https://doi.org/10.1140/epjc/s10052-013-2352-7
Regular Article - Theoretical Physics
Dark radiation and dark matter coupled to holographic Ricci dark energy
Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Ciudad Universitaria, Pabellón I, 1428, Buenos Aires, Argentina
* e-mail: martin@df.uba.ar
Received:
20
February
2013
Published online:
9
April
2013
We investigate a universe filled with interacting dark matter, holographic dark energy, and dark radiation for the spatially flat Friedmann–Robertson–Walker (FRW) spacetime. We use a linear interaction to reconstruct all the component energy densities in terms of the scale factor by directly solving the balance’s equations along with the source equation. We apply the χ
2 method to the observational Hubble data for constraining the cosmic parameters, contrast with the Union 2 sample of supernovae, and analyze the amount of dark energy in the radiation era. It turns out that our model exhibits an excess of dark energy in the recombination era whereas the stringent bound Ω
x
(z≃1010)<0.21 at big-bang nucleosynthesis is fulfilled. We find that the interaction provides a physical mechanism for alleviating the triple cosmic coincidence and this leads to 
.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2013
