of the fluctuation theorem to stochastic models that, in the limit of zero external drive, are not able to equilibrate with their environment, extending earlier results of…
ENERGY FLOW, PARTIAL EQUILIBRATION, AND EFFECTIVE TEMPERATURES IN SYSTEMS WITH SLOW DYNAMICS
We show that, in nonequilibrium systems with small heat flows, there is a time-scale-dependent effective temperature that plays the same role as the thermodynamical temperature in that it controls…
Effective temperature in driven vortex lattices with random pinning.
TLDR
An effective transverse temperature in the fluid moving phase is calculated that decreases with increasing driving force and becomes equal to the equilibrium melting temperature when the dynamic transverse freezing occurs.
Rheology of active-particle suspensions.
TLDR
The phenomena of cytoplasmic streaming, elastotaxis, and active mechanosensing find natural explanations within the model of hydrodynamic velocity, concentration, and stress fields in a suspension of active, energy-dissipating particles.
Dynamic particle tracking reveals the ageing temperature of a colloidal glass
The glass transition1 is considered to be one of the most fundamental problems in statistical physics. Despite decades of effort, a general consensus on the validity of a universal theory for the…
Testing the thermodynamic approach to granular matter with a numerical model of a decisive experiment
TLDR
Considering particles of different sizes in a slowly sheared dense granular system, an effective temperature is extracted from a relation connecting their diffusivity and mobility, and an explicit computation is performed to show that the effective temperature measured from this relation coincides with the Edwards configurational temperature.
Nonequilibrium dynamics and fluctuation-dissipation relation in a sheared fluid
The nonequilibrium dynamics of a binary Lennard-Jones mixture in a simple shear flow is investigated by means of molecular dynamics simulations. The range of temperature T investigated covers both…
Brownian dynamics with hydrodynamic interactions
A method for simulating the Brownian dynamics of N particles with the inclusion of hydrodynamic interactions is described. The particles may also be subject to the usual interparticle or external…
Strong Weak and Metastable Liquids Structural and Dynamical Aspects of the Liquid State
...
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