Fig. 1

Overview of how a PR discovers an SB in the citation network. Each node represents papers and edges shows their citation. (1, left) As soon as an SB is submitted, it is indistinguishable from ordinary papers in the community without being cited much. (2, middle) When the PR realised the importance of the SB and cited it, it spread to the rest of the scientific community and led to the paper being co-cited. (3, right) A sub-field created by a pair of papers becomes widely recognised, and a new field can emerge from it