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Related papers: More on Lensing by a Cosmological Constant

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The cosmological constant $\Lambda$ is usually interpreted as Dark Energy (DE) or modified gravity (MG). Here we propose instead that $\Lambda$ corresponds to a boundary term in the action of classical General Relativity. The action is zero…

General Relativity and Quantum Cosmology · Physics 2021-01-26 Enrique Gaztanaga

Recently a phenomenological relationship for the observed cosmological constant has been discussed by Motl and Carroll in the context of treating the cosmological constant as a $2\times 2$ matrix but no specific realization of the idea was…

High Energy Physics - Theory · Physics 2007-05-23 Michael McGuigan

We consider general relativity with a cosmological constant as a perturbative expansion around a completely solvable diffeomorphism invariant field theory. This theory is the $\Lambda\to\infty$ limit of general relativity. This allows an…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Rodolfo Gambini , Jorge Pullin

The presence of a cosmological constant, Lambda, in an action with higher powers of the curvature can produce rapidly oscillating metrics. We develop a perturbative approach for generating periodic solutions to the non-linear field…

High Energy Physics - Theory · Physics 2009-11-07 Hael Collins , Bob Holdom

This article aims at discussing the cosmological constant problem at a pedagogical but fully technical level. We review how the vacuum energy can be regularized in flat and curved space-time and how it can be understood in terms of Feynman…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Jerome Martin

Using the scalar and tensor virial equations, the Lane-Emden equation expressing the hydrostatic equilibrium and small oscillations around the equilibrium, we show how the cosmological constant $\Lambda$ affects various astrophysical…

Astrophysics · Physics 2009-11-13 A. Balaguera-Antolinez , M. Nowakowski

We suggest a new formula, which allows the Schwarzschild's solution and the Einstein radius to be applied to the dynamic universe, when our universe is hypothetically regarded as a single dynamic black hole. In this study, a cosmological…

General Relativity and Quantum Cosmology · Physics 2017-06-22 DongBong Yang , Heon-Ju Lee

We present a cosmological model containing a cosmological constant $\Lambda$ and a component with an inhomogeneous equation of state. We study the form of the inhomogeneous equation of state for which the model exhibits the relaxation of…

General Relativity and Quantum Cosmology · Physics 2008-12-01 Hrvoje Stefancic

We have identified seven (field) elliptical galaxies acting as strong gravitational lenses and have used them to measure cosmological parameters. To find the most likely value for Omega_m (= Omega_matter) and Lambda, we have used the…

Astrophysics · Physics 2009-10-28 Myungshin Im , Richard E. Griffiths , Kavan U. Ratnatunga

The recent OPERA experiment of superluminal neutrinos has deep consequences in cosmology. In cosmology a fundamental constant is the cosmological constant. From observations one can estimate the effective cosmological constant…

High Energy Physics - Phenomenology · Physics 2012-10-29 Mu-Lin Yan , Sen Hu , Wei Huang , Neng-Chao Xiao

This paper is based on two insights: (1) that general relativity alone does not specify how much of the matter density contributes to the source term in Friedmann's equation, and how much contributes as the source of the gravitational…

General Relativity and Quantum Cosmology · Physics 2024-04-23 Richard J. Cook

In this paper, we give a possible solution to the cosmological constant problem. It is shown hat the traditional approach, based on volume weighting of probabilities, leads to an incoherent onclusion: the probability that a randomly chosen…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Artyom V. Astashenok , Antonino Del Popolo

We investigate strong lensing by a spherically symmetric mass distribution in the framework of the Einstein-Straus solution with positive cosmological constant and concentrate on the case of a spatially closed Universe ($k=+1$). We develop…

General Relativity and Quantum Cosmology · Physics 2018-12-19 Mourad Guenouche , Sami Ryad Zouou

Some cosmological consequences of first order quantum corrections to Maxwell electrodynamics are investigated in the context of a spatially flat homogeneous and isotropic universe driven by a magnetic field plus a cosmological term…

Astrophysics · Physics 2007-05-23 M. R. de Garcia Maia , J. C. Carvalho , C. S. da Câmara Neto

By way of a complete integration of the Friedmann equations, in terms of observables, it is shown that for the cosmological constant $\Lambda > 0$ there exist non-flat FLRW models for which the total density parameter $\Omega$ remains $\sim…

Astrophysics · Physics 2009-11-10 Kayll Lake

In this paper we provide both a diagnosis and resolution of the cosmological constant problem, one in which a large (as opposed to a small) cosmological constant $\Lambda$ can be made compatible with observation. We trace the origin of the…

Astrophysics · Physics 2009-10-31 Philip D. Mannheim

We compute time delays for gravitational lensing in a flat LambdaCDM Swiss cheese universe. We assume a primary and secondary pair of light rays are deflected by a single point mass condensation described by a Kottler metric (Schwarzschild…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 Bin Chen , Ronald Kantowski , Xinyu Dai

We address a quantization mechanism that can allow us to understand why the cosmological constant is not large under the quantum corrections from studying the circle compactification solution of the Standard Model coupled to Einstein…

High Energy Physics - Theory · Physics 2023-03-15 Cao H. Nam

Inserting a varying Lambda in Einstein's field equations can be made consistent with the Bianchi identities by allowing for torsion, without the need to add scalar field degrees of freedom. In the minimal such theory, Lambda is totally free…

General Relativity and Quantum Cosmology · Physics 2019-10-07 Stephon Alexander , Marina Cortês , Andrew R. Liddle , João Magueijo , Robert Sims , Lee Smolin

Photons traveling in a background electromagnetic field may bend via the vacuum polarization effect with the background field. The bending in a Coulomb field by a heavy nucleus is small even at a large atomic number, rendering it difficult…

High Energy Physics - Phenomenology · Physics 2018-09-19 Taekoon Lee