Scalar perturbations in cosmological models with dark energy-dark matter interaction

Eingorn, Maxim; Kiefer, Claus

doi:10.1088/1475-7516/2015/07/036

Cited by 14 publications

(12 citation statements)

References 52 publications

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“…This is the main result of the present investigation, and it is in agreement with the results of other observational works [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], however it has been arisen through the novel use of the recently released cosmic chronometers data.…”

Section: Resultssupporting

confidence: 92%

“…Hence, many different scenarios of interacting dark energy have been constructed (see [7,8] for reviews and references therein). Interestingly enough, recently it has been shown that the current data might favor the late-time interaction between CDM and the vacuum energy [9][10][11][12] or the dynamical dark energy sector [13][14][15][16][17][18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

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New constraints on interacting dark energy from cosmic chronometers

2016

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We use the latest compilation of observational Hubble parameter measurements estimated with the differential evolution of cosmic chronometers, in combination with the local value of the Hubble constant recently measured with 2.4% precision, to constrain the cosmological scenario where dark energy interacts directly with the dark matter sector. To diminish the degeneracy between the parameters we additionally consider standard probes, such as Supernovae Type Ia from joint light curves (JLA) sample, Baryon Acoustic Oscillation distance measurements (BAO), and cosmic microwave background data from Planck 2015 estimations. Our analysis shows that the direct interaction between dark energy and dark matter is mildly flavored, while the dark energy equationof-state parameter is w < −1 at 3σ confidence level.PACS numbers: 95.36.+x, 95.35.+d, 98.80.Es

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Section: Resultssupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

New constraints on interacting dark energy from cosmic chronometers

2016

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“…We note that coupled states of perfect fluids were investigated in the case of a perfect fluid with a constant equation of state parameter [25] and for the following cosmological scenarios and constituents of the Universe: quark-gluon nuggets [27], the CPL model [28], Chaplygin gas [29], nonlinear f (R) gravity [30], as well as the models with a scalar field [31,32] and dark sector interactions [33,34].…”

Section: Equations For Gravitational Potential φmentioning

confidence: 99%

Scalar and vector perturbations in a universe with discrete and continuous matter sources

Eingorn

Kiefer

Zhuk

2016

J. Cosmol. Astropart. Phys.

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Abstract. We study a universe filled with dust-like matter in the form of discrete inhomogeneities (e.g., galaxies and their groups and clusters) and two sets of perfect fluids with linear and nonlinear equations of state, respectively. The background spacetime geometry is defined by the FLRW metric. In the weak gravitational field limit, we develop the first-order scalar and vector cosmological perturbation theory. Our approach works at all cosmological scales (i.e. sub-horizon and super-horizon ones) and incorporates linear and nonlinear effects with respect to energy density fluctuations. We demonstrate that the scalar perturbation (i.e. the gravitational potential) as well as the vector perturbation can be split into individual contributions from each matter source. Each of these contributions satisfies its own equation. The velocity-independent parts of the individual gravitational potentials are characterized by a finite time-dependent Yukawa interaction range being the same for each individual contribution. We also obtain the exact form of the gravitational potential and vector perturbation related to the discrete matter sources. The self-consistency of our approach is thoroughly checked. The derived equations can form the theoretical basis for numerical simulations for a wide class of cosmological models.

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“…Hence, in the literature one can find many such interacting scenarios (see [5,6] for review and references therein), independently of the specific dark-energy nature, namely whether it arises from fields [7,8] or through a gravitational modification [9,10,11]. The interacting scenarios can be very efficient in describing late-time universe, and moreover they seem * Electronic address: supriya.maths@presiuniv.ac.in † Electronic address: d11102004@163.com ‡ Electronic address: cs12ip026@iiserkol.ac.in § Electronic address: msaridak@phys.uoa.gr to be slightly favored comparing to non-interacting ones [12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29]. Additionally, they seem to be efficient in addressing the H 0 tension [30,31,32,33,34] as well as the σ 8 tension [34,35,36].…”

Section: Introductionmentioning

confidence: 99%

Observational constraints on sign-changeable interaction models and alleviation of the H0 tension

et al. 2019

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We investigate various scenarios which include interaction forms between dark matter and dark energy that exhibit sign reverse, namely where the transfer of energy between the dark fluids changes sign during evolution. We study the large-scale inhomogeneities in such interacting scenarios and we confront them with the latest astronomical data. Our analysis shows that the sign-changeable interaction models are able to produce stable perturbations. Additionally, the data seem to slightly favor a non-zero interaction, however, within 1σ confidence level (CL) the scenarios cannot be distinguished from non-interacting cosmologies. We find that the best-fit value of the dark-energy equation-of-state parameter lies in the phantom regime, while the quintessence region is also allowed nevertheless at more than 2σ CL. Examining the effect of the interaction on the CMB TT and matter power spectra we show that while from the simple spectra it is hard to distinguish the interacting case from ΛCDM scenario, in the residual graphs the interaction is indeed traceable. Moreover, we find that sign-changeable interaction models can reconcile the H0 tension, however the σ8 tension is still persisting. Finally, we examine the validity of the laws of thermodynamics and we show that the generalized second law is always satisfied, while the second derivative of the total entropy becomes negative at late times which implies that the universe tends towards thermodynamic equilibrium. 95.36.+x, 95.35.+d, 98.80.Es

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Scalar perturbations in cosmological models with dark energy-dark matter interaction

Cited by 14 publications

References 52 publications

New constraints on interacting dark energy from cosmic chronometers

New constraints on interacting dark energy from cosmic chronometers

Scalar and vector perturbations in a universe with discrete and continuous matter sources

Observational constraints on sign-changeable interaction models and alleviation of the H0 tension

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