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Related papers: Constraints on a variable dark energy model with r…

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We use late Universe probes - Type Ia Supernovae from the PantheonPlus compilation, Quasars, and Dark Energy Spectroscopic Instrument (DESI) Data Release 1 (DR1) BAO data - along with Cosmic Chronometers or Megamasers to constrain various…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Shubham Barua , Shantanu Desai

In this Letter, a modified Chaplygin gas (MCG) model of unifying dark energy and dark matter with the exotic equation of state $p_{MCG}=B\rho_{MCG} -\frac A{\rho_{MCG}^\alpha}$ is constrained from recently observed data: the 182 Gold SNe…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-07 Jianbo Lu , Lixin Xu , Jiechao Li , Baorong Chang , Yuanxing Gui , Hongya Liu

We present a Bayesian technique based on a maximum entropy method to reconstruct the dark energy equation of state $w(z)$ in a non--parametric way. This MaxEnt technique allows to incorporate relevant prior information while adjusting the…

Astrophysics · Physics 2008-11-26 C. Zunckel , R. Trotta

We study the constraints on the dark energy model with constant equation of state parameter $w=p/\rho$ and the holographic dark energy model by using the weak gravity conjecture. The combination of weak gravity conjecture and the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Ximing Chen , Jie Liu , Yungui Gong

We cross-correlate the new 3 year Wilkinson Microwave Anistropy Probe (WMAP3) cosmic microwave background (CMB) data with the NRAO VLA Sky Survey (NVSS) radio galaxy data, and find further evidence of late integrated Sachs-Wolfe (ISW)…

Astrophysics · Physics 2007-05-23 Davide Pietrobon , Amedeo Balbi , Domenico Marinucci

Classification of dark energy models in the plane of w and w', where w is the dark energy equation of state and w' its time-derivative in units of the Hubble time, has been studied in the literature. We take the current SN Ia, CMB and BAO…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-04 Chien-Wen Chen , Pisin Chen , Je-An Gu

We place observational constraints on models with the late-time cosmic acceleration based on a number of parametrizations allowing fast transitions for the equation of state of dark energy. In addition to the model of Linder and Huterer…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Antonio De Felice , Savvas Nesseris , Shinji Tsujikawa

We place observational constraints on a coupling between dark energy and dark matter by using 71 Type Ia supernovae (SNe Ia) from the first year of the five-year Supernova Legacy Survey (SNLS), the cosmic microwave background (CMB) shift…

Astrophysics · Physics 2010-04-28 Zong-Kuan Guo , Nobuyoshi Ohta , Shinji Tsujikawa

We present new constraints on the evolution of dark energy from an analysis of Cosmic Microwave Background, supernova and X-ray galaxy cluster data. Our analysis employs a minimum of priors and exploits the complementary nature of these…

Astrophysics · Physics 2008-11-26 David Rapetti , Steven W. Allen , Jochen Weller

We present strong evidence for dynamical dark energy that challenges the standard $\Lambda$CDM model. Several dark energy scenarios are explored, including $\omega_0\omega_a$CDM, logarithmic, exponential, JBP, and BA parameterizations,…

General Relativity and Quantum Cosmology · Physics 2025-11-18 Himanshu Chaudhary , Salvatore Capozziello , Subhrat Praharaj , Shibesh Kumar Jas Pacif , G. Mustafa

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

In this letter we argue that the CPL parameterisation for the dark energy equation of state is biased towards preferring such model over the constant $w$ while the latter bounds are still compatible with LCDM. For that we compare…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-27 Ziad Sakr

We present a nonparametric method to determine the sign of $w+1$ in the equation of state of dark energy. It is based on geometrical behaviour and is more tolerant to uncertainties of other cosmological parameters than fitting methods. It…

Astrophysics · Physics 2007-05-23 Houri Ziaeepour

In this paper, we use the Type Ia supernova data as well as the CMB and LSS data to constrain the agegraphic dark energy model recently proposed by Cai. Due to its peculiar nature, the parameter $n$ of this model cannot be well constrained…

Astrophysics · Physics 2007-10-02 Xing Wu , Yi Zhang , Hui Li , Rong-Gen Cai , Zong-Hong Zhu

We update the constraints on the cosmological parameters by adopting the Planck data released in 2015 and Baryon Acoustic Oscillation (BAO) measurements including the new DR14 quasar sample measurement at redshift $z=1.52$, and we conclude…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-06 Lu Chen , Qing-Guo Huang , Ke Wang

Models of dark energy are conveniently characterized by the equation-of-state parameter w=p/\rho, where \rho is the energy density and p is the pressure. Imposing the Dominant Energy Condition, which guarantees stability of the theory,…

Astrophysics · Physics 2011-05-12 Sean M. Carroll , Mark Hoffman , Mark Trodden

We assume the DE state equations w(a) = w_0+w_a(a_p-a), and study the dependence of the constraints on w_0 and w_a coefficients on the pivoting redshift 1+z_p=1/a_p. Coefficients are fitted to data including WMAP7, SNIa (Union 2.1), BAO's…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Dario Scovacricchi , Silvio A. Bonometto , Marino Mezzetti , Giuseppe La Vacca

In this paper, we use the type Ia supernovae data to constrain the holographic dark energy model proposed by Li. We also apply a cosmic age test to this analysis. We consider in this paper a spatially flat Friedmann-Robertson-Walker…

Astrophysics · Physics 2008-11-26 Xin Zhang , Feng-Quan Wu

Recent data and new data analysis methods show that most probably the parameter $w$ in the equation of state of the dark energy is smaller than -1 at low redshifts. We briefly review some of the models with such a property and without…

Astrophysics · Physics 2008-11-26 Houri Ziaeepour

We explore cosmological constraints on the sum of the three active neutrino masses $M_{\nu}$ in the context of dynamical dark energy (DDE) models with equation of state (EoS) parametrized as a function of redshift $z$ by…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-14 Sunny Vagnozzi , Suhail Dhawan , Martina Gerbino , Katherine Freese , Ariel Goobar , Olga Mena