Revealing the nonadiabatic nature of dark energy perturbations from galaxy clustering data

Velten, Hermano; Fazolo, Raquel Emy

doi:10.1103/physrevd.96.083502

Cited by 11 publications

(11 citation statements)

References 33 publications

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“…Our findings can be interpreted in the same way as in Ref. [1], i.e., while adiabatic dark energy models differs substantially from the standard ΛCDM cosmology if the equation of state parameter departures from the constant value w DE = p DE /ρ DE = −1, there seems to exist a sort of quasi-degeneracy between nonadiabatic dark energy models and the ΛCDM model.…”

Section: Discussionsupporting

confidence: 79%

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Degeneracy between nonadiabatic dark energy models and ΛCDM : Integrated Sachs-Wolfe effect and the cross correlation of CMB with galaxy clustering data

et al. 2018

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As recently pointed out in Ref. [Phys. Rev. D 96, 8, 083502 (2017)] the evolution of the linear matter perturbations in nonadiabatic dynamical dark energy models is almost indistinguishable (quasi-degenerated) to the standard ΛCDM scenario. In this work we extend this analysis to CMB observables in particular the integrated Sachs-Wolfe effect and its cross-correlation with large scale structure. We find that this feature persists for such CMB related observable reinforcing that new probes and analysis are necessary to reveal the nonadiabatic features in the dark energy sector.

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Section: Discussionsupporting

confidence: 79%

“…It has been found recently in Ref. [1] that nonadiabatic dark energy models are almost indistinguishable from the standard ΛCDM cosmology concerning the f σ 8 observable leading to an interesting degeneracy in the dark energy research context. Our focus in this work is to expand the analysis of Ref.…”

Section: Introductionmentioning

confidence: 99%

Degeneracy between nonadiabatic dark energy models and ΛCDM : Integrated Sachs-Wolfe effect and the cross correlation of CMB with galaxy clustering data

et al. 2018

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“…In [55] this method is applied and initial conditions are imposed at the radiation dominated epoch. On the other hand, in [56] the authors analyse the effects of non adiabaticity on the growth rate for several DE models and compute the observable f σ 8 .…”

Section: Introductionmentioning

confidence: 99%

Cosmological constraints of phantom dark energy models

Bouali

Albarran

Bouhmadi-López

et al. 2019

Physics of the Dark Universe

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We address three genuine phantom dark energy models where each of them induces the particular future events known as Big Rip, Little Rip and Little Sibling of the Big Rip. The background models are fully determined by a given dark energy equation of state. We first observationally constrain the corresponding model parameters that characterise each paradigm using the available data of supernova type Ia, Cosmic Microwave Background and Baryonic Acoustic Oscillations by using a Markov Chain Monte Carlo method. The obtained fits are used to solve numerically the first order cosmological perturbations. We compute the evolution of the density contrast of (dark) matter and DE, from the radiation dominated era till a totally DE dominated universe. Then, the obtained results are compared with respect to ΛCDM. We obtain the predicted current matter power spectrum and the evolution of f σ8 given by the models studied in this work. Finally, the models are tested by computing the reduced χ 2 for the "Gold2017" f σ8 dataset. * aminebouali smp@yahoo.com †

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“…Furthermore, in [47] the authors analyse the effects of a viscosity bulk within a modified gravity scenario endowed with the general action f (R, T ) and perform a test to check the validity of the studied models. The impact of the non adiabatic perturbations have been studied for example in [48,49]. In [48], the authors address a particular parametrisation of DE considering a linear combination of the intrinsic and entropy perturbations.…”

Section: Introductionmentioning

confidence: 99%

“…The impact of the non adiabatic perturbations have been studied for example in [48,49]. In [48], the authors address a particular parametrisation of DE considering a linear combination of the intrinsic and entropy perturbations. In the recent work [49], aside the non-adiabatic perturbations the non-vanishing anisotropic stress tensor is regarded as well.…”

Section: Introductionmentioning

confidence: 99%

A varying dark energy effective speed of sound parameter in the phantom Universe

2021

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We analyse the phenomenological effects of a varying Dark Energy (DE) effective speed of sound parameter, $$c^{2}_{\text {sd}}$$ c sd 2 , on the cosmological perturbations of three phantom DE models. Each of these models induce a particular abrupt future event known as Big Rip (BR), Little Rip (LR), and Little Sibling of the Big Rip (LSBR). In this class of abrupt events, all the bound structures in the Universe would be ripped apart at a finite cosmic time. We compute the evolution of the perturbations, $$f\sigma _{8}$$ f σ 8 growth rate and forecast the current matter power spectrum. We vary the $$c^{2}_{\text {sd}}$$ c sd 2 parameter in the interval [0, 1] and compute the relative deviation with respect $$c^{2}_{\text {sd}}=1$$ c sd 2 = 1 . In addition, we analyse the effect of gravitational potential sign flip that occurs at very large scale factors as compared with the current one.

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Revealing the nonadiabatic nature of dark energy perturbations from galaxy clustering data

Cited by 11 publications

References 33 publications

Degeneracy between nonadiabatic dark energy models and ΛCDM : Integrated Sachs-Wolfe effect and the cross correlation of CMB with galaxy clustering data

Degeneracy between nonadiabatic dark energy models and ΛCDM : Integrated Sachs-Wolfe effect and the cross correlation of CMB with galaxy clustering data

Cosmological constraints of phantom dark energy models

A varying dark energy effective speed of sound parameter in the phantom Universe

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