  Current auto- and cross-correlations are studied in a system of two
capacitively coupled quantum dots. We are interested in a role of Coulomb
interaction in dynamical correlations, which occur outside the Coulomb blockade
region (for high bias). After decomposition of the current correlation
functions into contributions between individual tunneling events, we can show
which of them are relevant and lead to sub-/supper-Poissonian shot noise and
negative/positive cross-correlations. The results are differentiated for a weak
and strong inter-dot coupling. Interesting results are for the strong coupling
case when electron transfer in one of the channel is strongly correlated with
charge drag in the second channel. We show that cross-correlations are
non-monotonic functions of bias voltage and they are in general negative
(except some cases with asymmetric tunnel resistances). This is effect of local
potential fluctuations correlated by Coulomb interaction, which mimics the
Pauli exclusion principle.
