Primordial Bispectrum from Multifield Inflation with Nonminimal Couplings

Abstract

Realistic models of high-energy physics include multiple scalar fields. Renormalization requires that the fields have nonminimal couplings to the spacetime Ricci curvature scalar, and the couplings can be large at the energy scales of early-universe inflation. The nonminimal couplings induce a nontrivial field-space manifold in the Einstein frame, and they also yield an effective potential in the Einstein frame with nontrivial curvature. The ridges or bumps in the Einstein-frame potential can lead to primordial non-Gaussianities of observable magnitude. We develop a covariant formalism to study perturbations in such models and calculate the primordial bispectrum. As in previous studies of non-Gaussianities in multifield models, our results for the bispectrum depend sensitively on the fields' initial conditions.

41 pages, 11 figures. Minor changes and references added to match published version

References in corpus (11)

• The Standard Model Higgs boson as the inflaton
• Primordial Non-Gaussianities from Inflation Models
• Perturbations in generalized multi-field inflation
• Conformal Transformations with Multiple Scalar Fields
• Primordial Non-Gaussianity in Multi-Scalar Slow-Roll Inflation
• Inflationary perturbation theory is geometrical optics in phase space
• Primordial Perturbations from Multifield Inflation with Nonminimal Couplings
• Reheating, Multifield Inflation and the Fate of the Primordial Observables
• Transport equations for the inflationary trispectrum
• Non-Gaussianities of Single Field Inflation with Non-minimal Coupling
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Cited by in corpus (12)

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• Tension between the power spectrum of density perturbations measured on large and small scales
• Multifield Dynamics of Higgs Inflation
• Primordial perturbations from inflation with a hyperbolic field-space
• Frame Covariant Nonminimal Multifield Inflation
• Power Spectra beyond the Slow Roll Approximation in Theories with Non-Canonical Kinetic Terms
• Post-Newtonian parameter $\gamma$ for multiscalar-tensor gravity with a general potential
• Numerically evaluating the bispectrum in curved field-space - with PyTransport 2.0
• Inflation in a two 3-form fields scenario
• Multi-field effects in a simple extension of $R^2$ inflation
• Perturbations of Single-field Inflation in Modified Gravity Theory
• Non-Gaussianities in DBI inflation with angular motion