English
Related papers

Related papers: Fine-structure constant constraints on dark energy…

200 papers

We study dependence of the CMB temperature anisotropy spectrum on the value of the fine structure constant $\alpha$ and the equation of state of the dark energy component of the total density of the universe. We find that bounds imposed on…

Astrophysics · Physics 2014-10-13 Greg Huey , Stephon Alexander , Levon Pogosian

We explore freezing dark energy, where the evolution of the field approaches that of a cosmological constant at late times. We propose two general, two parameter forms to describe the class of freezing field models, in analogy to ones for…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-22 Eric V. Linder

Cosmological observations of the recent universe suggest that dark energy equation of state parameter $w$ is growing with time, departing from a cosmological constant for which $w=-1$. Standard quintessence models allow for a varying…

High Energy Physics - Theory · Physics 2025-07-11 David Andriot

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

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 constrain cosmological parameters using only Hubble parameter data and quantify the impact of future Hubble parameter measurements on parameter estimation for the most typical dark energy models. We first constrain cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-27 Jia-Jia Geng , Rui-Yun Guo , Anzhong Wang , Jing-Fei Zhang , Xin Zhang

We explore the properties of dark energy from recent observational data, including the Gold Sne Ia, the baryonic acoustic oscillation peak from SDSS, the CMB shift parameter from WMAP3, the X-ray gas mass fraction in cluster and the Hubble…

Astrophysics · Physics 2008-11-26 Puxun Wu , Hongwei Yu

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 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

A major quest in cosmology is the understanding of the nature of dark energy. It is now well known that a combination of cosmological probes is required to break the underlying degeneracies on cosmological parameters. In this paper, we…

Astrophysics · Physics 2009-11-11 Ch. Yeche , A. Ealet , A. Refregier , C. Tao , A. Tilquin , J. -M. Virey , D. Yvon

In this work we provide updated constraints on coupled dark energy (CDE) cosmology with Peebles-Ratra (PR) potential and constant coupling strength $\beta$. This modified gravity scenario introduces a fifth force between dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-01 Adrià Gómez-Valent , Valeria Pettorino , Luca Amendola

For a general dark-energy equation of state, we estimate the maximum possible radius of massive structures that are not destabilized by the acceleration of the cosmological expansion. A comparison with known stable structures constrains the…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-16 V. Pavlidou , N. Tetradis , T. N. Tomaras

Precision measurements of nature's fundamental couplings and a first measurement of the cosmological redshift drift are two of the key targets for future high-resolution ultra-stable spectrographs such as CODEX. Being able to do both gives…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 P. E. Vielzeuf , C. J. A. P. Martins

The strong coupling alpha_s is a fundamental parameter of the Standard Model. In comparison to parameters like alpha_em and M_Z it is relatively poorly known. However the precision of alpha_s measurements has improved dramatically in recent…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. J. Stirling

We apply a parameterization-independent approach to fitting the dark energy equation-of-state (EOS). Utilizing the latest type Ia supernova data, combined with results from the cosmic microwave background and baryon acoustic oscillations,…

Astrophysics · Physics 2008-11-26 Scott Sullivan , Asantha Cooray , Daniel E. Holz

The present study reveals observational constraints on the coupling between dark components of anisotropic Bianchi type I universe. We assume interaction between dark matter and dark energy and split the continuity equation with inclusion…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-20 Hassan Amirhashchi , Anil Kumar Yadav , Nafis Ahmad , Vikrant Yadav

We use Pantheon Type Ia supernova (SN Ia) apparent magnitude, DES-3yr binned SN Ia apparent magnitude, Hubble parameter, and baryon acoustic oscillation measurements to constrain six spatially flat and non-flat cosmological models. These…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-21 Shulei Cao , Joseph Ryan , Bharat Ratra

We investigate whether the current Hubble parameter $H(z)$ measurements could help improve the constraints on dark energy on the basis of the mainstream cosmological probes including the type Ia supernovae (SN) observation, the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-16 Yan Liu , Rui-Yun Guo , Jing-Fei Zhang , Xin Zhang

Based on superfluid behavior of a (boson) dark matter as the light itself, a unified model for dark matter and quintessence is proposed. Inspired by (O'Dell et al. 2000) which in an exciting study showed that particular configurations of…

General Physics · Physics 2007-05-23 Reza Dastvan

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
‹ Prev 1 8 9 10 Next ›