Non-Reconstructability in the Stochastic Block Model

  title={Non-Reconstructability in the Stochastic Block Model},
  author={Joe Neeman and Praneeth Netrapalli},
We consider the problem of clustering (or reconstruction) in the stochastic block model, in the regime where the average degree is constant. For the case of two clusters with equal sizes, recent results [MNS13, Mas14, MNS14] show that reconstructability undergoes a phase transition at the Kesten-Stigum bound of λ 2 d = 1, where λ2 is the second largest eigenvalue of a related stochastic matrix and d is the average degree. In this paper, we address the general case of more than two clusters and… CONTINUE READING