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相关论文: Anisotropic massive Brans-Dicke gravity extension …

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By interacting ghost dark energy (ghost DE) in the framework of Brans-Dicke theory, a spatially homogeneous and anisotropic Bianchi type I Universe has been studied. For this purpose, we use the squared sound speed $c_s^2$ whose sign…

广义相对论与量子宇宙学 · 物理学 2017-02-24 Hossien Hossienkhani , Vahid Fayaz

We explore locally rotationally symmetric Bianchi I universe in Brans-Dicke gravity with self-interacting potential by using charged viscous cosmological string fluid. We use a relationship between the shear and expansion scalars and also…

广义相对论与量子宇宙学 · 物理学 2015-06-05 M. Sharif , Saira Waheed

The observed accelerated expansion of the Universe may be explained by dark energy or the breakdown of general relativity (GR) on cosmological scales. When the latter case, a modified gravity scenario, is considered, it is often assumed…

宇宙学与河外天体物理 · 物理学 2020-08-04 Jiro Matsumoto , Teppei Okumura , Misao Sasaki

In this paper, we derive observational constraints on an anisotropic $w$CDM model from observational data including Baryonic Acoustic Oscillations (BAOs), Cosmic Chronometer (CC), Big Bang Nucleosynthesis (BBN), Pantheon Plus (PP)…

宇宙学与河外天体物理 · 物理学 2024-09-17 Vikrant Yadav , Santosh Kumar Yadav , Rajpal

We examine the constraints that can be obtained on standard cold dark matter models from the most currently used data set: CMB anisotropies, type Ia supernovae and the SDSS luminous red galaxies. We also examine how these constraints are…

天体物理学 · 物理学 2015-05-13 L. D. Ferramacho , A. Blanchard , Y. Zolnierowski

Anisotropic dark energy cosmological models are constructed in the frame work of generalised Brans-Dicke theory with a self interacting potential. Wet dark fluid characterized by a linear equation of state is considered as the source of…

综合物理 · 物理学 2017-05-10 Sunil K. Tripathy , Dipanjali Behera , Bivudutta Mishra

We discuss various aspects of anisotropic gravity in $(d+D)$-dimensional spacetime where $D$ dimensions are treated as extra dimensions. It is based on the foliation preserving diffeomorphism invariance and anisotropic conformal invariance.…

高能物理 - 理论 · 物理学 2022-01-05 Jae-Hyuk Oh , Phillial Oh

We present constraints on extensions to the flat $\Lambda$CDM cosmological model by varying the spatial curvature $\Omega_K$, the sum of the neutrino masses $\sum m_\nu$, the dark energy equation of state parameter $w$, and the Hu-Sawicki…

We study a smooth cosmological solution within a generalized 5D standing wave braneworld modeled by gravity and a phantom scalar field. In this model the 3-brane is anisotropically warped along its spatial dimensions and contains a novel…

Two dimensional (2D) analogue of vacuum sector of the Brans Dicke (BD) gravity [1] is studied to obtain dynamics of anisotropic spherically symmetric perfect fluid. Our obtained static solutions behave as dark matter with state equation…

广义相对论与量子宇宙学 · 物理学 2017-06-29 Hossein Ghaffarnejad

We study asymptotically AdS Brans-Dicke (BD) backgrounds, where the Ricci tensor R is coupled to a scalar in the radial dimension, as effective models of metals with a varying coupling constant. We show that, for translational invariant…

高能物理 - 理论 · 物理学 2017-01-10 Antonio M. García-García , Bruno Loureiro , Aurelio Romero-Bermúdez

Measurements of the cosmic microwave background (CMB) spectral distortions (SDs) will open a new window on the very early universe, providing new information complementary to that gathered from CMB temperature and polarization anisotropies.…

宇宙学与河外天体物理 · 物理学 2022-01-12 Hao Fu , Matteo Lucca , Silvia Galli , Elia S. Battistelli , Deanna C. Hooper , Julien Lesgourgues , Nils Schöneberg

We study the homogeneous but anisotropic cosmological models of Bianchi in presence of a massive scalar field using the ADM Hamiltonian formalism. We begin to describe the main steps to find the ADM Hamiltonian of the General Relativity…

广义相对论与量子宇宙学 · 物理学 2014-04-15 Stephane Fay

The dynamics of the Brans-Dicke theory with a scalar field potential function is investigated. We show that the system with a barotropic matter content can be reduced to an autonomous three-dimensional dynamical system. For an arbitrary…

广义相对论与量子宇宙学 · 物理学 2013-09-11 Orest Hrycyna , Marek Szydlowski

We analyse the clustering of cosmic large scale structure using a consistent modified gravity perturbation theory, accounting for anisotropic effects along and transverse to the line of sight. The growth factor has a particular scale…

We use the joint measurement of geometry and growth from anisotropic galaxy clustering in the Baryon Oscillation Spectroscopic Survey Data Release 9 CMASS sample reported by Reid et al. to constrain dark energy properties and possible…

Anisotropic Bianchi-III cosmological model is investigated with variable gravitational and cosmological constants in the framework of Einstein's general relativity. The shear scalar is considered to be proportional to the expansion scalar.…

广义相对论与量子宇宙学 · 物理学 2015-06-23 S. K. Tripathy , D. Behera , T. R. Routray

Any Dark Energy (DE) or Modified Gravity (MG) model that deviates from a cosmological constant requires a consistent treatment of its perturbations, which can be described in terms of an effective entropy perturbation and an anisotropic…

宇宙学与河外天体物理 · 物理学 2015-02-26 Bjoern Soergel , Tommaso Giannantonio , Jochen Weller , Richard A. Battye

In the covariant cosmological perturbation theory, a 1+3 decomposition ensures that all variables in the frame-independent equations are covariant, gauge-invariant and have clear physical interpretations. We develop this formalism in the…

宇宙学与河外天体物理 · 物理学 2014-11-18 Fengquan Wu , Li-e Qiang , Xin Wang , Xuelei Chen

The Brans-Dicke model with a variable cosmological term ($BD\Lambda$) has been investigated with use of the coupling constant of $\omega=10^4$. Parameters inherent in this model are constrained from comparison between Big Bang…

宇宙学与河外天体物理 · 物理学 2015-05-19 E. P. B. A. Thushari , R. Nakamura , M. Hashimoto , K. Arai