2015/02/14 by Jinn-Ouk Gong, Gong, Jinn-Ouk, Misao Sasaki +1 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #Geophysics and Gravity Measurements #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Solar and Space Plasma Dynamics
paper · doi:10.48550/arxiv.1502.04167
openalex publication_date 2015/02/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We revisit the notion of slow-roll in the context of general single-field inflation. As a generalization of slow-roll dynamics, we consider an inflaton ϕ in an attractor phase where the time derivative of ϕ is determined by a function of ϕ, ϕ=ϕ(ϕ). In other words, we consider the case when the number of e-folds N counted backward in time from the end of inflation is solely a function of ϕ, N=N(ϕ). In this case, it is found that we need a new independent parameter to properly describe the dynamics of the inflaton field in general, in addition to the standard parameters conventionally denoted by ε, η, cs2 and s. Two illustrative examples are presented to discuss the non-slow-roll dynamics of the inflaton field consistent with observations.