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This paper treats nonrelativistic matter and a scalar field $\phi$ with a monotonically decreasing potential minimally coupled to gravity in flat Friedmann-Lema\^{i}tre-Robertson-Walker cosmology. The field equations are reformulated as a…

General Relativity and Quantum Cosmology · Physics 2015-11-11 Artur Alho , Claes Uggla

In this paper we investigate to which extent noncommutativity, a intrinsically quantum property, may influence the Friedmann-Robertson-Walker cosmological dynamics at late times/large scales. To our purpose it will be enough to explore the…

General Relativity and Quantum Cosmology · Physics 2011-08-10 Octavio Obregon , Israel Quiros

These are expanded lecture notes of a mini-course whose objectives were to introduce the basic concepts, constructions and techniques of noncommutative geometry, as well as their uses as a framework for modelling quantum spacetime. Key…

High Energy Physics - Theory · Physics 2025-12-08 Richard J. Szabo

A model for a noncommutative scalar field coupled to gravity is proposed via an extension of the Moyal product. It is shown that there are solutions compatible with homogeneity and isotropy to first non-trivial order in the perturbation of…

General Relativity and Quantum Cosmology · Physics 2009-11-07 O. Bertolami , L. Guisado

We consider two model field theories on a noncommutative plane that have smooth commutative limits. One is the single-component fermion theory with quartic interaction that vanishes identically in the commutative limit. The other is a…

High Energy Physics - Theory · Physics 2009-10-31 Dongsu Bak , Sung Ku Kim , Kwang-Sup Soh , Jae Hyung Yee

We derive the governing equations for multiple scalar fields minimally coupled to gravity in a flat Friedmann-Robertson-Walker (FRW) background spacetime on large scales. We include scalar perturbations up to second order and write the…

Astrophysics · Physics 2009-11-13 Karim A. Malik

We investigate the cosmological dynamics in a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker geometry in scalar-tensor and scalar-torsion theories where the nonminimally coupled scalar field is a complex field. We derive the…

General Relativity and Quantum Cosmology · Physics 2022-11-23 Andronikos Paliathanasis

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

We study some consequences of noncommutativity to homogeneous cosmologies by introducing a deformation of the commutation relation between the minisuperspace variables. The investigation is carried out for the Kantowski-Sachs model by means…

High Energy Physics - Theory · Physics 2009-11-10 G. D. Barbosa , N. Pinto-Neto

Using the bicomplex approach we discuss a noncommutative system in two--dimensional Euclidean space. It is described by an equation of motion which reduces to the ordinary sine--Gordon equation when the noncommutation parameter is removed,…

High Energy Physics - Theory · Physics 2007-05-23 Marcus T. Grisaru , Silvia Penati

We explore dynamics of cosmological models with a nonminimally coupled scalar field evolving on a spatially flat Friedmann-Lemaitre-Robertson-Walker background. We consider cosmological models including the Hilbert-Einstein curvature term…

General Relativity and Quantum Cosmology · Physics 2014-10-01 Maria A. Skugoreva , Alexey V. Toporensky , Sergey Yu. Vernov

We study the quantum cosmology of an empty (4+1)-dimensional Kaluza-Klein cosmology with a negative cosmological constant and a FRW type metric with two scale factors, one for 4-D universe and the other for one compact extra dimension. By…

General Relativity and Quantum Cosmology · Physics 2008-11-26 F. Darabi , A. Rezaei-Aghdam , A. R. Rastkar

Performing a relativistic approximation as the generalization to a curved spacetime of the flat space Klein-Gordon equation, an effective Hamiltonian which includes non-minimial coupling between gravity and scalar field and also quartic…

General Relativity and Quantum Cosmology · Physics 2009-02-16 Emine Mese , Nurettin Pirinccioglu , Irfan Acikgoz , Figen Binbay

We propose a possible new way to resolve the long standing problem of strong supersymmetry breaking coexisting with a small cosmological constant. We consider a scalar component of a minimally coupled N=1 supermultiplet in a general…

High Energy Physics - Theory · Physics 2010-08-27 Marina Shmakova , Valentin Burov

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

The Klein-Gordon equations were recently solved in general relativity for the case of a plane-symmetric static massless scalar field with cosmological constant. By analytic continuation, time-dependent solutions can be obtained that…

General Relativity and Quantum Cosmology · Physics 2009-04-22 Chris Vuille , Jocelyn Dunn

The present work deals with quantum cosmology for non-minimally coupled scalar field in the background of FLRW space--time model. The Wheeler-DeWitt equation is constructed and symmetry analysis is carried out. The Lie point symmetries are…

General Relativity and Quantum Cosmology · Physics 2019-06-26 Sourav Dutta , Muthusamy Lakshmanan , Subenoy Chakraborty

We consider the noncommutativity parameter of the space-time as a bosonic worldsheet field. By finding a fermionic super-partner for it, we can find star products between the boson-boson, boson-fermion and fermion-fermion fields of…

High Energy Physics - Theory · Physics 2009-11-07 Davoud Kamani

We study the effect of the non-commutativity on the creation of scalar particles from vacuum in the anisotropic universe space-time. We derive the deformed Klein-Gordon equation up to second order in the non-commutativity parameter using…

High Energy Physics - Theory · Physics 2016-09-06 Slimane Zaim

A model for the Universe is proposed whose constituents are: (a) a dark energy field modeled by a fermionic field non-minimally coupled with the gravitational field, (b) a matter field which consists of pressureless baryonic and dark matter…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. O. Ribas , F. P. Devecchi , G. M. Kremer