Probing the Early Universe with the CMB Scalar, Vector and Tensor Bispectrum

Abstract

Although cosmological observations suggest that the fluctuations of seed fields are almost Gaussian, the possibility of a small deviation of their fields from Gaussianity is widely discussed. Theoretically, there exist numerous inflationary scenarios which predict large and characteristic non-Gaussianities in the primordial perturbations. These model-dependent non-Gaussianities act as sources of the Cosmic Microwave Background (CMB) bispectrum; therefore, the analysis of the CMB bispectrum is very important and attractive in order to clarify the nature of the early Universe. Currently, the impacts of the primordial non-Gaussianities in the scalar perturbations, where the rotational and parity invariances are kept, on the CMB bispectrum have been well-studied. However, for a complex treatment, the CMB bispectra generated from the non-Gaussianities, which originate from the vector- and tensor-mode perturbations and include the violation of the rotational or parity invariance, have never been considered in spite of the importance of this information. On the basis of our current studies, this thesis provides the general formalism for the CMB bispectrum sourced by the non-Gaussianities not only in the scalar-mode perturbations but also in the vector- and tensor-mode perturbations. Applying this formalism, we calculate the CMB bispectrum from two scalars and a graviton correlation and that from primordial magnetic fields, and we then outline new constraints on these amplitudes. Furthermore, this formalism can be easily extended to the cases where the rotational or parity invariance is broken. We also compute the CMB bispectra from the non-Gaussianities of the curvature perturbations with a preferred direction and the graviton non-Gaussianities induced by the parity-violating Weyl cubic terms. We also present some unique impacts to the violation of these invariances on the CMB bispectrum.

The final version will be published in Springer Theses http://www.springer.com/astronomy/book/978-4-431-54179-0

References in corpus (53)

• Observational Signatures and Non-Gaussianities of General Single Field Inflation
• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• Generation of Large-Scale Magnetic Fields in Single-Field Inflation
• The shape of primordial non-Gaussianity and the CMB bispectrum
• CMB anisotropies from primordial inhomogeneous magnetic fields
• Scalar-Scalar, Scalar-Tensor, and Tensor-Tensor Correlators from Anisotropic Inflation
• Large-scale magnetic fields in the inflationary universe
• Can a vector field be responsible for the curvature perturbation in the Universe?
• Cosmological Magnetic Field: a fossil of density perturbations in the early universe
• Multi-brid inflation and non-Gaussianity
• Curvature and isocurvature perturbations from two-field inflation in a slow-roll expansion
• Non-Gaussianities in New Ekpyrotic Cosmology
• Probing polarization states of primordial gravitational waves with CMB anisotropies
• Parity Violation in Graviton Non-gaussianity
• Fast Estimator of Primordial Non-Gaussianity from Temperature and Polarization Anisotropies in the Cosmic Microwave Background
• Non-Gaussianities from ekpyrotic collapse with multiple fields
• Asymmetric Beams and CMB Statistical Anisotropy
• Large non-Gaussianity from multi-brid inflation
• Analytic Minkowski Functionals of the Cosmic Microwave Background: Second-order Non-Gaussianity with Bispectrum and Trispectrum
• The cosmic microwave background temperature bispectrum from scalar perturbations induced by primordial magnetic fields
• Perturbation Theory Reloaded II: Non-linear Bias, Baryon Acoustic Oscillations and Millennium Simulation In Real Space
• Imprints of Relic Gravitational Waves in Cosmic Microwave Background Radiation
• Non-gaussianity and cosmic uncertainty in curvaton-type models
• Anisotropic non-Gaussianity from vector field perturbations
• The cosmic microwave background bispectrum from the non-linear evolution of the cosmological perturbations
• The Impact of Stochastic Primordial Magnetic Fields on the Scalar Contribution to Cosmic Microwave Background Anisotropies
• Parity violation of primordial magnetic fields in the CMB bispectrum
• Particle Production of Vector Fields: Scale Invariance is Attractive
• The Odd-Parity CMB Bispectrum
• Sachs-Wolfe at second order: the CMB bispectrum on large angular scales
• Primordial Magnetic Field Limits from Cosmic Microwave Background Bispectrum of Magnetic Passive Scalar Modes
• Primordial non-Gaussianity from two curvaton decays
• Cosmic microwave background bispectrum on small angular scales
• Optimal limits on primordial magnetic fields from CMB temperature bispectrum of passive modes
• The CMB temperature bispectrum induced by cosmic strings
• Observable primordial vector modes
• General Single Field Inflation with Large Positive Non-Gaussianity
• Cosmic Microwave Background Trispectrum and Primordial Magnetic Field Limits
• Analytic formulae of the CMB bispectra generated from non-Gaussianity in the tensor and vector perturbations
• Non-Gaussian features of primordial magnetic fields in power-law inflation
• Cosmic microwave background bispectrum of tensor passive modes induced from primordial magnetic fields
• WMAP 7 year constraints on CPT violation from large angle CMB anisotropies
• CMB anisotropies in the presence of a stochastic magnetic field
• Non-Gaussianity as a Probe of the Physics of the Primordial Universe and the Astrophysics of the Low Redshift Universe
• Primordial magnetic fields from second-order cosmological perturbations: Tight coupling approximation
• Cosmic microwave background bispectrum of vector modes induced from primordial magnetic fields
• Generalized CMB initial conditions with pre-equality magnetic fields
• Non-Gaussianity and constraints for the variance of perturbations in the curvaton model
• Ultra High Energy Cosmology with POLARBEAR
• Scale-dependent bias from the primordial non-Gaussianity with a Gaussian-squared field
• Constraints on primordial non-Gaussianity from Galaxy-CMB lensing cross-correlation
• Non-gaussianity and Statistical Anisotropy in Cosmological Inflationary Models
• Theory of Magnetic Seed-Field Theory of Magnetic Seed-Field Generation during the Cosmological First-Order Electroweak Phase Transition

Cited by in corpus (10)

• Parameters Estimation for the Cosmic Microwave Background with Bayesian Neural Networks
• On CMB B-Mode Non-Gaussianity
• Breaking discrete symmetries in the effective field theory of inflation
• CMB power spectra induced by primordial cross-bispectra between metric perturbations and vector fields
• CMB circular and B-mode polarization from new interactions
• A New Solution for the Observed Isotropic Cosmic Birefringence Angle and its Implications for the Anisotropic Counterpart through a Boltzmann Approach
• Generation of magnetic fields in Einstein-Aether gravity
• Probing parity-odd bispectra with anisotropies of GW $V$ modes
• Primordial tensor bispectra in $\mu$-CMB cross-correlations
• Reduced bispectrum seeded by helical primordial magnetic fields