Year: 2008
Type: article
Abstract: We present a new mechanism for generating primordial statistical anisotropy of curvature perturbations. We introduce a vector field which has a non-minimal kinetic term and couples with a waterfall field in a hybrid inflation model. In such a system, the vector field gives fluctuations of the end of inflation and hence induces a subcomponent of curvature perturbations. Since the vector has a preferred direction, the statistical anisotropy could appear in the fluctuations. We present the explicit formula for the statistical anisotropy in the primordial power spectrum and the bispectrum of curvature perturbations. Interestingly, there is the possibility that the statistical anisotropy does not appear in the power spectrum but does appear in the bispectrum. We also find that the statistical anisotropy provides the shape dependence to the bispectrum.
Authors: Shuichiro Yokoyama, Jiro Soda
Institutions: Nagoya University, Kyoto University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: 高強度電磁場中の巨視的真空の幾何学的性質, Research on the possibility of experimentally/observationally verifying higher dimensional theory of spacetime, Probing Evolution of the Universe with Cosmological Gravitational-wave Backgrounds, Study on future galaxy redshift survey for testing dark energy, A Possible Lorentz Violation and Its Impact on Cosmology
OpenAlex ID: W2073441565