DBI Galileon in the Effective Field Theory of Inflation: Orthogonal non-Gaussianities and constraints from the Trispectrum

Understand

Very few explicit inflationary scenarios are known to generate a large bispectrum of orthogonal shape.

• Dirac-Born-Infeld Galileon inflation, in which an induced gravity term is added to the DBI action, is one such model.
• We formulate it in the language of the effective field theory of inflation by identifying the unitary gauge operators that govern the behavior of its cosmological fluctuations.
• We show how to recover rather easily from this its power spectrum and bispectrum, which we calculated previously using standard cosmological perturbation theory.