Multi-field inflation from single-field models. Issue 8 (20th August 2021)

• Record Type: Journal Article
• Authors: Bojowald, Martin; Brahma, Suddhasattwa; Crowe, Sean; Ding, Ding; McCracken, Joseph
• Is Part Of: Journal of cosmology and astroparticle physics. Volume 2021:Issue 8(2021)
• Publication Date: 2021-08-20
• Subjects: inflation -- initial conditions and eternal universe; Cosmology -- Periodicals; Astrophysics -- Periodicals; 523.0105
• DOI: 10.1088/1475-7516/2021/08/047
• Languages: English
• ISSNs: 1475-7516

Abstract

Abstract: Quantization implies independent degrees of freedom that do not appear in the classical theory, given by fluctuations, correlations, and higher moments of a state. A systematic derivation of the resulting dynamical systems is presented here in a cosmological application for near-Gaussian states of a single-field inflation model. As a consequence, single-field Higgs inflation is made viable observationally by becoming a multi-field model with a specific potential for a fluctuation field interacting with the inflaton expectation value. Crucially, non-adiabatic methods of semiclassical quantum dynamics reveal important phases that can set suitable initial conditions for slow-roll inflation (in combination with the uncertainty relation), and then end inflation after the observationally preferred number of e-folds. New parameters in the interaction potential are derived from properties of the underlying background state, demonstrating how background non-Gaussianity can affect observational features of inflation or, conversely, how observations may be used to understand the quantum state of the inflaton.