Figure 2
From: The concept of decentralization through time and disciplines: a quantitative exploration
Temporal evolution of the influence between clusters. Average knowledge flows \(K_{a \to b}(T)\) from each cluster a to each cluster b at level 3 in the period T= 1970-1989 (a), T= 1990-2007 (b) and T= 2008-2020 (c), represented by the different colors according to the colorbar in the bottom left part of the figure. A representative keyword for each cluster is reported on the bottom right part of the figure. White lines denote clusters belonging to the same 2nd level cluster, whereas red lines mark different branches at the 1st level. In the first period, little to no communication is happening between different clusters. In recent years, more communication happens inside the same 2nd level cluster, and towards the middle branch (cluster 11). However, little communication happens between the two other branches, roughly representing the STEM and social sciences communities respectively