Primordial statistical anisotropy generated at the end of inflation

  title={Primordial statistical anisotropy generated at the end of inflation},
  author={Shuichiro Yokoyama and J. Soda},
  journal={Journal of Cosmology and Astroparticle Physics},
We present a new mechanism for generating primordial statistical anisotropy of curvature perturbations. We introduce a vector field which has a non-minimal kinetic term and couples with a waterfall field in a hybrid inflation model. In such a system, the vector field gives fluctuations of the end of inflation and hence induces a subcomponent of curvature perturbations. Since the vector has a preferred direction, the statistical anisotropy could appear in the fluctuations. We present the… 
Non-Gaussianity and Statistical Anisotropy from Vector Field Populated Inflationary Models
We present a review of vector field models of inflation and, in particular, of the statistical anisotropy and non-Gaussianity predictions of models with SU(2) vector multiplets. Non-Abelian gauge
Statistical anisotropy in the inflationary universe
During cosmological inflation, quasiclassical perturbations are permanently generated on super-Hubble spatial scales, their power spectrum being determined by the fundamental principles of quantum
Anisotropic bispectrum of curvature perturbations from primordial non-Abelian vector fields
We consider a primordial SU(2) vector multiplet during inflation in models where quantum fluctuations of vector fields are involved in producing the curvature perturbation. Recently, a lot of
Non-gaussianities in the cosmological perturbation spectrum due to primordial anisotropy
We investigate possible signatures of a pre-inflationary anisotropic phase in two-point and three-point correlation functions of the curvature perturbation for high-momentum modes which exit the
Effective field theory of statistical anisotropies for primordial bispectrum and gravitational waves
We present the effective field theory studies of primordial statistical anisotropies in models of anisotropic inflation. The general action in unitary gauge is presented to calculate the leading
Non-Gaussianities in the Cosmological Perturbation Spectrum due to Primordial Anisotropy II
We investigate possible signatures of a pre-inflationary anisotropic phase in two-point and three-point correlation functions of the curvature perturbation for high-momentum modes which exit the
Simple Types of Anisotropic Inflation
We display some simple cosmological solutions of gravity theories with quadratic Ricci curvature terms added to the Einstein-Hilbert Lagrangian which exhibit anisotropic inflation. The Hubble
On the non-Gaussian correlation of the primordial curvature perturbation with vector fields
We compute the three-point cross-correlation function of the primordial curvature perturbation generated during inflation with two powers of a vector field in a model where conformal invariance is
Statistical anisotropy of the curvature perturbation from vector field perturbations.
The δN formula for the primordial curvature perturbation ζ is extended to include vector as well as scalar fields. Formulas for the tree-level contributions to the spectrum and bispectrum of ζ are
An estimator for statistical anisotropy from the CMB bispectrum
Various data analyses of the Cosmic Microwave Background (CMB) provide observational hints of statistical isotropy breaking. Some of these features can be studied within the framework of primordial


Cosmic Microwave Background Statistics for a Direction-Dependent Primordial Power Spectrum
Statistical isotropy of primordial perturbations is a common assumption in cosmology, but it is an assumption that should be tested. To this end, we develop cosmic microwave background statistics for
Imprints of a Primordial Preferred Direction on the Microwave Background
Rotational invariance is a well-established feature of low-energy physics. Violations of this symmetry must be extremely small today, but could have been larger in earlier epochs. In this paper we
Footprints of statistical anisotropies
We propose and develop a formalism to describe and constrain statistically anisotropic primordial perturbations. Starting from a decomposition of the primordial power spectrum in spherical harmonics,
Can a vector field be responsible for the curvature perturbation in the Universe
I investigate the possibility that the observed curvature perturbation is due to a massive vector field. To avoid generating a large scale anisotropy the vector field is not taken to be driving
Predictions from an anisotropic inflationary era
This paper investigates the predictions of an inflationary phase starting from a homogeneous and anisotropic universe of the Bianchi I type. After discussing the evolution of the background
Supergravity inspired Vector curvaton
It is investigated whether a massive Abelian vector field, whose gauge kinetic function is growing during inflation, can be responsible for the generation of the curvature perturbation in the
Creating statistically anisotropic and inhomogeneous perturbations
In almost all structure formation models, primordial perturbations are created within a homogeneous and isotropic universe, like the one we observe. Because their ensemble averages inherit the
Non-Gaussian features of primordial fluctuations in single field inflationary models
We compute the three point correlation functions for primordial scalar and tensor fluctuations in single field inflationary models. We obtain explicit expressions in the slow roll limit where the
Generation of density perturbations at the end of inflation
Recently a mechanism was proposed whereby the primordial density perturbations are generated at the end of inflation. We continue the analysis of the proposed model of this mechanism and calculate
A General Analytic Formula for the Spectral Index of the Density Perturbations Produced during Inflation.
During inflation'> vacuum fluctuations on scales less than the Hubble radius in scalar fields with effective masses much less than the Hubble parameter**> are magnified into classical perturbations