相关论文: Hubble redshift and the Heisenberg frequency uncer…
A generalisation to electrodynamics and Yang-Mills theory is presented that permits computation of the speed of light. The model presented herewithin indicates that the speed of light in vacuo is not a universal constant. This may be…
Does the Heisenberg uncertainty principle (HUP) apply along the time dimension in the same way it applies along the three space dimensions? Relativity says it should; current practice says no. With recent advances in measurement at the…
It is shown without making use of Lorentz transformation that there exists a phenomenon of relativistic zero-frequency shift in Doppler effect for a plane wave in free space, observed in two inertial frames of relative motion, and the zero…
Measured gravitational waveforms from black hole binary inspiral events directly determine absolute luminosity distances. To use these data for cosmology, it is necessary to independently obtain redshifts for the events, which may be…
The rate at which the universe is expanding today is a fundamental parameter in cosmology which governs our understanding of structure formation and dark energy. However, current measurements of the Hubble constant, $H_0$, show a…
In order to estimate the effects of local structure on the Hubble parameter we calculate the low-redshift expansion for $H(z)$ and $\frac{\delta H}{H}$ for an observer at the center of a spherically symmetric matter distribution in presence…
The lack of bright host galaxies in several recently examined gamma-ray burst (GRB) error boxes suggests that the redshifts of cosmological GRBs may be significantly higher than previously believed. On the other hand, the non-detection of…
The evolution of the Hubble parameter $H(z)$ with redshift $z$ is estimated from the Pantheon+ data of Type Ia supernovae, for the $\Lambda$CDM model and the three special cases of the eternal coasting (EC) cosmological model with three…
One of the problem revealed recently in cosmology is a so-called Hubble tension (HT), which is the difference between values of the present Hubble constant, measured by observation of the universe at redshift $z \lesssim 1$, and by…
One of main sources of uncertainty in modern cosmology is the present rate of the universe's expansion, H0, called the Hubble constant. Once again, different observational techniques bring about different results, causing new 'Hubble…
We use the deepest and most complete redshift catalog currently available (the Hubble Deep Field (HDF) North supplemented by new HDF South redshift data) to minimize residuals between photometric and spectroscopic redshift estimates. The…
We study some observational consequences of a recently proposed scale--dependent cosmological model for an inhomogeneous Universe. In this model the Universe is pictured as being inside a highly dense and rapidly expanding shell with the…
The Hubble tension, a significant discrepancy between the Hubble constant ($H_0$) values derived from early-time (Cosmic Microwave Background and Baryon Acoustic Oscillations) and late-time (Cepheid-calibrated Type Ia Supernovae)…
Fast radio bursts (FRBs) are among the most mysterious astronomical transients. Due to their short durations and cosmological distances, their dispersion measure (DM) - redshift ($z$) relation is useful for constraining cosmological…
The luminosity-redshift relation of cosmological standard candles provides information about the relative energy composition of our Universe. In particular, the observation of type Ia supernovae up to redshift of z~2 indicate a universe…
We present a fully relativistic framework to evaluate the impact of stochastic inhomogeneities on the prediction of the Hubble-Lema\^itre diagram. In this regard, we relate the fluctuations of the luminosity distance-redshift relation in…
Gravitational-wave (GW) events can serve as standard sirens for cosmology, as the luminosity distance to source can be directly measured from the waveform amplitude. Specifically, the ``dark'' siren method involves inferring cosmological…
Using a model-independent analysis method which bases on the Lagrange mean value theorem for obtaining the derivative of the Hubble function, we analyze $H(z)$ parameter data with some restrictive conditions. We find that: (a) the Universe…
Studies of the Hubble Deep Field (HDF) and other deep surveys have revealed an apparent peak in the ultraviolet (UV) luminosity density, and therefore the star-formation rate density, of the Universe at redshifts 1<z<2. We use photometric…
We consider ever-expanding Big Bang models with a cosmological constant, $\Lambda$, and investigate in detail the evolution of the observable part of the universe. We also discuss quintessence models from the same point of view. A new…