  We found analytical solution for the time evolution of localized electron
density in a system of two coupled single-level quantum dots (QDs) connected
with continuous spectrum states in the presence of Coulomb interaction. This
solution takes into account QD electrons correlation functions of all orders
neglecting any correlations between localized and conduction electron filling
numbers.
  We demonstrated that several time scales with the strongly different
relaxation rates appear in the system for a wide range of the Coulomb
interaction value. We revealed that specific non monotonic behavior of charge
relaxation in QD takes place due to Coulomb correlations.
  We also found out that besides the usual charge oscillations with the period
determined by the detuning between the energy levels of the QDs a new effect of
period doubling appears in the presence of Coulomb interaction at particular
range of the system parameters.
