The interconnection of synchronization threshold with effective diffusion coefficient of instantaneous phase of chaotic self-sustained oscillations

We investigate effective diffusion coefficient of instantaneous phase of chaotic self-sustained oscillations and its connection with synchronization threshold. It is showed that effective phase diffusion coefficient in contrast to maximal Lyapunov exponent allows to distinguish the regions of spiral and funnel attractor. We ascertain that synchronization threshold of chaos is in order-of-magnitude agreement with the value of diffusion coefficient divided by the mean frequency of self-sustained oscillations.