Origins and diagnostics of the nonequilibrium character of active systems. (3rd December 2018)

• Record Type: Journal Article
• Authors: Prawar Dadhichi, Lokrshi; Maitra, Ananyo; Ramaswamy, Sriram
• Is Part Of: Journal of statistical mechanics. (2018:Dec.)
• Publication Date: 2018-12-03
• Subjects: 16; Statistical mechanics -- Periodicals; Mechanics -- Statistical methods -- Periodicals; 530.1305
• DOI: 10.1088/1742-5468/aae852
• Languages: English
• ISSNs: 1742-5468

Abstract

Abstract: We present in detail a Langevin formalism for constructing stochastic dynamical equations for active-matter systems coupled to a thermal bath. We apply the formalism to clarify issues of principle regarding the sources and signatures of nonequilibrium behaviour in a variety of polar and apolar single-particle systems and polar flocks. We show that distance from thermal equilibrium depends on how time-reversal is implemented and hence on the reference equilibrium state. We predict characteristic forms for the frequency-resolved entropy production for an active polar particle in a harmonic potential, which should be testable in experiments.