  We study the effect of network topology on the collective dynamics of an
oscillator ensemble. Specifically, we explore explosive synchronization in a
system of interacting star networks. Explosive synchronization is characterized
by an abrupt transition from an incoherent state to a coherent state. In this
study, we couple multiple star networks through their hubs and study the
emergent dynamics as a function of coupling strength. The dynamics of each node
satisfies the equation of a Kuramoto oscillator. We observe that for a small
inter-star coupling strength, the hysteresis width between the forward and
backward transition point is minimal, which increases with an increase in the
inter-star coupling strength. This observation is independent of the size of
the network. Further, we find that the backward transition point is independent
of the number of stars coupled together and the inter-star coupling strength,
which is also verified using the Watanabe and Strogatz (WS) theory.
