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Related papers: An FLRW Cosmology with a Chameleon Field

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In this work, we have discussed the Maxwell's electrodynamics in non-linear forms in FRW universe. The energy density and pressure for non-linear electrodynamics have been written in the electro-magnetic universe. The Einstein's field…

General Physics · Physics 2012-08-29 Tanwi Bandyopadhyay , Ujjal Debnath

The chameleon, or generalizations thereof, is a light scalar that couple to matter with gravitational strength, but whose manifestation depends on the ambient matter density. A key feature is that the screening mechanism suppressing its…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Junpu Wang , Lam Hui , Justin Khoury

We discuss a field-theoretical approach based on variational principle to derive the field and hydrodynamic equations of motion of baryonic matter governed by cosmological perturbations of dark matter and dark energy. The action depends on…

General Relativity and Quantum Cosmology · Physics 2015-01-27 Sergei M. Kopeikin , Alexander N. Petrov

In this paper, we investigate the dynamics of the universe on the background of f-essence when a non-minimal coupling with gravity. Field equations are obtained and using the Noether theorem, explicit forms of the coupling function and the…

General Physics · Physics 2017-05-26 Tolkynay Myrzakul , Ertan Gudekli , Shynaray Myrzakul , Ratbay Myrzakulov

In a flat Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) geometry, we consider the expansion of the universe powered by the gravitationally induced `adiabatic' matter creation. To demonstrate how matter creation works well with the…

General Relativity and Quantum Cosmology · Physics 2016-06-07 Supriya Pan , Jaume de Haro , Andronikos Paliathanasis , Reinoud Jan Slagter

Considering the Friedmann--Lema\^{i}tre--Robertson--Walker (FLRW) metric and the Einstein scalar field system as an underlying gravitational model to construct fractional cosmological models has interesting implications in both classical…

General Relativity and Quantum Cosmology · Physics 2024-07-26 S. M. M. Rasouli , S. Cheraghchi , P. V. Moniz

This work deals with chameleon field cosmology (a scalar field nonminimally coupled to cold dark matter) in the background of flat Friedmann-Lemaitre-Robertson-Walker (FLRW) space-time. Both classical and quantum cosmology have been…

General Relativity and Quantum Cosmology · Physics 2023-03-01 Roshni Bhaumik , Sourav Dutta , Subenoy Chakraborty

A generalized version for the Rastall theory is proposed showing the agreement with the cosmic accelerating expansion. In this regard, a coupling between geometry and the pressureless matter fields is derived which may play the role of dark…

General Relativity and Quantum Cosmology · Physics 2017-05-24 H. Moradpour , Y. Heydarzade , F. Darabi , Ines G. Salako

Models where the accelerated expansion of our Universe is caused by a quintessence scalar field are reviewed. In the framework of high energy physics, the physical nature of this field is discussed and its interaction with ordinary matter…

Astrophysics · Physics 2009-06-23 Jerome Martin

In loop quantum cosmology, Friedmann-LeMaitre-Robertson-Walker (FLRW) space-times arise as well-defined approximations to specific \emph{quantum} geometries. We initiate the development of a quantum theory of test scalar fields on these…

General Relativity and Quantum Cosmology · Physics 2009-11-06 Abhay Ashtekar , Wojciech Kaminski , Jerzy Lewandowski

We consider a noncommutative standard model with a minimal coupling scalar field and a dynamical deformation between the canonical momenta of its scale factor and scalar field, and a chameleon model with a non-minimally coupling scalar…

General Relativity and Quantum Cosmology · Physics 2018-05-25 Nasim Saba , Mehrdad Farhoudi

Chameleons are scalar fields whose mass depends on the environment, specifically on the ambient matter density. While nearly massless in the cosmos, where the matter density is tiny, their mass is of order of an inverse millimeter on Earth,…

Astrophysics · Physics 2009-11-10 Ph. Brax , C. van de Bruck , A. C. Davis , J. Khoury , A. Weltman

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

A simplified Walecka-type model is investigated in a cosmological scenario. The model includes fermionic, scalar and vector fields as sources. It is shown that their interactions, taking place in a Robertson-Walker metric, could be…

General Relativity and Quantum Cosmology · Physics 2013-09-16 Marlos O. Ribas , Pedro Zambianchi , Fernando P. Devecchi , Gilberto M. Kremer

We have investigated the Brans-Dicke Chameleon theory of gravity and obtained exact solutions of the scale factor $a(t)$, scalar field $\phi(t)$, an arbitrary function $f(\phi)$ which interact with the matter Lagrangian in the action of the…

General Physics · Physics 2011-09-12 Mubasher Jamil , Ibrar Hussain , D. Momeni

The quantized Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) model minimally coupled to a free massless scalar field is studied and interpreted in the Bohm-de Broglie framework. We analyze the quantum bohmian trajectories corresponding to…

General Relativity and Quantum Cosmology · Physics 2016-11-09 E. Sergio Santini

One possibility to explain the current accelerated expansion of the universe may be related with the presence of cosmologically evolving scalar whose mass depends on the local matter density (chameleon cosmology). We point out that matter…

High Energy Physics - Theory · Physics 2009-09-17 Shin'ichi Nojiri , Sergei D. Odintsov

We study the most general cosmological model with real scalar field which is minimally coupled to gravity. Our calculations are based on Friedmann-Lemaitre-Robertson-Walker (FLRW) background metric. Field equations consist of three…

General Relativity and Quantum Cosmology · Physics 2023-03-22 Medine Ildes , Metin Arik

While considering the chameleon scalar field model with the spatially flat FLRW background, we investigate the late-time acceleration phase of the universe, wherein we apply the typical potential usually used in this model. Through setting…

General Relativity and Quantum Cosmology · Physics 2022-08-25 Raziyeh Zaregonbadi , Nasim Saba , Mehrdad Farhoudi

We develop a Lagrangian formulation for gravity with matter where the gravitational couplings are universally treated as being field-dependent. The solutions for FLRW geometries and the associated time evolution of the Newton and…

General Relativity and Quantum Cosmology · Physics 2025-10-15 Sandipan Sengupta