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Hydrodynamic interactions: Recent developments
 
The drag forces that particles exert on one another as they move through a fluid -- hydrodynamic interactions -- determine the dynamics of particulate liquids. The seminar will present three recent developments, which extend our understanding of hydrodynamic interactions beyond the usually considered scenarios. (i) Hydrodynamic interactions between inclusions in a fluid membrane. The quasi-two-dimensional nature of flows within a membrane leads to long-range correlations and anomalous concentration effects. (ii) Time-dependent hydrodynamic interactions in a narrow channel. Although the steady-state correlations are exponentially screened at large distances along the channel, the ones prior to steady state turn out to be extremely long-ranged and decay slowly with time.
(iii) Hydrodynamic interactions between driven particles. A new type of symmetry breaking has been identified in the interaction of particles that are driven along a curving trajectory, causing them to form stable pairs.