Generation of fluctuations during inflation: Comparison of stochastic and field-theoretic approaches

  title={Generation of fluctuations during inflation: Comparison of stochastic and field-theoretic approaches},
  author={Fabio Finelli and G. Marozzi and Alexei A. Starobinsky and Gian Paolo Vacca and Giovanni Venturi},
  journal={Physical Review D},
We prove that the stochastic and standard field-theoretical approaches produce exactly the same results for the amount of light massive scalar field fluctuations generated during inflation in the leading order of the slow-roll approximation. This is true both in the case for which this field is a test one and inflation is driven by another field, and the case for which the field plays the role of inflaton itself. In the latter case, in order to calculate the mean square of the gauge-invariant… 
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