English
Related papers

Related papers: Constraints on Dark Energy state equation with var…

200 papers

In this paper, we employ two model-independent approaches, including redshift binning method and polynomial interpolation method, to reconstruct dark energy (DE) equation of state (EoS) $w(z)$ and DE density function $f(z)$. Our analysis…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-18 Jun-Xian Li , Shuang Wang

We apply the technique of parameter-splitting to existing cosmological data sets, to check for a generic failure of dark energy models. Given a dark energy parameter, such as the energy density Omega_Lambda or equation of state w, we split…

Astrophysics · Physics 2008-11-26 Sheng Wang , Lam Hui , Morgan May , Zoltan Haiman

We explore the properties of dark energy models for which the equation-of-state, w, defined as the ratio of pressure to energy density, crosses the cosmological-constant boundary w = -1. We adopt an empirical approach, treating the dark…

Astrophysics · Physics 2010-04-06 Robert R. Caldwell , Michael Doran

Astrophysical tests of the stability of fundamental couplings, such as the fine-structure constant $\alpha$, are becoming an increasingly powerful probe of new physics. Here we discuss how these measurements, combined with local atomic…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-09 C. J. A. P. Martins , A. M. M. Pinho , R. F. C. Alves , M. Pino , C. I. S. A. Rocha , M. von Wietersheim

In this study, we investigate the oscillatory dark energy model $w_{\sin}\mathrm{CDM}$ based on the DESI BAO data together with OHD, Pantheon Plus, and SH0ES measurements. We examine how the DESI data influence the dark energy…

General Physics · Physics 2026-02-06 Manish Yadav , Archana Dixit , M. S. Barak , Anirudh Pradhan

We constrain plausible dark energy models, parametrized by multiple candidate equation of state, using the recently published Cosmic Microwave Background (CMB) temperature anisotropy data from Planck together with the WMAP-9 low-$\ell$…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-22 Dhiraj Kumar Hazra , Subhabrata Majumdar , Supratik Pal , Sudhakar Panda , Anjan A. Sen

In this work we have used the recent cosmic chronometers data along with the latest estimation of the local Hubble parameter value, $H_0$ at 2.4\% precision as well as the standard dark energy probes, such as the Supernovae Type Ia, baryon…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-02 Weiqiang Yang , Narayan Banerjee , Supriya Pan

We have studied constraints on the equation of state, $w$, and speed of sound, c_s, of the dark energy from a joint analysis of data from the cosmic microwave background, large scale structure and type-Ia supernovae. We find that current…

Astrophysics · Physics 2009-11-10 Steen Hannestad

We explore a scenario of interacting dynamical dark energy model with the interaction term $Q$ including the varying equation-of-state parameter $w$. Using the data combination of the cosmic microwave background, the baryon acoustic…

General Relativity and Quantum Cosmology · Physics 2021-12-21 Rui-Yun Guo , Lu Feng , Tian-Ying Yao , Xing-Yu Chen

In standard cosmologies, dark energy interacts only gravitationally with dark matter. There could be a non-gravitational interaction in the dark sector, leading to changes in the effective DE equation of state, in the redshift dependence of…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-13 Timothy Clemson , Kazuya Koyama , Gong-Bo Zhao , Roy Maartens , Jussi Väliviita

We consider the impact of the Heidelberg-Moscow claim for a detection of neutrino mass on the determination of the dark energy equation of state. By combining the Heidelberg-Moscow result with the WMAP 3-years data and other cosmological…

Astrophysics · Physics 2008-11-26 Paolo Serra , Rachel Bean , Axel De La Macorra , Alessandro Melchiorri

We examine the influence of percent-level dark energy corrections to the nonlinear matter power spectrum on constraints of the dark energy equation of state from future weak lensing probes. We explicitly show that a poor approximation (off…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-28 Shahab Joudaki , Asantha Cooray , Daniel E. Holz

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

We determine the range of parameter space of an interacting quintessence (IQ) model that best fits the luminosity distance of type Ia supernovae data and the recent WMAP measurements of Cosmic Microwave Background temperature anisotropies.…

Astrophysics · Physics 2009-11-13 German Olivares , Fernando Atrio-Barandela , Diego Pavon

A comparative study of various parametrizations of the dark energy equation of state $w(z)$ and its variation with the redshift is made. Astrophysical constraints from 'integrated tracking' are laid down to test the physical viability and…

Astrophysics · Physics 2007-05-23 Vinod B. Johri

Current observational bounds on dark energy depend on assumptions about the curvature of the universe. We present a simple and efficient method for incorporating constraints from CMB anisotropy data, and use it to derive constraints on…

Astrophysics · Physics 2010-04-06 Yun Wang , Pia Mukherjee

We apply a new non-parametric Bayesian method for reconstructing the evolution history of the equation-of-state $w$ of dark energy, based on applying a correlated prior for $w(z)$, to a collection of cosmological data. We combine the latest…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-20 Gong-Bo Zhao , Robert G. Crittenden , Levon Pogosian , Xinmin Zhang

The dark energy equation of state for theories with either a discretuum or continuum distribution of vacua is investigated. In the discretuum case the equation of state is constant $w=p/\rho=-1$. The continuum case may be realized by an…

High Energy Physics - Theory · Physics 2010-04-05 Savas Dimopoulos , Scott Thomas

Recent observations of Type Ia supernova at high redshifts establish that the dark energy component of the universe has (a probably constant) ratio between pressure and energy density $w=p/\rho=-1.02(^{+0.13}_{-0.19})$. The conventional…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Edgard Gunzig , Alberto Saa

In this work the observational constraints on interaction coupling parameter between dynamical dark energy and cold dark matter were obtained using CMB, BAO and SN Ia data. The dark energy in considered models is dynamical and evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-17 Roman Neomenko
‹ Prev 1 8 9 10 Next ›