Related papers: A Nuclear Data Approach for the Hubble Constant Me…
There is a persistent tension of about $5\sigma-6\sigma$ between the value of the Hubble constant, as derived from the local distance ladder vs. the cosmic microwave background, signaling either unaccounted for systematics in the…
Most of the calculations done to obtain the value of the cosmological constant use methods of quantum gravity, a theory that has not been established as yet, and a variety of results are usually obtained. The numerical value of the…
Recently, the idea of using neutrino oscillations to measure the Hubble constant was introduced. We show that such a task is unfeasible because for typical energies of cosmic neutrinos, oscillations average out over cosmological distances…
There are irreducible differences between the Hubble constant measured locally and the global value. They are due to density perturbations and finite sample volume (cosmic variance) and finite number of objects in the sample (sampling…
A review of the Hubble Space Telescope H0 Key Project is given, as presented at the IAU Symposium 183 on "Cosmological Parameters" held in Kyoto, Japan in August, 1997. An outline of the goals and progress toward this effort is given.…
The values of the Hubble constant obtained from the data of the early and of the late Universe differ by 10%. Data obtained by DESI Collaboration can help solve this problem, establishing with high precision the value of the product of the…
Nuclear chronometer, which predicts the ages of the oldest stars by comparing the present and initial abundances of long-lived radioactive nuclides, provides an independent dating technique for the cosmos. A new nuclear chronometer called…
The analysis of the data on measurements of the neutron lifetime is presented. A new most accurate result of the measurement of neutron lifetime [Phys. Lett. B 605 (2005) 72] 878.5 +/- 0.8 s differs from the world average value [Phys. Lett.…
The Hubble constant is of paramount importance in astrophysics and cosmology. A large number of methods have been developed with different electromagnetic probes to estimate its value. The most recent results show a tension between values…
Tension between cosmic microwave background-based and distance ladder-based determinations of the Hubble constant ${\rm H}_{\rm 0}$ motivates pursuit of independent methods that are not subject to the same systematic effects. A promising…
We report the results of a detailed numerical study designed to estimate both the absolute age and the uncertainty in age (with confidence limits) of the oldest globular clusters. Such an estimate is essential if a comparison with the…
In this paper, we study the cosmological constraints from the measurements of Hubble parameters---$H(z)$ data. Here, we consider two kinds of $H(z)$ data: the direct $H_0$ probe from the Hubble Space Telescope (HST) observations of Cepheid…
The apparent cosmological conflict between the age of the Universe, predicted in the standard Friedman cosmology by using the recent measurement of the larger Hubble constant from a direct calibration of the distance to the Virgo galaxy…
We propose a new cosmological model with a time-dependent cosmological constant ($\Lambda\propto 1/t^2$), which starting at the Planck time as $\Lambda_{Pl}\sim M^2_{Pl}$, evolves to the present-day allowed value of…
In this paper, we have investigated a bulk viscous anisotropic Universe and constrained its model parameters with recent $H(z)$ and Pantheon compilation data. Using cosmic chronometric technique, we estimate the present value of Hubble's…
The cosmic microwave background (CMB) monopole temperature evolves with the inverse of the cosmological scale factor, independent of many cosmological assumptions. With sufficient sensitivity, real-time cosmological observations could thus…
The present rate of the expansion of our Universe, the Hubble constant, can be predicted from the cosmological model using measurements of the early Universe, or more directly measured from the late Universe. But as these measurements…
The following review presents an attempt to discuss various issues of current interest in Observational Cosmology, the selection of which as well as the emphasis given, reflects my own preference and biases. After presenting some…
A new cosmological model makes the following predictions: (1) The deceleration parameter $q_{0}$ is approximately zero. (2) The mass density parameter $\Omega_{m}$ is less than 1. (3) The universe is spatially closed, but is asymptotically…
Joint analysis of Cosmic Microwave Background, Baryon Acoustic Oscillation, and supernova data has enabled precision estimation of cosmological parameters. New programs will push to 1% uncertainty in the dark energy equation of state and…