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Among the suggested solutions to the cosmological constant problem, we find the idea of a dynamic vacuum, with an energy density decaying with the universe expansion. We investigate the possibility of a variation in the gravitational…

General Relativity and Quantum Cosmology · Physics 2011-08-17 Saulo Carneiro

An ensemble of pure numbers of order near 10^122 is produced naturally from the fundamental parameters of modern cosmology. This new large-number coincidence problem is resolved by demonstrating implicit physical connections that follow…

General Physics · Physics 2015-06-26 Scott Funkhouser

For a universe presently dominated by static or dynamic vacuum energy, cosmological constant (LCDM) or quintessence (QCDM), we calculate the asymptotic collapsed mass fraction as function of the present ratio of vacuum energy to clustered…

Astrophysics · Physics 2016-11-03 Sidney Bludman

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

We applied the theory of regularly varying functions to the analysis of the cosmological parameters for the $\Lambda$CDM model with the matter dominated evolution. Carroll et al. proved in 1992 that for this type of universe with the…

Mathematical Physics · Physics 2017-11-21 Žarko Mijajlović , Nadežda Pejović , Viktor Radović

We show that it is possible to solve the cosmological constant (CC) problem in a discrete quantum gravity theory based on Regge calculus by using the effective action approach and a special path-integral measure. The effective cosmological…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Aleksandar Mikovic , Marko Vojinovic

The work shows that the associated Einstein like gravity for the Klein-Gordon field shows the spontaneous emergence of the cosmological pressure tensor density (CPTD) that in the classical limit leads to the cosmological constant (CC). Even…

General Physics · Physics 2020-07-07 Piero Chiarelli

For a flat universe presently dominated by smooth energy, either cosmological constant (LCDM) or quintessence (QCDM), we calculate the asymptotic collapsed mass fraction as function of the present ratio of smooth energy to matter energy…

Astrophysics · Physics 2009-10-31 Sidney Bludman , Matts Roos

We have critically compared different approaches to the cosmological constant problem, which is at the edge of elementary particle physics and cosmology. This problem is deeply connected with the difficulties formulating a theory of quantum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Stefan Nobbenhuis

It is pointed out that a collider experiment involves a local contribution to the energy-momentum tensor, a circumstance which not a common feature of the current state of the Universe at large characterized by the cosmological constant…

High Energy Physics - Theory · Physics 2015-06-26 Freydoon Mansouri

The assumption of a flat Universe that follows the cosmological principle, i.e., that the universe is statistically homogeneous and isotropic at large scales, comprises one of the core foundations of the standard cosmological model --…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-24 Mariana L. S. Dias , Antônio F. B. da Cunha , Carlos A. P. Bengaly , Rodrigo S. Gonçalves , Jonathan Morais

We use the latest Planck constraints, and in particular constraints on the derived parameters (Hubble constant and age of the Universe) for the local universe and compare them with local measurements of the same quantities. We propose a way…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-01 Licia Verde , Pavlos Protopapas , Raul Jimenez

An analysis of null geodesics in Schwarzschild de Sitter space is presented with special attention to their global `bending angles', local measurable angles, and the involvement of the cosmological constant. We make use of a general…

General Relativity and Quantum Cosmology · Physics 2016-09-19 Dmitri Lebedev , Kayll Lake

Strong gravitational lensing has traditionally been one of the few phenomena said to oppose a large cosmological constant; many analyses of lens statistics have given upper limits on $\Omega_\Lambda$ that are marginally inconsistent with…

Astrophysics · Physics 2009-11-07 Charles R. Keeton

The causal entropic principle aims to predict the unexpectedly small value of the cosmological constant Lambda using a weighting by entropy increase on causal diamonds. The original work assumed a purely isotropic and homogeneous cosmology.…

General Relativity and Quantum Cosmology · Physics 2012-01-20 Daniel Phillips , Andreas Albrecht

It is shown that the serious problem on the cosmological tension between the direct measurements of the Hubble constant at present and the constant derived from the Planck measurements of the CMB anisotropies can be solved by considering…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-09 Kenji Tomita

The (re)introduction of $\Lambda$ into cosmology has spurred debates that touch on central questions in philosophy of science, as well as the foundations of general relativity and particle physics. We provide a systematic assessment of the…

History and Philosophy of Physics · Physics 2023-03-06 Adam Koberinski , Bridget Falck , Chris Smeenk

We show by using the method of matched asymptotic expansions that a sufficient condition can be derived which determines when a local experiment will detect the cosmological variation of a scalar field which is driving the spacetime…

General Relativity and Quantum Cosmology · Physics 2008-11-26 John D. Barrow , Douglas J. Shaw

The search for a physical model which explains the observed recent acceleration of the universe is a compelling task of modern fundamental cosmology. Recently Fernandes \textit{et al.} presented low redshift observational constraints on a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-01 C. J. A. P. Martins , J. S. J. S. Oliveira , D. A. R. Pinheiro

We discuss a class of uniform and isotropic, spatially flat, decaying Lambda cosmologies, in the realm of a model where the gravitation constant G is a function of the cosmological time. Besides the usual de Sitter solution, the models at…

General Relativity and Quantum Cosmology · Physics 2010-03-19 S. Carneiro , J. A. S. Lima
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