Dresden 2014 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 40: Poster - Quantum Systems/ Stat. Phys./ Diffusive Process

DY 40.26: Poster

Thursday, April 3, 2014, 17:00–19:00, P3

Ageing and nonergodicity in the Standard map — •Tony Albers and Günter Radons — Technische Universität Chemnitz, Germany

We investigate diffusion processes occurring in the phase space of the well-known Standard map, which is a paradigmatic example for low-dimensional non-integrable Hamiltonian chaos. These diffusion processes deviate from the laws of normal diffusion and especially have non-stationary increments. As a consequence, statistical quantities depend on the elapsed time (ageing time) between the beginning of the process and the beginning of the measurement. Furthermore, ergodicity of these processes can be broken in the sense that ensemble and time averages do not coincide and time averages become random variables. We study the ageing and nonergodicity of the observed anomalous diffusion in terms of the mean squared displacement and the distribution of generalized diffusivities [1], which describes the fluctuations during the diffusion process around the generalized diffusion coefficient that is obtained from the asymptotic time dependence of the mean-squared displacement.

[1] T. Albers and G. Radons, EPL 102, 40006 (2013)