On the power spectrum generated during inflation
  Recently there have been differing viewpoints on how to evaluate the
curvature power spectrum generated during inflation. Since the primordial
curvature power spectrum is the seed for structure formation and provides a
link between observations and inflationary parameters, it is important to
resolve any disagreements over the expression for the power spectrum. In this
article we discuss these differing viewpoints and indicate issues that are
relevant to both approaches. We then argue why the standard expression is
valid.
