Non-adiabatic perturbations in Ricci dark energy model
نویسندگان
چکیده
منابع مشابه
Dark Energy and Non–linear Perturbations
One of the most important goals of contemporary cosmology is to unreveal the properties of dark energy. This energy form is thought to be responsible for the observed accelerating expansion of the present day universe. There are several methods used to study the properties of dark energy. The important ones make use of the anisotropies in the Cosmic Microwave Background Radiation (CMB), the evo...
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Perturbations in a Chaplygin gas, characterized by an equation of state p = −A/ρ, may acquire non-adiabatic contributions if spatial variations of the parameter A are admitted. This feature is shown to be related to a specific internal structure of the Chaplygin gas. We investigate how perturbations of this type modify the adiabatic sound speed. A reduction of the effective sound speed compared...
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The ΛCDM paradigm, characterised by a constant equation of state w = −1 for dark energy, is the model that better fits observations. However, the same observations strongly support the possibility of a dark energy content where the corresponding equation of state is close to but slightly smaller than −1. In this regard, we focus on three different models where the dark energy content is describ...
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Perturbations in a Chaplygin gas, characterized by an equation of state p = −A/ρ, may acquire non-adiabatic contributions if spatial variations of the parameter A are admitted. This feature is shown to be related to a specific internal structure of the Chaplygin gas. We investigate how perturbations of this type modify the adiabatic sound speed and influence the time dependence of the gravitati...
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ژورنال
عنوان ژورنال: Journal of Cosmology and Astroparticle Physics
سال: 2012
ISSN: 1475-7516
DOI: 10.1088/1475-7516/2012/01/017