The non-Gaussian statistics of
the primordial density perturbation have become a key test of the inflationary
scenario of the very early universe. Currently many techniques are used to
calculate the non-Gaussian signatures of a given model of inflation. In
particular, simple super-horizon techniques such as the deltaN formalism are
often used for models with more than one field, while more technical field
theory techniques, referred to as the In-In formalism, are typically used for
models where the quantum sub-horizon evolution is important. Recently we have
been developing an alternative point of view, called the transport approach.
This framework highlights the connections between these other techniques and
unifies them. Moreover, since it reduces the problem of calculating the
statistics to that of solving a set of coupled ODEs, numerical implementations
of the system are extremely simple.