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Related papers: Generalized ghost dark energy in Brans-Dicke theor…

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In this paper we revisit the dynamical dark energy model building based on single scalar field involving higher derivative terms. By imposing a degenerate condition on the higher derivatives in curved spacetime, one can select the models…

High Energy Physics - Theory · Physics 2015-06-03 Mingzhe Li , Taotao Qiu , Yifu Cai , Xinmin Zhang

Generalized second law of thermodynamics in the Bianchi type I universe with the generalized holographic Ricci dark energy model is studied in this paper. The behavior of dark energy's equation of state parameter indicates that it is…

General Relativity and Quantum Cosmology · Physics 2016-02-02 En-Kun Li , Yu Zhang , Jin-Ling Geng , Peng-Fei Duan

We investigate a generalized form of the phenomenologically emergent dark energy model, known as generalized emergent dark energy (GEDE), introduced by Li and Shafieloo [Astrophys. J. {\bf 902}, 58 (2020)] in light of a series of…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-15 Weiqiang Yang , Eleonora Di Valentino , Supriya Pan , Arman Shafieloo , Xiaolei Li

An interacting dark energy model with interaction term $Q= \lambda_m H\rho_m+\lambda_dH\rho_d$ is considered. By studying the model near the transition time, in which the system crosses the w=-1 phantom-divide-line, the conditions needed to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 H. Mohseni Sadjadi , M. Alimohammadi

We investigate about the stability of generalized QCD ghost dark energy model against perturbations in the FRW background. For this purpose, we use the squared sound speed $v_s^2$ whose sign determines the stability of the model. We explore…

General Physics · Physics 2015-06-12 Esmaeil Ebrahimi , Ahmad Sheykhi

In trying to explain the present accelerated expansion of the universe in the light of a five-dimensional Brans-Dicke theory, it is found that the fifth dimension itself here acts as a source of dark energy. It may be taken as a…

General Physics · Physics 2019-01-30 Koijam Manihar Singh , Kangujam Priyokumar Singh

The role that the auxiliary scalar field $\phi$ played in Brans-Dicke cosmology is discussed. If a constant vacuum energy is assumed to be the origin of dark energy, then the corresponding density parameter would be a quantity varying with…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Chi-Yi Chen , Kang Li , You-Gen Shen

We investigate several phenomenological dark energy parameterizations using a joint analysis of late-time cosmological observations, including cosmic-chromatometer measurements of the Hubble parameter, DESI DR2 baryon acoustic oscillation…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 Chanchal Kumari , Dinesh Kumar

In this Letter it is shown that when the holographic dark energy is combined with the Brans-Dicke field equations the transition from decelerated to accelerated expansion of the Universe can be more easily accounted for than when resort to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Narayan Banerjee , Diego Pavon

We investigate the cosmological implications of a generalized total equation of state (EoS) model by constraining its parameters using observational datasets to effectively characterize the universe's expansion history and its dynamic…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-14 M. Koussour , S. Bekov , A. Syzdykova , S. Muminov , I. Ibragimov , J. Rayimbaev

In this paper, we study some relevant cosmological features of a Dark Energy (DE) model with Granda-Oliveiros cut-off, which is just a specific case of Nojiri-Odintsov holographic DE unifying phantom inflation with late-time acceleration,…

General Relativity and Quantum Cosmology · Physics 2019-01-23 Antonio Pasqua , Surajit Chattopadhyay , Aroonkumar Beesham

In the framework of Brans-Dicke cosmology, we have studied the interacting power-law and logarithmic entropy-corrected holographic dark energy models with different cut-offs. The Brans-Dicke parameter is investigated versus the conditions…

General Relativity and Quantum Cosmology · Physics 2017-06-06 F. Darabi , F. Felegary

Cosmological models with variable and modified equations of state for dark energy are confronted with observational data, including Type Ia supernovae, Hubble parameter data $H(z)$ from different sources, and observational manifestations of…

General Relativity and Quantum Cosmology · Physics 2022-03-29 German S. Sharov , Vasily E. Myachin

Recently a lot of attention has been given to building dark energy models in which the equation-of-state parameter $w$ can cross the phantom divide $w=-1$. However, to our knowledge, these models with crossing the phantom divide only…

Astrophysics · Physics 2008-11-26 Hao Wei , Rong-Gen Cai

We explore the equation of state (EoS) for dark energy $w_{\mathrm{DE}}$ in modified gravitational theories to explain the current accelerated expansion of the universe. We explicitly demonstrate that the future crossings of the phantom…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Kazuharu Bamba

Cosmological magnetic fields are being observed with ever increasing correlation lengths, possibly reaching the size of superclusters, therefore disfavouring the conventional picture of generation through primordial seeds later amplified by…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-23 Federico R. Urban , Ariel R. Zhitnitsky

With a parametric form of the equation of state parameter of dark energy, a quintessence potential has been reconstructed. The potential is found to be a generalization of a double exponential potential. The constraints on the parameters…

General Relativity and Quantum Cosmology · Physics 2016-01-20 Ankan Mukherjee , Narayan Banerjee

We formulate an extended holographic dark energy scenario based on a recently proposed two-parameter generalized entropic functional. Unlike constructions that phenomenologically impose modified entropy-area relations at the horizon level,…

General Relativity and Quantum Cosmology · Physics 2026-03-12 G. G. Luciano , E. N. Saridakis

We construct a generalized interacting model of Barrow Holographic Dark Energy (BHDE) with infrared cutoff being given by the Hubble horizon. We analyze the cosmological evolution of a flat Friedmann-Lema\^itre-Robertson-Walker Universe…

General Relativity and Quantum Cosmology · Physics 2025-03-25 Giuseppe Gaetano Luciano , Jaume Giné

We discuss the exact solutions of brane universes and the results indicate the Friedmann equations on the branes are modified with a new density term. Then, we assume the new term as the density of dark energy. Using Wetterich's…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yongli Ping , Lixin Xu , Chengwu Zhang , Hongya Liu