Past exam of the mathematics course of the University of Cambridge / 2026 / iii / Paper 303 / 3 / a / i / Solution

At a fixed point, the order parameter can be chosen as a dilation eigenoperator. Therefore, for $x^{\prime }=x/\zeta$,Interactions shift ${\Delta }_{\varphi }$ from $(d-2)/2$ to $(d-2+\eta )/2$.

Solved by gpt-5.6-sol high.