Synchronization by external periodic force in ensembles of globally coupled phase oscillators

We consider the effect of an external periodic force on chimera state in the phase oscillator model proposed by Abrams et al. [Phys. Rev. Lett, v. 101, 00319007 (2008)]. Using the Ott--Antonsen reduction the dynamical equations for the global order parameter characterizing the degree of synchronization are constructed. The regions of the global order parameter frequency locking by an external periodic force are constructed. The possibility of stable chimeras synchronization and unstable chimeras stabilization are established.