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Related papers: Comments on an alternative theory for the accelera…

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In this paper, we examine the accelerated expansion of the Universe at late-time in the framework of $f\left( Q\right) $ gravity theory in which the non-metricity scalar $Q$ describes the gravitational interaction. To this, we propose a new…

General Relativity and Quantum Cosmology · Physics 2023-02-21 M. Koussour , S. K. J. Pacif , M. Bennai , P. K. Sahoo

In Brans Dicke theory of gravity, from the nature of the scalar field-potential considered, the dark energy, dark matter, radiation densities predicted by different observations and the closedness of the universe considered, we can fix our…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Ritabrata Biswas , Ujjal Debnath

A new universal constant of expansion has been discovered with amazing predictive power once its density-time relations have been deciphered. The new constant is kappa, the product of the gravitational constant, and the average total…

Astrophysics · Physics 2007-05-23 Charles B. Leffert

In this paper, the dynamical behavior of the accelerated expansion of the universe is discussed within the framework of $f(T)$ gravity, considering power law functional form of $ f(T)=\alpha (-T)^{n}$. Two distinct redshift-dependent…

General Relativity and Quantum Cosmology · Physics 2025-08-29 Shivank Pal , Romanshu Garg , Gyan Prakash Singh , Gauree Shanker

It is proposed that dark energy may become dominant over standard matter due to universe expansion (curvature decrease). Two models: non-linear gravity-matter system and modified gravity may provide the effective phantom or effective…

Astrophysics · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

We describe the non-minimal Standard Model, consisting of minimalistic extensions of the Standard Model, which for all we know is the theory of the universe, able to describe all of the universe from the beginning of time. Extensions…

High Energy Physics - Phenomenology · Physics 2021-07-07 J. J. van der Bij

We investigate the recent - low redshift - expansion history of the universe using the most recent observational data. Using only data from 42 measurements of $f_{gas}$ in clusters, we found that cosmic acceleration could have already…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Victor H. Cardenas , Carla Bernal , Alexander Bonilla

We study the late-time evolution of the Universe within the f(R,G) gravity framework, where R is the Ricci scalar and G is the Gauss-Bonnet term. To make the model tractable, we propose a parametrization scheme and determine its parameters…

General Relativity and Quantum Cosmology · Physics 2026-05-12 Santosh V. Lohakare , B. Mishra , S. K. Maurya

In a recent model Choudhury proposed that a collapsing matter generates an adiabatic pressure which can be used to explain the acceleration of the physical universe under certain approximation. In this work we superimpose the core pressure…

General Relativity and Quantum Cosmology · Physics 2008-05-26 A. M. Haruar Rashid , A. L. Choudhury

In this paper we propose that the accelerating expansion of the present matter-dominated universe, as suggested by the recent distance measurements of type Ia supernovae, is generated along with the evolution of space in extra dimensions.…

Astrophysics · Physics 2009-11-07 Je-An Gu , W-Y. P. Hwang

We present the model of transit universe from early deceleration phase to current acceleration phase under the framework of general relativity in presence of gravitational coupling $G(t)$ and cosmological terms $\Lambda(t)$. The Einstein's…

General Physics · Physics 2015-06-11 Anil Kumar Yadav , A. Sharma

Adding to our previous method for dealing with gravitational modifications at redshift $z\gtrsim3$ through a single parameter, we investigate treatment of lower redshift modifications to linear growth observables. We establish subpercent…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-29 Mikhail Denissenya , Eric V. Linder

As shown by Parker and Raval, quantum field theory in curved spacetime gives a possible mechanism for explaining the observed recent acceleration of the universe. This mechanism, which differs in its dynamics from quintessence models,…

Astrophysics · Physics 2009-11-07 Leonard Parker , William Komp , Daniel A. T. Vanzella

When using distance measurements to probe spatial curvature, the geometric degeneracy between curvature and dark energy in the distance-redshift relation typically requires either making strong assumptions about the dark energy evolution or…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-14 Michael J. Mortonson

It is shown that the accelerated expansion of the universe in the framework of the relativistic theory of gravitation can be achieved by the introduction of the quintessential term in the energy-momentum tensor. The value of the minimum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. L. Kalashnikov

The discovery of cosmic acceleration has stimulated theorists to consider dark energy or modifications to Einstein's General Relativity as possible explanations. The last decade has seen advances in theories that go beyond smooth dark…

The generalized $f(R)$ gravity with curvature-matter coupling in five-dimensional (5D) spacetime can be established by assuming a hypersurface-orthogonal spacelike Killing vector field of 5D spacetime, and it can be reduced to the 4D…

General Relativity and Quantum Cosmology · Physics 2014-04-22 Ya-Bo Wu , Yue-Yue Zhao , Jun-Wang Lu , Xue Zhang , Cheng-Yuan Zhang , Jia-Wei Qiao

We discuss recent evidence for an accelerating Universe from measurements of type Ia supernovae at high redshift, and describe tests of various systematic effects such as extinction and evolution that could be biasing the cosmological…

Astrophysics · Physics 2007-05-23 Saurabh Jha , the High-Z Supernova Search Team

Supernovae are bright luminous stellar objects observable up to redshifts close to z~1. They are used to probe the geometry of the Universe and its expansion rate by applying different methods. In this article, I review various approaches…

Astrophysics · Physics 2011-04-15 P. Ruiz-Lapuente

We investigate the properties of a cosmological scenario which undergoes a gravitational phase transition at late times. In this scenario, the Universe evolves according to general relativity in the standard, hot Big Bang picture until a…

Astrophysics · Physics 2013-05-29 Robert R. Caldwell , William Komp , Leonard Parker , Daniel A. T. Vanzella