| Contents |
| In the last decade, complex network theory has evolved towards more comprehensive ways of representing complex systems: from simple mappings of real-world structures up to functional networks, in which links represent the presence of some kind of relationship between the time series describing pairs of nodes. The last frontier is the multi-layer representation, in which links of different nature are considered. It has extensively been shown that disregarding the multi-layer structure can distort the understanding that we have of the system, as the dynamics of even simple processes, {\it e.g.} propagation of failures or information, strongly depends on the chosen network representation. Nevertheless, less attention has been devoted to the relationship between functional and multi-layer networks.
In this talk, I tackle this problem by dint of a multi-layer functional representation of the topology created by delay propagation in the European air transport system. By comparing different ways of projecting the dynamics and the topology, I show how any attempt at simplifying the representation results in catastrophic distortions of the characteristics of the system. Such results are relevant for understanding the limitations of the actual way of studying real-world systems, like for instance the human brain. |
|