Related papers: Coincidence of Universe age in $\Lambda$CDM and Mi…
The age of the universe in the Big Bang model can be calculated from three parameters: Hubble's constant, h; the mass density of the universe, Omega_m; and the cosmological constant, Omega_lambda. Recent observations of the cosmic microwave…
We present the interesting coincidence of cosmology and astrophysics that points toward a dimensionless age of the universe H_0*t_0 that is close to one. Despite cosmic deceleration for 9 Gyr and acceleration since then, we find H_0t*_0 =…
The now standard vanilla-flavoured LambdaCDM model has gained further confirmation with the release of the 3-year WMAP data combined with several other cosmological data-sets. As the parameters of this standard model become known with…
Over the last nine years of cosmic microwave background observations, the Wilkinson Microwave Anisotropy Probe ($WMAP$) results were consistent with a $\Lambda$CDM cosmological model in which the age of the Universe is one Hubble time, and…
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…
The details of the CMB power spectrum are being revealed through the combined efforts of the world's CMBologists. The current data set constrains several cosmological parameters. A combination with other (non-lensing) constraints yields…
Our proposed cosmological framework, which is based on fractional quantum cosmology, aims to address the issue of synchronicity in the age of the universe. To achieve this, we have developed a new fractional $\Lambda$CDM cosmological model.…
It is found that the ages of the most metal-poor Galactic globular clusters are probably around 18 Gyr. On the other hand a Hubble parameter of 82 +/- 8 km/sec/Mpc (in conjunction with the standard Einstein-de Sitter model with an Omega =1…
The age of the Universe depends on both the present-day Hubble Constant and on the history of cosmic expansion. For decelerating cosmologies such as Omega_m= 1, the dimensionless product H_0,t_0<1 and modestly high values of the Hubble…
The prevailing cosmological model with the lambda-term, in which the space is flat, is studied (section 1). The corresponding age of the Universe (t0) is calculated (assuming a Hubble constant consistent with the measurements of the Hubble…
The present standard model of cosmology, $\Lambda$CDM, contains some intriguing coincidences. Not only are the dominant contributions to the energy density approximately of the same order at the present epoch, but we note that contrary to…
The Hubble constant, which measures the expansion rate, together with the total energy density of the Universe, sets the size of the observable Universe, its age, and its radius of curvature. Excellent progress has been made recently toward…
If Omega_tot = 1 and structure formed from adiabatic initial conditions then the age of the Universe, as constrained by measurements of the cosmic microwave background (CMB), is t_0=14.0 +/- 0.5 Gyr. The uncertainty is surprisingly small…
We have reanalyzed the age of the universe problem under the assumption that the lower limit on the age of the globular clusters is 11Gyr, as predicted by the recent Hipparcos data. We find that the globular cluster and the expansion ages…
Recent improvements in astronomical observations lead to the conclusion that the Hubble constant lies between 60 and 80 Mpc km$^{-1}$ sec$^{-1}$ and the age of the universe between 11 and 14 Gigayears. Taken together with recent…
There are three independent techniques for determining the age of the universe: via cosmochronology of long-lived radioactive nuclei, via stellar modelling and population synthesis of the oldest stellar populations, and via the precision…
The cosmological parameters that I will emphasize are the Hubble parameter $H_0 \equiv 100 h$ km s$^{-1}$ Mpc$^{-1}$, the age of the universe $t_0$, the average matter density $\Omega_m$, the baryonic matter density $\Omega_b$, the neutrino…
A precise measurement of the curvature of the Universe is of primeval importance for cosmology since it could not only confirm the paradigm of primordial inflation but also help in discriminating between different early Universe scenarios.…
The ages of the oldest stellar objects in our galaxy provide an independent test of the current cosmological model as they give a lower limit to the age of the Universe. Recent accurate parallaxes by the Gaia space mission, accurate…
Analyses of various cosmological probes, including the latest Cosmic Microwave Background anisotropies, the 2dF Galaxy Redshift Survey and Cepheid-calibrated distance indicators suggest that the age of expansion is $13 \pm 3$ Gyr. We…