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This paper discusses a new model for galactic dark matter by combining an anisotropic pressure field corresponding to normal matter and a quintessence dark energy field having a characteristic parameter $\omega_q$ such that $-1<\omega_q<…

General Relativity and Quantum Cosmology · Physics 2011-07-15 F. Rahaman , Peter K. F. Kuhfittig , K. Chakraborty , M. Kalam , D. Hossain

Barrow holographic dark energy model is an extension of holographic dark energy that incorporates modifications to entropy due to quantum gravitational effects. In this work we study the cosmological properties of interacting Barrow…

General Relativity and Quantum Cosmology · Physics 2025-05-23 Priyanka Adhikary , Sudipta Das

If dark energy interacts with dark matter, this gives a new approach to the coincidence problem. But interacting dark energy models can suffer from pathologies. We consider the case where the dark energy is modelled as a fluid with constant…

Astrophysics · Physics 2008-11-26 Jussi Valiviita , Elisabetta Majerotto , Roy Maartens

A new kind of accelerating flat model with no dark energy that is fully dominated by cold dark matter (CDM) is investigated. The number of CDM particles is not conserved and the present accelerating stage is a consequence of the negative…

Astrophysics · Physics 2014-11-18 J. A. S. Lima , F. E. Silva , R. C. Santos

Cosmological models with variable and modified equations of state for dark energy are confronted with observational data, including Type Ia supernovae, Hubble parameter data $H(z)$ from different sources, and observational manifestations of…

General Relativity and Quantum Cosmology · Physics 2022-03-29 German S. Sharov , Vasily E. Myachin

Einstein gravity coupled to a massive skew symmetric field F_{\mu\nu\lambda} leads to an acceleration law that modifies the Newtonian law of attraction between particles. We use a framework of non-perturbative renormalization group…

Astrophysics · Physics 2009-11-10 J. W. Moffat

Non-gravitational interaction between dark matter and dark energy has been considered in a spatially flat Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) universe. The interaction rate is assumed to be linear in the energy densities of dark…

General Relativity and Quantum Cosmology · Physics 2020-07-07 Supriya Pan , Jaume de Haro , Weiqiang Yang , Jaume Amorós

We have witnessed different values of the Hubble constant being found in the literature in the past years. Albeit, early measurements often result in an $H_0$ much smaller than those from late-time ones, producing a statistically…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-11 Simony S da Costa , Dêivid R da Silva , Álvaro S de Jesus , Nelson Pinto-Neto , Farinaldo S Queiroz

The hypothesis of the scale invariance of the macroscopic empty space, which intervenes through the cosmological constant, has led to new cosmological models. They show an accelerated cosmic expansion and satisfy several major cosmological…

Astrophysics of Galaxies · Physics 2017-11-15 Andre Maeder

Using recent precision measurements of cosmological paramters, we re-examine whether these observations alone, independent of type Ia supernova surveys, are sufficient to imply the existence of dark energy. We find that best measurements of…

Astrophysics · Physics 2008-11-26 Greg Bothun , Stephen D. H. Hsu , Brian Murray

The existence of "dark matter", inferred from the observed rotation curves of galaxies, is a hypothesis which is widely regarded as problematic. This paper proposes an alternative hypothesis based on the space-time geometry near a rotating…

General Physics · Physics 2020-02-27 Colin Rourke

We use the latest compilation of observational Hubble parameter measurements estimated with the differential evolution of cosmic chronometers, in combination with the local value of the Hubble constant recently measured with 2.4% precision,…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-13 Rafael C. Nunes , Supriya Pan , Emmanuel N. Saridakis

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

This paper investigates the effects of spatial curvature in a model where dark matter and dark energy interact. The analysis employs a range of datasets, including CMB, BAO, Type Ia Supernova, $H(z)$ from cosmic chronometers, $H_0$…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-28 Trupti Patil , Sukanta Panda

A pressureless dark matter component fits well with several cosmological observations. However, there are indications that cold dark matter may encounter challenges in explaining observations at small scales, particularly at galactic…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-17 Weiqiang Yang , Supriya Pan , Eleonora Di Valentino , Olga Mena , David F. Mota , Subenoy Chakraborty

The non-gauge vector field with as simple as possible Lagrangian (\ref{Lagrangian}) turned out an adequate tool for macroscopic description of the main properties of dark matter. The dependence of the velocity of a star on the radius of the…

General Relativity and Quantum Cosmology · Physics 2016-05-24 Boris E. Meierovich

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

In this work we study a phenomenological non-gravitational interaction between dark matter and dark energy. The scenario studied in this work extends the usual interaction model proportional to the derivative of the dark component density…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-14 Josue De-Santiago , Iván E. Sánchez G. , David Tamayo

Dynamical dark energy has been recently suggested as a promising and physical way to solve the 3.4 sigma tension on the value of the Hubble constant $H_0$ between the direct measurement of Riess et al. (2016) (R16, hereafter) and the…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-24 Eleonora Di Valentino , Alessandro Melchiorri , Eric V. Linder , Joseph Silk

We outline a dynamical dark energy scenario whose signatures may be simultaneously tested by astronomical observations and laboratory experiments. The dark energy is a field with slightly sub-gravitational couplings to matter, a logarithmic…

Astrophysics · Physics 2009-06-23 Nemanja Kaloper