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In this work we study the cosmological evolution of a dark energy model with two scalar fields, i.e. the tachyon and the phantom tachyon. This model enables the equation of state $w$ to change from $w>-1$ to $w<-1$ in the evolution of the…

Astrophysics · Physics 2009-12-04 Shang-Gang Shi , Yun-Song Piao , Cong-Feng Qiao

We study some aspects of cosmological evolution in a universe described by a viable curvature corrected exponential $F(R)$ gravity model, in the presence of matter fluids consisting of collisional matter and radiation. Particularly, we…

General Relativity and Quantum Cosmology · Physics 2015-06-23 V. K. Oikonomou , N. Karagiannakis , Miok Park

We study the phenomenon of cosmological particle production of Dirac fermions in a Friedman-Robertson-Walker spacetime, focusing on a (1+1)-dimensional case in which the evolution of the scale factor is set by the equations of…

Cosmological perturbations on a manifold admitting signature change are studied. The background solution consists in a Friedmann-Lemaitre-Robertson- Walker (FLRW) Universe filled by a constant scalar field playing the role of a cosmological…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Jerome Martin

We explore the dynamical properties of a cosmological model that includes viscous effects in the dark matter sector of the fluid equations in a flat Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime. The bulk viscous effects are…

General Relativity and Quantum Cosmology · Physics 2022-11-14 Gilberto Aguilar-Pérez , Ana A. Avilez-López , Miguel Cruz

We consider a 5-dimensional Ricci flat bouncing cosmological model in which the 4-dimensional induced matter contains two components at late times - the cold dark matter (CDM)+baryons and dark energy. We find that the arbitrary function…

Astrophysics · Physics 2009-11-13 Lixin Xu , Hongya Liu

We investigate the possibility that part of the dark matter is not made out of the usual cold dark matter (CDM) dustlike particles, but is under the form of a fluid of strings with barotropic factor $w_s = -1/3$ of cosmic origin. To this…

Astrophysics · Physics 2009-11-11 S. Capozziello , V. F. Cardone , G. Lambiase , A. Troisi

We study the conditions for the consistency of the Friedmann-Robertson-Walker (FRW) metric with the dynamical Chern-Simons modified gravity. It turns out to be that in this situation the accelerated expansion of the Universe takes place,…

High Energy Physics - Theory · Physics 2011-07-14 C. Furtado , J. R. Nascimento , A. Yu. Petrov , A. F. Santos

In the context of f(R, T) gravity theory for the flat Friedmann Lemaitre Robertson Walker (FLRW) model, the accelerating expansion of the universe is investigated using a specific form of the emergent Hubble parameter. Datasets from H(z),…

General Relativity and Quantum Cosmology · Physics 2025-01-16 N. Myrzakulov , S. H. Shekh , Anirudh Pradhan , Archana Dixit

We present a detailed analysis of the phase-space for the field equations in scalar field cosmology with a chameleon cosmology in a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker spacetime. For the matter source we assume that…

General Relativity and Quantum Cosmology · Physics 2023-06-07 Andronikos Paliathanasis

We show that modelling the universe as a pre-geometric system with emergent quantum modes, and then constructing the classical limit, we obtain a new account of space and gravity that goes beyond Newtonian gravity even in the…

General Physics · Physics 2007-09-20 Reginald T Cahill

We revisit the evolution of the scale factor in a flat FRW spacetime with a new generalized decay rule for the dynamic $\Lambda$-term under modified theories of gravity. It analyses certain cosmological parameters and examines their…

General Physics · Physics 2021-08-02 Anirudh Pradhan , De Avik , Tee How Loo , D. C. Maurya

It is extraordinary that a number of observations indicate that we live in a spatially flat, low matter density Universe, which is currently undergoing a period of accelerating expansion. The effort to explain this current state has focused…

Astrophysics · Physics 2010-02-18 R. R. Caldwell

We consider the spatially flat Friedmann-Lemaitre-Robertson-Walker space time in the teleparallel model of gravity and assume that the universe is filled nearly by cold dark matter and a nonminimally coupled scalar field with a power-law…

General Relativity and Quantum Cosmology · Physics 2017-04-11 H. Mohseni Sadjadi

The current Universe is composed by a mixture of relativistic species, baryonic matter, dark matter and dark energy which evolve in a non-trivial way at perturbative level. An advanced description of the cosmological dynamics should include…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-22 Winfried Zimdahl , Júlio Fabris , Hermano Velten , Ramón Herrera

In this paper we present the cosmological dynamics of a perfect fluid and the Dark Energy (DE) component of the Universe, where our model of the dark energy is the string-theoritic Dirac-Born-Infeld (DBI) model. We assume that the potential…

General Relativity and Quantum Cosmology · Physics 2021-03-05 Subhajyoti Pal , Subenoy Chakraborty

We investigate the cosmological dynamics of a homogeneous scalar field non-minimally coupled to torsion gravity, which also interacts with cold dark matter through energy and momentum transfer. The matter and radiation perfect fluids are…

General Relativity and Quantum Cosmology · Physics 2025-02-05 Carlos Rodriguez-Benites , Manuel Gonzalez-Espinoza , Giovanni Otalora , Manuel Alva-Morales

The standard paradigm of cosmology assumes two distinct dark components, namely dark matter and dark energy. However, the necessity of splitting the dark-side world into two sectors has not been experimentally or theoretically proven.…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-12 Yan Su , Zhiqi Huang , Yanhong Yao , Junchao Wang , Jianqi Liu

We provide a detailed description for power-law scaling FRW cosmological models in Brans-Dicke theory dominated by two interacting fluid components during the expansion of the universe.

General Relativity and Quantum Cosmology · Physics 2015-05-18 H. Farajollahi , N. Mohamadi , H. Amiri

We examine a spatially flat Friedmann-Robertson-Walker (FRW) universe filled with interacting dark matter and a modified holographic Ricci dark energy (MHRDE). The interaction term is selected as a significant rational function of the total…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Luis P. Chimento , Martín G. Richarte
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