Large-scale structure and integrated Sachs–Wolfe effect in decaying vacuum cosmology

In cosmology, phenomenologically motivated expressions for running vacuum are commonly parametrized as linear functions Λ(H 2 ) or Λ(R). Such kind of models assume an equation of state for vacuum given by P Λ = − ρ Λ , relating their background pressure P Λ and mean energy density ρ Λ ≡ Λ/8πG. This equation of state requires that the dynamic for vacuum is due to the energy exchange with the material species. Most of the approaches to background level consider only the energy exchange between vacuum and the transient dominant material component of the universe. We extend such models assuming the running vacuum as the sum of independent contributions ρ Λ = i ρ Λi , associated with (and interacting with) each of the i material species. We derive the linear scalar perturbations for two running scenarios, modeling its cosmic evolution and identifying their different imprints on the cosmic microwave background anisotropies and the matter power spectrum. In the Λ(H 2 ) scenario the running vacuum are coupled with all the material species in the universe, whereas the Λ(R) description only leads to coupling between vacuum and the non-relativistic matter components; which produces different imprints of the two models on the matter power spectrum. A comparison with the Planck 2015 data was made in order to constrain the free parameters of the models. In the case of the Λ(H 2 ) model, it was found that Ω Λ = 0.705 ± 0.027 and H 0 = 69.6 ± 2.9 km M pc −1 s −1 , which diminish the tension with the low redshift expectations. * elduartep@usp.br †

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“…In this limit, ω i = P i /ρ i = const., expressions (28) and (29) reduce to (33) and (34), respectively.…”

Section: A Coupling Terms For Massive Neutrinosmentioning

confidence: 99%

Running vacuum cosmological models: linear scalar perturbations

Perico

Tamayo

2017

J. Cosmol. Astropart. Phys.

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“…The background and perturbation solutions when conserved baryons are explicitly considered were studied in Ref. [7]. The background is determined by the conservation and Friedmann equations 5,6 aHρ m + 3Hρ m = Γρ m , (30) 2aHH + ρ m = 0.…”

Section: Perturbationsmentioning

confidence: 99%

“…Actually, all these observations are directly sensitive to the gravitational potential generated by the total matter. It is possible to shown[7] that, despite the suppression in the dark matter contrast, the gravitational potential is almost unaffected, because it is proportional to δρm, not to δm 5. In equations (30)-(33), the prime means derivative w.r.t.…”

mentioning

confidence: 99%

Dynamical system analysis of interacting models

Carneiro

Borges

2017

Gen Relativ Gravit

Self Cite

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We perform a dynamical system analysis of a cosmological model with linear dependence between the vacuum density and the Hubble parameter, with constant-rate creation of dark matter. We show that the de Sitter spacetime is an asymptotically stable critical point, future limit of any expanding solution. Our analysis also shows that the Minkowski spacetime is an unstable critical point, which eventually collapses to a singularity. In this way, such a prescription for the vacuum decay not only predicts the correct future de Sitter limit, but also forbids the existence of a stable Minkowski universe. We also study the effect of matter creation on the growth of structures and their peculiar velocities, showing that it is inside the current errors of redshift space distortions observations.Comment: 6 pages, 3 figures. A section was added with an analysis of structures growth rate and peculiar velocities. To appear in General Relativity and Gravitatio

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“…The procedure described above has been performed in details in Ref. [32]. The resulting cross-correlation spectrum for the dark energy models studied here are shown in Figs In Fig.…”

Section: Confronting Scalar Perturbations With Cmb-lss Cross Cormentioning

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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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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Large-scale structure and integrated Sachs–Wolfe effect in decaying vacuum cosmology

Cited by 22 publications

References 27 publications

Running vacuum cosmological models: linear scalar perturbations

Running vacuum cosmological models: linear scalar perturbations

Dynamical system analysis of interacting models

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

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