论文标题
BCFT中的操作员扩展，层敏感性和两点功能
Operator expansions, layer susceptibility and two-point functions in BCFT
论文作者
论文摘要
我们表明，在边界CFT中，存在两点相关函数的边界运算符的扩展与层易感性的功率系列扩展之间存在一对一的对应关系。该一般属性允许直接识别边界频谱和层敏感性的扩展系数，并为在BCFT中有效计算两点相关器开辟了新的方法。为了展示它的工作原理，我们在相关函数$ \ langledarlex_i ϕ^i \ rangle $ $（n）模型的非凡过渡中的$ \ langle ϕ_i ϕ^i \ rangle $中，以4- $ $ $ε$尺寸半infinite空间到订单$ o（ε）$。两点函数的批量操作员产品扩展可访问散装CFT的光谱。在我们的示例中，我们获得了O（n）模型的标量复合算子的平均异常尺寸，以订购$ O（ε^2）$。这些与已知的结果均以$ε$和大N扩展为一致。
We show that in boundary CFTs, there exists a one-to-one correspondence between the boundary operator expansion of the two-point correlation function and a power series expansion of the layer susceptibility. This general property allows the direct identification of the boundary spectrum and expansion coefficients from the layer susceptibility and opens a new way for efficient calculations of two-point correlators in BCFTs. To show how it works we derive an explicit expression for the correlation function $\langleϕ_i ϕ^i\rangle$ of the O(N) model at the extraordinary transition in 4-$ε$ dimensional semi-infinite space to order $O(ε)$. The bulk operator product expansion of the two-point function gives access to the spectrum of the bulk CFT. In our example, we obtain the averaged anomalous dimensions of scalar composite operators of the O(N) model to order $O(ε^2)$. These agree with the known results both in $ε$ and large-N expansions.
