标题： 非最小耦合标量场理论中的非高斯性 显示英文标题

标题： Non-Gaussianity in Nonminimally Coupled Scalar Field Theory

摘要： 我们研究了单场暴胀模型中非高斯性，此时标量场与引力的非最小耦合。具有非最小耦合的引力理论可以通过适当的共形变换转化为爱因斯坦引力和规范动能项。我们发现规范不变量 $\zeta_i$ 的非线性推广在共形变换下是不变的。借助这一共形不变性质，我们在非最小耦合标量场理论中计算了由非线性参数 $f_{NL}$ 表征的非高斯性。 显示英文摘要

摘要： We consider the non-Gaussianity of the nonlinear density perturbations in a single-field inflationary model when a scalar field couples nonminimally with gravity. Gravity theories with a nonminimal coupling can be transformed into the Einstein gravity with canonical kinetic terms by using a suitable conformal transformation. We find that a nonlinear generalization of the gauge invariant quantity $\zeta_i$ is invariant under the conformal transformation. With the help of this conformal invariant property, we calculate the non-Gaussianity, which is characterized by a nonlinear parameter $f_{NL}$, in nonminimal coupled scalar field theory.