期刊
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
卷 -, 期 10, 页码 -出版社
IOP PUBLISHING LTD
DOI: 10.1088/1475-7516/2010/10/031
关键词
alternatives to inflation; non-gaussianity; cosmological perturbation theory; quantum gravity phenomenology
资金
- Mitsubishi Foundation
- World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan
- [21.8966]
- [17740134]
- [19GS0219]
- [21111006]
- [21540278]
A Lifshitz scalar with the dynamical critical exponent z = 3 obtains scale-invariant, super-horizon field fluctuations without the need of an inflationary era. Since this mechanism is due to the special scaling of the Lifshitz scalar and persists in the presence of unsuppressed self-couplings, the resulting fluctuation spectrum can deviate from a Gaussian distribution. We study the non-Gaussian nature of the Lifshitz scalar's intrinsic field fluctuations, and show that primordial curvature perturbations sourced from such field fluctuations can have large non-Gaussianity of order f(NL) = O(100), which will be detected by upcoming CMB observations. We compute the bispectrum and trispectrum of the fluctuations, and discuss their con figurations in momentum space. In particular, the bispectrum is found to take various shapes, including the local, equilateral, and orthogonal shapes. Intriguingly, all integrals in the in-in formalism can be performed analytically.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据