Spectral analysis of a blogosphere

A blogosphere is a representative example of online social networks. In this paper, we address spectral analysis of a blogosphere. We model a real-world blogosphere as a matrix and a tensor, and then analyze it by using the SVD and PARAFAC decomposition. According to the results, the SVD successfully identified communities, each of which focuses on a specific topic, and also found hub blogs and authoritative posts within each community. The PARAFAC decomposition also succeeded in extracting more communities of finer granules than the SVD. Also, the PARAFAC decomposition could identify the dominant keywords in addition to the hub blogs and authoritative posts honored in each community.