For a single free scalar field in d ≥ 2 dimensions, almost all the unitary conformal defects must be ‘trivial’ in the sense that they cannot hold interesting dynamics. The only possible exceptions are monodromy defects in d ≥ 4 and co-dimension three defects in d ≥ 5. As an intermediate result we show that the n -point correlation functions of a conformal theory with a generalized free spectrum must be those of the generalized free theory.

中文翻译：

---

自由标量场的线和表面缺陷

对于 d ≥ 2 维的单个自由标量场，几乎所有的幺正共形缺陷都必须是“微不足道的”，因为它们不能保持有趣的动力学。唯一可能的例外是 d ≥ 4 中的单向性缺陷和 d ≥ 5 中的共维三缺陷。 作为中间结果，我们表明具有广义自由谱的共形理论的 n 点相关函数必须是广义自由谱的那些自由理论。