Large-scale cosmic flows and moving dark energy

Jiménez, Jose Beltrán; Maroto, Antonio L.

doi:10.1088/1475-7516/2009/03/015

Cited by 16 publications

(10 citation statements)

References 37 publications

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“…This feature resembles the relative motions that appear among all the cosmic components in models with moving DE[71][72][73][74]. However, while the relative motions appear on all scales for moving DE models, the interaction considered in this work only generates appreciable relative motions between baryons and DM on sub-horizon scales.…”

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confidence: 51%

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On structure formation from a small-scales-interacting dark sector

Asghari

Jiménez

Khosravi

et al. 2019

J. Cosmol. Astropart. Phys.

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We consider a cosmological model with an interaction between dark matter and dark energy which leaves the background cosmology unaffected and only affects the evolution of the perturbations. This is achieved by introducing a coupling given in terms of the relative velocities of dark matter and dark energy. This interaction has the distinctive feature of appearing predominantly on small scales, where peculiar velocities can become important. We confront the predictions of the model to cosmological observations and find a potential alleviation of the known tension in the amplitude of density perturbations as measured by low redshift galaxy surveys and the Planck data. The model also predicts a shift in the turnover of the matter power spectrum which does not depend on the horizon at equality (fixed by the background cosmology and, thus, unaffected by the perturbations) and is entirely due to the interaction between dark matter and dark energy. A bias in the peculiar velocity between baryons and dark matter is also shown to be a unique feature of this type of interactions in the dark sector.

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confidence: 51%

“…The possibility that dark energy could have a different large scale rest frame from the rest of components has been explored in e.g. [71][72][73][74] (see also the recent paper [75] with a very thorough analysis of cosmologies with non-comoving fluids). In these models, our interaction would have effects also at the background level.…”

Section: Introductionmentioning

confidence: 99%

On structure formation from a small-scales-interacting dark sector

Asghari

Jiménez

Khosravi

et al. 2019

J. Cosmol. Astropart. Phys.

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“…To repeat the cautionary note, we started with: there are other exotic possibilities for the nature of matter in the universe than those assumed here, for example we do not know for certain that the dark energy does not have a large velocity relative to the baryon rest frame. A relativistic ‘wind’ of dark energy could significantly alter the ‘horizons’ discussed in this article (Maroto 2006; Jimenez & Maroto 2009). However, this is not the standard view; if such physics were to eventually turn out to be the case, what is presented here would have to be modified accordingly.…”

Section: Conclusion: the Domains Of Influencementioning

confidence: 97%

The evolution of our local cosmic domain: effective causal limits

Ellis

Stoeger

2009

Monthly Notices of the Royal Astronomical Society

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The causal limit usually considered in cosmology is the particle horizon, delimiting the possibilities of causal connection in the expanding universe. However it is not a realistic indicator of the effective local limits of important interactions in spacetime. We consider here the matter horizon for the Solar System, that is, the comoving region which has contributed matter to our local physical environment. This lies inside the effective domain of dependence, which (assuming the universe is dominated by dark matter along with baryonic matter and vacuum-energy-like dark energy) consists of those regions that have had a significant active physical influence on this environment through effects such as matter accretion and acoustic waves. It is not determined by the velocity of light c, but by the flow of matter perturbations along their world lines and associated gravitational effects. We emphasize how small a region the perturbations which became our Galaxy occupied, relative to the observable universe -even relative to the smallestscale perturbations detectable in the cosmic microwave background radiation. Finally, looking to the future of our local cosmic domain, we suggest simple dynamical criteria for determining the present domain of influence and the future matter horizon. The former is the radial distance at which our local region is just now separating from the cosmic expansion. The latter represents the limits of growth of the matter horizon in the far future. keywords cosmology: theory

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“…• Anisotropic dark energy equation of state [46][47][48] due perhaps to the existence of vector fields [49,50]. • Dark matter perturbations on a few Gpc scale [51,52]. For example an off center observer in a 1 Gpc void would experience the existence of a preferred cosmological axis through the Lemaître-Tolman-Bondi metric [53][54][55][56][57].…”

Section: Models Based On Energetic Violation Of the Cosmological Prinmentioning

confidence: 99%

Large Scale Cosmological Anomalies and Inhomogeneous Dark Energy

Perivolaropoulos

2014

Galaxies

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A wide range of large scale observations hint towards possible modifications on the standard cosmological model which is based on a homogeneous and isotropic universe with a small cosmological constant and matter. These observations, also known as "cosmic anomalies" include unexpected Cosmic Microwave Background perturbations on large angular scales, large dipolar peculiar velocity flows of galaxies ("bulk flows"), the measurement of inhomogenous values of the fine structure constant on cosmological scales ("alpha dipole") and other effects. The presence of the observational anomalies could either be a large statistical fluctuation in the context of ΛCDM or it could indicate a non-trivial departure from the cosmological principle on Hubble scales. Such a departure is very much constrained by cosmological observations for matter. For dark energy however there are no significant observational constraints for Hubble scale inhomogeneities. In this brief review I discuss some of the theoretical models that can naturally lead to inhomogeneous dark energy, their observational constraints and their potential to explain the large scale cosmic anomalies.

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Large-scale cosmic flows and moving dark energy

Cited by 16 publications

References 37 publications

On structure formation from a small-scales-interacting dark sector

On structure formation from a small-scales-interacting dark sector

The evolution of our local cosmic domain: effective causal limits

Large Scale Cosmological Anomalies and Inhomogeneous Dark Energy

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