报告题目：Effective field theory and in-in correlators

报 告 人：Guanhao Sun 孙冠豪 (Chongqing University)

报告时间：2025年11月6日14：30

报告地点：物理楼W260

内容摘要：Equal-time in-in correlation functions are important observables for cosmological models and quantum field theories. In this talk, I will explore how the Wilsonian renormalization group and effective field theory (EFT) apply to these observables in both flat and de Sitter space. Specifically, matching the UV and IR requires additional terms not captured by conventional EFT. These terms are localized at the time of the measurement, and (semi-)local in space. In flat spacetime, an explicit matching calculation is given for in-in correlators of light scalars interacting with a heavy field. I will then show how these additional terms arise generically via exact RG. Finally, I will check the corresponding theory in de Sitter and show that the local terms typically redshift away. Some ongoing and potential future follow-up works will be briefly discussed at the end.

报告人简介：孙冠豪，重庆大学弘深青年教师。2022年博士毕业于哥伦比亚大学物理系，2022-25年任加州大学圣迭戈分校博士后研究员。主要研究方向为有效场论和宇宙学。发表文章涵盖暴胀理论，基础量子场论，凝聚态有效场论，黑洞超辐射等主题。