**Theory Seminar**

KEK 素粒子原子核研究所・理論セミナー

TITLE： | A further discriminatory signature of inflation |

(in English) | |

SPEAKER： |
Dr. Laila Alabidi
(Yukawa Institute for Theoretical Physics, Kyoto University) |

DATE： | Mar. 19 (Mon.) 15:00 − 16:00 |

PLACE: | Kenkyuhonkan, 1F, Meeting Room 3 |

（ABSTRACT）

In this talk I revise the current status of canonical single field models of inflation in light of the WMAP 7 data, using the observational bounds on the spectral index and tensor fraction, extracted using the large scale measurements of the Cosmic Microwave Background. I then extend this analysis to include models which predict a significant positive running of the spectral index, which can lead to the production of Primordial Black Holes (PBHs) towards the end of inflation. I then explain the concept of induced gravitational waves, which are gravitational waves induced by scalar perturbations re- entering the horizon during nucleosynthesis. I consider the case where the scalar perturbations are created by Hilltop-type and Running Mass Models, and where the gravitational waves are induced early on in the radiation phase of the Universe. I explore the impact a detection of such GWs would have on the field of Inflation Model Discrimination in general. I show that the Hilltop-type model can produce observable induced gravitational waves within the range of BBO and DECIGO for integral and fractional powers of the potential within a reasonable number of e−folds. I also show that the running mass model can produce a spectrum within the range of these detectors, but require that inflation terminates after an unreasonably small number of e−folds.