Hidden strange nonchaotic dynamics in a non-autonomous model

We report the existence of a hidden strange nonchaotic attractor (SNA) in the system devoid of equilibrium. To identify the hidden SNAs, we have added a two frequency sinusoidal driving. The resultant model exhibits smooth basin of attraction with extended bounded dynamics. Further, we found two prominent routes namely, gradual fractalization and Heagy–Hammel for the emergence of hidden SNAs, for two different parametric regimes. The contemplated hidden SNA is characterized through Lyapunov exponents, spectral measures and phase sensitivity exponent. Besides, we incorporated the recurrence quantification analysis to investigate the onset of hidden SNAs in the chosen model. We also provide experimental evidence for the observation through electronic analog simulation which agrees with numerical simulations. We propose this approach as a generic method to witness hidden SNAs in any model without equilibria.