  How to identify the influential spreaders in social networks is crucial for
accelerating/hindering information diffusion, increasing product exposure,
controlling diseases and rumors, and so on. In this paper, by viewing the
k-shell value of each node as its mass and the shortest path distance between
two nodes as their distance, then inspired by the idea of the gravity formula,
we propose a gravity centrality index to identify the influential spreaders in
complex networks. The comparison between the gravity centrality index and some
well-known centralities, such as degree centrality, betweenness centrality,
closeness centrality, and k-shell centrality, and so forth, indicates that our
method can effectively identify the influential spreaders in real networks as
well as synthetic networks. We also use the classical
Susceptible-Infected-Recovered (SIR) epidemic model to verify the good
performance of our method.
