Effect of Fluctuations in Complex Plasmas on the Dynamics of Charged Dust Grains

The effect of random forces, which are caused by fluctuations in a complex plasma, on the dynamics of charged dust grains is studied. Analytical dependences are obtained for the kinetic energy, the autocorrelation functions of velocities, the mass transfer functions, and the mean-square average displacements of the grains in the case of a grain moving under the effect of two random forces. A method is proposed for accounting for more than two random forces of different nature. The possibility is discussed of simulating the motion of dust grains in complex plasma by the Langevin equations with a temperature that is not equal to the temperature of the surrounding gas.