Connections between Minkowski and Cosmological Correlation Functions
  We show how cosmological correlation functions of massless fields can be
rewritten in terms of Minkowski correlation functions, by extracting
symmetry-breaking operators from the cosmological correlators. This technique
simplifies some cosmological calculations. Also, known properties of Minkowski
correlation functions can be translated to non-trivial properties of
cosmological correlations. To illustrate this idea, inflation to Minkowski and
matter bounce to Minkowski relations are presented for the interactions of
general single field inflation. And a Minkowski recursion relation is
translated to a novel relation for inflation.
