Higher order non-linear parameters with PLANCK
  We investigate how higher order non-linear parameters affect lower order ones
through loop effects. We calculate the loop corrections up to two-loops and
explicitly show that the tree contribution is stable against loop terms in most
cases. We argue that, nevertheless, observational constraints on non-linear
parameters such as fNL and tauNL can also give a limit even for higher order
ones due to the loop contribution. We discuss these issues both for
single-source and multi-source cases.
