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Related papers: FRW in cosmological self-creation theory

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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

We investigate the phase-space of a flat FRW universe including both a scalar field, $\phi,$ coupled to matter, and radiation. The model is inspired in scalar-tensor theories of gravity, and thus, related with $F(R)$ theories through…

General Relativity and Quantum Cosmology · Physics 2010-09-06 Genly Leon , Pavel Silveira , Carlos R. Fadragas

We show that Einstein's field equations for spatially flat Friedmann-Robertson-Walker (FRW) space times have a form invariance symmetry (FIS) realized by the form invariance transformations (FIT) which are indeed generated by an invertible…

General Relativity and Quantum Cosmology · Physics 2013-04-01 Luis P. Chimento , Martín G. Richarte , Iván E. Sánchez G

The aim of this paper is to explore warm inflation in the background of $f(\mathcal{G})$ theory of gravity using scalar fields for the FRW universe model. We construct the field equations under slow-roll approximations and evaluate the…

General Relativity and Quantum Cosmology · Physics 2016-09-21 M. Sharif , Ayesha Ikram

Extending the approach developed by Ara\'ujo and Stoeger [1] and improved in Ara\'ujo {\it et al} [2], we have shown how to construct dust-filled $\Lambda \neq 0$ Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) cosmological models from FLRW…

Astrophysics · Physics 2009-02-20 M. E. Araujo , W. S. Stoeger , R. C. Arcuri , M. L. Bedran

This paper invokes a new mechanism for reducing a coupled system of fields (including Einstein's equations without a cosmological constant) to equations that possess solutions exhibiting characteristics of immediate relevance to current…

General Relativity and Quantum Cosmology · Physics 2019-11-05 Robin W. Tucker , Timothy J. Walton , Manuel Arrayás , José L. Trueba

The mechanism of the initial inflation of the universe is based on gravitationally coupled scalar fields $\phi$. Various scenarios are distinguished by the choice of an {\it effective self--interaction potential} $U(\phi)$ which simulates a…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Franz E. Schunck , Eckehard W. Mielke

In this paper, we consider the problem of existence and uniqueness of solutions to the Einstein field equations for a spatially flat FLRW universe in the context of stochastic eternal inflation where the stochastic mechanism is modelled by…

Mathematical Physics · Physics 2016-12-28 Ikjyot Singh Kohli , Michael C. Haslam

We revisit spatially flat FLRW cosmology in light of recent advances in standard model relativistic fluid dynamics. Modern fluid dynamics requires the presence of curvature-matter terms in the energy-momentum tensor for consistency. These…

General Relativity and Quantum Cosmology · Physics 2019-07-09 Rudolf Baier , Sayantani Lahiri , Paul Romatschke

In this paper, we study the model of the late universe with the homogeneous, isotropic and flat Friedmann-Robertson-Walker metric, where the source of the gravitational field is based on the fermion and boson field, with the Maxwell term…

General Relativity and Quantum Cosmology · Physics 2020-07-13 O. Razina , P. Tsyba , B. Meirbekov , R. Myrzakulov

We argue that, when coupled to Einstein's theory of gravity, the Yukawa theory may solve the cosmological constant problem in the following sense: The radiative corrections of fermions generate an effective potential for the scalar field,…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Tomislav Prokopec

We consider spatially homogeneous and isotropic Friedmann-Robertson-Walker (FRW) solutions of Milgrom's recently proposed class of bimetric theories of gravity. These theories have two different regimes, corresponding to high and low…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Timothy Clifton , Thomas G. Zlosnik

The dynamical evolution of the scale factor of FRW cosmological model is presented, when the equation of state of the material content assume the form $\rm p=\gamma \rho$, $\rm \gamma=constant$, including the cosmological term. We use the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. R. Berbena , A. V. Berrocal , J. Socorro , Luis O. Pimentel

This paper discusses the problem of inflation in the context of Friedmann-Robertson-Walker Cosmology. We show how, after a simple change of variables, to quantize the problem in a way which parallels the classical discussion. The result is…

High Energy Physics - Theory · Physics 2007-05-23 Marvin Weinstein , Ratindranath Akhoury

In the framework of polynomial Palatini cosmology, we investigate a simple cosmological homogeneous and isotropic model with matter in the Einstein frame. We show that in this model during cosmic evolution, it appears the early inflation…

General Relativity and Quantum Cosmology · Physics 2018-05-22 Marek Szydlowski , Aleksander Stachowski

In the paper, hep-th/0501055 (R.G. Cai and S.P. Kim, JHEP {\bf 0502}, 050 (2005)), it is shown that by applying the first law of thermodynamics to the apparent horizon of an FRW universe and assuming the geometric entropy given by a quarter…

High Energy Physics - Theory · Physics 2008-11-26 M. Akbar , Rong-Gen Cai

Based on an earlier introduced new class of generalized gravity-matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space-time manifold, we…

High Energy Physics - Theory · Physics 2016-11-29 Eduardo Guendelman , Ramon Herrera , Pedro Labrana , Emil Nissimov , Svetlana Pacheva

We investigate the most general exact solutions of Brans-Dicke cosmology by choosing the scale factor "a" as the new independent variable. It is shown that a set of three field equations can be reduced to a constraint equation and a first…

General Relativity and Quantum Cosmology · Physics 2023-02-15 Medine Ildes , Metin Arik

In the context of a recently proposed nonlinear massive gravity with Lorentz-invariant mass terms, we investigate open Friedmann-Robertson-Walker (FRW) universes driven by arbitrary matter source. While the flat FRW solutions were recently…

High Energy Physics - Theory · Physics 2015-03-12 A. Emir Gumrukcuoglu , Chunshan Lin , Shinji Mukohyama

Despite impressive phenomenological successes, cosmological models are incomplete without an understanding of what happened at the big bang singularity. Maxwell electrodynamics, considered as a source of the classical Einstein field…

General Relativity and Quantum Cosmology · Physics 2017-02-17 A. Övgün