  A common external forcing can cause a saddle-node bifurcation in an ensemble
of identical Duffing oscillators by breaking the symmetry of the individual
bistable (double-well) unit. The strength of the forcing determines the
separation between the saddle and node, which in turn dictates different
dynamical transitions depending on the distribution of the initial states of
the oscillators. In particular, chimera-like states appear in the vicinity of
the saddle-node bifurcation for which theoretical explanation is provided from
the stability of slow-scale dynamics of the original system of equations.
Further, as a consequence, it is shown that even a linear nearest neighbor
coupling can lead to the manifestation of the chimera states in an ensemble of
identical Duffing oscillators in the presence of the common external forcing.
