Non-gaussianity and Statistical Anisotropy in Cosmological Inflationary Models

Abstract

We study the statistical descriptors for some cosmological inflationary models that allow us to get large levels of non-gaussianity and violations of statistical isotropy. Basically, we study two different class of models: a model that include only scalar field perturbations, specifically a subclass of small-field slow-roll models of inflation with canonical kinetic terms, and models that admit both vector and scalar field perturbations. We study the former to show that it is possible to attain very high, including observable, values for the levels of non-gaussianity f_{NL} and \tao_{NL} in the bispectrum B_ζ and trispectrum T_ζ of the primordial curvature perturbation ζ respectively. Such a result is obtained by taking care of loop corrections in the spectrum P_ζ, the bispectrum B_ζ and the trispectrum T_ζ. Sizeable values for f_{NL} and \tao_{NL} arise even if ζ is generated during inflation. For the latter we study the spectrum P_ζ, bispectrum B_ζ and trispectrum $T_ζ of the primordial curvature perturbation when ζ is generated by scalar and vector field perturbations. The tree-level and one-loop contributions from vector field perturbations are worked out considering the possibility that the one-loop contributions may be dominant over the tree level terms. The levels of non-gaussianity f_{NL} and \tao_{NL}, are calculated and related to the level of statistical anisotropy in the power spectrum, g_ζ. For very small amounts of statistical anisotropy in the power spectrum, the levels of non-gaussianity may be very high, in some cases exceeding the current observational limit.

Latex file, 113 pages. PhD Thesis. Supervisor: Yeinzon Rodriguez.

References in corpus (49)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
• Three Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Polarization Analysis
• Inflationary Universe with Anisotropic Hair
• Vector Inflation
• Hemispherical power asymmetry in the three-year Wilkinson Microwave Anisotropy Probe sky maps
• Quantum Contributions to Cosmological Correlations II: Can These Corrections Become Large?
• Detection of primordial non-Gaussianity (fNL) in the WMAP 3-year data at above 99.5% confidence
• Primordial perturbations and non-Gaussianities in DBI and general multi-field inflation
• Instability of anisotropic cosmological solutions supported by vector fields
• Primordial trispectrum from inflation
• Theory of cosmological perturbations in an anisotropic universe
• On the one loop corrections to inflation and the CMB anisotropies
• Cosmic Microwave Background Statistics for a Direction-Dependent Primordial Power Spectrum
• Angular Trispectrum of CMB Temperature Anisotropy from Primordial Non-Gaussianity with the Full Radiation Transfer Function
• Primordial fluctuations and non-Gaussianities in multi-field DBI inflation
• Can a vector field be responsible for the curvature perturbation in the Universe?
• Non-gaussianity from the second-order cosmological perturbation
• Anisotropic Inflation from Vector Impurity
• On the One Loop Corrections to Inflation II: The Consistency Relation
• Non-gaussianity from the trispectrum in general single field inflation
• Inflation from N-Forms and its stability
• 21-cm Background Anisotropies Can Discern Primordial Non-Gaussianity
• Large non-Gaussianity from multi-brid inflation
• Primordial Non-Gaussianities of General Multiple Field Inflation
• On the Issue of the ζSeries Convergence and Loop Corrections in the Generation of Observable Primordial Non-Gaussianity in Slow-Roll Inflation. Part I: the Bispectrum
• Anisotropic non-Gaussianity from vector field perturbations
• Testable polarization predictions for models of CMB isotropy anomalies
• Non-gaussianity of inflationary field perturbations from the field equation
• Cosmological perturbations from vector inflation
• Non-minimally coupled vector curvaton
• The trispectrum of 21-cm background anisotropies as a probe of primordial non-Gaussianity
• de Sitter limit of inflation and nonlinear perturbation theory
• Classicality of the primordial perturbations
• Creating Statistically Anisotropic and Inhomogeneous Perturbations
• Entanglement of Quantum Fluctuations in the Inflationary Universe
• Supergravity inspired Vector Curvaton
• The Trispectrum in the Multi-brid Inflation
• Non-Gaussianity from Baryon Asymmetry
• WMAP-normalized Inflationary Model Predictions and the Search for Primordial Gravitational Waves with Direct Detection Experiments
• Modulated Inflation
• Bayesian Limits on Primordial Isotropy Breaking
• An anisotropic, non-singular early universe model leading to a realistic cosmology
• Where does Cosmological Perturbation Theory Break Down?
• Probing Non-Gaussianity In The Cosmic Microwave Background Anisotropies: One Point Distribution Function
• Revisiting non-Gaussianity of multiple-field inflation from the field equation
• Nonlinear curvature perturbations in an exactly soluble model of multi-component slow-roll inflation
• Comment on non-Gaussianity in hybrid inflation
• Spectrum of Curvature Perturbation of Multi-field Inflation with Small-Field Potential
• Cosmology in non-minimal Yang-Mills/Maxwell theory