Log-Normal Superstatistics for Brownian Particles in a Heterogeneous Environment

Physics

Luiz Menon Junior¹  MaikeAntonio Faustino dos Santos² 

[1] Department of Physics, Federal University of Paraná, 81531-990 Curitiba, Brazil;Department of Physics, Pontifical Catholic University of Rio de Janeiro, Rua Marquês de São Vicente, 225, 22451-900 Rio de Janeiro, Brazil;

关键词: non-Gaussian diffusion;    superstatistics;    langevin equation;    scaled brownian motion;    random diffusivity;   

DOI  :  10.3390/physics2040032

来源: DOAJ

【 摘 要 】

Superstatistical approaches have played a crucial role in the investigations of mixtures of Gaussian processes. Such approaches look to describe non-Gaussian diffusion emergence in single-particle tracking experiments realized in soft and biological matter. Currently, relevant progress in superstatistics of Gaussian diffusion processes has been investigated by applying ${\chi }^2$-gamma and ${\chi }^2$-gamma inverse superstatistics to systems of particles in a heterogeneous environment whose diffusivities are randomly distributed; such situations imply Brownian yet non-Gaussian diffusion. In this paper, we present how the log-normal superstatistics of diffusivities modify the density distribution function for two types of mixture of Brownian processes. Firstly, we investigate the time evolution of the ensemble of Brownian particles with random diffusivity through the analytical and simulated points of view. Furthermore, we analyzed approximations of the overall probability distribution for log-normal superstatistics of Brownian motion. Secondly, we propose two models for a mixture of scaled Brownian motion and to analyze the log-normal superstatistics associated with them, which admits an anomalous diffusion process. The results found in this work contribute to advances of non-Gaussian diffusion processes and superstatistical theory.

【 授权许可】

Unknown