New constraints on multi-field inflation with nonminimal coupling

Abstract

We study the dynamics and perturbations during inflation and reheating in a multi-field model where a second scalar field $\chi$ is nonminimally coupled to the scalar curvature $(\frac{1}{2}\xi R{\chi }^2$). When $\xi$ is positive, the usual inflationary prediction for large-scale anisotropies is hardly altered while the $\chi$ fluctuation in sub-Hubble modes can be amplified during preheating for large $\xi$. For negative values of $\xi$, however, long-wave modes of the $\chi$ fluctuation exhibit exponential increase during inflation, leading to the strong enhancement of super-Hubble metric perturbations even when $|\xi |$ is less than unity. This is because the effective $\chi$ mass becomes negative during inflation. We constrain the strength of $\xi$ and the initial $\chi$ by the amplitude of produced density perturbations. One way to avoid nonadiabatic growth of super-Hubble curvature perturbations is to stabilize the $\chi$ mass through a coupling to the inflaton. Preheating may thus be necessary in these models to protect the stability of the inflationary phase.

20 pages, 8 figures, submitted to Physical Review D

References in corpus (6)

• A new approach to the evolution of cosmological perturbations on large scales
• Parametric Amplification of Metric Fluctuations During Reheating in Two Field Models
• Multi-field fermionic preheating
• A new twist to preheating
• Renormalization Group Approach to Cosmological Back Reaction Problems
• Preheating with extra dimensions

Cited by in corpus (33)

• Adiabatic and entropy perturbations from inflation
• On initial conditions for the Hot Big Bang
• The Higgs field as an inflaton
• Cosmological perturbations from multi-field inflation in generalized Einstein theories
• Density perturbations in generalized Einstein scenarios and constraints on nonminimal couplings from the Cosmic Microwave Background
• Cosmological Perturbations with Multiple Fluids and Fields
• Correlation-consistency cartography of the double inflation landscape
• Preheating - cosmic magnetic dynamo ?
• Constraints on braneworld inflation from CMB anisotropies
• Testing for double inflation with WMAP
• Backreaction and the Parametric Resonance of Cosmological Fluctuations
• Scale-invariance in expanding and contracting universes from two-field models
• Some Aspects of Tachyon Field Cosmology
• When can preheating affect the CMB?
• Composite Inflation Setup and Glueball Inflation
• Primordial Perturbations from Multifield Inflation with Nonminimal Couplings
• Inflation, the Hubble Tension and Early Dark Energy: an alternative overview
• Non-Minimal Inflation Revisited
• Braneworld non-minimal inflation with induced gravity
• Non-Gaussianities of Single Field Inflation with Non-minimal Coupling
• Inflationary entanglement
• Effect of transitions in the Planck mass during inflation on primordial power spectra
• The effect of multiple features on the power spectrum in two-field inflation
• Brane preheating
• Fermion production from preheating-amplified metric perturbations
• Tracking the Multifield Dynamics with Cosmological Data: A Monte Carlo approach
• Stability analysis of the cosmological solutions with induced gravity and scalar field on the brane
• Chaotic dynamics in preheating after inflation
• Modulated inflation from kinetic term
• Non-adiabatic quantum effects from a Standard Model time-dependent Higgs vev
• More on the Non-Gaussianity of Perturbations in a Non-Minimal Inflationary Model
• Testing a Two Field Inflation Beyond the Slow-Roll Approximation
• Testing an Inflation Model with Nonminimal Derivative Coupling in the Light of PLANCK 2015 Data