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arXiv · 1809.03329

Brans-Dicke cosmology mimicking running vacuum

Javier de Cruz Perez·Joan Sola
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Abstract

Brans-Dicke (BD) cosmology is reconsidered from an approach in which the model can be formulated in $Λ$CDM form, but at the expense of replacing the rigid cosmological constant $Λ$ with a dynamical quasivacuum component which depends on a small parameter $ε$. The product of $ε$ times the BD-parameter $ω_{\rm BD}$ becomes exactly determined in terms of the ordinary cosmological parameters. The GR limit is recovered for $ω_{\rm BD}\to\infty$ when $ε\to 0$. We solve the background cosmology of the model as well as the perturbations equations. When fitted to the cosmological data, we find that the BD-cosmology, transcribed in such an effective GR form, appears to be competitive with the $Λ$CDM and emulates the running vacuum model.

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BibTeXRIS

Javier de Cruz Perez, Joan Sola. 2018-11-03. Brans-Dicke cosmology mimicking running vacuum. https://doi.org/10.1142/s0217732318502280

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