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The measurements of the cosmic microwave background (CMB) have played a significant role in understanding the nature of dark energy. In this article, we investigate the dynamics of the dark energy equation of state, utilizing high-precision…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-23 Mahdi Najafi , Supriya Pan , Eleonora Di Valentino , Javad T. Firouzjaee

A cosmological model with an energy transfer between dark matter (DM) and dark energy (DE) can give rise to comparable energy densities at the present epoch. The present work deals with the perturbation analysis, parameter estimation and…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-02 Srijita Sinha

Dark energy equation of state $w(z)$ parametrizations with two parameters and given monotonicity are generically either convex or concave functions. This makes them suitable for fitting either freezing or thawing quintessence models but not…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-11 G. Pantazis , S. Nesseris , L. Perivolaropoulos

Reconstructed from lensing tomography, the evolution of the dark matter density field in the well-understood linear regime can provide model-independent constraints on the growth function of structure and the evolution of the dark energy…

Astrophysics · Physics 2008-11-26 Wayne Hu

Recent DESI DR2 BAO measurements, when combined with CMB and SNeIa data, exhibit a $3.2\sigma$-$3.4\sigma$ preference for dynamical dark energy (DE) described by the CPL-parametrized equation of state. A particularly striking feature of…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-25 Mine Gökçen , Özgür Akarsu , Eleonora Di Valentino

We examine the Chevallier-Polarski-Linder (CPL) parametrization, in the context of quintessence and barotropic dark energy models, to determine the subset of such models to which it can provide a good fit. The CPL parametrization gives the…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-12 Robert J. Scherrer

We investigate the behaviour of dark energy using the recently released supernova data of Riess et al ~(2004) and a model independent parameterization for dark energy (DE). We find that, if no priors are imposed on $\Omega_{0m}$ and $h$, DE…

Astrophysics · Physics 2009-11-10 Ujjaini Alam , Varun Sahni , A. A. Starobinsky

We look for evidence for the evolution in dark energy density by employing Principal Component Analysis (PCA). Distance redshift data from supernovae and baryon acoustic oscillations (BAO) along with WMAP7 distance priors are used to put…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Remya Nair , Sanjay Jhingan

This paper examines interacting dark energy models within the Chevallier-Polarski-Linder (CPL) parametrization, emphasizing both theoretical structure and observational viability. Two commonly adopted interaction terms are considered: $Q =…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-28 Gerald Neumann , Nelson Videla , Dorian Araya

We introduce a modified form of the Phenomenologically Emergent Dark Energy (PEDE) model by showing a very elegant approach. The model is named as Modified Emergent Dark Energy (MEDE) to distinguish from PEDE model and it includes…

General Relativity and Quantum Cosmology · Physics 2020-08-24 H. B. Benaoum , Weiqiang Yang , Supriya Pan , Eleonora Di Valentino

It has been theorized that Dynamical Dark Energy (DDE) could be a possible solution to the Hubble tension. To avoid the degeneracy between the Hubble parameter $H_0$ and the sound horizon scale $r_d$, in this article we use their…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-02 Denitsa Staicova

The DESI collaboration have recently analyzed their first year of data, finding a preference for thawing dark energy scenarios when using parameterized equations of state for dark energy. We investigate whether this preference persists when…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-30 Omar F. Ramadan , Jeremy Sakstein , David Rubin

Recent cosmological measurements are hinting that dark energy may evolve, with its equation of state, $w_\mathrm{DE}$, even showing oscillatory patterns. In this work, we employ a model-independent approach to jointly reconstruct…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-19 Pietro Ghedini , Rasmi Hajjar , Olga Mena

In this work we explore signatures of evolution for the dark energy density $X(z)=\rho_{de}(z)/\rho_{de}(0)$ using latest observations on SNIa and H(z). The models consist of parametrizations of the dark energy density and consequently a…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-27 Daniela Grandon , Victor H. Cardenas

It is well known that there are several long-standing problems implying the discordance of the $\Lambda$CDM model. Although most of the models proposed to resolve these problems assume that dark matter is pressureless, it is still possible…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-31 Yan-Hong Yao , Jun-Chao Wang , Xin-He Meng

We investigate the cosmological viability of symmetric teleparallel gravity, specifically the $f(Q)$ gravity model with a power-law form $f(Q) = \alpha Q^n$, in combination with two widely used dark energy parameterizations: Chevallier…

General Relativity and Quantum Cosmology · Physics 2025-07-09 Rajdeep Mazumdar , Mrinnoy M. Gohain , Kalyan Bhuyan

We revisit the evolution of cosmic acceleration in a spatially flat $w_0w_a$CDM universe, in which the equation of state of dark energy takes the CPL parametrization, using the latest baryon acoustic oscillation (BAO) measurements from the…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-12 Jincheng Wang , Hongwei Yu , Puxun Wu

Investigations on dark energy (DE) are currently inconclusive about its time evolution. Hints of this possibility do however glow now and then in the horizon. Herein we assess the current status of dynamical dark energy (DDE) in the light…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-06 Joan Sola Peracaula , Adria Gomez-Valent , Javier de Cruz Perez

We parameterize the equation of state of late-time dark energy as $w_{\mathrm{bin}}(z)$, with three redshift bins, characterized by a constant equation of state in each bin. Then, we constrain the parameters of the $w_{\mathrm{bin}}$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-28 Ye-Huang Pang , Xue Zhang , Qing-Guo Huang

A large number of cosmological parameters have been suggested for obtaining information on the nature of dark energy. In this work, we study the efficacy of these different parameters in discriminating theoretical models of dark energy,…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-08 Alexander V. Pan , Ujjaini Alam
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