The wheels: an infinite family of bi-connected planar synchronizing graphs

Almost global synchronization property of Kuramoto coupled oscillations was recently introduced and stands for the case where almost every initial condition of the dynamical system leads to the synchronization of all the agents. When the oscillators are all identical, the property only depends on the the underlying interconnection graph. If the property is present, the interconnection graph is called synchronizing. It is known that a graph is synchronizing if and only if its block are. So, the characterization of synchronizing graphs can be restricted to the class of bi-connected graphs. In this work, we present the first known infinite family of biconnected planar synchronizing graphs, named, the wheels. Besides, we present two graph which are the first known chordal graph and Halin graphs that not synchronize.