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Related papers: The redshift in Hubble's constant

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Assuming the Central Limit Theorem, experimental uncertainties in any data set are expected to follow the Gaussian distribution with zero mean. We propose an elegant method based on Kolmogorov-Smirnov statistic to test the above; and apply…

Cosmology and Nongalactic Astrophysics · Physics 2020-02-11 Meghendra Singh , Shashikant Gupta , Ashwini Pandey , Satendra Sharma

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…

General Relativity and Quantum Cosmology · Physics 2025-06-19 Rosa Poggiani

The redshift of all cosmological sources drifts by a systematic velocity of order a few m/s over a century due to the deceleration of the Universe. The specific functional dependence of the predicted velocity shift on the source redshift…

Astrophysics · Physics 2011-02-11 Abraham Loeb

We measure the speed of light with current observations, such as Type Ia Supernova, galaxy ages, radial BAO mode, as well as simulations of forthcoming redshift surveys and gravitational waves as standard sirens. By means of a Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-02 Jaiane Santos , Carlos Bengaly , Jonathan Morais , Rodrigo S. Gonçalves

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…

Astrophysics · Physics 2009-10-30 Xiangdong Shi , Michael S. Turner

Contemporary observational and theoretical studies on the temporal nature of microscopic measurements renewed the discussion about the fundamental constants, leading to the possibility of light speed variation and superluminal pulse…

General Physics · Physics 2007-05-23 R Assumpcao

An alternative model describing the dynamics of a flat Universe without cosmological constant and allowing a gradual change of c with time is proposed. New relationships of redshift vs. distance and cosmic background radiation temperature…

Astrophysics · Physics 2007-05-23 Juan Casado Gimenez

The Hubble constant $H_0$ is the value of the cosmic expansion rate at one time (the present), and cannot be adjusted successfully without taking into account the entire expansion history and cosmology. We outline some conditions, that if…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-25 Eric V. Linder

In any Big Bang cosmology, the frequency $\omega$ of light detected from a distant source is continuously and linearly changing (usually redshifting) with elapsed observer's time $\delta t$, because of the expanding Universe. For small…

Astrophysics · Physics 2008-05-19 Richard Lieu

Recent observations of Cepheids in the Virgo cluster have bolstered the evidence that supports a Hubble constant in 70-90 km/s/Mpc range. This evidence, by and large, probes the expansion of the Universe within 100 Mpc. We investigate the…

Astrophysics · Physics 2015-06-24 Xiangdong Shi , Lawrence M. Widrow , L. Jonathan Dursi

The long-standing problem of whether the cosmological constant affects directly the deflection of light caused by a gravitational lens is reconsidered. We use a new approach based on the Hawking quasilocal mass of a sphere grazed by light…

General Relativity and Quantum Cosmology · Physics 2017-01-25 Valerio Faraoni , Marianne Lapierre-Leonard

The invariance of the speed of light in all inertial frames is shown to be an inevitable consequence of the relativity principle of special relativity contrary to the view held by Hsu and Hsu in taiji relativity where the speed of light is…

General Physics · Physics 2007-05-23 Harihar Behera

The cosmological constant, i.e., the energy density stored in the true vacuum state of all existing fields in the Universe, is the simplest and the most natural possibility to describe the current cosmic acceleration. However, despite its…

Astrophysics · Physics 2008-11-26 S. Carneiro , M. A. Dantas , C. Pigozzo , J. S. Alcaniz

The Hubble Constant measured from the anisotropy in the cosmic microwave background (CMB) is shown to be independent of small changes from the standard model of the redshift dependence of dark energy. Modifications of the Friedmann equation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Jeremy Mould

In this contribution the question of the isotropy of the one-way speed of light from an experimental perspective is addressed. In particular, we analyze two experimental methods commonly used in its determination. The analysis is aimed at…

Classical Physics · Physics 2011-05-24 Israel Perez

At least one dimensionless physical constant (i.e., a physically observable) must change for the cosmic time to make the varying speed of light (VSL) models phenomenologically feasible. Various physical constants and quantities also should…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-04 Seokcheon Lee

All experiments attempting to verify the invariance of speed of light directly are based on two-way speed measurement. The challenge in one-way speed measurement, the requirement of spatially separated synchronised clocks, can be possibly…

Classical Physics · Physics 2013-03-20 Evan John Philip

The product of two empirical constants, the dimensionless fine structure constant and the von Klitzing constant (an electrical resistance), turns out to be an exact dimensionless number. Then the accuracy and cosmological time variation (if…

General Physics · Physics 2014-11-20 Antonio Alfonso-Faus

We prove here that Newtons universal gravitation and momentum conservation laws together reproduce Weinbergs relation. It is shown that the Hubble parameter H must be built in this relation, or equivalently the age of the Universe t. Using…

General Physics · Physics 2011-04-11 Antonio Alfonso-Faus

We present a determination of the Hubble constant from the joint, free-form analysis of 8 strongly, quadruply lensing systems. In the concordance cosmology, we find $H_0 = 71.8^{+3.9}_{-3.3}\,\mathrm{km}\,\mathrm{s}^{-1}\,\mathrm{Mpc}^{-1}$…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-22 Philipp Denzel , Jonathan P. Coles , Prasenjit Saha , Liliya L. R. Williams
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