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Related papers: Universal expansion with spatially varying $G$

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Idealizing matter as a pressureless fluid and representing its motion by a peculiar--velocity field superimposed on a homogeneous and isotropic Hubble expansion, we apply (Lagrangian) spatial averaging on an arbitrary domain $\cal D$ to the…

Astrophysics · Physics 2011-09-29 Thomas Buchert , Juergen Ehlers

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

Modified theories of gravity have recently been studied by several authors as possibly viable alternatives to the cosmological concordance model. Such theories attempt to explain the accelerating expansion of the universe by changing the…

Astrophysics · Physics 2013-05-29 T. Multamaki , I. Vilja

We examine the evolution of the Friedmann Universe within our recent model of space-time identified with an elastic continuous medium whose deformations are described by a vector field constrained to obey a generalized four-dimensional…

General Relativity and Quantum Cosmology · Physics 2015-12-22 Fayçal Hammad

The acceleration of the universe can be explained either through dark energy or through the modification of gravity on large scales. In this paper we investigate modified gravity models and compare their observable predictions with dark…

Astrophysics · Physics 2008-11-26 Edmund Bertschinger , Phillip Zukin

The current standard cosmological model is constructed within the framework of general relativity with a cosmological constant $\Lambda$, which is often associated with dark energy, and phenomenologically explains the accelerated cosmic…

General Relativity and Quantum Cosmology · Physics 2023-06-27 Jiamin Hou , Julian Bautista , Maria Berti , Carolina Cuesta-Lazaro , César Hernández-Aguayo , Tilman Tröster , Jinglan Zheng

The quantum model of homogeneous and isotropic universe filled with the uniform scalar field is considered. This model predicts effective inverse square-law dependence of the mean total energy density <\rho> on the expectation value of…

Astrophysics · Physics 2007-05-23 V. E. Kuzmichev , V. V. Kuzmichev

There is sufficient amount of internal evidence in the nature of gravitational theories to indicate that gravity is an emergent phenomenon like, e.g, elasticity. Such an emergent nature is most apparent in the structure of gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 T. Padmanabhan

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

A wealth of astronomical data indicate the presence of mass discrepancies in the Universe. The motions observed in a variety of classes of extragalactic systems exceed what can be explained by the mass visible in stars and gas. Either (i)…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-28 Benoit Famaey , Stacy McGaugh

The discovery that the cosmic expansion is accelerating has been followed by an intense theoretical and experimental response in physics and astronomy. The discovery implies that our most basic notions about how gravity work are violated on…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-15 Robert R. Caldwell , Marc Kamionkowski

We have probed a cosmological model in $f(R)$-gravity, which is a cubic equation in scalar curvature $R$. The terms arise due to nonlinear $f(R)$ function are treated as energy due to curvature inspired geometry. As a result, we find…

General Relativity and Quantum Cosmology · Physics 2023-05-03 G. K. Goswami , Rita Rani , Harshna Balhara , J. K. Singh

We discuss the notion of generating a cosmic inflation without any big bang singularity. It has been proved recently by Good and Linder (arXiv : 2503.02380v1) that such an expansion of the universe can be driven by quantum fluctuations…

General Relativity and Quantum Cosmology · Physics 2025-08-12 Soumya Chakrabarti

Verlinde presents the gravitational force as due to gradients of entropy, an emergent force, with far reaching consequences. Using the Hawking-Bekenstein entropy formulation, we arrive at the conclusion that the Mass-Boom effect, presented…

General Physics · Physics 2010-09-14 Antonio Alfonso-Faus

We show that modelling the universe as a pre-geometric system with emergent quantum modes, and then constructing the classical limit, we obtain a new account of space and gravity that goes beyond Newtonian gravity even in the…

General Physics · Physics 2007-09-20 Reginald T Cahill

I consider the growth of inhomogeneities in a low-density baryonic, vacuum energy-dominated universe in the context of modified Newtonian dynamics (MOND). I first write down a two-field Langrangian-based theory of MOND (non-relativistic),…

Astrophysics · Physics 2009-10-31 R. H. Sanders

General relativistic entropic acceleration theory may explain the present cosmic acceleration from first principles without the need of introducing a cosmological constant. Following the covariant formulation of non-equilibrium phenomena in…

General Relativity and Quantum Cosmology · Physics 2021-10-20 Juan Garcia-Bellido , Llorenc Espinosa-Portales

We show that the description of the space-time of general relativity as a diagonal four dimensional submanifold immersed in an eight dimensional hypercomplex manifold, in torsionless case, leads to a geometrical origin of the cosmological…

General Relativity and Quantum Cosmology · Physics 2016-10-31 Hemza Azri , A. Bounames

Padmanabhan in his paper [arxiv: 1206.4916] put forth an intriguing idea arguing that the accelerated expansion of the universse can be viewed as the emergence of cosmic space as cosmic time progresses, with the expansion triggered due to…

General Relativity and Quantum Cosmology · Physics 2018-12-26 Mahith M. , Krishna P. B. , Titus K. Mathew

We propose a model of the Universe based on Minkowski flat space-time metric. In this model the space-time does not evolve. Instead the matter evolves such that all the mass parameters increase with time. We construct a model based on…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-15 Pankaj Jain