English
Related papers

Related papers: Testing the growth rate in homogeneous and inhomog…

200 papers

We study the effects of vacuum energy perturbations on the evolution of the dark matter growth rate in a decomposed Chaplygin gas model with interacting dark matter and vacuum energy. We consider two different cases: (i) geodesic dark…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-12 Humberto A. Borges , Patrícia Hepp

We study the main cosmological properties of the Generalized Chaplygin Gas (GCG) dark energy model at the background and perturbation levels. By using the latest cosmological data in both the background and perturbation levels, we implement…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 S. F. Salahedin , M. Malekjani , K. Y. Roobiat , R. Pazhouhesh

Any unified dark matter cosmology can be decomposed into dark matter interacting with vacuum energy, without introducing any additional degrees of freedom. We present observational constraints on an interacting vacuum plus dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-16 Yuting Wang , David Wands , Lixin Xu , Josue De-Santiago , Alireza Hojjati

We study cosmological perturbations in the context of an interacting dark energy model, in which the cosmological term decays linearly with the Hubble parameter, with concomitant matter production. A previous joint analysis of the…

Astrophysics · Physics 2008-11-26 H. A. Borges , S. Carneiro , J. C. Fabris , C. Pigozzo

Vacuum energy is a simple model for dark energy driving an accelerated expansion of the universe. If the vacuum energy is inhomogeneous in spacetime then it must be interacting. We present the general equations for a spacetime-dependent…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-01 Josue De-Santiago , David Wands , Yuting Wang

We present improved constraints on an interacting vacuum model using updated astronomical observations including the first data release from Planck. We consider a model with one dimensionless parameter, $\alpha$, describing the interaction…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-09 Yuting Wang , David Wands , Gong-Bo Zhao , Lixin Xu

We exploit the gauge-invariant formalism to analyse the perturbative behaviour of two cosmological models based on the generalized Chaplygin gas describing both dark matter and dark energy in the present Universe. In the first model we…

Astrophysics · Physics 2009-06-23 V. Gorini , A. Y. Kamenshchik , U. Moschella , O. F. Piattella , A. A. Starobinsky

In this paper, we undertake a unified study of background dynamics and cosmological perturbations in the presence of the Chaplygin gas. This is done by first constraining the background cosmological parameters of different Chaplygin gas…

General Relativity and Quantum Cosmology · Physics 2023-10-12 Shambel Sahlu , Heba Sami , Renier Hough , Maye Elmardi , Anna-Mia Swart , Amare Abebe

We analyse three interacting vacuum dark energy models with the aim of exploring whether the $H_0$ and $\sigma_8$ tensions can be simultaneously resolved in such models. We present the first ever derivation of the covariant gauge-invariant…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-13 Marco Sebastianutti , Natalie B. Hogg , Marco Bruni

In this work we explore the background dynamics when dark energy is coupled to dark matter with a suitable interaction in the universe described by brane cosmology. Here DGP and the RSII brane models have been considered separately. Dark…

General Physics · Physics 2015-06-05 Prabir Rudra

We discuss an interacting dark sector model featuring decaying vacuum energy and dark matter empowered by gravitationally induced matter creation. Motivated by quantum field theoretic considerations of vacuum decay and adiabatic particle…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-17 Lokesh Chander , C P Singh

We investigate the impact of a non-gravitational interaction between dark matter and dark energy on the growth rate of matter density perturbations within the framework of a $w$CDM scenario, where the coupling is proportional to the dark…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-06 Fan Yang , Rongrong Zhai , Xiangyun Fu , Bing Xu , Kaiwen Liu , Chikun Ding , Yang Huang

We investigate the cosmological perturbation dynamics for a universe consisting of pressureless baryonic matter and a viscous fluid, the latter representing a unified model of the dark sector. In the homogeneous and isotropic background the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 W. S. Hipólito-Ricaldi , H. E. S. Velten , W. Zimdahl

The generalized Chaplygin gas (GCG) model allows for an unified description of the cosmologically recent accelerated expansion of the Universe and of the evolution of energy density perturbations. This dark energy - dark matter unification…

Astrophysics · Physics 2007-05-23 O. Bertolami

In the present work, we study a cosmological model composed of a viscous dark matter interacting with decaying vacuum energy in a spatially flat Universe. In the first part, we find the analytical solution of different cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-27 Vinita Khatri , C. P. Singh , Milan Srivastava

We examine the growth of structure in three different cosmological models with interacting dark matter and vacuum energy. We consider the case of geodesic dark matter with zero sound speed, where the relativistic growing mode in…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-20 Humberto A Borges , David Wands

Different models of the cosmic substratum which pretend to describe the present stage of accelerated expansion of the Universe like the $\Lambda$CDM model or a Chaplygin gas, can be seen as special realizations of a holographic dark energy…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Winfried Zimdahl

We use observations of cosmic microwave background anisotropies, supernova luminosities and the baryon acoustic oscillation signal in the galaxy distribution to constrain the cosmological parameters in a simple interacting dark energy model…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-18 Jussi Valiviita , Roy Maartens , Elisabetta Majerotto

We study the asymptotic dynamics of dark energy as a mixture of pressureless matter and an interacting vacuum component. We find that the only dynamics compatible with current observational data favors an asymptotically vanishing…

General Relativity and Quantum Cosmology · Physics 2018-09-19 Georgia Kittou

Yes, but only for a parameter value that makes it almost coincide with the standard model. We reconsider the cosmological dynamics of a generalized Chaplygin gas (gCg) which is split into a cold dark matter (CDM) part and a dark energy (DE)…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-03 R. F. vom Marttens , L. Casarini , W. Zimdahl , W. S. Hipólito-Ricaldi , D. F. Mota
‹ Prev 1 2 3 10 Next ›