Exploration of stochastic dynamics and complexity in an epidemic system.

Abstract

We investigate the effect of noise in an epidemic system. We have studied dynamics and complexity for both the deterministic and its noise-induced model. We have verified the stochastic sensitivity under the variation of noise strength and changing the initial conditions of the noise-induced system. It confirms that noise can make significant perturbation in the stochastic sensitivity. To quantify the dynamics, phase space analysis is done under both noisy and noise free conditions. The transition between regular and chaotic dynamics has been examined by 0--1 test. Corresponding complexity analysis is also done using the weighted recurrence entropy method. Numerical results confirm the chaotic dynamics in the noise-induced epidemic system within a larger region of parameters compared to the same in its noise free part.