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Related papers: One-parameter dynamical dark energy: Hints for osc…

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We compute the Bayesian evidences for one- and two-parameter models of evolving dark energy, and compare them to the evidence for a cosmological constant, using current data from Type Ia supernova, baryon acoustic oscillations, and the…

Astrophysics · Physics 2008-11-26 Andrew R Liddle , Pia Mukherjee , David Parkinson , Yun Wang

We introduce a new parametrization for the dark energy, led by the same idea to the linear expansion of the equation of state in scale factor $a$ and in redshift $z$, which diverges neither in the past nor future and contains the same…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-01 Ozgur Akarsu , Tekin Dereli , J. Alberto Vazquez

In this work, we explore the evolution of the dark energy equation of state {\omega} by using Chevalliear-PolarskiLinder (CPL) parametrization and the binned parametrizations. For binned parametrizations, we adopt three methods to choose…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-05 Xiaolin Luo , Shuang Wang , Sixiang Wen

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…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-15 Chan-Gyung Park , Javier de Cruz Perez , Bharat Ratra

We investigate the dark energy phenomenology in an extended parameter space where we allow the curvature density of our universe as a free-to-vary parameter. The inclusion of the curvature density parameter is motivated from the recently…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-29 Mehdi Rezaei , Supriya Pan , Weiqiang Yang , David F. Mota

Recent DESI results indicate a strong preference for dynamical dark energy (DE) when baryon acoustic oscillation (BAO) measurements are combined with supernovae (SNe) and cosmic microwave background (CMB) data using the…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-26 Shubham Barua , Shantanu Desai

Evidences for evolving dark energy are shown using baryon acoustic oscillation measurements from the recent Dark Energy Spectroscopic Instrument Data Release 2 , combined with different Type Ia supernova datasets (Pantheon$^+$, DES-Dovekie,…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-25 Himanshu Chaudhary , Salvatore Capozziello , Vipin Kumar Sharma , Isidro Gómez-Vargas , G. Mustafa

Recent measurements of Baryon Acoustic Oscillations (BAO) and distance moduli from Type Ia supernovae suggest a preference for Dynamical Dark Energy (DDE) scenarios characterized by a time-varying equation of state (EoS). This focused…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-11 William Giarè , Tariq Mahassen , Eleonora Di Valentino , Supriya Pan

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…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-15 Wei Zheng , Si-Yu Li , Hong Li , Jun-Qing Xia , Mingzhe Li , Tan Lu

Dark energy (DE) models with many free parameters are often considered excessive, as constraining all parameters poses a significant challenge. While such models offer greater flexibility to probe the DE sector in more detail. With the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-25 Hanyu Cheng , Supriya Pan , Eleonora Di Valentino

We present updated constraints on cosmological parameters in a 12-parameter model, extending the standard six-parameter $\Lambda$CDM by including dynamical dark energy (DE: $w_0$, $w_a$), the sum of neutrino masses ($\sum m_{\nu}$), the…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-19 Shouvik Roy Choudhury , Teppei Okumura

We study structure formation in alternative cosmological models constrained by background observations, including $\Lambda$CDM, wCDM, the Chevallier-Polarski-Linder parametrisation and a flexible Chebyshev expansion of the dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-15 Greco A. Peña , Mario H. Amante , Javier Chagoya , Cristian Barrera-Hinojosa , C. Ortiz , Graeme Candlish

Baryon acoustic oscillation measurements by the Dark Energy Spectroscopic Instrument (Data Release 1) have revealed exciting results that show evidence for dynamical dark energy at $\sim3\sigma$ when combined with cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-30 Bikash R. Dinda , Roy Maartens

Recent results from Type Ia supernovae (SNe Ia) and baryon acoustic oscillations (BAO), in combination with cosmic microwave background (CMB) measurements, have focused renewed attention on dark energy models with a time-varying…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-31 Anowar J. Shajib , Joshua A. Frieman

We explore an extension of the $\Lambda$CDM model in which the pressure $p$ of the dark energy (DE) fluid evolves with the expansion of the Universe, expressed as a function of the scale factor $a$. The corresponding energy density $\rho$…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-22 Hanyu Cheng , Eleonora Di Valentino , Luis A. Escamilla , Anjan A. Sen , Luca Visinelli

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…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-14 Yuecheng Zhang , Hanyu Zhang , Dandan Wang , Yanghan Qi , Yuting Wang , Gong-Bo Zhao

We develop here a relatively simple description of dark energy based on the dynamics of non-minimally coupled to gravity phantom scalar field which, in limit, corresponds to cosmological constant. The dark energy equation of state, obtained…

Astrophysics · Physics 2014-11-18 Aleksandra Kurek , Orest Hrycyna , Marek Szydlowski

In this paper we obtain observational constraints on three dynamical cold dark energy models ,include PL , CPL and FSL, with most recent cosmological data and investigate their implication for structure formation, dark energy clustering and…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-15 Aghileh S. Ebrahimi , M. Monemzadeh , H. Moshafi

We consider a 12-parameter cosmological model with non-phantom dynamical dark energy (NPDDE), where non-phantom implies that the equation of state (EoS) of dark energy (DE), $w(z)\geq-1$ for all redshifts $z$. Thus, the DE EoS covers the…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-20 Shouvik Roy Choudhury , Teppei Okumura , Keiichi Umetsu

We show that the latest empirical constraints on cosmology, from a combination of DESI, CMB and supernova data, can be accounted for if a small component of dark matter has an evolving and oscillating equation of state within $-1<w<1$. From…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-22 Xingang Chen , Abraham Loeb