Multiple spectator condensates from inflation

Abstract

We investigate the development of spectator (light test) field condensates due to their quantum fluctuations in a de Sitter inflationary background, making use of the stochastic formalism to describe the system. In this context, a condensate refers to the typical field value found after coarse-graining using the Hubble scale $H$, which can be essential to seed the initial conditions required by various post-inflationary processes. We study models with multiple coupled spectators and for the first time we demonstrate that new forms of stationary solution exist (distinct from the standard exponential form) when the potential is asymmetric. Furthermore, we find a critical value for the inter-field coupling as a function of the number of fields above which the formation of stationary condensates collapses to $H$. Considering some simple two-field example potentials, we are also able to derive a lower limit on the coupling, below which the fluctuations are effectively decoupled, and the standard stationary variance formulae for each field separately can be trusted. These results are all numerically verified by a new publicly available python class (https://github.com/umbralcalc/nfield) to solve the coupled Langevin equations over a large number of fields, realisations and timescales. Further applications of this new tool are also discussed.

arXiv comment18 pages, 10 figures, paragraph added to match published version in JCAP

References in corpus (20)

• Generating the curvature perturbation without an inflaton
• Adiabatic CMB perturbations in pre-big bang string cosmology
• Effects of Cosmological Moduli Fields on Cosmic Microwave Background
• Equilibrium State of a Massless Self-Interacting Scalar Field in the De Sitter Background
• Nongaussian Isocurvature Perturbations from Inflation
• Stochastic Quantum Gravitational Inflation
• Breakdown of Semiclassical Methods in de Sitter Space
• The simplest curvaton model
• Stochastic inflation in phase space: Is slow roll a stochastic attractor?
• M-flation: Inflation From Matrix Valued Scalar Fields
• The stochastic spectator
• Multiple Fields in Stochastic Inflation
• Statistical nature of infrared dynamics on de Sitter background
• Spectator field dynamics in de Sitter and curvaton initial conditions
• Cosmology is not a Renormalization Group Flow
• A novel way to determine the scale of inflation
• Massive scalar field evolution in de Sitter
• Stochastic dark energy from inflationary quantum fluctuations
• A Quantum Window Onto Early Inflation
• Horizon Feedback Inflation

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