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相关论文: Noncommutativity, Saez-Ballester theory and kineti…

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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…

广义相对论与量子宇宙学 · 物理学 2024-08-19 S. M. M. Rasouli , João Marto

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…

广义相对论与量子宇宙学 · 物理学 2018-05-01 S. M. M. Rasouli , N. Saba , M. Farhoudi , J. Marto , P. Moniz

In this paper, we introduce a noncommutative version of the Brans-Dicke (BD) theory and obtain the Hamiltonian equations of motion for a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker universe filled with a perfect fluid. We…

广义相对论与量子宇宙学 · 物理学 2014-11-06 S. M. M. Rasouli , Paulo Vargas Moniz

Non-commutative geometry indicates a deformation of the energy-momentum dispersion relation $f(E)\equiv\frac{E}{pc}(\neq 1)$ for massless particles. This distorted energy-momentum relation can affect the radiation dominated phase of the…

宇宙学与河外天体物理 · 物理学 2012-02-27 U. D. Machado , R. Opher

In this paper, we study a constant-roll inflationary model in the presence of a noncommutative parameter with a homogeneous scalar field minimally coupled to gravity. The specific noncommutative inflation conditions proposed new…

高能物理 - 理论 · 物理学 2023-02-14 J. Sadeghi , S. Noori Gashti

By assuming the spatially flat~FLRW line-element and employing the Hamiltonian formalism, a noncommutative (NC) setting of the Brans-Dicke (BD) theory is introduced. We investigate gravity-driven acceleration and kinetic inflation in this…

广义相对论与量子宇宙学 · 物理学 2017-01-18 S. M. M. Rasouli , Paulo Vargas Moniz

In our previous work we have constructed a model of noncommutative (NC) gravity based on $SO(2,3)_\star$ gauge symmetry. In this paper we extend the model by adding matter fields: fermions and a $U(1)$ gauge field. Using the enveloping…

高能物理 - 理论 · 物理学 2018-08-01 Marija Dimitrijević Ćirić , Dragoljub Gočanin , Nikola Konjik , Voja Radovanović

In this paper, by establishing a Brans-Dicke (BD) cosmology by means of a deformed phase space, in the absence of any scalar potential, cosmological constant and ordinary matter, we show that it is feasible to overcome obstacles reported in…

广义相对论与量子宇宙学 · 物理学 2019-02-13 S. M. M. Rasouli , J. Marto , P. V. Moniz

In the present paper we have developed a Non-Commutative (NC) generalization of perfect fluid model from first principles, in a Hamiltonian framework. The noncommutativity is introduced at the Lagrangian (particle) coordinate space brackets…

高能物理 - 理论 · 物理学 2017-01-20 Praloy Das , Subir Ghosh

The interaction between two initially causally disconnected regions of the universe is studied using analogies of non-commutative quantum mechanics and deformation of Poisson manifolds. These causally disconnect regions are governed by two…

广义相对论与量子宇宙学 · 物理学 2017-10-18 J. Gamboa , P. Gondolo , H. Falomir , F. Méndez

As is well known, the non-Gaussianity parameter $f_{_{\rm NL}}$, which is often used to characterize the amplitude of the scalar bi-spectrum, can be expressed completely in terms of the scalar spectral index $n_{\rm s}$ in the squeezed…

宇宙学与河外天体物理 · 物理学 2015-06-23 V. Sreenath , Dhiraj Kumar Hazra , L. Sriramkumar

We study noncommutative classical Friedmann-Robertson-Walker cosmological models. The constant curvature of the spatial sections can be positive ($k=1$), negative ($k=-1$) or zero ($k=0$). The matter is represented by a perfect fluid with…

广义相对论与量子宇宙学 · 物理学 2017-01-06 G. Oliveira-Neto , A. R. Vaz

In this work, we study constant-roll inflation driven by a scalar field with non-minimal derivative coupling to gravity, via the Einstein tensor. This model contains a free parameter, $\eta$, which quantifies the non-minimal derivative…

广义相对论与量子宇宙学 · 物理学 2019-10-23 A. Oliveros , Hernán E. Noriega

In this Letter we construct the noncommutative (NC) gravity model on the $\theta$-constant NC space-time. We start from the NC $SO(2,3)_\star$ gauge theory and use the enveloping algebra approach and the Seiberg-Witten map to construct the…

高能物理 - 理论 · 物理学 2017-08-02 Marija Dimitrijevic Ciric , Biljana Nikolic , Voja Radovanovic

Inflation due to a non-minimally coupled scalar field with a large non-minimal coupling, as first proposed by Salopek, Bardeen and Bond (SBB), is in good agreement with the observed value of the spectral index and constraints on the…

宇宙学与河外天体物理 · 物理学 2016-08-17 John McDonald

We study a classical, noncommutative (NC), Friedmann-Robertson-Walker cosmological model. The spatial sections may have positive, negative or zero constant curvatures. The matter content is a generic perfect fluid. The initial…

广义相对论与量子宇宙学 · 物理学 2016-02-12 G. A. Monerat , E. V. Corrêa Silva , C. Neves , G. Oliveira-Neto , L. G. Rezende Rodrigues , M. Silva de Oliveira

Noncommutative inflation is based upon the consideration of some effects of the space-time uncertainty principle motivated by ideas from string/M theory. The CMB anisotropies may carry a signature of this very early Universe correction from…

天体物理学 · 物理学 2009-11-11 Xin Zhang , Feng-Quan Wu

In this work, we will analyze a noncommutative (NC) version of the Friedmann-Robert-Walker cosmological models within the gravitational Ho\v{r}ava-Lifshitz theory. The matter content of the models is described by a perfect fluid and the…

广义相对论与量子宇宙学 · 物理学 2019-08-14 E. M. C. Abreu , A. C. R. Mendes , G. Oliveira-Neto , J. Ananias Neto , L. G. Rezende Rodrigues , M. Silva de Oliveira

The Bopp's shifts will be generalized through symplectic formalism. A special procedure, like a "diagonalization", which drives the completely deformed symplectic matrix to the standard symplectic form was found as suggested by…

高能物理 - 理论 · 物理学 2018-01-31 M. A. De Andrade , C. Neves

We argue that the non-detection of primordial tensor modes has taught us a great deal about the primordial universe. In single-field slow-roll inflation, the current upper bound on the tensor-to-scalar ratio, $r < 0.07$ $(95 \% ~CL)$,…

高能物理 - 理论 · 物理学 2017-06-21 Enrico Pajer , Guilherme L. Pimentel , Jaap V. S. Van Wijck
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