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相关论文: Uncovering the bias in the evidence for dynamical …

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We search for physically consistent realizations of evolving dark energy suggested by the cosmological fit of DESI, Planck and Supernovae data. First we note that any lagrangian description of the standard Chevallier-Polarski-Linder (CPL)…

宇宙学与河外天体物理 · 物理学 2024-11-18 Alessio Notari , Michele Redi , Andrea Tesi

We examine the validity of the $\Lambda$CDM model, and probe for the dynamics of dark energy using latest astronomical observations. Using the $Om(z)$ diagnosis, we find that different kinds of observational data are in tension within the…

宇宙学与河外天体物理 · 物理学 2017-06-14 Yuecheng Zhang , Hanyu Zhang , Dandan Wang , Yanghan Qi , Yuting Wang , Gong-Bo Zhao

We test the robustness and flexibility of the Chevallier-Polarski-Linder (CPL) parameterization of the Dark Energy equation of state $w(z)=w_0+w_a \frac{z}{1+z}$ in recovering a four-parameter step-like fiducial model. We constrain the…

天体物理学 · 物理学 2009-06-23 Sebastian Linden , Jean-Marc Virey

We investigate a dynamical reconstruction of the dark energy equation of state parameter by assuming that it satisfies a law of motion described by an autonomous second-order differential equation, with the limit of the cosmological…

宇宙学与河外天体物理 · 物理学 2025-12-25 Andronikos Paliathanasis

Most dark energy models have the $\Lambda$CDM as their limit, and if future observations constrain our universe to be close to $\Lambda$CDM Bayesian arguments about the evidence and the fine-tuning will have to be employed to discriminate…

宇宙学与河外天体物理 · 物理学 2018-11-27 Olga Avsajanishvili , Yiwen Huang , Lado Samushia , Tina Kahniashvili

In this paper, we set the new limits on the equation of state parameter (EoS) of dark energy with the observations of cosmic microwave background radiation (CMB) from Planck satellite, the type Ia supernovae from Pan-STARRS and the baryon…

宇宙学与河外天体物理 · 物理学 2014-08-15 Wei Zheng , Si-Yu Li , Hong Li , Jun-Qing Xia , Mingzhe Li , Tan Lu

Recent baryon acoustic oscillation measurements from the DESI, when combined with CMB data and Type Ia supernovae observations, indicate a preference for dynamical dark energy when considering the Chevallier-Polarski-Linder (CPL) model,…

宇宙学与河外天体物理 · 物理学 2025-12-12 Ziad Sakr

In this work, we perform a comprehensive joint analysis of three representative dark energy models - ${\rm{\Lambda}CDM}$, the Chevallier-Polarski-Linder (CPL) parametrization, and the Generalised Emergent Dark Energy (GEDE) model - using…

宇宙学与河外天体物理 · 物理学 2025-12-10 Tonghua Liu , Xiaolei Li , Jieci Wang

We study the performance of the spatially-flat dynamical dark energy (DE) $w_0w_a$CDM parameterization, with redshift-dependent DE fluid equation of state parameter $w(z) = w_0 + w_a z/(1+z)$, with and without a varying CMB lensing…

宇宙学与河外天体物理 · 物理学 2025-09-15 Chan-Gyung Park , Javier de Cruz Perez , Bharat Ratra

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…

宇宙学与河外天体物理 · 物理学 2024-05-30 Omar F. Ramadan , Jeremy Sakstein , David Rubin

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…

宇宙学与河外天体物理 · 物理学 2024-07-23 Mahdi Najafi , Supriya Pan , Eleonora Di Valentino , Javad T. Firouzjaee

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…

宇宙学与河外天体物理 · 物理学 2025-12-24 Sk. Sohail , Sonej Alam , Md. Wali Hossain

We introduce a minimal two-parameter formulation of the dark energy (DE) density evolution normalized to its present-day value, $f_{\rm DE}(z) \equiv \rho_{\rm DE}(z)/\rho_{\rm DE,0}$, in terms of $f_p\equiv f_{\rm DE}(z_p)$ and the DE…

宇宙学与河外天体物理 · 物理学 2026-03-27 Gabriele Montefalcone , Richard Stiskalek

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…

宇宙学与河外天体物理 · 物理学 2026-03-25 Mine Gökçen , Özgür Akarsu , Eleonora Di Valentino

We report the constraints on the dark energy equation-of-state w(z) using the latest 'Constitution' SNe sample combined with the WMAP5 and SDSS data. Based on the localized principal component analysis and the model selection criteria, we…

宇宙学与河外天体物理 · 物理学 2010-04-30 Gong-Bo Zhao , Xinmin Zhang

Are geometrical summaries of the CMB and LSS sufficient for estimating cosmological parameters? And how does our choice of a dark energy model impact the current constraints on standard cosmological parameters? We address these questions in…

宇宙学与河外天体物理 · 物理学 2009-03-17 Rahul Biswas , Benjamin D. Wandelt

We investigate the generalized Chevallier-Polarski-Linder (CPL) parametrization, which contains the pivoting redshift $z_p$ as an extra free parameter. We use various data combinations from cosmic microwave background (CMB), baryon acoustic…

宇宙学与河外天体物理 · 物理学 2018-11-19 Weiqiang Yang , Supriya Pan , Eleonora Di Valentino , Emmanuel N. Saridakis

We constrain two dynamical dark energy models that are parametrized by the logarithm form of $w(z)=w_{0}+w_{1}\left(\frac{\ln (2+z)}{1+z}-\ln 2\right)$ and the oscillating form of…

广义相对论与量子宇宙学 · 物理学 2023-11-28 Tian-Ying Yao , Rui-Yun Guo , Xin-Yue Zhao

The dark energy component of the universe is often interpreted either in terms of a cosmological constant or as a scalar field. A generic feature of the scalar field models is that the equation of state parameter w= P/rho for the dark…

天体物理学 · 物理学 2009-11-13 H. K. Jassal , J. S. Bagla , T. Padmanabhan

We study spatially-flat dynamical dark energy parametrizations, $w(z)$CDM, with redshift-dependent dark energy equation of state parameter $w(z)$ expressed using three different quadratic and other polynomial forms (as functions of $1-a$,…

宇宙学与河外天体物理 · 物理学 2025-07-03 Chan-Gyung Park , Bharat Ratra