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Related papers: Two new diagnostics of dark energy

200 papers

The current paper provides a comprehensive examination of a dark energy cosmological model in the classical regime, in which a generic scalar field is regarded as a dark energy source. Einstein's field equations are solved in model…

General Relativity and Quantum Cosmology · Physics 2022-09-07 Ritika Nagpal , Shibesh Kumar Jas Pacif , Abhishek Parida

Observations restrict the parameter space of Holographic Dark Energy (HDE) so that a turning point in the Hubble parameter $H(z)$ is inevitable. Concretely, cosmic microwave background (CMB), baryon acoustic oscillations (BAO) and Type Ia…

General Relativity and Quantum Cosmology · Physics 2021-08-11 Eoin Ó Colgáin , M. M. Sheikh-Jabbari

This study explores the possibility of a time-varying dark energy (DE) equation of state (EoS) deviating from -1. We employ a comprehensive dataset of usual astronomical probes (Type Ia supernovae, baryon acoustic oscillations, Big Bang…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-23 Mehdi Rezaei , Supriya Pan , Weiqiang Yang , David F. Mota

A higher value of Hubble constant has been obtained from measurements with nearby Type Ia supernovae, than that obtained at much higher redshift. With the peculiar motions of their hosts, we find that the matter content at such low redshift…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-25 Shuang-Nan Zhang , Yin-Zhe Ma

We examine the dark energy and matter densities allowed by precision measurements of distances out to various redshifts, in the presence of spatial curvature and (near) arbitrary behavior of the dark energy equation of state. Degeneracies…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-22 Arman Shafieloo , Eric V. Linder

While there is plentiful evidence in all fronts of experimental cosmology for the existence of a non-vanishing dark energy (DE) density \rho_D in the Universe, we are still far away from having a fundamental understanding of its ultimate…

Astrophysics · Physics 2011-07-19 Javier Grande , Ana Pelinson , Joan Sola

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 critically examine the state of current constraints on the dark energy (DE) equation of state (EoS) $w$. Our study is motivated by the observation that, while broadly consistent with the cosmological constant value $w=-1$, several…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-22 Luis A. Escamilla , William Giarè , Eleonora Di Valentino , Rafael C. Nunes , Sunny Vagnozzi

The coupling between the dark components provides a new approach to mitigate the coincidence problem of cosmological standard model. In this paper, dark energy is treated as a fluid with a constant equation of state, whose coupling with…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-18 Weiqiang Yang , Lixin Xu

Constraining the dark energy equation of state, $w_x(z)$, is one of the main issues of current and future cosmological surveys. In practice, this requires making assumptions about the evolution of $w_x$ with redshift $z$, which can be…

General Relativity and Quantum Cosmology · Physics 2019-07-29 Celia Escamilla-Rivera , Salvatore Capozziello

In this work, we have proposed a general dark energy density parametrization to study the evolution of the universe. We have also constrained the model parameters using the combination of Type Ia supernova (SNIa), baryonic acoustic…

General Relativity and Quantum Cosmology · Physics 2018-07-25 Abdulla Al Mamon

In this paper a new theory of Dark Matter is proposed. Experimental analysis of several Galaxies show how the non-gravitational contribution to galactic Velocity Rotation Curves can be interpreted as that due to the Cosmological Constant…

Astrophysics · Physics 2007-05-23 G. V. Kraniotis , S. B. Whitehouse

Holographic dark energy (HDE) describes the vacuum energy in a cosmic IR region whose total energy saturates the limit of avoiding the collapse into a black hole. HDE predicts that the dark energy equation of the state transiting from…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-04 Wei-Ming Dai , Yin-Zhe Ma , Hong-Jian He

We introduce a new diagnostic for the null tests of dynamical dark energy alongside two other combined equivalent diagnostics. These diagnostics are useful, especially when we include anisotropic baryon acoustic oscillation (BAO) data in an…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-05 Bikash R. Dinda

In this paper, a well-motivated parametrization of the Hubble parameter ($H$% ) is revisited that renders two models of dark energy showing some intriguing features of the late-time accelerating Universe. A general quintessence field is…

General Relativity and Quantum Cosmology · Physics 2023-09-19 Amine Bouali , Himanshu Chaudhary , Amritansh Mehrotra , S. K. J. Pacif

We compare four different methods that can be used to analyze the type Ia supernovae (SnIa) data, ie to use piecewise-constant functions in terms of: the dark energy equation of state $w(z)$, the deceleration parameter $q(z)$, the Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 Savvas Nesseris , Domenico Sapone

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

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

In the statistical framework of model-independent Gaussian processes (GP), we search for the evidence of dynamical dark energy (DDE) using the "Joint Light-curve Analysis" (JLA) Type Ia supernovae (SNe Ia) sample, the 30 latest cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-02 Deng Wang , Wei Zhang , Xin-He Meng

We reconstruct evolution of the dark energy (DE) density using a nonparametric Bayesian approach from a combination of latest observational data. We caution against parameterizing DE in terms of its equation of state as it can be singular…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 Yuting Wang , Levon Pogosian , Gong-Bo Zhao , Alex Zucca