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This article provides a discussion on the construction of conformal Gaussian gauge systems to study the evolution of solutions to the Einstein field equations with positive Cosmological constant. This is done by means of a gauge based on…

General Relativity and Quantum Cosmology · Physics 2023-08-10 Marica Minucci

Deviations from general relativity in order to explain cosmic acceleration generically have both time and scale dependent signatures in cosmological data. We extend our previous work by investigating model independent gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-23 Scott F. Daniel , Eric V. Linder

The Machian Universe, is usually described with Newtonian Physics, We give an alternative General Relativistic picture for Mach's Universe. As such, we show that, in the correct Machian limit, Schwarzschild's metric is coherent with…

General Physics · Physics 2012-11-08 Marcelo Samuel Berman

A new idea of deriving a cosmological term from an underlying theory has been proposed in order to explain the expansion history of the universe. We obtain the scale factor with this derived cosmological term and demonstrate that it…

General Relativity and Quantum Cosmology · Physics 2008-10-15 Supratik Pal

We investigate a conformal invariant gravitational model which is taken to hold at pre-inflationary era. The conformal invariance allows to make a dynamical distinction between the two unit systems (or conformal frames) usually used in…

High Energy Physics - Theory · Physics 2009-11-10 Yousef Bisabr

We discuss the linearization of Einstein equations in the presence of a cosmological constant, by expanding the solution for the metric around a flat Minkowski space-time. We demonstrate that one can find consistent solutions to the…

General Relativity and Quantum Cosmology · Physics 2010-04-14 Jose Bernabeu , Catalina Espinoza , Nick E. Mavromatos

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

In this paper we suppose that the cosmological constant will change when the universe expends. For a general consideration, the cosmological constant is assumed to be a function of scale factor and Hubble constant. According to the ADM…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-03 Jin-Zhang Tang , Qiang Xu

This work investigates the cosmology of a thick brane within the context of $f(\mathbb{Q})$ gravity, an extension of symmetric teleparallelism. Using a five-dimensional Friedmann-Lema\^itre-Robertson-Walker metric, we solve the field…

General Relativity and Quantum Cosmology · Physics 2026-03-05 J. J. Ramos , J. E. G. Silva

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

In this paper, using $f(R)$ theory of gravity we explicitly calculate cosmological evolution in the presence of a perfect fluid source in four and five dimensional, space time in which this cosmological evolution in self-creation is…

General Relativity and Quantum Cosmology · Physics 2014-01-20 A. Aghmohammadi , Kh. Saaidi , M. R. Abolhassani , A. Vajdi

The cosmic time dilation observed in Type Ia supernova light curves suggests that the passage of cosmic time varies throughout the evolution of the Universe. This observation implies that the rate of proper time is not constant, as assumed…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-25 Vaclav Vavrycuk

We revisit the question of whether the cosmological constant $\Lambda$ affects the cosmological gravitational bending of light, by numerical integration of the geodesic equations for a Swiss cheese model consisting of a point mass and a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-16 Lingyi Hu , Alan Heavens , David Bacon

Since its decovery during the late 90's, the dimming of distant SN Ia apparent luminosity has been mostly ascribed to the influence of a mysterious dark energy component. Based upon the cosmological "principle" hypothesis, this…

Astrophysics · Physics 2016-11-15 Marie-Noëlle Célérier

This study is devoted to the implications of scale-dependent gravity in Cosmology. Redshift-space distortion data indicate that there is a tension between $\Lambda$CDM and available observations as far as the value of the rms density…

General Relativity and Quantum Cosmology · Physics 2021-06-08 Grigoris Panotopoulos , Ángel Rincón

I briefly discuss the challenges presented by attempting to modify general relativity to obtain an explanation for the observed accelerated expansion of the universe. Foremost among these are the questions of theoretical consistency - the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Mark Trodden

We have found that the conformally coupled induced gravity can be an infrared fixed point of induced gravity with Yukawa couplings with matter. The late time cosmology with a uniform mean matter distribution can be described by the…

General Relativity and Quantum Cosmology · Physics 2013-09-10 Yongsung Yoon

We consider a cosmology in which a spherically symmetric large scale inhomogeneous enhancement or a void are described by an inhomogeneous metric and Einstein's gravitational equations. For a flat matter dominated universe the inhomogeneous…

Astrophysics · Physics 2008-11-26 J. W. Moffat

This is the third of a series of papers in which we derive simultaneous constraints on cosmological parameters and X-ray scaling relations using observations of the growth of massive, X-ray flux-selected galaxy clusters. Our data set…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 David Rapetti , Steven W. Allen , Adam Mantz , Harald Ebeling

Although big bang cosmology effectively models even the most puzzling observational data, it offers no insight into why the cosmological expansion should occur at all. In this paper it is suggested that a finite Universe poses particular…

General Physics · Physics 2007-05-23 Alasdair Macleod