  Discovering communities in complex networks helps to understand the behaviour
of the network. Some works in this promising research area exist, but
communities uncovering in time-dependent and/or multiplex networks has not
deeply investigated yet. In this paper, we propose a communities detection
approach for multislice networks based on modularity optimization. We first
present a method to reduce the network size that still preserves modularity.
Then we introduce an algorithm that approximates modularity optimization (as
usually adopted) for multislice networks, thus finding communities. The network
size reduction allows us to maintain acceptable performances without affecting
the effectiveness of the proposed approach.
