  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 2- and
3-point correlators at horizon crossing are recovered, as well as the
next-to-leading corrections, controlled by the special conformal
transformations.
