Critical Number of Fields in Stochastic Inflation.

@article{Vennin2017CriticalNO,
  title={Critical Number of Fields in Stochastic Inflation.},
  author={Vincent Vennin and Hooshyar Assadullahi and Hassan Firouzjahi and Mahdiyar Noorbala and David Wands},
  journal={Physical review letters},
  year={2017},
  volume={118 3},
  pages={
          031301
        }
}
Stochastic effects in generic scenarios of inflation with multiple fields are investigated. First passage time techniques are employed to calculate the statistical moments of the number of inflationary e-folds, which give rise to all correlation functions of primordial curvature perturbations through the stochastic δN formalism. The number of fields is a critical parameter. The probability of exploring arbitrarily large-field regions of the potential becomes nonvanishing when more than two… 

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