题 目：Effective field theory and in-in correlators
报 告 人：孙冠豪（加州大学圣迭戈分校，博士后）
时 间：2025年3月3号（星期一）上午10:00
地 点：腾讯会议：307-595-513 （线下物理学院LE201 ）
邀 请 人：郑绪昌
报告摘要：Equal-time in-in correlation functions are important observables for cosmological models and quantum field theories in other spacetimes. In this talk, we 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 the EFT. These terms are localized at the time of the measurement, and local or semilocal in space. In flat spacetime, an explicit matching calculation is given for in-in correlators of light scalars interacting with a heavy field. We will then show how these additional terms arise generically via exact RG. Finally, we check the corresponding theory in de Sitter and show that the local terms typically redshift away. We will discuss possible future works, including relations to momentum space entanglement that arises from tracing over short-wavelength modes.
报告人介绍：孙冠豪，加州大学圣迭戈分校博士后研究员。2022年博士毕业于哥伦比亚大学物理系。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。
