Understanding the suppression of structure formation from dark matter-dark energy momentum coupling

Models in which scalar field dark energy interacts with dark matter via a pure momentum coupling have previously been found to potentially ease the structure formation tension between early and late-Universe observations. In this paper, we explore the physical mechanism underlying this feature. We a...

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Bibliographic Details
Published in:Physical review. D 2020-02, Vol.101 (4), p.1, Article 043531
Main Authors: Chamings, Finlay Noble, Avgoustidis, Anastasios, Copeland, Edmund J., Green, Anne M., Pourtsidou, Alkistis
Format: Article
Language:English
Subjects:
Couplings
Dark energy
Dark matter
Momentum
Perturbation methods
Power law
Scalars
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Summary:Models in which scalar field dark energy interacts with dark matter via a pure momentum coupling have previously been found to potentially ease the structure formation tension between early and late-Universe observations. In this paper, we explore the physical mechanism underlying this feature. We argue analytically that the perturbation growth equations imply the suppression of structure growth, illustrating our discussion with numerical calculations. Then we generalize the previously studied quadratic coupling between the dark energy and dark matter to a more general power-law case, also allowing for the slope of the dark energy exponential potential to vary. We find that the structure growth suppression is a generic feature of power-law couplings and it can, for a range of parameter values, be larger than previously found.
ISSN:2470-0010
2470-0029
DOI:10.1103/PhysRevD.101.043531