Resilience of the standard predictions for primordial tensor modes

摘要: We show that the prediction for primordial tensor power spectrum cannot be modified at leading order in derivatives. Indeed, one can always set to unity speed of propagation gravitational waves during inflation by a suitable disformal transformation metric, while conformal make Planck mass time independent. Therefore, amplitude unambiguously fixes energy scale inflation. Using effective field theory inflation, we check predictions are independent choice frame, as expected. The first corrections standard come from two parity violating operators with three Also correlator ⟨γγγ⟩ is and only receives higher derivative corrections. These results hold also multifield models alternatives connection between (quasi-)scale-invariant completely robust.