First and second order cosmological perturbations in light mass Galileon
  models
  In this paper, we investigate the first and second order cosmological
perturbations in the light mass Galileon (LMG) scenario. LMG action includes
cubic Galileon term along with the standard kinetic term and a potential which
is added phenomenologically to achieve late time acceleration. The scalar field
is nonminimally coupled to matter in the Einstein frame. Integral solutions of
growing and decaying modes are obtained. The effect of the conformal coupling
constant ($\beta$), at the perturbation level, has been studied. In this
regard, we have studied linear power spectrum and bispectrum. Though different
values of $\beta$ has different effects on power spectrum on reduced bispectrum
the effect is not significant. It has been found that the redshift-space
distortions (RSD) data can be very useful to constrain $\beta$. In this study
we consider potentials which can lead to tracker behavior of the scalar field.
