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Related papers: Observational tests of non-adiabatic Chaplygin gas

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

General Relativity and Quantum Cosmology · Physics 2014-11-17 M. C. Bento , O. Bertolami , A. A. Sen

The hypothesis that dark matter and dark energy are unified through the Chaplygin gas is reexamined. Using generalizations of the spherical model which incorporate effects of the acoustic horizon we show that an initially perturbative…

Astrophysics · Physics 2008-11-26 Neven Bilic , Robert J. Lindebaum , Gary B. Tupper , Raoul D. Viollier

Perturbations in a Chaplygin gas, characterized by an equation of state $p = -A/\rho$, may acquire non-adiabatic contributions if spatial variations of the parameter $A$ are admitted. This feature is shown to be related to a specific…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Winfried Zimdahl , Julio C. Fabris

We consider the possibility of an interaction in the dark sector in the presence of massive neutrinos, and study the observational constraints on three different scenarios of massive neutrinos using the most recent CMB anisotropy data in…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Suresh Kumar , Rafael C. Nunes

Understanding the behavior of the matter power spectrum on non-linear scales beyond the $\Lambda$CDM model is crucial for accurately predicting the large-scale structure (LSS) of the Universe in non-standard cosmologies. In this work, we…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-31 Emanuelly Silva , Ubaldo Zúñiga-Bolaño , Rafael C. Nunes , Eleonora Di Valentino

We consider the perturbation dynamics for the cosmic baryon fluid and determine the corresponding power spectrum for a $\Lambda(t)$CDM model in which a cosmological term decays into dark matter linearly with the Hubble rate. The model is…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-30 R. F. vom Marttens , W. S. Hipólito-Ricaldi , W. Zimdahl

Recently we proposed a new approach to the testing of dark energy models based on the observational data. In that work we focused particularly on quintessence models for demonstration and invoked a widely used parametrization of the dark…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-22 Chien-Wen Chen , Je-An Gu , Pisin Chen

We investigate the implications for some nonstandard cosmological models using data from the first three years of the Supernova Legacy Survey (SNLS3), assuming a spatially flat universe. A comparison between the constraints from the SNLS3…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-26 Zhengxiang Li , Puxun Wu , Hongwei Yu

The present study reveals observational constraints on the coupling between dark components of anisotropic Bianchi type I universe. We assume interaction between dark matter and dark energy and split the continuity equation with inclusion…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-20 Hassan Amirhashchi , Anil Kumar Yadav , Nafis Ahmad , Vikrant Yadav

We devise a fully self-consistent simulation pipeline for the first time to study the interaction between dark matter and dark energy. We perform convergence tests and show that our code is accurate on different scales. Using the parameters…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-03 Jiajun Zhang , Rui An , Shihong Liao , Wentao Luo , Zhaozhou Li , Bin Wang

We study the clustering Generalized Chaplygin Gas (GCG) as a possible candidate for dark matter-dark energy unification. The vanishing speed of sound ($c_{s}^2 = 0$) for the GCG fluid can be obtained by incorporating higher derivative…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-22 Sumit Kumar , Anjan A. Sen

The consequences of taking the generalized Chaplygin gas as the dark energy constituent of the Universe on the gravitational waves are studied and the spectrum obtained from this model, for the flat case, is analyzed. Besides its importance…

General Relativity and Quantum Cosmology · Physics 2009-11-10 J. C. Fabris , S. V. B. Goncalves , M. S. dos Santos

We compare supernovae and Baryon Acoustic Oscillations data to the predictions of a cosmological model of interacting dark matter and dark energy. This theoretical model can be derived from the effective field theory of Einstein-Cartan…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-01 Damien Bégué , Clément Stahl , She-Sheng Xue

Models proposing a non-gravitational interaction between dark energy (DE) and dark matter (CDM) have been extensively studied as alternatives to the standard cosmological model. A common approach to describing the DE-CDM coupling assumes it…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-22 Jaelsson S. Lima , Rodrigo von Marttens , Luciano Casarini

The nature of the dark components (dark matter and dark energy) that dominate the current cosmic evolution is a completely open question at present. In reality, we do not even know if they really constitute two separated substances. In this…

Astrophysics · Physics 2009-11-10 Abha Dev , Deepak Jain , J. S. Alcaniz

Using various latest cosmological datasets including Type-Ia supernovae, cosmic microwave background radiation, baryon acoustic oscillations, and estimations of the Hubble parameter, we test some dark energy models with parameterized…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-28 Jing Yang , Xin-Yan Fan , Chao-Jun Feng , Xiang-Hua Zhai

We investigate the observational signatures of the holographic dark energy models in this paper, including both the original model and a model with an interaction term between the dark energy and dark matter. We first delineate the…

Astrophysics · Physics 2010-04-14 Yin-Zhe Ma , Yan Gong , Xuelei Chen

We constrain an interacting, holographic dark energy model, first proposed by two of us in [1], with observational data from supernovae, CMB shift, baryon acoustic oscillations, x-rays, and the Hubble rate. The growth function for this…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 Iván Durán , Diego Pavón , Winfried Zimdahl

We explore the implications of type Ia supernovae (SNIa) observations on flat cosmological models whose matter content is an exotic fluid with equation of state, p=-M^(4(a+1))/rho^a. In this scenario, a single fluid component may drive the…

Astrophysics · Physics 2016-08-30 Martin Makler , Sergio Quinet de Oliveira , Ioav Waga

We use different combinations of data samples to investigate the new generalized Chaplygin gas (NGCG) model in the context of dark energy (DE) cosmology. Using the available cosmological data, we put constraints on the the free parameters…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-19 Fataneh Salahedin , Reza Pazhouhesh , Mohammad Malekjani