Non-Markovian effects in liquid dielectrics

The set of kinetic equations for the time correlation function of polarization in the correlation approximation of the second order has been obtained with the help of the Zwanzig-Mori projection operators method. In the range of the orientational polarization this approximation appears as a result of using the Bogolubov's time scale hierarchy and neglecting the inertia effects in the molecule dynamics. The non-Markovian parameter of the orientational polarization process was introduced. The obtained dielectric spectra are the non-Debye ones and depend on the polarization process non-Markovian parameter. The narrowing of the dielectric losses line /spl epsi/"(/spl omega/) in the polar liquids in the Poley absorption range is explained by the non-Markovian nature of the angle velocity time correlation of the molecule. The Debye type of polarization in the formulae obtained is a particular limiting case. The microscopic expressions for the orientational relaxation time and the non-Markovian parameter were obtained.