English
Related papers

Related papers: Observational constraints on a generalized equatio…

200 papers

The dark energy model with the equation of state p_d=-rho_d - A rho_d^alpha is studied. The model comprises and provides realization of several types of singularities in different parameter regimes: the divergence of the dark energy density…

Astrophysics · Physics 2008-11-26 Hrvoje Stefancic

The present work is based upon a parametric reconstruction of the effective or total equation of state in a model for the universe with accelerated expansion. The constraints on the model parameters are obtained by maximum likelihood…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-27 Ankan Mukherjee

In this paper, we study the cosmological implications of the 100 square degree Weak Lensing survey (the CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS surveys). We combine these weak lensing data with the cosmic microwave background (CMB)…

Astrophysics · Physics 2010-05-07 Hong Li , Jie Liu , Jun-Qing Xia , Lei Sun , Zu-Hui Fan , Charling Tao , Andre Tilquin , Xinmin Zhang

We investigate the hypothesis that the evolution of the Universe can be described by a single dark fluid whose effective equation of state (EoS), $\omega_{\rm{eff}}$, is a linear combination of a logarithmic term and a power law term, both…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-30 Vipin Chandra Dubey , Subhajit Saha , Abdulla Al Mamon

The study conducted in this research paper utilizes the $f(Q,T)$ gravity, where $Q$ represents non-metricity and $T$ represents the trace of the energy-momentum tensor, to investigate the accelerated expansion of the universe. To complete…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-17 M. Koussour , N. Myrzakulov , J. Rayimbaev , A. Errehymy , Orhan Donmez

In this work, we confront ten cosmological models with observational $H(z)$ data. The possible interaction between dark energy and dust matter is allowed in some of these models. Also, we consider the possibility of (effective)…

Astrophysics · Physics 2010-04-05 Hao Wei , Shuang Nan Zhang

A phenomenological approach is proposed to the problem of universe accelerated expansion and of the dark energy nature. A general class of models is introduced whose energy density depends on the redshift $z$ in such a way that a smooth…

Astrophysics · Physics 2009-11-10 V. F. Cardone , A. Troisi , S. Capozziello

The consensus of opinion in cosmology is that the Universe is currently undergoing a period of accelerated expansion. With current and proposed high precision experiments it offers the hope of being able to discriminate between the two…

Astrophysics · Physics 2011-02-09 P. S. Corasaniti , E. J. Copeland

We perform a study of cosmic evolution with an equation of state parameter $\omega(t)=\omega_0+\omega_1(t\dot H/H)$ by selecting a phenomenological $\Lambda$ model of the form, $\dot\Lambda\sim H^3$. This simple proposition explains both…

General Relativity and Quantum Cosmology · Physics 2009-11-13 A. A. Usmani , P. P. Ghosh , Utpal Mukhopadhyay , P. C. Ray , Saibal Ray

While there is mounting evidence in all fronts of experimental cosmology for a non-vanishing dark energy component in the Universe, we are still far away from understanding its ultimate nature. A fundamental cosmological constant, Lambda,…

Astrophysics · Physics 2008-11-26 Joan Sola , Hrvoje Stefancic

In this study, we investigated the effects of incorporating barotropic fluids on cosmological solutions within the general relativity (GR) framework. We proposed a modified version of the barotropic fluid with the EoS, $p=\zeta _0 \rho…

General Relativity and Quantum Cosmology · Physics 2025-04-29 Rajdeep Mazumdar , Mrinnoy M. Gohain , Kalyan Bhuyan

One of the main aims in the next generation of precision cosmology experiments will be an accurate determination of the equation of state (EOS) for the dark energy (DE). If the latter is dynamical, the resulting barotropic index \omega…

Astrophysics · Physics 2009-11-13 Joan Sola , Hrvoje Stefancic

In this paper, observational constraints on the cosmic equation of state of dark energy ($p = w \rho$) have been investigated using gravitational lensing statistics. A likelihood analysis of the lens surveys has been carried out to…

Astrophysics · Physics 2009-09-25 Abha Dev , Deepak Jain , N. Panchapakesan , S. Mahajan , V. B. Bhatia

In this paper, we propose a new phenomenological two parameter parametrization of $q(z)$ to constrain barotropic dark energy models by considering a spatially flat FRW universe, neglecting the radiation component, and reconstructing the…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Jaime Roman-Garza , Tomas Verdugo , Juan Magana , Veronica Motta

We use a variant of principal component analysis to investigate the possible temporal evolution of the dark energy equation of state, $w(z)$. We constrain $w(z)$ in multiple redshift bins, utilizing the most recent data from Type Ia…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-17 Paolo Serra

We propose and implement a novel test to assess deviations from well-established concordance $\Lambda$CDM cosmology while inferring dark energy properties. In contrast to the commonly implemented parametric forms of the dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-27 Upala Mukhopadhyay , Sandeep Haridasu , Anjan A Sen , Suhail Dhawan

We present an updated reconstruction of the DE equation of state (EoS), $w(a)$, employing the newly released DESI DR2 Baryon Acoustic Oscillation data. This analysis constrains the cosmological scenarios influenced by different models…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-17 Saddam Hussain , Simran Arora , Anzhong Wang , Ben Rose

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

In this article, we introduce an innovative parametric representation of the Hubble parameter, providing a model-independent means to explore the dynamics of an accelerating cosmos. The model's parameters are rigorously constrained through…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-16 M. Koussour , N. Myrzakulov , M. K. M. Ali

The increasing richness of data related to cold dense matter, from laboratory experiments to neutron-star observations, requires a framework for constraining the properties of such matter that makes use of all relevant information. Here, we…

High Energy Astrophysical Phenomena · Physics 2020-01-08 M. Coleman Miller , Cecilia Chirenti , Frederick K. Lamb
‹ Prev 1 4 5 6 7 8 10 Next ›