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Related papers: Testing the EoS of dark matter with cosmological o…

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Using late-Universe observations, we demonstrate that freeing dark energy and dark matter equations of state (EoS) dramatically alters the inferred strength and direction of their interactions. When dark sector EoS are fixed to…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-25 Peng-Ju Wu , Ming Zhang , Shang-Jie Jin

A puzzling implication of current data interpreted in the $\Lambda$CDM cosmology is the preference for a negative sum of neutrino masses. Moving to $w_0w_a$CDM brings an appreciable fraction of the neutrino mass posterior back to positive…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-17 Weiqiang Yang , Eleonora Di Valentino , Eric V. Linder , Sibo Zhang , Supriya Pan

In the background of a homogeneous and isotropic spacetime with zero spatial curvature, we consider interacting scenarios between two barotropic fluids, one is the pressureless dark matter (DM) and the other one is dark energy (DE), in…

General Relativity and Quantum Cosmology · Physics 2017-02-01 German S. Sharov , Subhra Bhattacharya , Supriya Pan , Rafael C. Nunes , Subenoy Chakraborty

Several independent cosmological data, collected within the last twenty years, revealed the accelerated expansion rate of the Universe, usually assumed to be driven by the so called dark energy, which, according to recent estimates,…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-16 Marek Demianski , Elisabeta Lusso , Maurizio Paolillo , Ester Piedipalumbo , Guido Risaliti

We investigate potential deviations from cold dark matter (CDM) using the latest Baryon Acoustic Oscillations (BAO) measurements from the Dark Energy Spectroscopic Instrument (DESI). Analyzing DESI data alone constrains the dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-22 Utkarsh Kumar , Abhijith Ajith , Amresh Verma

We investigate the constraints on cosmological parameters especially for EoS of dark energy, inflationary parameters, neutrino mass and curvature of universe using simulated Planck data. Firstly we determine cosmological parameters with…

Astrophysics · Physics 2014-11-18 Jun-Qing Xia , Hong Li , Gong-Bo Zhao , Xinmin Zhang

White Dwarfs (WDs), the final evolutionary stage of most stars, are frequently modeled considering only a dense plasma matter. However, their potential interaction with dark matter (DM), especially in galactic halos where DM is expected to…

Solar and Stellar Astrophysics · Physics 2025-11-07 Sílvia P. Nunes , José D. V. Arbañil , Juan M. Z. Pretel , Sérgio B. Duarte

In this study, we explore the impact of various combinations of CMB-independent datasets, including the recent DESI BAO measurements, on the equation of state (EoS) of dark energy and other cosmological parameters within the framework of…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-13 Manisg Yadav , Archana Dixit , M. S. Barak , Anirudh Pradhan

The paper brings a novel approach to unification of dark matter and dark energy in terms of a cosmic fluid. A model is introduced in which the cosmic fluid speed of sound squared is defined as a function of its equation of state (EoS)…

General Relativity and Quantum Cosmology · Physics 2019-08-06 Dalibor Perkovic , Hrvoje Stefancic

Abandoning the perfect fluid hypothesis, we investigate here the possibility that the dark energy equation of state (EoS) $w$ is a nonlinear function of the energy density $\rho$. To this aim, we consider four different EoS describing…

Astrophysics · Physics 2009-11-13 V. F. Cardone , C. Tortora , A. Troisi , S. Capozziello

We investigate the possibility that part of the dark matter is not made out of the usual cold dark matter (CDM) dustlike particles, but is under the form of a fluid of strings with barotropic factor $w_s = -1/3$ of cosmic origin. To this…

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

It is well known that there are several long-standing problems implying the discordance of the $\Lambda$CDM model. Although most of the models proposed to resolve these problems assume that dark matter is pressureless, it is still possible…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-31 Yan-Hong Yao , Jun-Chao Wang , Xin-He Meng

We study the late-time evolution of the Universe where dark energy (DE) is presented by a barotropic fluid on top of cold dark matter (CDM). We also take into account the radiation content of the Universe. Here by the late stage of the…

General Relativity and Quantum Cosmology · Physics 2015-07-24 Ozgur Akarsu , Mariam Bouhmadi-López , Maxim Brilenkov , Ruslan Brilenkov , Maxim Eingorn , Alexander Zhuk

In this paper we investigate a new phenomenological parameterization for unified dark matter and dark energy based on the polynomial expansion of the barotropic equation of state parameter $w$. Our parameterization provides well-behaving…

General Relativity and Quantum Cosmology · Physics 2018-08-01 Zahra Davari , Mohammad Malekjani , Michal Artymowski

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 introduce a set of two-parameter models for the dark energy equation of state (EOS) $w(z)$ to investigate time-varying dark energy. The models are classified into two types according to their boundary behaviors at the redshift…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Qing-Jun Zhang , Yue-Liang Wu

In this paper, we study a model which is composed by the cosmological constant and dark matter with nonzero equation of state parameter, which could be called as $\Lambda$wDM. In the synchronous gauge, we obtain the perturbation equations…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-01 Weiqiang Yang , Lixin Xu

In a recent work [Phys. Rev. D 98, 043521 (2018)], we have investigated a dark matter (DM)-photon coupling model in which the DM decays into photons in the presence of dark energy (DE) with the constant equation of state (EoS) parameter.…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-30 Santosh Kumar Yadav

Cold Dark Matter (CDM) is a crucial constituent of the current concordance cosmological model. Having a vanishing equation of state (EoS), its energy density scales with the inverse cosmic volume and is thus uniquely described by a single…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-11 Michael Kopp , Constantinos Skordis , Daniel B. Thomas , Stéphane Ilić

We investigate the model of dark matter-dark energy (DM-DE) interaction with coupling strength proportional to the multiplication of dark sector densities with different power indices $Q = \gamma \rho_{\rm c}^{\alpha} \rho_{\rm d}^{\beta}$.…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-26 Gong Cheng , Yin-Zhe Ma , Fengquan Wu , Jiajun Zhang , Xuelei Chen