Do Observations Favour Galileon Over Quintessence?

TL;DR

This paper investigates whether current cosmological observations favor the Galileon scalar field model, derived from DGP theory, over traditional quintessence models, finding that data prefers Galileon for certain potentials.

Contribution

It demonstrates that observational data can distinguish Galileon models from quintessence, favoring Galileon for linear, quadratic, and exponential potentials, highlighting the importance of higher derivative corrections.

Findings

Data prefers Galileon over quintessence for specific potentials

Galileon corrections are necessary for accurate late-time universe modeling

Higher derivative terms improve fit to observational data

Abstract

We study the Galileon scalar field model arising as a decoupling limit of the Dvali-Gababdaze-Porrati (DGP) construction for the late time acceleration of the universe. The model has one extra Galileon correction term over and above the standard kinetic and potential energy terms for a canonical quintessence field. We aim to study whether the current observational data can distinguish between this Galileon field and the quintessence field. Our study shows the remarkable result that for potentials like linear, square or exponential, the data prefers the Galileon model over quintessence field. It confirms that the observable universe demands the inclusion of higher derivative Galileon corrections in the standard quintessence scalar field models.