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相关论文: K-essence scalar field as dynamical dark energy

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We study a class of extended quintessence cosmologies where the scalar field playing the role of the dark energy is exponentially coupled to the Ricci scalar. We find that the dynamics induced by the effective gravitational potential in the…

天体物理学 · 物理学 2014-10-13 Valeria Pettorino , Carlo Baccigalupi , Gianpiero Mangano

A broad class of dark energy models can be written in the form of k-essence, whose Lagrangian density is a two-variable function of a scalar field $\phi$ and its kinetic energy $X\equiv \frac{1}{2}\partial^\mu\phi \partial_\mu\phi$. In the…

宇宙学与河外天体物理 · 物理学 2022-09-14 Zhiqi Huang

We present here some recent results concerning scalar-tensor Dark Energy models. These models are very interesting in many respects: they allow for a consistent phantom phase, the growth of matter perturbations is modified. Using a…

天体物理学 · 物理学 2016-11-15 R. Gannouji , D. Polarski , A. Ranquet , A. A. Starobinsky

The Effective Field Theory of Dark Energy (EFTofDE) provides a systematic and model-independent framework to study dark energy (DE) and modified gravity (MG) with one additional scalar degree of freedom. It can describe the known models…

宇宙学与河外天体物理 · 物理学 2025-09-18 Chi Zheng , Wei Liu , Zonghao Zhan , Wenjuan Fang

An axion-like field comprising $\sim 10\%$ of the energy density of the universe near matter-radiation equality is a candidate to resolve the Hubble tension; this is the "early dark energy" (EDE) model. However, as shown in Hill et al.…

宇宙学与河外天体物理 · 物理学 2020-11-04 Mikhail M. Ivanov , Evan McDonough , J. Colin Hill , Marko Simonović , Michael W. Toomey , Stephon Alexander , Matias Zaldarriaga

We study the primordial nucleosynthesis (BBN) in the stepwise scalar field model proposed by Ti\'an [arXiv:1912.13208, Phys. Rev. D 101, 063531 (2020)], which provides a multiaccelerating Universe solution to the cosmological coincidence…

广义相对论与量子宇宙学 · 物理学 2023-02-27 S. X. Tian

Within the framework of FRW cosmology, we study the QCD modified ghost scalar field models of dark energy in the presence of both interaction and viscosity. For a spatially non-flat FRW universe containing modified ghost dark energy (MGDE)…

综合物理 · 物理学 2013-04-30 K. Karami , S. Asadzadeh , M. Mousivand , Z. Safari

Important observables to reveal the nature of dark energy are the equation of state $w$ and its time derivative in units of the Hubble time $w'$. Recently, it is shown that the simplest scalar field models of dark energy (quintessence)…

天体物理学 · 物理学 2014-10-13 Takeshi Chiba

We have considered N-dimensional Einstein field equations in which four-dimensional space-time is described by a FRW metric and that of extra dimensions by an Euclidean metric. We have chosen the exponential forms of scale factors a and d…

综合物理 · 物理学 2015-05-30 Chayan Ranjit , Shuvendu Chakraborty , Ujjal Debnath

In this paper we consider that dark energy could be described solely by a complex scalar field with a Bose-Einstein condensate-like potential (denoted as CSFDE), that is, with a self-interaction and a mass term. In particular, we analyse a…

广义相对论与量子宇宙学 · 物理学 2021-03-17 Belen Carvente , Víctor Jaramillo , Celia Escamilla-Rivera , Darío Núñez

We have developed an accelerating cosmological model for the present universe which is phantom for the period $ (0 \leq z \leq 1.99)$ and quintessence phase for $(1.99 \leq z \leq 2.0315)$. The universe is assumed to be filled with…

广义相对论与量子宇宙学 · 物理学 2021-08-02 G. K. Goswami , Anirudh Pradhan , A. Beesham

We consider scalar dark matter models where the theory has a shift symmetry only broken by the scalar mass term. We restrict ourselves to K-essence kinetic terms where the shift symmetric part of the Lagrangian is a function of the first…

宇宙学与河外天体物理 · 物理学 2020-03-11 Philippe Brax , Jose A. R. Cembranos , Patrick Valageas

The presented paper is a comprehensive analysis of two dark energy (DE) cosmological models wherein exact solutions of the Einstein field equations (EFEs) are obtained in a model-independent way (or by cosmological parametrization). A…

综合物理 · 物理学 2022-07-20 S. K. J. Pacif

We previously showed that we can use di quark pairs as a model of how nucleation of a new universe occurs. We now can construct a model showing evolution from a dark matter dark energy mix to a pure cosmological constant cosmology due to…

广义相对论与量子宇宙学 · 物理学 2007-05-23 A. W. Beckwith

Early dark energy (EDE) is an extension to the $\Lambda$CDM model, proposed to reduce the tension between the measurements of the Hubble constant $H_0$ from the cosmic microwave background (CMB) and from the local cosmic distance ladder.…

The present work is a second in the series of investigation of the background dynamics in brane cosmology when dark energy is coupled to dark matter by a suitable interaction. Here, dark matter is chosen in the form of perfect fluid with…

综合物理 · 物理学 2019-06-21 Sujay Kr. Biswas , Subenoy Chakraborty

By using the effective field theory approach, we investigate the role of initial condition for the dark energy or modified gravity models. In details, we consider the constant and linear parametrization of the effective Newton constant…

宇宙学与河外天体物理 · 物理学 2018-01-10 Xue-Wen Liu , Bin Hu , Yi Zhang

Motivated by the work of Granda and Oliveros [L.N. Granda, A. Oliveros, Phys. Lett. B {\bf 671}, 199 (2009)], we generalize their work to the non-flat case. We study the correspondence between the quintessence, tachyon, K-essence and…

广义相对论与量子宇宙学 · 物理学 2010-04-30 K. Karami , J. Fehri

We consider a connection between the holographic dark energy density and the kinetic k-essence energy density in a flat FRW universe. With the choice $c\geq1$, the holographic dark energy can be described by a kinetic k-essence scalar field…

广义相对论与量子宇宙学 · 物理学 2009-09-28 Norman Cruz , Pedro F. Gonzalez-Diaz , Alberto Rozas-Fernandez , Guillermo Sanchez

We propose a new Dark Energy parametrization based on the dynamics of a scalar field. We use an equation of state $w=(x-1)/(x+1)$, with $x=E_k/V$, the ratio of kinetic energy $E_k=\dot\phi^2/2$ and potential $V$. The eq. of motion gives…

宇宙学与河外天体物理 · 物理学 2011-12-09 Axel de la Macorra