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Related papers: Accelerating universe at the end of time

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The paper deals with dynamical system analysis of a coupled scalar field in the Randall-Sundrum(RS)2 brane world. The late time attractor describes the final state of the cosmic evolution. In RS2 based phantom model there is no late-time…

General Relativity and Quantum Cosmology · Physics 2016-01-05 Jibitesh Dutta , H. Zonunmawia

In view of late-time cosmic acceleration, a dark energy cosmological model is revisited wherein Einstein's cosmological constant is considered as a candidate of dark energy. Exact solution of Einstein field equations (EFEs) is derived in a…

General Relativity and Quantum Cosmology · Physics 2019-11-22 S. K. J. Pacif , Md Salahuddin Khan , L. K. Paikroy , Shalini Singh

In braneworld models a variable vacuum energy may appear if the size of the extra dimension changes during the evolution of the universe. In this scenario the acceleration of the universe is related not only to the variation of the…

General Relativity and Quantum Cosmology · Physics 2015-06-25 J. Ponce de Leon

We present a systematic study of accelerating cosmologies obtained from M/string theory compactifications of hyperbolic spaces with time-varying volume. A set of vacuum solutions where the internal space is a product of hyperbolic manifolds…

High Energy Physics - Theory · Physics 2011-05-05 Chiang-Mei Chen , Pei-Ming Ho , Ishwaree P. Neupane , Nobuyoshi Ohta , John E. Wang

The effects of noncommutativity on the phase space of a dilatonic cosmological model is investigated. The existence of such noncommutativity results in a deformed Poisson algebra between the minisuperspace variables and their momenta…

General Relativity and Quantum Cosmology · Physics 2010-04-30 B. Vakili , P. Pedram , S. Jalalzadeh

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 find exact power-law solutions for scalar-tensor theories and clarify the conditions under which they can account for an accelerated expansion of the Universe. These solutions have the property that the signs of both the Hubble rate and…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 C. E. M. Batista , W. Zimdahl

We show that scalar field fluctuations alone can drive cosmic acceleration, provided the universe is spatially closed and the Compton wavelength of the field exceeds the radius of curvature. This mechanism may open new perspectives on…

General Relativity and Quantum Cosmology · Physics 2026-02-12 Daniel Jiménez-Aguilar

We describe the late-time acceleration of the Universe within the paradigm of the brane-world scenario. More precisely, we show how a phantom-like behaviour or a crossing of the cosmological constant line can be achieved safely in a…

High Energy Physics - Theory · Physics 2008-11-26 Mariam Bouhmadi-López

We show that, for the scalar field cosmology with exponential potential, the set of values of the coupling parameter for which the solutions undergo a transient period of acceleration is much larger than the set discussed in the literature.…

General Relativity and Quantum Cosmology · Physics 2014-01-29 Mustapha Azreg-Aïnou

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

If our Universe is allowed to absorb baby universes, one obtains a modified Friedmann equation that can explain the late time acceleration of our Universe and there is no need for a cosmological constant. In addition the modified Friedmann…

General Relativity and Quantum Cosmology · Physics 2024-01-17 Jan Ambjorn , Yoshiyuki Watabiki

We consider the cosmological evolution of a bulk scalar field and ordinary matter living on the brane world in the light of the constraints imposed by the matter dominated cosmological evolution and a small cosmological constant now. We…

High Energy Physics - Theory · Physics 2016-09-06 Ph. Brax , A. C. Davis

I consider an extension of General Relativity by an auxiliary non-dynamical dimension that enables our space-time to acquire an extrinsic curvature. Obtained gravitational equations, without or with a cosmological constant, have a…

High Energy Physics - Theory · Physics 2014-11-20 Gregory Gabadadze

A refined version of a recently introduced method for analysing the dynamics of an inhomogeneous irrotational dust universe is presented. A fully non-perturbative numerical computation of the time dependence of volume in this framework…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-01 Harald Skarke

In the context of a cosmological string model describing the propagation of strings in a time-dependent Robertson-Walker background space-time, we show that the asymptotic acceleration of the Universe can be identified with the square of…

High Energy Physics - Theory · Physics 2009-09-11 John Ellis , N. E. Mavromatos , D. V. Nanopoulos

We show that a single constrained scalar field with non-minimal coupling to gravity can give rise to an accelerating Universe. First, we consider this model in the absence of external matter. In the original Jordan frame, we show that the…

High Energy Physics - Theory · Physics 2025-07-02 Anamaria Hell , Misao Sasaki

We examine the scenario of non-minimally coupled relativistic fluid and $k$-essence scalar field in a flat Friedmann-Lemaitre-Robertson-Walker universe. By adding a non-minimal coupling term in the Lagrangian level, we study the variation…

General Relativity and Quantum Cosmology · Physics 2024-07-23 Anirban Chatterjee , Saddam Hussain , Kaushik Bhattacharya

Fractional cosmology modifies the standard derivative to Caputo's fractional derivative of order $\mu$, generating changes in General Relativity. Friedmann equations are modified, and the evolution of the species densities depends on $\mu$…

General Relativity and Quantum Cosmology · Physics 2022-10-26 Miguel A. García-Aspeitia , Guillermo Fernandez-Anaya , A. Hernández-Almada , Genly Leon , Juan Magaña

In this paper, a general FRW cosmological model has been constructed in $f(R,T)$ gravity reconstruction with variable cosmological constant. A number of solutions to the field equations has been generated by utilizing a form for the Hubble…

General Relativity and Quantum Cosmology · Physics 2018-10-17 Nasr Ahmed , Sultan Z. Alamri
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