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In this paper such Riemann metrics are established whose Laplace-Beltrami operators are identical to familiar Hamilton operators of elementary particle systems. Such metrics are the natural positive definite invariant metrics defined on…

Spectral Theory · Mathematics 2009-09-23 Zoltan Imre Szabo

A new approach to the dynamics of the universe based on work by O Murchadha, Foster, Anderson and the author is presented. The only kinematics presupposed is the spatial geometry needed to define configuration spaces in purely relational…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Julian Barbour

It is shown that a first-order cosmological perturbation theory for the open, flat and closed Friedmann-Lema\^itre-Robertson-Walker universes admits one, and only one, gauge-invariant variable which describes the perturbation to the energy…

General Relativity and Quantum Cosmology · Physics 2014-10-02 P. G. Miedema , W. A. van Leeuwen

Observations show that the expansion of the Universe is accelerating. This requires that the dominant constituent of matter in the Universe has some unusual properties like negative pressure. This exotic component has been given the name…

Popular Physics · Physics 2019-01-17 Manvendra Pratap Rajvanshi , Tuneer Chakraborty , J. S. Bagla

The Einstein equations of general relativity reduce, when the spacetime metric is of the Friedmann--Lemaitre--Robertson--Walker type governing an isotropic and homogeneous universe, to the Friedmann equations, which is a set of nonlinear…

General Relativity and Quantum Cosmology · Physics 2024-07-30 Yisong Yang

The large-scale dynamics of the universe is generally described in terms of the time-dependent scale factor $a(t)$. To make contact with observational data, the $a(t)$ function needs to be related to the observable $z(r)$ function, redshift…

General Physics · Physics 2025-06-17 Jan Stenflo

We investigate the gravitational property of the quantum vacuum by treating its large energy density predicted by quantum field theory seriously and assuming that it does gravitate to obey the equivalence principle of general relativity. We…

General Relativity and Quantum Cosmology · Physics 2019-04-22 Qingdi Wang , Zhen Zhu , William G. Unruh

A tetrad-based procedure is presented for solving Einstein's field equations for spherically-symmetric systems; this approach was first discussed by Lasenby et al. in the language of geometric algebra. The method is used to derive metrics…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Roshina Nandra , Anthony N. Lasenby , Michael P. Hobson

In a recent paper, a cosmological model based on El Naschie {\it E} infinity cantorian spacetime was presented [Iovane, G.; Chaos, Solitons and Fractals, 20: 657-667, (2004)]. In that work it was claimed that the present accelerated…

Astrophysics · Physics 2007-05-23 Eduardo Sergio Santini , Guillermo Andrés Lemarchand

In this paper, it is shown that the cosmological model that was introduced in a sequence of three earlier papers under the title, A Dust Universe Solution to the Dark Energy Problem can be used to analyse and solve the Cosmological…

General Physics · Physics 2008-07-13 James G. Gilson

We consider a non-singular origin for the Universe starting from an Einstein static Universe, the so called "emergent universe" scenario, in the framework of a theory which uses two volume elements $\sqrt{-{g}}d^{4}x$ and $\Phi d^{4}x$,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Eduardo Guendelman , Pedro Labrana

Assuming that observers located inside the Universe measure a time flow which is different from the time appearing in the Friedmann-Lemaitre equation, and determining this time flow such that the Universe always appears flat to these…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-24 Pierre Magain

Cosmological consequences of a strictly valid total energy conservation for the whole universe are investigated in this paper. Interestingly enough as one consequence of ergodically behaving universes very specific scaling laws with the…

Astrophysics · Physics 2016-10-21 H. J. Fahr , M. Heyl

As we showed in a preceding arXiv:gr-qc Einstein equations, conveniently written, provide the more orthodox and simple description of cosmological models with a time dependent speed of light $c$. We derive here the concomitant dependence of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ll. Bel

The accepted idea that the expansion of the universe is accelerating needs, for compatibility to general relativity, the introduction of some unusual forms of matter. However, several authors have proposed that instead of making weird…

General Relativity and Quantum Cosmology · Physics 2025-03-20 Fábio dos Anjos , Mario Novello

We prove here that Newtons universal gravitation and momentum conservation laws together reproduce Weinbergs relation. It is shown that the Hubble parameter H must be built in this relation, or equivalently the age of the Universe t. Using…

General Physics · Physics 2011-04-11 Antonio Alfonso-Faus

We construct high-precision models of the Universe that contain radiation, a cosmological constant, and periodically distributed inhomogeneous matter. The density contrasts in these models are allowed to be highly non-linear, and the…

General Relativity and Quantum Cosmology · Physics 2017-02-24 Viraj A. A. Sanghai , Timothy Clifton

In Plasma Physics the concept of the Debye length \lambdaD is defined. This length gives the size of a volume such that from outside it the inside electrical charges, positive and negative, electrically screen each other. Given the enormous…

General Physics · Physics 2011-09-08 Antonio Alfonso-Faus , David Sanchez Aguado

We generalize f(R,T) gravity into the two-scalar theory that includes two independent scalar fields by the variational method, and we derive its field equations in Einstein frame using conformal transformation. Based on Friedmann equations…

General Relativity and Quantum Cosmology · Physics 2018-07-26 Jia-Cheng Ding , Ping Li , Cong Li , Qi-Qi Fan , Jian-Bo Deng

We use Wetterich's parameterization equation of state (EOS) of dark energy to a $5D$ Ricci-flat cosmological solution and we suppose the universe contains three major components: matter, radiation and dark energy. By using the relation…

Astrophysics · Physics 2009-11-11 Chengwu Zhang , Hongya Liu , Lixin Xu , P. S. Wesson
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