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Related papers: Holographic dark energy with time varying $c^2$ pa…

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We study a generalized holographic dark energy model in which the infrared cutoff depends on the Hubble parameter and its first two time derivatives. The inclusion of the $\ddot H$ term introduces a finite relaxation timescale for the…

General Relativity and Quantum Cosmology · Physics 2026-01-13 Swapnil Kumar Singh

In this article, we investigate a new parametrization of the dark energy equation of state (EoS) with a single parameter for a barotropic fluid that deviates from the standard $\Lambda$CDM cosmology. We derive observational constraints on…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-31 D. Revanth Kumar , Santosh Kumar Yadav

In this paper, the holographic dark energy in Brans-Dicke theory is confronted by cosmic observations from SN Ia, BAO and CMB shift parameter. The best fit parameters are found in $1\sigma$ region: $\Omega_{h0}=0.683^{+0.035}_{-0.038}$,…

Cosmology and Nongalactic Astrophysics · Physics 2009-05-27 Lixin Xu , Jianbo Lu , Wenbo Li

We scrutinized the Locally Rotational Symmetry (LRS) Bianchi type-I cosmological model in the presence of fractional holographic dark energy. We calculate the value of the Hubble parameter $H(z)$ using the field equations. After that, we…

General Relativity and Quantum Cosmology · Physics 2025-06-23 Shivangi Rathore , Elangbam Chingkheinganba Meetei , S. Surendra Singh

In this paper, we have studied a model of holographic dark energy (HDE) with a homogeneous and anisotropic Bianchi type-I Universe in the framework of Gauss-Bonnet (GB) gravity or $f(G)$ gravity. To find an exact solution of the field…

General Relativity and Quantum Cosmology · Physics 2022-04-13 M. Koussour , H. Filali , S. H. Shekh , M. Bennai

Under the commonly used assumption that clumped objects can be well described by a spherical top-hat matter density profile, we investigate the evolution of the cosmic growth index in clustering dark energy (CDE) scenarios on sub-horizon…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-06 Ahmad Mehrabi , Mohammad Malekjani , Francesco Pace

We investigated evolution of metric and density perturbations for Tsallis model of holographic dark energy with energy density $\sim L^{2\gamma - 4}$, where $L$ is length of event horizon or inverse Hubble parameter and $\gamma$ is…

General Relativity and Quantum Cosmology · Physics 2025-08-25 Artyom V. Astashenok , Alexander S. Tepliakov

Thermodynamics-Gravity conjecture implies that there is a deep connection between the gravitational field equations and the first law of thermodynamics. Therefore, any modification to the entropy expression, directly modifies the field…

General Relativity and Quantum Cosmology · Physics 2023-04-10 Ahmad Sheykhi , Maral Sahebi Hamedan

We propose a logarithmic parametrization form of energy density for the scalar field dark energy in the framework of the standard theory of gravity, which supports the necessary transition from the decelerated to the accelerated behavior of…

General Relativity and Quantum Cosmology · Physics 2023-07-31 Dan Wang , M. Koussour , Adnan Malik , N. Myrzakulov , G. Mustafa

In this paper, we discuss cosmological application of holographic Dark Energy (HDE) in the framework of $f(G)$ modified gravity. For this purpose, we construct $f(G)$ model with the inclusion of HDE and a well-known power law form of the…

General Physics · Physics 2015-06-12 Abdul Jawad , Antonio Pasqua , Surajit Chattopadhyay

It was argued that the vacuum energy of the Veneziano ghost field of QCD, in a time-dependent background, can be written in the general form, $H + O(H^2)$, where $H$ is the Hubble parameter. Based on this, a phenomenological dark energy…

General Relativity and Quantum Cosmology · Physics 2013-07-24 A. Sheykhi , E. Ebrahimi , Y. Yosefi

Holographic dark energy cosmology, also known as entropic cosmology, provides a concrete physical understanding of the late accelerated expansion of the universe. The acceleration appears to be a consequence of entropy associated with…

General Relativity and Quantum Cosmology · Physics 2024-06-03 Facundo Abaca , Dario Javier Zamora

We present the cosmic expansion scenario in the framework of $f(T)$ gravity by employing a dark energy equation of state (EoS) parameter. Specifically, we proceed with the power-law form of the function $f(T) = \alpha$$(-T)^{n}$, in…

General Relativity and Quantum Cosmology · Physics 2026-04-21 Khomesh R. Patle , G. P. Singh

The current paper provides a comprehensive examination of a dark energy cosmological model in the classical regime, in which a generic scalar field is regarded as a dark energy source. Einstein's field equations are solved in model…

General Relativity and Quantum Cosmology · Physics 2022-09-07 Ritika Nagpal , Shibesh Kumar Jas Pacif , Abhishek Parida

We present logistic dark energy model (LDEM), where the dark energy density follows a logistic function for the scale factor. The equation of state parameter of dark energy ($w_D$) transitioned from $-1$ in the distant past to its current…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-27 Sarath Nelleri , Gopi Krishna , Navaneeth Poonthottathil

In this work, the Renyi holographic dark energy (RHDE)and its behaviour has been explored with the anisotropic and spatially homogeneous Bianchi type-I Universe in the framework of $f(G)$ gravity. We use IR cutoff as the Hubble and…

High Energy Physics - Theory · Physics 2022-11-10 Md Khurshid Alam , S. Surendra Singh , L. Anjana Devi

We study dynamical dark energy models that allow for general late time behaviour while admitting non-phantom dynamics at early times, including thawing, scaling$+$thawing, and effective fluid extensions. Using current cosmological data, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-24 Sk. Sohail , Sonej Alam , Md. Wali Hossain

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

This paper explores the dark energy phenomenon within the context of $f(R,L_m)$ gravity theory. Two specific non-linear $f (R, L_m)$ models are considered: $f(R,L_m)=\frac{R}{2}+L_m^\alpha$ and $f(R,L_m)=\frac{R}{2}+(1+\alpha R)L_m$, where…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-13 S. Myrzakulova , M. Koussour , N. Myrzakulov

In a previous paper, we proposed a heterotic dark energy model, called $\Lambda$HDE, in which dark energy is composed of two components: cosmological constant (CC) and holographic dark energy (HDE). The aim of this work is to give a more…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-17 Shuang Wang , Sixiang Wen , Lanjun Zhou , Miao Li
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