  We present a graph bisection and partitioning algorithm based on graph neural
networks. For each node in the graph, the network outputs probabilities for
each of the partitions. The graph neural network consists of two modules: an
embedding phase and a partitioning phase. The embedding phase is trained first
by minimizing a loss function inspired by spectral graph theory. The
partitioning module is trained through a loss function that corresponds to the
expected value of the normalized cut. Both parts of the neural network rely on
SAGE convolutional layers and graph coarsening using heavy edge matching. The
multilevel structure of the neural network is inspired by the multigrid
algorithm. Our approach generalizes very well to bigger graphs and has
partition quality comparable to METIS, Scotch and spectral partitioning, with
shorter runtime compared to METIS and spectral partitioning.

Machine Learning