title: Minimal model of stochastic athermal systems: origin of non-Gaussian noise.
abstract: For a wide class of stochastic athermal systems, we derive Langevin-like equations driven by non-Gaussian noise, starting from master equations and developing a new asymptotic expansion. We found an explicit condition whereby the non-Gaussian properties of the athermal noise become dominant for tracer particles associated with both thermal and athermal environments. Furthermore, we derive an inverse formula to infer microscopic properties of the athermal bath from the statistics of the tracer particle. We apply our formulation to a granular motor under viscous friction and analytically obtain the angular velocity distribution function. Our theory demonstrates that the non-Gaussian Langevin equation is the minimal model of athermal systems.
authors: Yukawa Institute for Theoretical Physics, Kyoto University, Kitashirakawa-oiwake cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors: Kiyoshi
authors: K
authors: Kanazawa
authors: Yukawa Institute for Theoretical Physics, Kyoto University, Kitashirakawa-oiwake cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors: Tomohiko G
authors: TG
authors: Sano
authors: Department of Basic Science, The University of Tokyo, Komaba, Meguro-ku 153-8902, Japan.
authors: Takahiro
authors: T
authors: Sagawa
authors: Yukawa Institute for Theoretical Physics, Kyoto University, Kitashirakawa-oiwake cho, Sakyo-ku, Kyoto 606-8502, Japan.
authors: Hisao
authors: H
authors: Hayakawa