标题： 光束求和规则和c-异常 显示英文标题

标题： Light-ray sum rules and the c-anomaly

摘要： 在一个四维量子场论中，该理论在重整化群下在两个固定点之间流动，共形异常$\Delta a$的变化已被与平均零能相关联。我们将这一结果扩展，以推导出另一个异常系数$\Delta c$的求和规则，该规则以应力张量三点函数表示。虽然$\Delta a$的求和规则是平均零能算符的期望值，因此为正，但$\Delta c$的结果涉及非对角矩阵元，因此没有固定的符号。 显示英文摘要

摘要： In a four-dimensional quantum field theory that flows between two fixed points under the renormalization group, the change in the conformal anomaly $\Delta a$ has been related to the average null energy. We extend this result to derive a sum rule for the other anomaly coefficient, $\Delta c$, in terms of the stress tensor three-point function. While the sum rule for $\Delta a$ is an expectation value of the averaged null energy operator, and therefore positive, the result for $\Delta c$ involves the off-diagonal matrix elements, so it does not have a fixed sign.