Powered spectral methods achieve weak recovery in the stochastic block model

From papers

Let SBM(n,p,Q/n)\mathrm{SBM}(n,p,Q/n) be a stochastic block model in which vertices from every community have the same expected degree. Let A(r)A^{(r)} and B(r)B^{(r)} be the powered adjacency and powered nonbacktracking matrices, respectively, and let dd be the graph diameter. Weak recovery means recovering the communities with nontrivial accuracy.

Powered spectral recovery conjecture. Choose pp and QQ such that vertices from every community have the same expected degree and there is an efficient algorithm that solves weak recovery on SBM(n,p,Q/n)\mathrm{SBM}(n,p,Q/n). There exists 0<r0<10<r_0<1 such that, for every constant r<r0r<r_0, the algorithm that finds the second-largest-eigenvalue eigenvector of A(rd)A^{(rd)} or B(rd)B^{(rd)} and partitions vertices by the median of the sums of entries corresponding to incident edges solves weak recovery on SBM(n,p,Q/n)\mathrm{SBM}(n,p,Q/n).

The conjecture extends the proposed diameter-scale powering approach to the stochastic block model at smaller constant fractions of the diameter. The source gives no resolution.

Progress summary

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Sources & referencesView supporting material

Primary source

Emmanuel Abbe, Enric Boix, Peter Ralli and Colin Sandon, “Graph powering and spectral robustness”, arXiv:1809.04818 (2018).

Solutions 0

No solutions have been posted yet.