Fermi Liquid Fixed Point Deformations due to Codimension Two Defects
Codimension-two defects in Fermi liquids deform renormalization group flow via a marginally relevant coupling, creating logarithmic running different from the Kondo problem. This occurs because momentum constraints along the defect axis induce particle-hole asymmetry, allowing generic couplings to run. The mechanism is distinct from dynamical impurities and requires an effective field theory approach.