报告题目：On the importance of heavy fields in pseudo-scalar inflation
报 告 人：王子威（博士后），中国科学院紫金山天文台（南京）
邀 请 人：周思益
时 间： 2023年8月11号（星期五）9:00
地 点： 腾讯会议197-102-247 和 重庆大学物理学院LE201
Abstract: Pseudo-scalar inflation coupled with U(1) gauge fields through the Chern-Simons term has been extensively studied. However, new physics arising from UV theories may still influence the pseudo-scalar field at low-energy scales, potentially impacting predictions of inflation. In the realm of effective field theory (EFT), we investigated axion inflation, where operators from heavy fields are also present, in addition to the axion and gauge fields. The integrated out fields have two significant effects: the non-linear dispersion regime and coupling heavy modes to the Chern-Simons term. The first effect changes the propagation of the curvature fluctuation, while the second one results in additional operators that contribute to curvature fluctuation via inverse decay. We derived the power spectrum and magnitude of equilateral non-Gaussianity in this low-energy EFT. We found that the second effect could become significant as the mass of heavy fields approaches Hubble scale.
Brief CV: 王子威博士2017年本科毕业于中国科学技术大学严济慈物理英才班，2017年至2022年在麦克吉尔大学读博士。博士导师是Robert Brandenberger教授。2022年至2023年在日本神户大学担任JSPS博士后。2023年起在南京中科院紫金山天文台担任博士后研究员。研究方向为宇宙学，主要从事暗物质、宇宙起源及早期演化相关理论研究。目前在国际期刊上发表11篇论文。
