Hierarchical patterns in complex systems

Inaugural lecture by associate professor Joachim Mathiesen 

Abstract: At every turn in nature, we are confronted with complex patterns. Often these patterns have a hierarchical structure with characteristic features repeated in a self-similar way on a wide range of scales. A familiar example is the network of fractures formed in drying mud by nucleation and growth of fractures on smaller and smaller scales. Another example is the roughening of material interfaces in multiphase systems by mass transport and mass exchange between individual phases. Patterns formed in such systems will be shown and discussed.

Hierarchical patterns are also seen in the organization of research units.
Here we consider the ratio of support and academic staff at Scandinavian research units and universities. We show that this ratio is broadly consistent with a simple hierarchical model of organization of research units and discuss possible consequences.