# Non-Gaussian Tail of the Curvature Perturbation in Stochastic Ultraslow-Roll Inflation: Implications for Primordial Black Hole Production.

@article{Figueroa2020NonGaussianTO, title={Non-Gaussian Tail of the Curvature Perturbation in Stochastic Ultraslow-Roll Inflation: Implications for Primordial Black Hole Production.}, author={Daniel G. Figueroa and Sami Raatikainen and Syksy R{\"a}s{\"a}nen and Eemeli Tomberg}, journal={Physical review letters}, year={2020}, volume={127 10}, pages={ 101302 } }

We consider quantum diffusion in ultraslow-roll (USR) inflation. Using the ΔN formalism, we present the first stochastic calculation of the probability distribution P(R) of the curvature perturbation during USR. We capture the nonlinearity of the system, solving the coupled evolution of the coarse-grained background with random kicks from the short wavelength modes, simultaneously with the mode evolution around the stochastic background. This leads to a non-Markovian process from which we…

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