Related papers: Testing the paradigm of adiabaticity
Large-scale cosmic microwave background anisotropies in homogeneous, globally anisotropic cosmologies are investigated. We perform a statistical analysis in which the four-year data from the Cosmic Background Explorer satellite is searched…
We develop and examine the principles governing the formation of distortions in the cosmic microwave background. Distortions in the frequency or spectral distribution of the background probe the thermal history of the universe whereas those…
The recent announcement from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite experiment combined with other recent advances in observational cosmology verifies key components of the standard cosmological model. However, we argue…
CMB anisotropy data could put powerful constraints on theories of the evolution of our Universe. Using the observations of the large number of CMB experiments, many studies have put constraints on cosmological parameters assuming different…
Analysis of the Planck 2018 data set indicates that the statistical properties of the cosmic microwave background (CMB) temperature anisotropies are in excellent agreement with previous studies using the 2013 and 2015 data releases. In…
Recent cosmological observations, including measurements of the CMB anisotropy and the primordial helium abundance, indicate the existence of an extra radiation component in the Universe beyond the standard three neutrino species. In this…
Several early Universe scenarios predict a direction-dependent spectrum of primordial curvature perturbations. This translates into the violation of the statistical isotropy of cosmic microwave background radiation. Previous searches for…
We investigate whether non-adiabatic perturbations from inflation could produce an asymmetric distribution of temperature anisotropies on large angular scales in the cosmic microwave background (CMB). We use a generalised non-linear $\delta…
We search for the presence of cosmological neutrino background (CNB) anisotropies in recent WMAP 5-year data using their signature imprinted on modifications to cosmic microwave background (CMB) anisotropy power spectrum. By parametrizing…
We constrain the deviation of adiabatic evolution of the Universe using the data on the Cosmic Microwave Background (CMB) temperature anisotropies measured by the {\it Planck} satellite and a sample of 481 X-ray selected clusters with…
We introduce new symmetry-based methods to test for isotropy in cosmic microwave background radiation. Each angular multipole is factored into unique products of power eigenvectors, related multipoles and singular values that provide 2 new…
I give a status report and outlook concerning the use of the cosmic microwave background anisotropies to constrain the inflationary cosmology, and stress its crucial role as an underlying paradigm for the estimation of cosmological…
We present a comprehensive and gauge invariant treatment of perturbations around cosmological scaling solutions for two canonical scalar fields coupled through a common potential in the early universe, in the presence of neutrinos, photons…
Much of modern cosmology relies on the Cosmological Principle, the assumption that the Universe is isotropic and homogeneous on sufficiently large scales, but it remains worthwhile to examine cosmological models that violate this principle…
Working toward a model independent understanding of cosmic microwave background (CMB) anisotropies and their significance, we undertake a comprehensive and self-contained study of scalar perturbation theory. Initial conditions, evolution,…
The Universe's initial conditions, in particular baryon and cold dark matter (CDM) isocurvature perturbations, are poorly constrained on sub-Mpc scales. In this paper, we develop a new formalism to compute the effect of small-scale baryon…
A survey is made of the present observational status on cosmological parameters from microwave background anisotropies. I then move to some non-standard aspect of parameter extraction like quintessence, extra-background of relativistic…
Forthcoming cosmic microwave background experiments (CMB) will provide precise new tests of structure-formation theories. The geometry of the Universe may be determined robustly, and the classical cosmological parameters, such as the…
There are evidences that the cosmic microwave background (CMB) large-angle anomalies imply a departure from statistical isotropy and hence from the standard cosmological model. We propose a LCDM model extension whose dark energy component…
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 vector fields in inflationary theories…