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We quantize a flat FRW cosmology in the context of the $f(R)$ gravity by Noether symmetry approach. We explicitly calculate the form of $f(R)$ for which such symmetries exist. It is shown that the existence of a Noether symmetry yields a…

General Relativity and Quantum Cosmology · Physics 2010-04-30 Babak Vakili

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

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

Quantum field theories on noncommutative spacetime have many different properties from those on commutative spacetime. In this paper, we study the microcausality of free scalar field on noncommutative spacetime. We expand the scalar field…

High Energy Physics - Theory · Physics 2007-07-30 Zheng Ze Ma

If one is willing to give up the cherished hypothesis of spatial isotropy, many interesting cosmological models can be developed beyond the simple anisotropically expanding scenarios. One interesting possibility is presented by shear-free…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-22 Thiago S. Pereira , Guillermo A. Mena Marugán , Saulo Carneiro

We consider a noncommutative (NC) inflationary model with a homogeneous scalar field minimally coupled to gravity. The particular NC inflationary setting produces entirely new consequences. We first analyze the free field case and…

General Relativity and Quantum Cosmology · Physics 2018-05-01 S. M. M. Rasouli , N. Saba , M. Farhoudi , J. Marto , P. Moniz

We consider here a spherically symmetric but inhomogeneous universe filled with a massless scalar field. The model obeys two constraints. The first one is that the gradient of the scalar field is timelike everywhere. The second constraint…

General Relativity and Quantum Cosmology · Physics 2011-04-20 Swastik Bhattacharya , Pankaj S. Joshi , Ken-ichi Nakao

We consider the symmetric teleparallel $f\left( Q\right) $-gravity in Friedmann--Lema\^{\i}tre--Robertson--Walker cosmology with nonzero spatial curvature. For a nonlinear $f\left( Q\right) $ model there exist always the limit of General\…

General Relativity and Quantum Cosmology · Physics 2023-10-09 Andronikos Paliathanasis

Quantisation of Lorentz invariant scalar field theory in Doplicher-Fredenhagen-Roberts (DFR) space-time, a Lorentz invariant, non-commutative space-time is studied. Absence of a unique Lagrangian in non-commutative space-time necessitates…

High Energy Physics - Theory · Physics 2022-01-11 E. Harikumar , Vishnu Rajagopal

In this paper we present noncommutative version of scalar field cosmology. We find the noncommutative Friedmann equations as well as the noncommutative Klein-Gordon equation. Interestingly the noncommutative contributions are only present…

General Relativity and Quantum Cosmology · Physics 2011-03-02 W. Guzmán , M. Sabido , J. Socorro

In the framework of teleparallel gravity, the Friedman-Robertson-Walker cosmological model with scalar tensor theory where scalar field is non-minimally coupled to both the torsion scalar and boundary term is studied. Utilizing the Noether…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Ganim Gecim , Yusuf Kucukakca

One possible description for the current accelerated expansion of the universe is quintessence dynamics. The basic idea of quintessence consists of analyzing cosmological scenarios driven by scalar fields. In this work we present some…

General Relativity and Quantum Cosmology · Physics 2014-04-10 P. H. R. S. Moraes , J. R. L. Santos

The possibility that the universe may have a fundamental and positive cosmological constant has motivated an interesting cosmological model, in which initially the universe is in a cosmological constant sea, then the local quantum…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Yun-Song Piao

The purpose of this work is to investigate spatially homogeneous and flat cosmological solutions of the Einstein equations coupled to a non-variational ``near-minimal'' scalar field. This coupling model represents a minimal departure from…

General Relativity and Quantum Cosmology · Physics 2026-05-05 Joshua Ritchie

The space of inflationary models is vast, containing wide varieties of mechanisms, symmetries, and spectra of particles. Consequently, the space of observational signatures is similarly complex. Hence, it is natural to look for boundaries…

High Energy Physics - Theory · Physics 2020-10-29 Daniel Green , Enrico Pajer

This paper explores cosmological scenarios in a scalar-tensor theory of gravity, including both a non-minimal coupling with scalar curvature of the form $R\phi^2$ and a non-minimal derivative coupling of the form…

General Relativity and Quantum Cosmology · Physics 2025-10-13 Ravil R. Fatykhov , Sergey V. Sushkov

We study the cosmological aspects of a noncommutative, multidimensional universe where the matter source is assumed to be a scalar field which does not commute with the internal scale factor. We show that such noncommutativity results in…

General Relativity and Quantum Cosmology · Physics 2010-11-11 N. Khosravi , S. Jalalzadeh , H. R. Sepangi

In the present work, we study the noncommutative version of a quantum cosmology model. The model has a Friedmann-Robertson-Walker geometry, the matter content is a radiative perfect fluid and the spatial sections have zero constant…

General Relativity and Quantum Cosmology · Physics 2016-05-05 G. Oliveira-Neto , M. Silva de Oliveira , G. A. Monerat , E. V. Corrêa Silva

This work presents a comparative analysis of the quasi-normal modes and ringdowns of scalar field perturbations in the non-commutative Schwarzschild black hole spacetime, focusing on two distinct non-minimal curvature couplings: in the…

General Relativity and Quantum Cosmology · Physics 2026-05-29 Majid Karimabadi , Davood Mahdavian Yekta , S. A. Alavi

We apply a very simple procedure to construct non-singular cosmological models for flat Friedmann universes filled with minimally coupled scalar fields or by tachyon Born-Infeld-type fields. Remarkably, for the minimally coupled scalar…

General Relativity and Quantum Cosmology · Physics 2024-03-14 Alexander Kamenshchik , Polina Petriakova