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Related papers: Dark Energy Models With Variable Equation Of State…

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We show that the dark energy effects can be modeled by using an \emph{Ising perfect fluid} with network interactions, whose low redshift equation of state, i.e. $\omega_0$, becomes $\omega_0=-1$ as in the $\Lambda$CDM model. In our picture,…

High Energy Physics - Theory · Physics 2015-06-15 Orlando Luongo , Damiano Tommasini

We investigate constraints on some key cosmological parameters by confronting metastable dark energy models with different combinations of the most recent cosmological observations. Along with the standard $\Lambda$CDM model, two…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-14 Xiaolei Li , Arman Shafieloo , Varun Sahni , Alexei A. Starobinsky

We propose a model-independent parametrization of dark energy motivated by thermodynamics. To this aim, we consider Pad\'e polynomials to reconstruct the form of deceleration parameter adequate to describe different epochs of cosmic history…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-24 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

In this work we discuss a general approach for the dark energy thermodynamics considering a varying equation of state (EoS) parameter of the type $\omega(a)=\omega_0+F(a)$ and taking into account the role of a non-zero chemical potential…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-12 H. H. B. Silva , R. Silva , R. S. Gonçalves , Zong-Hong Zhu , J. S. Alcaniz

We consider a field theory model of coupled dark energy which treats dark energy as a three-form field and dark matter as a spinor field. By assuming the effective mass of dark matter as a power-law function of the three-form field and…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-04 YanHong Yao , YangJie Yan , XinHe Meng

We perform a detailed confrontation of various oscillating dark-energy parame-trizations with the latest sets of observational data. In particular, we use data from Joint Light Curve analysis (JLA) sample from Supernoave Type Ia, Baryon…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Supriya Pan , Emmanuel N. Saridakis , Weiqiang Yang

Some dark energy cosmological models are constructed in the framework of a generalised Brans-Dicke theory which contains a self interacting potential and a dynamical coupling parameter. The dark sector of the universe is considered through…

General Relativity and Quantum Cosmology · Physics 2022-07-19 S. K. Tripathy , Sasmita K Pradhan , Z. Naik , D. Behera , B. Mishra

We use parameterized post-Friedmann (PPF) description for dark energy and apply ellipsoidal nested sampling to perform the Bayesian model selection method on different time-dependent dark energy models using a combination of $Planck$ and…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-13 Mohsen Khorasani , Moein Mosleh , Ahmad Sheykhi

Late-time cosmic acceleration is one of the most interesting unsolved puzzles in modern cosmology. The explanation most accepted nowadays, dark energy, raises questions about its own nature, e.g. what exactly is dark energy, and…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-26 Williams J. M. Ribeiro

We present a theoretical study of an early dark energy (EDE) model. The equation of state $\omega(z)$ evolves during the thermal history in a framework of a Friedmann-Lemaitre-Robertson-Walker Universe, following an effective…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-17 Luz Ángela García , Leonardo Castañeda , Juan Manuel Tejeiro

We assess the viability of successful reconstruction of the evolution of the dark energy equation of state using varying fundamental couplings, such as the fine structure constant or the proton-to-electron mass ratio. We show that the same…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 P. P. Avelino , L. Losano , R. Menezes , J. C. R. E. Oliveira

As an alternative to the popular parametrisations of the dark energy equation of state, we construct a quintessence model where the scalar field has a linear dependence on the number of e-folds. Constraints on more complex models are…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-17 Vitor da Fonseca , Tiago Barreiro , Nelson J. Nunes

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 the holographic dark energy model in a generalized scalar tensor theory. In a universe filled with cold dark matter and dark energy, the effect of potential of the scalar field is investigated in the equation of state parameter. We…

General Relativity and Quantum Cosmology · Physics 2009-02-18 Yousef Bisabr

Exploring the diversity of dark energy dynamics, we discover a calibration relation, a uniform stretching of the amplitude of the equation of state time variation with scale factor. This defines homogeneous families of dark energy physics.…

Astrophysics · Physics 2009-11-13 Roland de Putter , Eric V. Linder

We introduce a unified model of early and late dark energy. We call it {\it quintessential early dark energy} model where early and late dark energy are explained by a single scalar field {\it i.e.}, two different energy scales are related…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-19 Sk. Sohail , Sonej Alam , Shiriny Akthar , Md. Wali Hossain

We propose a completely new parametrisation of the dark energy equation of state, which uses the dark energy density, $\Omega_e$ as a cosmic clock. We expand the equation of state in a series of orthogonal polynomials, with $\Omega_e$ as…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-13 Ewan R. M. Tarrant , Edmund J. Copeland , Antonio Padilla , Constantinos Skordis

Nearly all proposed tests for the nature of dark energy measure some combination of four fundamental observables: the Hubble parameter H(z), the distance-redshift relation d(z), the age-redshift relation t(z), or the linear growth factor…

Astrophysics · Physics 2009-11-13 David H. Weinberg

In this paper, we study two different models of dark energy based on Chaplygin gas equation of state. The first model is the variable modified Chaplygin gas while the second one is the extended Chaplygin gas. Both models are considered in…

General Relativity and Quantum Cosmology · Physics 2015-02-10 E. O. Kahya , M. Khurshudyan , B. Pourhassan , R. Myrzakulov , A. Pasqua

We investigate whether the recent DESI DR2 measurements provide or not evidences for dynamical dark energy by exploring the $\omega_0\omega_a$CDM model and its extensions with free $\sum m_{\nu}$ and $N_{\mathrm{eff}}$. Using a…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-25 Salvatore Capozziello , Himanshu Chaudhary , Tiberiu Harko , Ghulam Mustafa
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