Fig. 13From: Co-occurrence simplicial complexes in mathematics: identifying the holes of knowledgeAuthors’ entropy versus null model. Here we compare the entropy for authors in our dataset with average entropy over a null model. Entropy for authors is computed as the average over all authors with k concepts, while entropy for the null model is the average over 1000 random extractions of k concepts from our list. Average entropy for authors is always below the null model, and it is bounded above by a horizontal asymptoteBack to article page