Primordial non-Gaussianity as a signature of pre-inflationary radiation
  era
  Primordial non-Gaussianity generated in an inflationary model where inflation
is preceded by a radiation era is discussed. It is shown that both bispectrum
and trispectrum non-Gaussianities are enhanced due to the presence of
pre-inflationary radiation era. One distinguishing feature of such a scenario
is that the trispectrum non-Gaussianity is larger than the bispectrum one.
