标题： 两点闭弦振幅在BRST形式主义中 显示英文标题

标题： Two-point closed string amplitudes in the BRST formalism

摘要： 两点树级振幅在玻色闭弦理论中由BRST形式下的相关函数描述，该相关函数尊重显式的洛伦兹和共形不变性。 在推导两点振幅时，我们使用了主要的BRST精确算符，该算符已用于两点开弦振幅，并且还使用了一个鬼数为三的闭弦顶点，该顶点已在我们的近期工作中进行了探索，除了传统的算符之外。 显示英文摘要

摘要： Two-point tree-level amplitudes in bosonic closed string theory are described by a correlation function within the BRST formalism, which respects manifest Lorentz and conformal invariance. In the derivation of the two-point amplitudes, we use the mostly BRST exact operator, which has been introduced for two-point open string amplitudes, and a closed string vertex with ghost number three, which has been explored in our recent work, in addition to the conventional one.