Experimental constraints on the uncoupled Galileon model from SNLS3 data and other cosmological probes
Résumé
Aims. The Galileon model is a modified gravity theory that may provide
an explanation for the accelerated expansion of the Universe. This model does not suffer
from instabilities or ghost problems (normally associated with higher-order derivative
theories), restores local General Relativity – thanks to the Vainshtein screening effect –
and predicts late-time acceleration of the expansion.Methods. We derive a new definition of the Galileon parameters that
allows us to avoid having to choose initial conditions for the Galileon field. We tested
this model against precise measurements of the cosmological distances and the rate of
growth of cosmic structures.Results. We observe a weak tension between the constraints set by growth
data and those from distances. However, we find that the Galileon model remains consistent
with current observations and is still competitive with the ΛCDM model, contrary to what
was concluded in recent publications.
Origine : Publication financée par une institution
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