English
Related papers

Related papers: Hubble Energy

200 papers

The cosmological constant and many other possible origins for acceleration of the cosmic expansion possess variations in the dark energy properties slow on the Hubble time scale. Given that models with more rapid variation, or even phase…

Astrophysics · Physics 2009-08-21 Eric V. Linder

The dependence of luminosity distance on observed resdhift and the cosmological parameters H and q is derived for a contracting Friedmann universe with no cosmological constant. The result is consistent with recent supernovae observations.

Astrophysics · Physics 2007-05-23 W. Q. Sumner , E. E. Vityaev

We explore the possibility that the entire departure of galactic rotational velocities from their luminous Newtonian expectation be cosmological in origin, and show that within the framework of conformal gravity (but not Einstein gravity…

Astrophysics · Physics 2016-08-30 Philip D. Mannheim

Inflationary cosmology predicts that the particle horizon should be generically much bigger than the present-day Hubble radius, $1/H_0$. This implies a special regime of super-Hubble scale energy density fluctuations imprinted on the cosmic…

Astrophysics · Physics 2009-10-30 Arjun Berera , Li-Zhi Fang , Gary Hinshaw

We consider the evolution of a flat Friedmann-Robertson-Walker Universe, filled with a causal bulk viscous cosmological fluid, in the presence of variable gravitational and cosmological constants. The basic equation for the Hubble…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. K. Mak , J. A. Belinchon , T. Harko

The present standard model of cosmology states that the known particles carry only a tiny fraction of total mass and energy of the Universe. Rather, unknown dark matter and dark energy are the dominant contributions to the cosmic energy…

Astrophysics · Physics 2009-06-23 Nan Li , Marina Seikel , Dominik J. Schwarz

In the more recent literature on cosmological evolutions of the universe the cosmic vacuum energy has become a non-renouncable ingredient. The cosmological constant $\Lambda$, first invented by Einstein, but later also rejected by him,…

General Relativity and Quantum Cosmology · Physics 2016-10-28 H. J. Fahr , M. Heyl

Although cosmologists have been trying to determine the value of the Hubble constant for nearly 65 years, they have only succeeded in limiting the range of possibilities: most of the current observational determinations place the Hubble…

Astrophysics · Physics 2009-10-22 J. G. Bartlett , A. Blanchard , J. Silk , M. S. Turner

Due to Lorentz invariance of General Relativity gravitational interaction is limited to the speed of light. Thus for particles, moving within a matter field, retardation leads to loss of energy by emission of gravitational radiation. This…

Astrophysics · Physics 2008-05-14 Ernst Fischer

The solution of the problem of describing the Friedmann observables (the Hubble law, the red shift, etc.) in quantum cosmology is proposed on the basis of the method of gaugeless Hamiltonian reduction in which the gravitational part of the…

General Relativity and Quantum Cosmology · Physics 2009-10-30 A. M. Khvedelidze , V. V. Papoyan , Yu. G. Palii , V. N. Pervushin

We reexamine cosmological applications of the holographic energy density in the framework of sourced Friedmann equations. This framework is suitable because it can accommodate a macroscopic interaction between holographic and ordinary…

High Energy Physics - Theory · Physics 2010-04-05 Yun Soo Myung

Understanding the evolution of dark energy poses a significant challenge in modern cosmology, as it is responsible for the universe's accelerated expansion. In this study, we focus on a specific $f(T)$ cosmological model and analyze its…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-14 A. Zhadyranova , M. Koussour , S. Bekkhozhayev , V. Zhumabekova , J. Rayimbaev

Light rays received on earth from distant stars show redshift, being attributed conventionally to the well-known Doppler-effect of wave dynamics. The present study concludes that cosmic redshift rather is an effect of the quantum mechanical…

General Physics · Physics 2011-08-03 Wolfgang Hebel

We present here a general relativistic mechanism for accelerated cosmic expansion and the Hubble's constant. It is shown that spacetime vorticity coupled to the magnetic field density in galaxies causes the galaxies to recede from one…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-20 Babur M. Mirza

The recent discovery of apparent cosmic acceleration has highlighted the depth of our ignorance of the fundamental properties of nature. It is commonly assumed that the explanation for acceleration must come from a new form of energy…

Astrophysics · Physics 2008-11-26 Chris Clarkson , Bruce A. Bassett , Teresa Hui-Ching Lu

Despite the success of Maxwell's electromagnetism in the description of the electromagnetic interactions on small scales, we know very little about the behaviour of electromagnetic fields on cosmological distances. Thus, it has been…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-07 Jose Beltran Jimenez , Antonio L. Maroto

It is suggested that the apparently disparate cosmological phenomena attributed to so-called 'dark matter' and 'dark energy' arise from the same fundamental physical process: the emergence, from the quantum level, of spacetime itself. This…

General Relativity and Quantum Cosmology · Physics 2017-08-18 R. E. Kastner , S. Kauffman

We investigate various dark energy models by taking into account the thermal effects induced from Hawking radiation on the apparent horizon of the Universe, for example near a finite-time future singularity. If the dark energy density…

General Relativity and Quantum Cosmology · Physics 2021-02-17 Artyom V. Astashenok , Sergei D. Odintsov , Vasilis K. Oikonomou

The meaning of the expansion of the universe, or the `expansion of space,' is explored using two phenomena: the motion of a test particle against a homogeneous background and the cosmological redshift. Contrary to some expectations, a…

Astrophysics · Physics 2007-05-23 Alan B. Whiting

We introduce a theoretical framework to interpret the Hubble tension, based on the combination of a metric $f(R)$ gravity with a dynamical dark energy contribution. The modified gravity provides the non-minimally coupled scalar field…

General Relativity and Quantum Cosmology · Physics 2023-11-07 Giovanni Montani , Mariaveronica De Angelis , Flavio Bombacigno , Nakia Carlevaro