Lyth David H, Rodríguez Yeinzon
Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom.
Phys Rev Lett. 2005 Sep 16;95(12):121302. doi: 10.1103/PhysRevLett.95.121302.
We extend the deltaN formalism so that it gives all of the stochastic properties of the primordial curvature perturbation zeta if the initial field perturbations are Gaussian. The calculation requires only the knowledge of some family of unperturbed universes. A formula is given for the normalization f(NL) of the bispectrum of zeta, which is the main signal of non-Gaussianity. Examples of the use of the formula are given, and its relation to cosmological perturbation theory is explained.
我们扩展了δN形式体系，以便在初始场扰动为高斯分布时，它能给出原初曲率微扰ζ的所有随机性质。该计算仅需要一些未微扰宇宙族的知识。给出了ζ的双谱归一化f(NL)的公式，ζ的双谱是非高斯性的主要信号。给出了该公式的使用示例，并解释了它与宇宙学微扰理论的关系。
