Explain why it makes sense to introduce the factor 1
α
and the parameter γ
in the expression for the weight operator (18.34). Consider possible modifications of
this formula, which do not violate the homogeneity of the propagator of the different
modes of the metric perturbations and ghosts in the UV limit.
Observation. The reader can postpone this exercise until after sections 18.3, 20.4 and
20.5.
ses