  Connections in complex networks are inherently fluctuating over time and
exhibit more dimensionality than analysis based on standard static graph
measures can capture. Here, we introduce the concepts of temporal paths and
distance in time-varying graphs. We define as temporal small world a
time-varying graph in which the links are highly clustered in time, yet the
nodes are at small average temporal distances. We explore the small-world
behavior in synthetic time-varying networks of mobile agents, and in real
social and biological time-varying systems.
