Non-perturbative approach for curvature perturbations in stochastic-$\delta N$ formalism

Abstract

In our previous paper, we have proposed a new algorithm to calculate the power spectrum of the curvature perturbations generated in inflationary universe with use of the stochastic approach. Since this algorithm does not need the perturbative expansion with respect to the inflaton fields on super-horizon scale, it works even in highly stochastic cases. For example, when the curvature perturbations are very large or the non-Gaussianities of the curvature perturbations are sizable, the perturbative expansion may break down but our algorithm enables to calculate the curvature perturbations. We apply it to two well-known inflation models, chaotic and hybrid inflation, in this paper. Especially for hybrid inflation, while the potential is very flat around the critical point and the standard perturbative computation is problematic, we successfully calculate the curvature perturbations.

25 pages, 9 figures, 2 tables

References in corpus (8)

• Generalised constraints on the curvature perturbation from primordial black holes
• Generation of fluctuations during inflation: comparison of stochastic and field-theoretic approaches
• Stochastic growth of quantum fluctuations during slow-roll inflation
• On the divergences of inflationary superhorizon perturbations
• Single-field inflation, anomalous enhancement of superhorizon fluctuations, and non-Gaussianity in primordial black hole formation
• Hybrid inflation along waterfall trajectories
• Gamma-rays from ultracompact minihalos: potential constraints on the primordial curvature perturbation
• Perturbations in stochastic inflation

Cited by in corpus (31)

• Primordial Black Holes
• Implications of stochastic effects for primordial black hole production in ultra-slow-roll inflation
• Cancellation of quantum corrections on the soft curvature perturbations
• Review on stochastic approach to inflation
• Inflation is always semi-classical: Diffusion domination overproduces Primordial Black Holes
• The Open Effective Field Theory of Inflation
• Gravitational Waves and Primordial Black Holes from Supersymmetric Hybrid Inflation
• Large fluctuations and Primordial Black Holes
• Quantum Diffusion in Sharp Transition to Non-Slow-Roll Phase
• Numerical stochastic inflation constrained by frozen noise
• Stochastic Effects in Anisotropic Inflation
• STOLAS: STOchastic LAttice Simulation of cosmic inflation
• Stochastic Effects in Axion Inflation and Primordial Black Holes Formation
• Finding origins of CMB anomalies in the inflationary quantum fluctuations
• Extended $\delta N$ formalism: Nonspatially Flat Separate Universe Approach
• Primordial Helical Magnetic Fields from Inflation?
• Primordial Black Holes from Effective Field Theory of Stochastic Single Field Inflation at NNNLO
• Computing First-Passage Times with the Functional Renormalisation Group
• Stochastic inflation with gradient interactions
• Inflation with Stochastic Boundary
• Stochastic inflation and non-perturbative power spectrum beyond slow roll
• Stochastic origin of primordial fluctuations in the Sky
• Itô, Stratonovich, and zoom-in schemes in stochastic inflation
• Classicality of Stochastic Noise Away From Quasi-de Sitter Inflation
• Improved quantum algorithm for calculating eigenvalues of differential operators and its application to estimating the decay rate of the perturbation distribution tail in stochastic inflation
• Stochastic-tail of the curvature perturbation in hybrid inflation
• Stochastic Inflation with Interacting Noises
• Time-reversed Stochastic Inflation
• Emergent particles of de Sitter: thermal interpretation of the stochastic formalism and beyond
• Deviations from Gaussian White Noise in Stochastic Inflation
• Calculating the power spectrum in stochastic inflation by Monte Carlo simulation and least squares curve fitting