Ruling out the Modified Chaplygin Gas cosmologies

Fabris, J. C.; Velten, Hermano; Ogouyandjou, Carlos; Tossa, J.

doi:10.1016/j.physletb.2010.10.022

Cited by 47 publications

(42 citation statements)

References 22 publications

(23 reference statements)

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“…This is consistent with the constraint on the GCG class of models reported in [29] (B < 10 −6 ). On the other hand, Lyman-alpha constraints on the matter power spectrum on comoving wavenumbers up to k ∼ 2 Mpc −1 [43,44] are expected to lead to even tighter limits on the value of B, only slightly less constraining than the ones obtained in the present paper using the galactic rotation curves.…”

Section: B Other Observational Constraintssupporting

confidence: 91%

“…This model incorporates an extra parameter which is associated to a lower bound on the sound speed of the effective DM component. The MCG has been observationally constrained using the redshift dependence of the apparent magnitude of type Ia supernovae, the Cosmic Microwave Background (CMB) anisotropies, and the matter power spectrum, including Baryonic Acoustic Oscillations (BAO) [25][26][27][28][29][30][31][32][33][34]. Further extensions incorporating additional terms accounting for a possible growth of the comoving Jeans length with cosmic density have also been proposed in the literature (see, e.g., [35]).…”

Section: Introductionmentioning

confidence: 99%

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Constraints on the dark matter sound speed from galactic scales: The cases of the modified and extended Chaplygin gas

Avelino¹,

Ferreira²

2015

Phys. Rev. D

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We show that the observed rotation curves of spiral galaxies constrain the sound speed of the dark matter to be cs < 10 −4 c, where c is the speed of light in vacuum. Using the Modified Chaplygin Gas as a representative example of a class of unified dark energy models incorporating an effective dark matter component with a non-zero sound speed, we determine the most stringent constraint to date on the value of the constant contribution to the equation of state parameter in this class of models. Finally, we explain the reason why previous constraints using the Cosmic Microwave Background and Baryonic Acoustic Oscillations were not as competitive as the one presented in this paper and discuss the limitations of the recently proposed Extended Chaplygin Gas.

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Section: B Other Observational Constraintssupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Constraints on the dark matter sound speed from galactic scales: The cases of the modified and extended Chaplygin gas

Avelino¹,

Ferreira²

2015

Phys. Rev. D

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“…(27), the scale factor varies from zero to infinity and so the energy density. In the second t varies from the positive value which nullifies the expression between parenthesis in Eq.…”

Section: Integration Of the Exactly Solvable Casesmentioning

confidence: 99%

Bouncing solutions in Rastall’s theory with a barotropic fluid

et al. 2013

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Rastall's theory is a modification of Einstein's theory of gravity where the covariant divergence of the stress-energy tensor is no more vanishing, but proportional to the gradient of the Ricci scalar. The motivation of this theory is to investigate a possible non-minimal coupling of the matter fields to geometry which, being proportional to the curvature scalar, may represent an effective description of quantum gravity effects. Non-conservation of the stressenergy tensor, via Bianchi identities, implies new field equations which have been recently used in a cosmological context, leading to some interesting results. In this paper we adopt Rastall's theory to reproduce some features of the effective Friedmann's equation emerging from loop quantum cosmology. We determine a class of bouncing cosmological solutions and comment about the possibility of employing these models as effective descriptions of the full quantum theory. *

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“…The Chaplygin gas type equation of state is frequently studied in the literature and used to describe standard matter and dark energy as a single fluid [8,9,10,11,12,13,14]. Such equations of state can be generated by a standard scalar field with a specific potential [8,15] or a tachyon scalar field [16], which can be also applied in various other contexts [17,18,19].…”

Section: Introductionmentioning

confidence: 99%

The van der Waals fluid and its role in cosmology

Jantsch

Christmann

Kremer

2016

Int. J. Mod. Phys. D

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We analyze the properties of a generic cosmological fluid described by the van der Waals equation of state. Exact solutions for the energy density evolution are found as implicit functions of the scale factor for a flat Friedmann-Robertson-Walker space-time. The possible values of the free parameter in the van der Waals equation are selected a posteriori, in accordance with asymptotic behaviors that are physically relevant. The stability of the model against small perturbations is studied through the hydrodynamic perturbations of the fluid for the relevant cases. It is found that a van der Waals fluid seems appropriate to describe non-eternal inflationary scenarios.

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Ruling out the Modified Chaplygin Gas cosmologies

Cited by 47 publications

References 22 publications

Constraints on the dark matter sound speed from galactic scales: The cases of the modified and extended Chaplygin gas

Constraints on the dark matter sound speed from galactic scales: The cases of the modified and extended Chaplygin gas

Bouncing solutions in Rastall’s theory with a barotropic fluid

The van der Waals fluid and its role in cosmology

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