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Related papers: Interpretation of the Cosmological Metric

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The existence of 'peculiar' velocities due to the formation of cosmic structure marks a point of discord between the real Universe and the usually assumed Friedmann-Lema\'{i}tre-Robertson-Walker metric which accomodates only the smooth…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-09 Roya Mohayaee , Mohamed Rameez , Subir Sarkar

This work wants to show how standard General Relativity (GR) is able to explain galactic rotation curves without the need for dark matter, this starting from the idea that when Einstein's equations are applied to the dynamics of a galaxy…

Astrophysics of Galaxies · Physics 2014-09-16 Elias A. S. Mégier

Gravitational waves (GWs) are regarded as standard sirens for Cosmology. GWs from compact binary coalescence (CBC) can directly determine the luminosity distance but usually can not obtain information about the redshift. However, if the…

General Relativity and Quantum Cosmology · Physics 2024-12-23 Ye Jiang , Wen-Biao Han

In the context of the new standard LambdaCDM cosmology we resolve conflicts in the literature regarding fundamental aspects of the expansion of the universe and cosmic horizons and we link these concepts to observational tests. We derive…

Astrophysics · Physics 2007-05-23 Tamara M. Davis

The next generation of telescopes will usher in an era of precision cosmology, capable of determining the cosmological model to beyond the percent level. For this to be effective, the theoretical model must be understood to at least the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Obinna Umeh , Chris Clarkson , Roy Maartens

Some recent supernovae studies have extended the distance versus velocity Hubble plot to very high redshift, and have revealed the apparent presence of a cosmic repulsion. We show that such a repulsion has a natural origin within conformal…

Astrophysics · Physics 2007-05-23 Philip D. Mannheim

We show that it is possible to equate the intensity reduction of a light wave caused by weak absorption with a geometrical reduction in intensity caused by a "transverse" conformal transformation of the spacetime metric in which the wave…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Bin Chen , Ronald Kantowski

All direct measurements of peculiar velocities of glaxies assume the Hubble law at low redshifts. However, it has been suggested by Segal et al (1993) that the correlation of redshifts and fluxes in a complete sample of IRAS galaxies is…

Astrophysics · Physics 2007-05-23 Michael Strauss , Daniel Koranyi

This paper describes how the non-gravitational contribution to Galactic Velocity Rotation Curves can be explained in terms of a negative Cosmological Constant ($\Lambda$). It will be shown that the Cosmological Constant leads to a velocity…

Astrophysics · Physics 2007-05-23 S. B. Whitehouse , G. V. Kraniotis

From the equivalence principle, one gets the strength of the gravitational effect of a mass $M$ on the metric at position r from it. It is proportional to the dimensionless parameter $\beta^2 = 2GM/rc^2$, which normally is $<< 1$. Here $G$…

General Physics · Physics 2013-11-22 Antonio Alfonso-Faus , Màrius Josep Fullana i Alfonso

The relativity of cosmic time is developed within the framework of Cosmological Relativity in five dimensions of space, time and velocity. A general linearized metric element is defined to have the form $ds^2 = (1+\phi) c^2 dt^2 - dr^2 +…

General Physics · Physics 2016-05-30 Firmin J. Oliveira

The cosmological redshift phenomenon can be described by the dark matter field fluid model, the results deduced from this model agree very well with the observations. The observed cosmological redshift of light depends on both the speed of…

General Physics · Physics 2007-05-23 Hongjun Pan

We analyse the possibility that our Universe could be described by the model recently proposed by Melia & Shevchuk (2012), where the Hubble scale R_h=c/H is at all times equal to the distance ct that light has travelled since the Big Bang.…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-28 Maciej Bilicki , Marina Seikel

Although the Universe is far from understood, we are fairly confident about some key features: Special Relativity (SR) describes the kinematics of inertial frames; General Relativity (GR) explains gravitation; the Universe had a beginning…

General Physics · Physics 2007-05-23 Alasdair Macleod

A very general class of axially-symmetric metrics in general relativity (GR) that includes rotations is used to discuss the dynamics of rotationally-supported galaxies. The exact vacuum solutions of the Einstein equations for this extended…

General Relativity and Quantum Cosmology · Physics 2023-02-15 Yogendra Srivastava , Giorgio Immirzi , John Swain , Orland Panella , Simone Pacetti

The cosmological scale factor $a(t)$ of the flat-space Robertson-Walker geometry is examined from a Hamiltonian perspective wherein $a(t)$ is interpreted as an independent dynamical coordinate and the curvature density $\sqrt {- g(a)}…

General Physics · Physics 2008-10-04 M. Ibison

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…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-18 Fulvio Melia

Constancy of the speed of light together with the Hubble law lead in a doctrine of expanding universe to a conclusion that universe evolution is not only an expansion of space but also a deceleration of the course of physical time (Taganov,…

General Physics · Physics 2008-07-28 Igor N. Taganov

The acceleration parameter defined through the local volume expansion is negative for a pressureless, irrotational fluid with positive energy density. In the presence of inhomogeneities or anisotropies the volume expansion rate results from…

In the standard cosmological paradigm cosmic acceleration is to only be a very recent (viz. $z \leq 1$) phenomenon, with the universe being required to be decelerating at all higher redshifts. We suggest that this particular expectation of…

Astrophysics · Physics 2009-11-07 Philip D. Mannheim