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In a series of articles, we have shown that the newly discovered plasma-redshift cosmology gives a simpler, more accurate and consistent explanation of many cosmological phenomena than the big-bang cosmology. The SNe Ia observations are in…

Astrophysics · Physics 2007-05-23 Ari Brynjolfsson

The structure of the equation of state $\omega$ could be very complicate in nature while a few linear models have been successful in cosmological predictions. Linear models are treated as leading approximation of a complete Taylor series in…

General Relativity and Quantum Cosmology · Physics 2007-05-23 W. F. Kao

We present a proof-of-principle determination of the Hubble parameter $H(z)$ from photometric data, obtaining a determination at an effective redshift of $z=0.75$ ($0.65<z<0.85$) of $H(0.75) =105.0\pm 7.9(stat)\pm 7.3(sys)$ km s$^{-1}$…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-21 Raul Jimenez , Michele Moresco , Licia Verde , Benjamin D. Wandelt

We compile an updated list of 38 measurements of the Hubble parameter $H(z)$ between redshifts $0.07 \leq z \leq 2.36$ and use them to place constraints on model parameters of constant and time-varying dark energy cosmological models, both…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Omer Farooq , Foram Madiyar , Sara Crandall , Bharat Ratra

Photometric redshifts have been calculated for the Hubble Deep Fields. The redshift distributions of the fields differ; there is a large excess of galaxies in the HDF-North in the redshift range 0.4<z<1.2. The difference is consistent with…

Astrophysics · Physics 2007-05-23 Stephen D. J. Gwyn

The rotational velocity of distant galaxies, when interpreted as a size (luminosity) indicator, may be used as a tool to select high redshift standard rods (candles) and probe world models and galaxy evolution via the classical angular…

One of the possible extensions of Einstein's General Theory of Relativity consists in allowing for the presence of spacetime torsion. The form of the underlying torsion tensor can be chosen such that the homogeneity and isotropy of…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-20 C. M. J. Marques , C. J. A. P. Martins

A paper by Harmut Traunm\"uller [1] showed from statistical studies of observational data that the most adequate equation to represent observations on magnitude and redshift from 892 type 1a supernovae is $\mu = 5\,log[(1+z)\,ln(1+z)] +…

General Physics · Physics 2018-04-11 Jean-Marie Vigoureux , Dorian Vigoureux , Pierre Vigoureux , Michel Langlois

We study cosmographic expansions of the luminosity distance for a variety of Lemaitre-Tolman-Bondi models which we specify inspired by local large-scale structures of the universe. We consider cosmographic expansions valid for general…

General Relativity and Quantum Cosmology · Physics 2024-11-11 Asha B. Modan , S. M. Koksbang

Even in a universe that is homogeneous on large scales, local density fluctuations can imprint a systematic signature on the cosmological inferences we make from distant sources. One example is the effect of a local under-density on…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Benjamin Sinclair , Tamara M. Davis , Troels Haugbolle

The results from the Supernova Cosmology Project indicate a relation between cosmic distance and redshift that corresponds to an accelerating Universe, and, as a consequence, the presence of an energy component with negative pressure. This…

Astrophysics · Physics 2007-05-23 Daniel Enstrom , Sverker Fredriksson , Johan Hansson

The quantum model of the homogeneous and isotropic universe predicts logarithmic-law dependence of coordinate distance to source on redshift z which is in good agreement with type Ia supernovae and radio galaxies observations for the…

Astrophysics · Physics 2007-05-23 V. E. Kuzmichev , V. V. Kuzmichev

The Hubble diagram of quasars, as candidates to ``standardizable" candles, has been used to measure the expansion history of the Universe at late times, up to very high redshifts ($z \sim 7$). It has been shown that this history, as…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-12 Chen Sun , Manuel A. Buen-Abad , JiJi Fan

Naively applying Hubble's law to a sufficiently distant object gives a receding velocity larger than the speed of light. By discussing a very similar situation in special relativity, we argue that Hubble's law is meaningful only for nearby…

General Physics · Physics 2012-09-11 Ali Kaya

The current expansion rate of the Universe, the Hubble constant $H_0$, is an important cosmological quantity. However, two different ways to measure its value do not agree -- building a low-redshift distance ladder leads to a higher value…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-29 Isaac Tutusaus , Martin Kunz , Léo Favre

A linearity test shows H_0 to decrease by 7% out to 18000 km/s. The value at 10000 km/s is a good approximation to the mean value of Ho over very large scales. The construction of the extragalactic distance scale is discussed. Field…

Astrophysics · Physics 2007-05-23 G. A. Tammann

There are many different approaches to using observations to constrain or determine the global cosmological parameters that describe our universe. Methods that rely upon a determination of the coordinate distance to high-redshift sources…

Astrophysics · Physics 2009-11-07 Ruth A. Daly , Matthew P. Mory , Erick J. Guerra

The current discrepancy between the Hubble constant $H_0$ derived from the local distance ladder and from the cosmic microwave background is one of the most crucial issues in cosmology, as it possibly indicates unknown systematics or new…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 X. D. Jia , J. P. Hu , F. Y. Wang

We use the K-z relation for radio galaxies to illustrate why it has proved difficult to obtain definitive cosmological results from studies based entirely on catalogues of the brightest radio sources, e.g. 3C. To improve on this situation…

On small scales the observable Universe is highly inhomogeneous, with galaxies and clusters forming a complex web of voids and filaments. The optical properties of such configurations can be quite different from the perfectly smooth…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Viraj A. A. Sanghai , Pierre Fleury , Timothy Clifton