Speaker
Description
Robert Brown reported the jiggling motion of micron-sized pollen granules observed
in his microscope in 1828. Since this first observation of diffusion, experimental
techniques have been advanced massively. Today, for instance, individual molecules
diffusing in living biological cells can be followed at the resolution of few nano-
metres at millisecond intervals. Such measured trajectories reveal a lot about the
physical properties of their environment.
To extract this information, dedicated models need to be established and analysed.
This is at the core of modern non-equilibrium statistical physics. In my talk I am
going to address several aspects of what we call anomalous diffusion, when the mea-
sured dynamics deviates from that of normal Brownian motion. The earliest example
is so-called Richardson diffusion in turbulent media, as measured by pilot balloos
experiments in 1926. Other examples include motion characterised by energetic trap-
ping and processes with long-range correlations.
The physical phenomena addressed in the talk include (weak) non-ergodicity, non-ex-
ponential relaxation, long-time retention effects in hydrology, non-Gaussian beha-
viour, and boundary effects.
