English
Related papers

Related papers: Sounds of instability from generalized QCD ghost d…

200 papers

We investigate the instability of the ghost dark energy model against perturbations in different cases. To this goal we use the squared sound speed $v_s^2$ whose sign determines the stability of the model. When $v_s^2<0$ the model is…

High Energy Physics - Theory · Physics 2015-03-19 Esmaeil Ebrahimi , Ahmad Sheykhi

A phenomenological generalized ghost dark energy model has been studied under the framework of FRW universe. In ghost dark energy model the energy density depends linearly on Hubble parameter (H) but in this dark energy model, the energy…

General Relativity and Quantum Cosmology · Physics 2019-08-14 Mahasweta Biswas , Ujjal Debnath , Shounak Ghosh , B. K. Guha

This paper focuses on developing a generalized ghost dark energy model $f\mathcal{(Q,T)}$ through the correspondence scheme for a non-interacting scenario involving pressureless matter and a power-law scale factor. We analyze the…

General Relativity and Quantum Cosmology · Physics 2024-09-06 M. Sharif , Iqra Ibrar

We study the stability of the ghost dark energy model versus perturbation. Since this kind of dark energy is instable in Einsteinian general relativity theory, then we study a new type of Brans-Dicke theory which has non-minimal coupling…

General Relativity and Quantum Cosmology · Physics 2012-02-21 Khaled Saaidi

This paper aims to develop non-interacting ghost dark energy and generalized ghost dark energy models within the framework of $f(Q)$ theory using the correspondence scheme. We use pressureless matter and a power-law scale factor. The cosmic…

General Relativity and Quantum Cosmology · Physics 2025-07-04 M. Sharif , Madiha Ajmal

In this paper, we investigate the cosmological consequences of ghost dark energy model in modified Gauss-Bonnet gravity. We construct ghost dark energy $f(G)$ model by using correspondence scenario for both interacting and non-interacting…

General Relativity and Quantum Cosmology · Physics 2019-08-21 M. Sharif , Saadia Saba

In this manuscript, we use the correspondence principle to construct the generalized ghost dark energy $f(Q)$ model, where $Q$ is the non-metricity. For this purpose, we use the Friedman-Robertson-Walker universe model with power-law scale…

General Relativity and Quantum Cosmology · Physics 2024-03-05 M. Sharif , Madiha Ajmal

We explore the whole phase space of the so called Veneziano/QCD ghost dark energy models where the dynamics of the inner trapping horizon is ignored and also the more realistic models where the time-dependence of the horizon is taken into…

General Relativity and Quantum Cosmology · Physics 2013-08-30 Ricardo Garcia-Salcedo , Tame Gonzalez , Israel Quiros , Michael Thompson-Montero

We study a phenomenological dark energy model which is rooted in the Veneziano ghost of QCD. In this dark energy model, the energy density of dark energy is proportional to Hubble parameter and the proportional coefficient is of the order…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Rong-Gen Cai , Qiping Su , Zhong-Liang Tuo , Hong-Bo Zhang

We study generic single-field dark energy models, by a parametrization of the most general theory of their perturbations around a given background, including higher derivative terms. In appropriate limits this approach reproduces standard…

Astrophysics · Physics 2009-02-17 Paolo Creminelli , Guido D'Amico , Jorge Noreña , Filippo Vernizzi

The new agegraphic Dark Energy (NADE) model (based on generalized uncertainty principle) interacting with Dark Matter (DM) is considered in this study via power-law form of the scale factor $a(t)$. The equation of state (EoS) parameter…

General Physics · Physics 2013-11-14 Antonio Pasqua , Surajit Chattopadhyay , Iuliia Khomenko

This paper explores the generalized ghost dark energy model in the framework of $f(\textsl{Q}, \textsl{L}_{m})$ gravity, where $\textsl{Q}$ represents the non-metricity scalar and $\textsl{L}_{m}$ denotes the matter-Lagrangian density. We…

General Relativity and Quantum Cosmology · Physics 2025-01-03 M. Zeeshan Gul , M. Sharif , Shan Ali Qureshi , Baiju Dayanandan

We investigate the agegraphic dark energy models which were recently proposed to explain the dark energy-dominated universe. For this purpose, we calculate their equation of states and squared speeds of sound. We find that the squared speed…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Kyoung Yee Kim , Hyung Won Lee , Yun Soo Myung

We investigate the ghost model of dark energy in the framework of DGP braneworld. We explore the cosmological consequences of this model by determining the equation of state parameter, $\omega_D$, the deceleration and the density…

General Relativity and Quantum Cosmology · Physics 2018-10-31 M. Abdollahi Zadeh , A. Sheykhi

We study a correspondence between $f(R)$ model of gravity and a phenomenological kind of dark energy (DE), which is known as QCD ghost dark energy. Since this kind of dark energy is not stable in the context of Einsteinian theory of gravity…

General Physics · Physics 2014-01-21 Kh. Saaidi , Ali. Aghamohammadi , B. Sabet , O. Farooq

The present work reports a reconstruction scheme for f(T) gravity based on QCD ghost dark energy. Two models of f(T) have been generated and the pressure and density contributions due to torsion have been reconstructed. Two realistic models…

General Relativity and Quantum Cosmology · Physics 2014-05-14 Surajit Chattopadhyay

We have studied constraints on the equation of state, $w$, and speed of sound, c_s, of the dark energy from a joint analysis of data from the cosmic microwave background, large scale structure and type-Ia supernovae. We find that current…

Astrophysics · Physics 2009-11-10 Steen Hannestad

We investigate a generalized power-law dark energy equation of state of the form $p = w\rho - \beta\rho^m$ in a flat FLRW universe, analyzing its dynamical stability and thermodynamic consistency. The model exhibits a rich phase space…

General Relativity and Quantum Cosmology · Physics 2025-07-08 S. Kazemi , M. A. Ramzanpour , E. Yusofi , A. R. Amani

We investigate the generalized Quantum Chromodynamics (QCD) ghost model of dark energy in the framework of Einstein gravity. First, we study the non-interacting generalized ghost dark energy in a flat Friedmann-Robertson-Walker (FRW)…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Esmaeil Ebrahimi , Ahmad Sheykhi , Hamzeh Alavirad

This paper studies the reconstruction criterion in the framework of $f(Q,T)$ gravity using ghost dark energy model, where $Q$ represents the non-metricity and $T$ is the trace of energy-momentum tensor. In this regard, the correspondence…

General Relativity and Quantum Cosmology · Physics 2024-05-09 M. Sharif , Iqra Ibrar
‹ Prev 1 2 3 10 Next ›