One extra field could make quantum gravity both finite and consistent

Quantum gravity has long faced a fundamental tension: approaches that remove infinities typically violate unitarity, and vice versa. By introducing a Lagrange multiplier field that constrains quantum corrections at one-loop order, this model sidesteps that conflict while recovering standard Einstein field equations in the classical limit. The construction is minimal — no extra propagating degrees of freedom are added beyond what the constraint requires. If the unitarity and renormalizability claims hold under further scrutiny, this would represent a technically conservative path toward a self-consistent perturbative quantum gravity.