theorem Keff_zero_at_critical {J : ℕ} {ρ Tstar : ℝ} (hT : 0 < Tstar) :
effectiveCurvatureKeff J ρ Tstar Tstar = 0 := by
unfold effectiveCurvatureKeff
rw [div_self (ne_of_gt hT), sub_self, max_eq_left (le_refl 0), mul_zero]Renormalization Group for CES: