title: Entropy production of a Brownian ellipsoid in the overdamped limit.
abstract: We analyze the translational and rotational motion of an ellipsoidal Brownian particle from the viewpoint of stochastic thermodynamics. The particle's Brownian motion is driven by external forces and torques and takes place in an heterogeneous thermal environment where friction coefficients and (local) temperature depend on space and time. Our analysis of the particle's stochastic thermodynamics is based on the entropy production associated with single particle trajectories. It is motivated by the recent discovery that the overdamped limit of vanishing inertia effects (as compared to viscous fricion) produces a so-called "anomalous" contribution to the entropy production, which has no counterpart in the overdamped approximation, when inertia effects are simply discarded. Here we show that rotational Brownian motion in the overdamped limit generates an additional contribution to the "anomalous" entropy. We calculate its specific form by performing a systematic singular perturbation analysis for the generating function of the entropy production. As a side result, we also obtain the (well-known) equations of motion in the overdamped limit. We furthermore investigate the effects of particle shape and give explicit expressions of the "anomalous entropy" for prolate and oblate spheroids and for near-spherical Brownian particles.
authors: Nordita, Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm, Sweden.
authors: Raffaele
authors: R
authors: Marino
authors: Nordita, Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-106 91 Stockholm, Sweden.
authors: Ralf
authors: R
authors: Eichhorn
authors: Department of Computational Biology and ACCESS Linnaeus Centre and Center for Quantum Materials, KTH-Royal Institute of Technology, AlbaNova University Center, SE-106 91 Stockholm, Sweden and Deptartments of Information and Computer Science and Applied Physics, Aalto University, Espoo, Finland.
authors: Erik
authors: E
authors: Aurell
mesh_terms: D003102:Colloids / Q000737:chemistry; D019277:Entropy; D008962:Models, Theoretical; D009038:Motion; D013269:Stochastic Processes
chemical_list: D003102:Colloids