Matter bispectrum in cubic Galileon cosmologies

Abstract

In this paper we obtain the bispectrum of dark matter density perturbations in the frame of covariant cubic Galileon theories. This result is obtained by means of a semi-analytic approach to second-order perturbations in Galileon cosmologies, assuming Gaussian initial conditions. In particular, we show that, even in the presence of large deviations of the linear growth-rate w.r.t. the ΛCDM one, at the bispectrum level such deviations are reduced to a few percent.

38 pages, 8 figures. Minor changes. References added. Published version