Stochastic chaos in chemical Lorenz system: Interplay of intrinsic noise and nonlinearity

Abstract

In this paper, we address the question of whether the phenomenon of chaos can occur in a purely stochastic system or not. We show that chaos can arise in a purely stochastic chemical Lorenz system. A robust regime of stochastic chaos develops like the onset of chaos in a deterministic system. Stochastic trajectories, which are initially very close, show sensitivity to initial states where they diverge exponentially as time progress. The interplay of nonlinearity and intrinsic noise in the chemical Lorenz system is studied to understand the effect of intrinsic noise. We observe that intrinsic noise can destabilize the fixed points and limit cycle attractors where stochastic trajectories make excursions along the unstable manifold, giving rise to the noisy chaotic attractors. This study uses quantitative measures like power spectrums and invariant measures to characterize the strange noisy attractors. Our study establishes that the interplay of intrinsic noise and nonlinearity gives rise to chaos in the stochastic Lorenz system. © 2022 Elsevier Ltd