Related papers: Another coincidence problem for $\Lambda$CDM?
Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data confirm the ellipticity of anisotropies of Cosmic Microwave Background (CMB) maps, found previously for Boomerang and WMAP 1-year high sensitivity maps. The low noise level of the WMAP…
Measurements of the Hubble constant, and more generally measurements of the expansion rate and distances over the interval $0 < z < 1$, appear to be inconsistent with the predictions of the standard cosmological model ($\Lambda$CDM) given…
The age of the Universe at a given redshift is a fundamental relationship in cosmology. For many years, the uncertainties in it were dauntingly large, close to a factor of 2. In this age of precision cosmology, they are now at the percent…
(Abridged) New full sky temperature and polarization maps based on seven years of data from WMAP are presented. The new results are consistent with previous results, but have improved due to reduced noise from the additional integration…
The large-angle (low-ell) correlations of the Cosmic Microwave Background (CMB) as reported by the Wilkinson Microwave Anisotropy Probe (WMAP) after their first year of observations exhibited statistically significant anomalies compared to…
The parameters of cosmological model with cold dark matter and cosmological constant (Lambda CDM) have been determined on a basis of three-year cosmic microwave background observations by space mission WMAP, as well as the data on the…
Problems with the concordance cosmology $\Lambda$CDM as the cosmological constant problem, coincidence problems and Hubble tension has led to many proposed alternatives, as the $\Lambda(t)$CDM, where the now called $\Lambda$ cosmological…
We constrain the thermal evolution of the universe with a decaying cosmological term by using the method of the analysis for the Wilkinson Microwave Anisotropy Probe (WMAP) observation data. The cosmological term is assumed to be a function…
The question of whether Cosmic Microwave Background (CMB) temperature and polarization data from Planck favor a spatially closed Universe with curvature parameter $\Omega_K<0$ has been the subject of recent intense discussions. Attempts to…
We present a novel test of the cosmological principle: the idea that, on sufficiently large scales, the universe should appear homogeneous and isotropic to observers comoving with the Hubble flow. This is a fundamental assumption in modern…
We perform a comparison of WMAP 9-year (WMAP9) and Planck 2015 cosmic microwave background (CMB) temperature power spectra across multipoles $30\leq\ell\leq1200$. We generate simulations to estimate the correlation between the two datasets…
We use a complete and rigorous statistical indicator to measure the level of concordance between cosmological data sets, without relying on the inspection of the marginal posterior distribution of some selected parameters. We apply this…
We perform a detailed comparison of the Wilkinson Microwave Anisotropy Probe (WMAP) measurements of the cosmic microwave background (CMB) temperature and polarization anisotropy with the predictions of quintessence cosmological models of…
The cosmic microwave background (CMB) offers a unique window into the early universe, providing insights into cosmological parameters like the Hubble constant. Recent precise measurements of the CMB by experiments like Planck seem to point…
We re-formulate cosmological perturbations in the decaying cold dark matter model, and calculate cosmological microwave background (CMB) anisotropies. By comparing our theoretical predictions with recent observational data from the…
Measurements of the cosmic microwave background (CMB) allow high precision observation of the Last Scattering Surface at redshift $z\sim$1100. After the success of the NASA satellite COBE, that in 1992 provided the first detection of the…
The recent measurements of the power spectrum of Cosmic Microwave Background anisotropies are consistent with the simplest inflationary scenario and big bang nucleosynthesis constraints. However, these results rely on the assumption of a…
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…
Concordance $\Lambda$CDM universe is the simplest model that is consistent with a large variety of cosmological observations till date. But few recent observations indicate inconsistencies in $\Lambda$CDM model. In this paper, we consider…
Age consistency for the Universe today has been an important cosmological test. Even more powerful consistency tests at times as early as 10^{-32} sec lie ahead in the precision era of cosmology. I outline tests based upon cosmic microwave…