Tilt and Tensor-to-Scalar Ratio in Multi-Scalar Field Inflation: Non-Sum-Separable Case

Abstract

The canonical multi-scalar field inflation where the kinetic and potential terms are sum-separable is ruled out by the current observations for the chaotic-type potential $V={\sum }_i{\mu }_i{\varphi }_i^p$. This paper explores the non-sum-separable case to validate the chaotic-type potential in the multi-scalar field, incorporating a linear coupling term between the kinetic and potential terms in the canonical Lagrangian. This coupling influences the slow-roll parameters and also alters our predictions for the spectral index $n_s$ and the tensor-to-scalar ratio $r$, which directly depend on those parameters. In fact, compared to standard canonical multi-field inflation, the values of $n_s$ and $r$ decrease to levels consistent with the recent Planck+BICEP/Keck constraint.

arXiv commentV2: 7 pages, 2 figures, and 2 tables, title changed, version accepted by Physics of the Dark Universe

References in corpus (42)

• Planck 2018 results. X. Constraints on inflation
• Particle Physics Models of Inflation and the Cosmological Density Perturbation
• Generating the curvature perturbation without an inflaton
• Observational Signatures and Non-Gaussianities of General Single Field Inflation
• A General Analytic Formula for the Spectral Index of the Density Perturbations produced during Inflation
• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• Adiabatic CMB perturbations in pre-big bang string cosmology
• Effects of Cosmological Moduli Fields on Cosmic Microwave Background
• Density Perturbations and Black Hole Formation in Hybrid Inflation
• Semiclassicality and Decoherence of Cosmological Perturbations
• Completing Natural Inflation
• N-flation
• Primordial non-gaussianities from multiple-field inflation
• Non-Gaussianities in two-field inflation
• Correlated adiabatic and isocurvature perturbations from double inflation
• Supernatural Inflation: Inflation from Supersymmetry with No (Very) Small Parameters
• Perturbations in generalized multi-field inflation
• Primordial Black Hole Formation in a Double Inflation Model in Supergravity
• Generalized Assisted Inflation
• Random Matrices and the Spectrum of N-flation
• Non-Gaussianities in Multi-field Inflation
• Dynamics of Assisted Inflation
• Multiple field inflation
• Double Inflation and the Low CMB Quadrupole
• A covariant approach to general field space metric in multi-field inflation
• Primordial Non-Gaussianity in Multi-Scalar Slow-Roll Inflation
• Multi-Natural Inflation
• On Classification of Models of Large Local-Type Non-Gaussianity
• M-flation: Inflation From Matrix Valued Scalar Fields
• A geometric description of the non-Gaussianity generated at the end of multi-field inflation
• Natural and Multi-Natural Inflation in Axion Landscape
• Hierarchical Axion Inflation
• Encyclopaedia Curvatonis
• Non-Gaussianities in N-flation
• Multi-field inflation with random potentials: field dimension, feature scale and non-Gaussianity
• Dynamics and perturbations in assisted chaotic inflation
• Observational constraints on K-inflation models
• Confrontation of Double-Inflationary Models with Observations
• Gravitational wave consistency relations for multifield inflation
• Runnings in the Curvaton
• Curvaton in large field inflation
• Path integral for multi-field inflation