%0 Journal Article
%T From single-particle to collective effective temperatures in an active fluid of self-propelled particles
%+ Laboratoire Charles Coulomb (L2C)
%A Levis, Demian
%A Berthier, Ludovic
%Z 6 pages, 3 figs. Réf Journal: EPL 111, 60006 (2015)
%< avec comité de lecture
%Z L2C:15-203
%@ 0295-5075
%J EPL - Europhysics Letters
%I European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing
%V 111
%P 60006
%8 2015-11-16
%D 2015
%Z 1506.08553
%R 10.1209/0295-5075/111/60006
%Z Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech]
%Z Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft]Journal articles
%X We present a comprehensive analysis of effective temperatures based on fluctuation-dissipation relations in a model of an active fluid composed of self-propelled hard disks. We first investigate the relevance of effective temperatures in the dilute and moderately dense fluids. We find that a unique effective temperature does not in general characterize the non-equilibrium dynamics of the active fluid over this broad range of densities, because fluctuation-dissipation relations yield a lengthscale-dependent effective temperature. By contrast, we find that the approach to a non-equilibrium glass transition at very large densities is accompanied by the emergence of a unique effective temperature shared by fluctuations at all lengthscales. This suggests that an effective thermal dynamics generically emerges at long times in very dense suspensions of active particles due to the collective freezing occurring at non-equilibrium glass transitions.
%G English
%L hal-01229483
%U https://hal.science/hal-01229483
%~ CNRS
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ UM-2015-2021