Observational status of the Galileon model general solution from cosmological data and gravitational waves

Understand

The Galileon model is a tensor-scalar theory of gravity which explains the late acceleration of the Universe expansion with no instabilities and recovers General Relativity in the strong field limit.

• Most constraints obtained so far on Galileon model parameters from cosmological data were derived for the limited subset of tracker solutions and reported tensions between the model and data.
• This paper presents the first exploration of the general solution of the Galileon model, which is confronted against recent cosmological data for both background observables and linear perturbations, using Monte-Carlo Markov chains.
• As representative scenarios of the Galileon models, we study the full Galileon model with disformal coupling to matter and the uncoupled cubic Galileon model.