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Related papers: Cosmology: From Hubble to HST

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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…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-20 Lorenzo Zaninetti

The observed value of the cosmological constant poses large theoretical problems. We find that topology of the Universe provides a natural source for it. Restricting dynamically an Einstein-Cartan gravity to General Relativity in our…

General Relativity and Quantum Cosmology · Physics 2020-06-16 M. Le Delliou , J. Lorca Espiro

Last couple of decades have been the golden age for cosmology. High quality data confirmed the broad paradigm of standard cosmology but have thrusted upon us a preposterous composition for the universe which defies any simple explanation,…

General Relativity and Quantum Cosmology · Physics 2016-11-23 T. Padmanabhan

Cosmological implications of neutrinos are reviewed. The subjects considered involve: (a) bounds on neutrino mass from the observational limits on the universe age and the Hubble constant both in cosmology with and without cosmological…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. D. Dolgov

Significant progress has been made during the last 10 years toward resolving the debate over the expansion rate of the Universe. The current value of the Hubble parameter, Ho, is now arguably known with an accuracy of 10%, largely due to…

Astrophysics · Physics 2007-05-23 Joseph B. Jensen , John L. Tonry , John P. Blakeslee

We study how the determination of the Hubble constant from cosmological distance measures is affected by models of dark energy and vice versa. For this purpose, constraints on the Hubble constant and dark energy are investigated using the…

Astrophysics · Physics 2008-11-26 Kazuhide Ichikawa , Tomo Takahashi

The Hubble diagram is one of the cornerstones of observational cosmology. It is usually analysed assuming that, on average, the underlying relation between magnitude and redshift matches the prediction of a…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-05 Pierre Fleury , Chris Clarkson , Roy Maartens

The common attribute of all Big Bang cosmologies is that they are based on the assumption that the universe is expanding. However examination of the evidence for this expansion clearly favours a static universe. The major topics considered…

General Physics · Physics 2014-07-10 David F. Crawford

The cosmological standard model at present is widely accepted as containing mainly things we do not understand. In particular the appearance of a Cosmological Constant, or dark energy, is puzzling. This was first inferred from the Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-01 Jeppe Trost Nielsen

There are three independent techniques for determining the age of the universe: via cosmochronology of long-lived radioactive nuclei, via stellar modelling and population synthesis of the oldest stellar populations, and via the precision…

Astrophysics · Physics 2009-11-06 I. Ferreras , A. Melchiorri , J. Silk

The Hubble parameter is kinematically defined in terms of the positions and velocities of all particles in a universe which may or may not be finite. This definition is set equal to the Hubble parameter as defined in the Friedman-Lema\^itre…

General Physics · Physics 2014-02-07 David Savickas

Using recent precision measurements of cosmological paramters, we re-examine whether these observations alone, independent of type Ia supernova surveys, are sufficient to imply the existence of dark energy. We find that best measurements of…

Astrophysics · Physics 2008-11-26 Greg Bothun , Stephen D. H. Hsu , Brian Murray

A diverse set of observations now compellingly suggest that Universe possesses a nonzero cosmological constant. In the context of quantum-field theory a cosmological constant corresponds to the energy density of the vacuum, and the wanted…

Astrophysics · Physics 2014-10-13 Lawrence M. Krauss , Michael S. Turner

The dynamical age of the universe depends upon the rate of the expansion of the universe, which explicitly involves the dark energy equation of state parameter $w(z)$. Consequently, the evolution of $w(z)$ has a direct imprint on the age of…

Astrophysics · Physics 2009-11-11 Vinod B. Johri , P. K. Rath

We use the age measurements of 114 old astrophysical objects (OAO) in the redshift range $0\lesssim z\lesssim 8$ to explore the Hubble tension. The age of the Universe at any $z$ is inversely proportional to the Hubble constant, $H_0$, so…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-13 Jun-Jie Wei , Fulvio Melia

The formation of the cosmic structures in the late Universe is considered using Vlasov kinetic approach. The crucial point is the use of the gravitational potential with repulsive term of the cosmological constant which provides a solution…

General Relativity and Quantum Cosmology · Physics 2025-02-26 V. G. Gurzadyan , N. N. Fimin , V. M. Chechetkin

Lorentz time is replaced by three parameters: a global time, a local rate of aging, and a new spatial coordinate. This enables successful reconstruction of relativity's observables in a four dimensional Euclidean hyperspace. The new…

Astrophysics · Physics 2007-05-23 Gary D. Warren

We give an estimate of the gravitational field of force exerted on a test particle by the far galaxies, in the frame of the weak field approximation. In virtue of Hubble's law, the action of the far matter turns out to be non negligible,…

Astrophysics · Physics 2011-11-10 A. Carati , S. L. Cacciatori , L. Galgani

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 possibility of having an extension of the cosmological standard model with a Hubble expansion rate $H$ constrained to a finite interval is considered. Two periods of accelerated expansion arise naturally when the Hubble expansion rate…

Astrophysics · Physics 2010-04-14 J. L. Cortes , J. Indurain
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