Cosmological correlation functions in scalar and vector inflationary models

Abstract

This thesis is centered on three main subjects within the theory of inflation and cosmological perturbations: loop corrections to the power spectrum of curvature fluctuations generated during inflation; evolution of cosmological fluctuations in anisotropic pre-inflationary cosmologies; statistical anisotropy and non-Gaussianity predictions of models of inflation populated with vector fields. Currently, what makes even more interesting the study of 2-nd and higher order corrections to cosmological correlation functions as well as the computation of higher-than-two order correlators, is the almost unprecedented chance to confront theories with new and increasingly accurate experimental data that will shed more light in the physics of the early Universe. In the context of loop calculations, we have computed the corrections arising from scalar-tensor interactions in models of single-field inflation (both for the standard slow-roll model and for models described by Lagrangians with non-canonical kinetic terms). In the context of anisotropic cosmologies, also motivated by the observation of "anomalies" in the Cosmic Microwave Background (CMB) fluctuations, we have computed the bispectrum and the trispectrum of the curvature fluctuations in inflationary models with SU(2) vector fields, analyzing the statistical anisotropy features of the correlators in these models; finally, we have studied cosmological perturbations for a Universe with a Bianchi type-I background metric, with an energy density dominated by a pressureless fluid and in the presence of a cosmological constant.

Ph.D thesis

References in corpus (29)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Observational Signatures and Non-Gaussianities of General Single Field Inflation
• Inflationary Universe with Anisotropic Hair
• Vector Inflation
• Generation of Large-Scale Magnetic Fields in Single-Field Inflation
• Quantum Contributions to Cosmological Correlations II: Can These Corrections Become Large?
• Primordial trispectrum from inflation
• Theory of cosmological perturbations in an anisotropic universe
• Optimal limits on f_{NL}^{local} from WMAP 5-year data
• Angular Trispectrum of CMB Temperature Anisotropy from Primordial Non-Gaussianity with the Full Radiation Transfer Function
• Predictions from an anisotropic inflationary era
• The Inflationary Trispectrum for Models with Large Non-Gaussianities
• Can a vector field be responsible for the curvature perturbation in the Universe?
• Instability of the ACW model, and problems with massive vectors during inflation
• On the divergences of inflationary superhorizon perturbations
• Anisotropic Inflation from Vector Impurity
• On the evolution of universes in quadratic theories of gravity
• Dark energy as a massive vector field
• Non-gaussianity from the trispectrum in general single field inflation
• Inflation from N-Forms and its stability
• P-nflation: generating cosmic Inflation with p-forms
• Anisotropic non-Gaussianity from vector field perturbations
• Simple Bounds from the Perturbative Regime of Inflation
• Cosmological perturbations from vector inflation
• Non-minimally coupled vector curvaton
• On the full quantum trispectrum in multi-field DBI inflation
• Primordial Trispectrum from Entropy Perturbations in Multifield DBI Model
• Gravity Waves Signatures from Anisotropic pre-Inflation
• Dirac-field model of inflation in Einstein-Cartan theory