Non-Gaussian perturbations from multi-field inflation
Non-Gaussian perturbations from multi-field inflation
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DOI：
10.1088/1475-7516/2006/01/006
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发表时间：
2006-01-01
影响因子：
6.4
通讯作者：
Wands, D
中科院分区：
文献类型：
--
作者：
Allen, LE;Gupta, S;Wands, D
我们展示了如何原始的密度扰动的双谱，从通货膨胀的特点是明显规范不变的宇宙学扰动在二阶。描述大尺度上均匀密度超曲面的扰动扩张的原始度量扰动zeta与未扰动（空间上）上的标量场扰动有关。at）一阶和二阶超曲面。度规扰动的双谱因此由（i）二阶规范变换的局域贡献和（ii）空间上的场扰动的本征双谱组成。在超曲面上我们概括了以前的结果，以考虑到超哈勃尺度上的场之间可以发展的标量场功率谱和相关性的尺度依赖性。
We show how primordial bispectrum of density perturbations from inflation may be characterized in terms of manifestly gauge-invariant cosmological perturbations at second order. The primordial metric perturbation, zeta, describing the perturbed expansion of uniform-density hypersurfaces on large scales is related to scalar field perturbations on unperturbed (spatially. at) hypersurfaces at first and second order. The bispectrum of the metric perturbation is thus composed of (i) a local contribution due to the second-order gauge transformation, and (ii) the intrinsic bispectrum of the field perturbations on spatially. at hypersurfaces. We generalize previous results to allow for scale dependence of the scalar field power spectra and correlations that can develop between fields on super-Hubble scales.