English
Related papers

Related papers: Non commutative classical and Quantum fractionary …

200 papers

In an open Friedmann-Robertson-Walker (FRW) space background, we study the classical and quantum cosmological models in the framework of the recently proposed nonlinear massive gravity theory. Although the constraints which are present in…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Babak Vakili , Nima Khosravi

We study the effects of an information-theoretically motivated nonlinear correction to the Wheeler-deWitt equation in the minisuperspace scheme for flat, $k=0$, Friedmann-Robertson-Walker (FRW) universes. When the only matter is a…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Le-Huy Nguyen , Rajesh R. Parwani

We investigate the evolution of a spatially flat Friedmann-Robertson-Walker (FRW) universe in the framework of scalar non-metricity theory of gravity. In the model, we consider dark matter (DM) and dark energy (DE) described by the scalar…

General Relativity and Quantum Cosmology · Physics 2025-08-05 Bikash Chandra Roy , Bikash Chandra Paul

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 positive constant…

General Relativity and Quantum Cosmology · Physics 2016-05-05 G. Oliveira-Neto , G. A. Monerat , E. V. Corrêa Silva , C. Neves , L. G. Ferreira Filho

One presents a phase-space noncommutative extension of Quantum Cosmology in the context of a Kantowski-Sachs (KS) minisuperspace model. We obtain the Wheeler-DeWitt (WDW) equation for the noncommutative system through the ADM formalism and…

High Energy Physics - Theory · Physics 2009-07-24 C. Bastos , O. Bertolami , N. Dias , J. Prata

It is well known that the canonical quantization of the Friedmann-Lema\^itre-Robertson-Walker (FLRW) filled with a perfect fluid leads to nonsingular universes which, for later times, behave as their classical counterpart. This means that…

General Relativity and Quantum Cosmology · Physics 2013-05-09 J. P. M. Pitelli , P. S. Letelier

In this work we construct a noncommutative version of the Friedmann equations in the framework of effective loop quantum cosmology, extending and applying the ideas presented in a previous proposal by some of the authors. The model under…

General Relativity and Quantum Cosmology · Physics 2019-11-05 Luis Rey Díaz-Barrón , Abraham Espinoza-García , S. Pérez-Payán , J. Socorro

We consider the effects of noncommutativity and the generalized uncertainty principle on the FRW cosmology with a scalar field. We show that, the cosmological constant problem and removability of initial curvature singularity find natural…

General Relativity and Quantum Cosmology · Physics 2008-11-26 A. Bina , K. Atazadeh , S. Jalalzadeh

We study the classical and quantum models of a flat Friedmann-Robertson-Walker (FRW) space-time, coupled to a perfect fluid, in the context of the consensus and a gauge-fixed Lagrangian frameworks. It is shown that, either in the usual or…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Babak Vakili

In this work, a flat Friedmann-Robertson-Walker (FRW) universe with dust and a cosmological constant is quantized. By means of a canonical transformation, the classical Hamiltonian is reduced to that of either a harmonic oscillator or…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Edésio M. Barboza , Nivaldo A. Lemos

Considering an arbitrary dimensional FLRW universe in the framework of a generalized S\'{a}ez--Ballester (SB) theory, we establish a noncommutative (NC) cosmological model. We concentrate on the predictions of NC model and compare them with…

General Relativity and Quantum Cosmology · Physics 2024-08-19 S. M. M. Rasouli , João Marto

It is well known that classical Unimodular Gravity (UG) is equivalent to General Relativity, but is not clear the equivalence at the quantum level. Here we exhibit, in the UG framework, the Quantum Cosmology (QC) for a…

General Relativity and Quantum Cosmology · Physics 2022-08-31 J. A. Astorga-Moreno , Miguel A. García-Aspeitia , E. A. Mena-Barboza

We study the classical and quantum models of a scalar field Friedmann-Robertson-Walker (FRW) cosmology with an eye to the issue of time problem in quantum cosmology. We introduce a canonical transformation on the scalar field sector of the…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Babak Vakili

We study the classical and quantum models of a Friedmann-Robertson-Walker (FRW) cosmology, coupled to a perfect fluid, in the context of the scalar-metric gravity. Using the Schutz' representation for the perfect fluid, we show that, under…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Babak Vakili

In this work, first, we study a flat Friedmann-Robertson-Walker Universe with two scalar fields but only one potential term, which can be thought as a simple quintessence plus a K-essence model. Employing the Hamiltonian formalism we are…

General Relativity and Quantum Cosmology · Physics 2021-07-07 J. Socorro , S. Pérez-Payán , Rafael Hernández , Abraham Espinoza-García , Luis Rey Díaz-Barrón

In this paper we consider a spatially flat Friedmann-Robertson-Walker (FRW) cosmological model whit cosmological constant, containing a stiff fluid and a classical Dirac field. The proposed cosmological scenario describes the evolution of…

Astrophysics · Physics 2007-10-24 Mauricio Cataldo , Luis P. Chimento

The consequence of energy conservation in the flat Friedmannn-Robertson-Walker (FRW) cosmology is a strictly positive accelerating expansion. A mechanism is proposed for this expansion due to the effect of the attractive (negative)…

General Relativity and Quantum Cosmology · Physics 2009-01-09 Steven Maxson

In this paper we consider a spatially flat Friedmann-Robertson-Walker (FRW) cosmological model with cosmological constant, containing a stiff fluid and a classical Dirac field. The proposed cosmological scenario describes the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Mauricio Cataldo , Luis Chimento

We present a parallel between commutative and non-commutative polymorphisms. Our emphasis is the applications to conditional distributions from stochastic processes. In the classical case, both the measures and the positive definite kernels…

Quantum Physics · Physics 2025-01-22 Palle E. T. Jorgensen , James Tian

We discuss cosmological effects of the quantum loops of massless particles, which lead to temporal non-localities in the equations of motion governing the scale factor a(t). For the effects discussed here, loops cause the evolution of a(t)…

General Relativity and Quantum Cosmology · Physics 2014-06-11 John F. Donoghue , Basem Kamal El-Menoufi