Networks Theory Linking Life Sciences and Physical Systems

In the last decade, physics has been expanding to new research areas. In particular, life-related sciences (ecology, sociology, economics, and last but not least biology) show striking analogies with complex systems arising from more “classical” physical areas. Such approaching has happened from both fronts: on the life science side, huge amounts of data have become available for detailed analysis, thanks also to the Internet, through which these data are nowadays easily collectable and queryable (e.g. stock market financial series, tables of social relationships from movie co-partnership to e-mail fluxes, high-throughput biological data). On the other side, many physical and mathematical tools, that had been proven useful in explaining complex phenomena like polymer growth or spin glasses, began to spread to other research areas involving less elementary particles, like biology and sociology in a broad sense. The common trait can be found in the framework of network theory, that focusing on the relationships among elements allows to draw general conclusions even though the details of the system are not completely known or easily tractable from a mathematical point of view. Relaxing the attention to the details of the specific interaction or element, network theory aims to provide tools for the characterization of a set of relationships, represented as edges or links, occurring among similar elements, referred to as vertices or nodes.