Figure 3.

Analysis of the degree-degree correlations for two specific days, i.e. 19 February and 5 March 2018. As the trend of ${\kappa }_{\alpha }^{\mathit{nn}}$ reveals, the daily semantic networks are disassortative for all communities, i.e. nodes with small degree are (preferentially) connected to nodes with high degree and vice versa. A close inspection of behaviors of the CDX and the CSX communities shows groups of nodes with a larger value of the ANND: these clusters of hashtags constitute the core of the Twitter discussion in the corresponding community which appear in correspondence of specific events and disappear the day after.