Year: 2025
Type: article
Abstract: The curvature perturbation in a model of constant-roll (CR) inflation is interpreted in view of the logarithmic duality discovered in ref. [1] according to the δN formalism. We confirm that the critical value β:=φ̈/(Hφ̇)= -3/2 determining whether the CR condition is stable or not is understood as the point at which the dual solutions, i.e., the attractor and non-attractor solutions of the field equation, are interchanged. For the attractor-solution domination, the curvature perturbation in the CR model is given by a simple logarithmic mapping of a Gaussian random field, which can realise both the exponential tail (i.e., the single exponential decay) and the Gumbel-distribution-like tail (i.e., the double exponential decay) of the probability density function, depending on the value of β. Such a tail behaviour is important for, e.g., the estimation of the primordial black hole (PBH) abundance.
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: Stochastic lattice simulation of the inflationary universe, Theoretical study toward multi-messenger observations of black holes, G3333672055, Detailed investigation of the standard cosmological model with large galaxy imaging surveys, G4073843068, G4118976479, Primordial black hole formation and gravitational wave cosmology based on inflationary universe models, G6883445009, Inflationary universe in light of stochastic calculus, primordial black holes, and gravitational waves, The Primordial Black Hole Universe Explored by Precise Theory and Various Astronomical Observations, Study on the statistical properties of primordial fluctuations in the era of precision cosmology and toward verification of ultra-high energy physics, G7936860932, G8181039722
OpenAlex ID: W4407744226