Primordial Fluctuations from Inflation with a Triad of Background Gauge Fields

Abstract

We study the linear perturbation of the recently proposed model of inflation where a uniform gauge-kinetic coupling of the inflaton to multiple vector fields breaks the cosmic no-hair conjecture while maintaining the isotropy. We derive the general quadratic action for the perturbation and calculate the power spectra of scalar and tensor modes at the end of inflation by in-in formalism. It is shown that the model predicts slightly red spectra and the tensor-to-scalar ratio tends to be suppressed. The comparison with the data from WMAP 7-year does not impose strong constraints on the parameters and both weak- and strong- gauge-field regimes are consistent with the current observations.

A discussion on vector mode added

References in corpus (11)

• Inflationary Universe with Anisotropic Hair
• Vector Inflation
• Magnetic fields from inflation?
• Instability of anisotropic cosmological solutions supported by vector fields
• The Nature of Primordial Fluctuations from Anisotropic Inflation
• Scalar-Scalar, Scalar-Tensor, and Tensor-Tensor Correlators from Anisotropic Inflation
• Anisotropic Power-law Inflation
• Inflation from N-Forms and its stability
• Anisotropic Inflation from Charged Scalar Fields
• Particle Production of Vector Fields: Scale Invariance is Attractive
• Gauge field back-reaction in Born Infeld cosmologies

Cited by in corpus (8)

• Gauge-flation trajectories in Chromo-Natural Inflation
• The TT, TB, EB and BB correlations in anisotropic inflation
• Inflationary Dynamics with a Non-Abelian Gauge Field
• Stochastic Effects in Anisotropic Inflation
• Anisotropic constant-roll inflation for the Dirac-Born-Infeld model
• Dynamics of inflation with mutually orthogonal vector fields in a closed universe
• Geometric structure of multi-form-field isotropic inflation and primordial fluctuations
• Dipole Modulation in Tensor Modes: Signatures in CMB Polarization