Normalization and the scalar second variation

These are the coefficient equations of (eq:equations). They are assumptions defining the model, not equations derived from the Enter records.

The exact zero-scalar background is $(\eta ,0)$. A nonzero ${\varphi }_0$ in (eq:expansion) is a leading coupling-expansion coefficient. It is not asserted to be an exact nonzero Minkowski Einstein–scalar background at nonzero coupling. This distinction is also essential in VI CheungVI.