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## Divergence of dust particles trajectories in dusty plasma model

The description of the properties of the plasma–dust system can be improved by using elements of thermodynamics. Divergence of the dusty particles trajectories allows us to estimate Krylov–Kolmogorov–Sinai entropy for a system of dust particles in plasma. In this way, we can verify if the behavior of the K-entropy of the dusty plasma subsystem in the partial equilibrium is close to the physical entropy. A picture of the divergence of trajectories for the dusty plasma model is obtained. The memory time of the model is estimated. The dependence of K-entropy on the number of dust particles and on the average kinetic energy of the dust particles are presented. The similarity of the behavior of the K-entropy parameter in the plasma–dust system and in the classical molecular-dynamic gas model is shown. The possibility of using this parameter for the description of dusty plasma is discussed.