Constraints on the interacting vacuum-geodesic CDM scenario
| Autor: | Marco Bruni, M. Martinelli, David Wands, Natalie B. Hogg, Simone Peirone |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Physics
Cosmology and Nongalactic Astrophysics (astro-ph.CO) Cold dark matter Geodesic Cosmic microwave background Dark matter RCUK FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics ST/N504245/1 Redshift dark matter symbols.namesake Theoretical physics Vacuum energy Space and Planetary Science cosmology: theory Dark energy symbols ST/N000668/1 Planck dark energy STFC Astrophysics - Cosmology and Nongalactic Astrophysics |
| Zdroj: | Monthly Notices of the Royal Astronomical Society, 488(3), 3423–3438 Martinelli, M, Hogg, N, Peirone, S, Bruni, M & Wands, D 2019, ' Constraints on the interacting vacuum-geodesic CDM scenario ', Monthly Notices of the Royal Astronomical Society, vol. 488, no. 3, pp. 3423-3438 . https://doi.org/10.1093/mnras/stz1915 |
| DOI: | 10.1093/mnras/stz1915 |
| Popis: | We investigate an interacting dark sector scenario in which the vacuum energy is free to interact with cold dark matter (CDM), which itself is assumed to cluster under the sole action of gravity, i.e. it is in free fall (geodesic), as in $\Lambda$CDM. The interaction is characterised by a dimensionless coupling $q_{\rm V}$ that we constrain using cosmic microwave background data from the Planck 2015 data release, along with baryon acoustic oscillation, redshift space distortion and Type Ia supernova measurements. We present the full linear perturbation theory of this interacting scenario and use MCMC sampling to study five different cases: two cases in which we have $\Lambda$CDM evolution in the distant past, until a set redshift $z_{\rm trans}$, below which the interaction switches on and $q_{\rm V}$ is the single sampled parameter, with $z_{\rm trans}$ fixed at $z_{\rm trans}=3000$ and $z_{\rm trans}=0.9$ respectively; a case where we allow this transition redshift to vary along with $q_{\rm V}$; a case in which the vacuum energy is zero for $z>z_{\rm trans}$ and then begins to grow once the interaction switches on; and the final case in which we bin $q_{\rm V}(z)$ in four redshift bins to investigate the possibility of a dynamical interaction, reconstructing the redshift evolution of the function using Gaussian processes. We find that, in all cases where the high redshift evolution is not modified, the results are compatible with a vanishing coupling, thus finding no significant deviation from $\Lambda$CDM. Comment: 17 pages, 14 figures. Version 2 aligns with the published MNRAS article (some model comparison discussion added with respect to version 1) |
| Databáze: | OpenAIRE |
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