| 日時: |
2014-06-10 14:00 - 15:00 |
| 場所: |
研究本館１階会議室1 |
| 会議名: |
Non-Gaussianities of primordial perturbations and tensor sound speed |
| 連絡先: |
田邉 健太朗、ktanabe-AT-post.kek.jp |
| 講演者: |
山口 昌英 教授 (東京工業大学) |
| 講演言語: |
英語 |
| アブストラクト: |
We investigate the relation between the non-Gaussianities of the primordial perturbations and the sound speed of the tensor perturbations, that is, the propagation speed of the gravitational waves. We find that the sound speed of the tensor perturbations is directly related not to the auto-bispectrum of the tensor perturbations but to the cross-bispectrum of the primordial perturbations, especially, the scalar-tensor-tensor bispectrum. This result is in sharp contrast with the case of the scalar (curvature) perturbations, where their reduced sound speed enhances their auto-bispectrum. Our findings indicate that the scalar-tensor-tensor bispectrum can be a powerful tool to probe the sound speed of the tensor perturbations. |
|
