The cosmological Slavnov-Taylor (ST) identity of the Einstein-Hilbert action coupled to a single inflaton field is obtained from the Becchi-Rouet-Stora-Tyutin (BRST) symmetry associated with diffeomorphism invariance in the Arnowitt-Deser-Misner (ADM) formalism. The consistency conditions between the correlators of the scalar and tensor modes in the squeezed limit are then derived from the ST identity, together with the softly broken conformal symmetry. Maldacena's original relations connecting the correlators of 2- and 3-point functions are also recovered. In this case, we point out a finite correction to the consistency conditions involving one soft graviton which depends on the angle between the soft and the hard momenta.
Date of publication:
JCAP 1603 (2016) no.03, 045