Common noise-induced synchronization of relaxation oscillators*

Common noise-induced synchronization is widely observed in various nonlinear oscillators. We used the relaxation oscillators that have two internal states changed by their threshold values. We investigated how the relaxation oscillators synchronize by common 1/fα noise. As a result, we found that characteristics of the noise-induced synchronization of these relaxation systems depend on how the common 1/fα noise is applied, namely to the internal state or to the threshold value.