相关论文: The redshift in Hubble's constant
Recent attempts at measuring the variation of $c$ using an assortment of standard candles and the redshift-dependent Hubble expansion rate inferred from the currently available catalog of cosmic chronometers have tended to show that the…
It is shown that the Hubble constant can be derived from the standard luminosity function of galaxies as well as from a new luminosity function as deduced from the mass-luminosity relationship for galaxies. An analytical expression for the…
In this paper we extend a new method to measure possible variation of the speed of light by using Baryon Acoustic Oscillations and the Hubble function presented in our earlier paper [V. Salzano, M. P. D\c{a}browski, and R. Lazkoz, Phys.…
We have had the chance to live through a fascinating revolution in measuring the fundamental empirical cosmological Hubble law. The key progress is analysed : 1) improvement of observational means (ground-based radio and optical…
We consider a hypothetical possibility of the variability of light velocity with time and position in space which is derived from two natural postulates. For the consistent consideration of such variability we generalize translational…
I review the current state of determinations of the Hubble constant, which gives the length scale of the Universe by relating the expansion velocity of objects to their distance. There are two broad categories of measurements. The first…
We derive explicit and exact expressions for the physical velocity of a free particle comoving with the Hubble flow as measured by a static observer, and for the frequency shift of light emitted by a comoving source and received, again, by…
Recently E. Harrison has argued the Red Shift distance law proposed by Hubble and velocity-distance law developed later on theoretical grounds has no general proof demonstrating the two laws are actually equivalent. It is the purpose of…
The possible time variation of the fundamental constants of nature has been an active subject of research in modern physics. In this paper, we propose a new method to investigate such possible time variation of the speed of light $c$ using…
The speed of light in vacuum, one of the most important and precisely measured natural constants, is fixed by convention to $c=299 792 458$ m/s. Advanced theories predict possible deviations from this universal value, or even quantum…
On the basis of Galilean invariance and the Doppler formula, combined with an observational condition, it is shown that the constancy of the velocity of light {\it in vacuo} can be derived, together with time-dilatation and Lorentz…
We introduce a novel way of measuring $H_0$ from a combination of independent geometrical datasets, with no need of calibration nor of the choice of a cosmological model. We build on the {\it distance duality relation} which sets the ratio…
An exact determination of the Hubble constant remains one of key problems in cosmology for almost a century. However, its modern values derived by various methods still disagree from each other by almost 10%; the greater values being…
We consider light propagation in an inhomogeneous irrotational dust universe with vanishing cosmological constant, with initial conditions as in standard linear perturbation theory. A non-perturbative approach to the dynamics of such a…
A powerful test of fundamental physics consists on probing the variability of fundamental constants in Nature. Although they have been measured on Earth laboratories and in our Solar neighbourhood with extremely high precision, it is…
It has been known that dimensional constants such as $\hbar$, $c$, $G$, $e$, and $k$ are merely human constructs whose values and units vary depending on the chosen system of measurement. Therefore, the time variation of dimensional…
By exploring the relationship between the propagation of electromagnetic waves in a gravitational field and the light propagation in a refractive medium, it is shown that, in the presence of a positive cosmological constant, the velocity of…
We present a simultaneous analysis of 18 galaxy lenses with time delay measurements. For each lens we derive mass maps using pixelated simultaneous modeling with shared Hubble constant. We estimate the Hubble constant to be 66_{-4}^{+6}…
Theories proposing a varying speed of light have recently been widely promoted under the claim that they offer an alternative way of solving the standard cosmological problems. Recent observational hints that the fine structure constant may…
Recent observations of the fine structure of spectral lines in the early universe have been interpreted as a variation of the fine structure constant. From the assumed validity of Maxwell equations in general relativity and well known…