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The galactic `dark matter' effect is regarded as one of the major problems in fundamental physics. Here it is explained as a self-interaction dynamical effect of space itself, and so is not caused by an unknown form of matter. Because it…

General Physics · Physics 2007-05-23 Reginald T. Cahill

We analyze, within the framework of unified brane gravity, the weak-field perturbations caused by the presence of matter on a 3-brane. Although deviating from the Randall-Sundrum approach, the masslessness of the graviton is still…

High Energy Physics - Theory · Physics 2009-08-13 Ilya Gurwich , Aharon Davidson

In a previous work it was shown that by considering the quantum nature of the gravitational field mediator, it is possible to introduce the momentum energy of the graviton into the Einstein equations as an effective cosmological constant.…

General Physics · Physics 2022-03-16 Tonatiuh Matos , Luis Osvaldo Tellez-Tovar

We consider a possible connection between matter and cosmological constant $\Lambda$ via the Newtonian cosmic potential of the matter within the expanding particle horizon. Consistent with GR, an increasing potential may drive the metric…

General Physics · Physics 2014-05-30 Herman Telkamp

The cosmological constant problem is explained by a theory based on the discrete space-time hypothesis. The calculated cosmological constant value is of the order of 10^-52[m]^-2 or equivalent to about 0.7 of the critical mass density. It…

Astrophysics · Physics 2007-05-23 H. M. Mok

Phenomena currently attributed to Dark Energy (DE) and Dark Matter (DM) are merely a result of the interplay between gravitational energy density, generated by the contraction of space by matter, and the energy density of the Cosmological…

Astrophysics · Physics 2008-12-25 Shlomo Barak , Elia M Leibowitz

Although there is overwhelming evidence of dark matter from its gravitational interaction, we still do not know its precise gravitational interaction strength or whether it obeys the equivalence principle. Using the latest available…

High Energy Physics - Phenomenology · Physics 2015-10-21 Yang Bai , Jordi Salvado , Ben A. Stefanek

A higher value of Hubble constant has been obtained from measurements with nearby Type Ia supernovae, than that obtained at much higher redshift. With the peculiar motions of their hosts, we find that the matter content at such low redshift…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-25 Shuang-Nan Zhang , Yin-Zhe Ma

We review current observations of the homogeneous cosmological expansion which, because they measure only kinematic variables, cannot determine the dynamics driving the recent accelerated expansion. The minimal fit to the data, the flat…

Astrophysics · Physics 2015-05-13 Sidney Bludman

We advance the viewpoint that only relevant modes of the vacuum fluctuations, namely, with wavelengths conditioned by the size, homogeneity, geometry and topology of the Universe, do contribute into the cosmological constant. A formula is…

Astrophysics · Physics 2014-10-13 V. G. Gurzadyan , She-Sheng Xue

We discuss a model of the universe where dark energy is replaced by electrically-charged extremely-massive dark matter. The cosmological constant has a value of the same order as the mean matter density, consistent with observations, and is…

General Physics · Physics 2026-01-26 Paul H. Frampton

Dark energy in the universe is assumed to be vacuum energy. The energy-momentum of vacuum is described by a scale-dependent cosmological constant. The equations of motion imply for the density of matter (dust) the sum of the usual matter…

General Physics · Physics 2008-11-09 Walter Petry

Context. The external regions of galaxy clusters may be under strong influence of the dark energy, discovered by observations of the SN Ia at redshift z < 1. Aims. The presence of the dark energy in the gravitational equilibrium equation,…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-05 Marco Merafina , Gennady S. Bisnovatyi-Kogan , Martina Donnari

Assuming the validity of the general relativistic description of gravitation on astrophysical and cosmological length scales, we analytically infer that the Friedmann-Robertson-Walker cosmology with Einsteinian cosmological constant, and a…

Astrophysics · Physics 2008-11-26 D. V. Ahluwalia-Khalilova

In this article the cosmological constant problems, as well as the astronomical evidence for a cosmologically significant homogeneous exotic energy density with negative pressure (quintessence), are reviewed for a broad audience of…

Astrophysics · Physics 2007-05-23 Norbert Straumann

It is suggested that the true ground state of the world has exactly vanishing vacuum energy and that the cosmological constant that seems to have been observed is due to our region of the universe being stuck in a false vacuum, whose energy…

High Energy Physics - Phenomenology · Physics 2011-05-12 S. M. Barr , D. Seckel

After a short history of the $\Lambda$-term it is explained why the (effective) cosmological constant is expected to obtain contributions from short-distance-physics, corresponding to an energy scale of at least 100 GeV. The actual tiny…

Astrophysics · Physics 2009-10-31 N. Straumann

One hope to solve the cosmological constant problem is to identify a symmetry principle, based on which the cosmological constant can be reduced either to zero, or to a tiny value. Here, we note that requiring that the vacuum state is…

General Relativity and Quantum Cosmology · Physics 2011-06-01 Jurjen F. Koksma , Tomislav Prokopec

General Relativity allows for a cosmological constant ($\Lambda$) which has inspired models of cosmic Inflation and Dark Energy. We show instead that $r_\Lambda = \sqrt{3/\Lambda}$ corresponds to an event horizon: a causal boundary term in…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-02 Enrique Gaztanaga

I describe an approach which relates classical gravity to the quantum microstructure of spacetime. In this approach, the field equations arise from maximizing the density of states of the matter plus geometry. The former is identified using…

General Relativity and Quantum Cosmology · Physics 2017-08-22 Thanu Padmanabhan
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