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Emergence of extreme events in coupled systems with time-dependent interactions
We present a class of extreme events manifested in dynamical systems involving time-dependentattractive and repulsive couplings. We consider two cases of time-varying coupling strengths -(i) explicit time-dependence (periodically varying) and (ii) implicit time dependence (distance-dependent coupling). In both of these cases, the coupled systems generate quasi-stable equilibriumpoints, which in turn are responsible for the generation of extreme events. In the explicit time-dependent case, the quasi-stable equilibrium points are periodically created whenever the amplitudeof the external force is higher than the threshold value. In the implicit time-dependent case, theyexist whenever the distance between the trajectories is below a critical distance. We demonstrate theresults with the examples of two, three, and a network of hundred coupled Stuart-Landau oscillators.We also show the prevalence of this phenomenon in other dynamical systems (van der Pol oscillator)and highlight its applications in natural systems.