The Primordial Curvature Perturbation from Vector Fields of General non-Abelian Groups

Abstract

We consider the generation of primordial curvature perturbation by general non-Abelian vector fields without committing to a particular group. Self-interactions of non-Abelian fields make the field perturbation non-Gaussian. We calculate the bispectrum of the field perturbation using the in-in formalism at tree level. The bispectrum is dominated by the classical evolution of fields outside the horizon. In view of this we show that the dominant contribution can be obtained from the homogeneous classical equation of motion. Then we calculate the power spectrum of the curvature perturbation. The anisotropy in spectrum is suppressed by the number of fields. This makes it possible for vector fields to be responsible for the total curvature perturbation in the Universe without violating observational bounds on statistical anisotropy. The bispectrum of the curvature perturbation is also anisotropic. Finally we give an example of the end-of-inflation scenario in which the curvature perturbation is generated by vector gauge fields through varying gauge coupling constant(s), which in covariant derivatives couples the Higgs field to the vector fields. We find that reasonably large gauge groups may result in the observable anisotropy in the power spectrum of the curvature perturbation.

Published in JCAP. Minor corrections. References added

References in corpus (25)

• Inflationary Universe with Anisotropic Hair
• Vector Inflation
• The non-Gaussian Cold Spot in the 3-year WMAP data
• Non-Abelian Gauge Field Inflation
• The Nature of Primordial Fluctuations from Anisotropic Inflation
• Cosmic Microwave Background Statistics for a Direction-Dependent Primordial Power Spectrum
• Scalar-Scalar, Scalar-Tensor, and Tensor-Tensor Correlators from Anisotropic Inflation
• Anisotropic Power-law Inflation
• Can a vector field be responsible for the curvature perturbation in the Universe?
• Asymmetric Beams and CMB Statistical Anisotropy
• Imprints of anisotropic inflation on the cosmic microwave background
• Anisotropic Inflation from Charged Scalar Fields
• Anisotropic non-Gaussianity from vector field perturbations
• Inflation with stable anisotropic hair: is it cosmologically viable?
• Cosmological perturbations from vector inflation
• Non-gaussianity of inflationary field perturbations from the field equation
• Particle Production of Vector Fields: Scale Invariance is Attractive
• Non-minimally coupled vector curvaton
• Anisotropic Inflation with Non-Abelian Gauge Kinetic Function
• Classicality of the primordial perturbations
• Gravitational waves in vector inflation
• Supergravity inspired Vector Curvaton
• Testing a direction-dependent primordial power spectrum with observations of the Cosmic Microwave Background
• Violation of the Rotational Invariance in the CMB Bispectrum
• Feynman-like Rules for Calculating n-Point Correlators of the Primordial Curvature Perturbation

Cited by in corpus (19)

• The anisotropic power spectrum and bispectrum in the f(phi) F^2 mechanism
• Gravity waves and non-Gaussian features from particle production in a sector gravitationally coupled to the inflaton
• Observable non-gaussianity from gauge field production in slow roll inflation, and a challenging connection with magnetogenesis
• Extended Gauss-Bonnet gravities in Weyl geometry
• Anisotropic Non-Gaussianity from a Two-Form Field
• Anisotropic power-law k-inflation
• δN Formalism in Anisotropic Inflation and Large Anisotropic Bispectrum and Trispectrum
• Observational signatures of anisotropic inflationary models
• Curvature Perturbations in Anisotropic Inflation with Symmetry Breaking
• Parity Violating Statistical Anisotropy
• Non-Abelian gauge preheating
• Primordial Anisotropies in Gauged Hybrid Inflation
• Stability analysis of inflation with an SU(2) gauge field
• The charged inflaton and its gauge fields: preheating and initial conditions for reheating
• Statistical Anisotropy from Vector Curvaton in D-brane Inflation
• Curvature Perturbations from a Massive Vector Curvaton
• Statistics of Anisotropies in Inflation with Spectator Vector Fields
• Dynamical Analysis of Anisotropic Inflation
• Modulation of the waterfall by a gauge field