Felix Höfling, Freie Universität Berlin
Anomalous transport in the Lorentz model and in crowded cells
Anomalous, slow transport is widely observed for tracer particles in heterogeneous host structures, which are typically found in (quasi-)arrested liquids and, approximately, in densely crowded cellular fluids. I will discuss the Lorentz model for transport in such structures, which serves as paradigm for a classical localisation transition. Here, an underlying percolation phenomenon entails critical slowing down of the tracer motion, visible as subdiffusion at criticality. Guided by large-scale simulations, we have developed an elaborate scaling description of the anomalous transport. I will also make connections to random resistor networks and to the "ant in the labyrinth" and discuss universality. Eventually, I will apply the obtained insight to cellular fluids, where anomalous transport of, e.g., proteins can be measured on a spatio-temporal level by variable-lengthscale fluorescence correlation spectroscopy.