Related papers: Spectator stresses and CMB observables
Recent analyses of the WMAP 5-year data constrain possible non-adiabatic contributions to the initial conditions of CMB anisotropies. Depending upon the early dynamics of the plasma, the amplitude of the entropic modes can experience a…
I describe briefly the Cosmic Microwave Background (hereafter CMB) physics which explains why high accuracy observations of its spatial structure are a unique observational tool both for the determination of the global cosmological…
This paper presents a complete analysis of the effects of second order gravitational perturbations on Cosmic Microwave Background anisotropies, taking explicitly into account scalar, vector and tensor modes. We also consider the second…
Weak lensing distortion of the background cosmic microwave background (CMB) temperature and polarization patterns by the foreground density fluctuations is well studied in the literature. We discuss the gravitational lensing modification to…
We study microwave background anisotropies induced by scaling seed perturbations in a universe dominated by cold dark matter. Using a gauge invariant linear perturbation analysis, we solve the perturbation equations on super-horizon scales,…
Damping of primordial gravitational waves due to the anisotropic stress contribution owing to the cosmological neutrino background (C$\nu$B) is investigated in the context of a radiation-to-matter dominated Universe. Besides its inherent…
The Cosmic Microwave Background (CMB) anisotropy constrains the geometry of the Universe because the positions of the acoustic peaks of the angular power spectrum depend strongly on the curvature of underlying three-dimensional space. In…
We combine detections of anisotropy in the Cosmic Microwave Background radiation with observations of inhomogeneity in the large-scale distribution of galaxies to test the predictions of models of cosmological structure formation. This…
The analysis of anisotropies in the cosmic microwave background (CMB) has become an extremely valuable tool for cosmology. We even have hopes that planned CMB anisotropy experiments may revolutionize cosmology. Together with determinations…
This article investigates the non-linear evolution of cosmological perturbations on sub-Hubble scales in order to evaluate the unavoidable deviations from Gaussianity that arise from the non-linear dynamics. It shows that the dominant…
The damping of primordial perturbations at small scales gives rise to distortions of the cosmic microwave background (CMB). Here, the dependence of the distortion on the different types of cosmological initial conditions is explored,…
The vector perturbations induced on the brane by gravitational waves propagating in the bulk are studied in a cosmological framework. Cosmic expansion arises from the brane motion in a non-compact five-dimensional anti-de Sitter spacetime.…
It seems generic to have vacua with lower dimensionality than ours. We consider the possibility that the observable universe originated in a transition from one of these vacua. Such a universe has anisotropic spatial curvature. This may be…
Skewness of temperature fluctuations of the cosmic microwave background (CMB) produced by initially Gaussian adiabatic perturbations with the flat (Harrison-Zeldovich) spectrum, which arises due to non-linear corrections to a gravitational…
This paper introduces a systematic treatment of the linear theory of scalar gravitational perturbations in the presence of a fully inhomogeneous magnetic field. The analysis is conducted both in the synchronous and in the conformally…
The cosmic neutrino background anisotropy is calculated for massive neutrino states by solving the full Boltzmann equation. The effect of weak gravitational lensing, including the Limber approximation, is also derived for massive particles,…
These lecture notes present the computation of the full system of Boltzmann equations describing the evolution of the photon, baryon and cold dark matter fluids up to second order in perturbation theory, as recently studied in (Bartolo,…
This lecture is a sketch of the physics of the cosmic microwave background. The observed anisotropy can be divided into four main contributions: variations in the temperature and gravitational potential of the primordial plasma, Doppler…
Cosmic microwave background (CMB) anisotropy may result from both scalar and tensor perturbations. For a sufficiently narrow range of angular scales, CMB perturbations can be characterized by four parameters. Results from the Cosmic…
Possible existence of the primordial magnetic fields has affected the structure formation of the universe. In this paper it is shown that the initial conditions for density perturbations with magnetic fields derived in previous works are…