May 2, 2011
I will discuss some results obtained in the framework of the effective theory of inflation. First, I will discuss the consequences on non-Gaussianities of imposing an approximate Galilean symmetry on the effective theory. I will describe new shapes of non-Gaussianity and the possibility of observing a large four-point function. Afterwards, I will prove that, in generic single field models, the consistency relation for the 3-point function in the squeezed limit receives corrections that vanish quadratically in the ratio of the momenta. This has important consequences for large scale structure observations: a detection of a bispectrum signal suppressed by one power of momentum compared to the local shape would rule out all single-field models.
