Speaker
Dr. Chia-Hsien Shen
Date/Time
Date(s) - 03/12/2025
13:30 - 15:00
Announcing the QFT Colloquium on Wednesday, 3 December, at 13:30, at room 1.221 (CSMB building), Zum Großen Windkanal 2, 12489 Berlin.
Dr. Chia-Hsien Shen (Uppsala University & National Taiwan University)
Abstract:
Renormalization group (RG) evolution is a fundamental feature of quantum field theory, playing a pivotal role in both its formal structures and phenomenological applications in particle physics and beyond. While the framework for calculating RG flows is well established, unexpected patterns continue to emerge. In this talk, I will leverage fundamental principles—unitarity and analyticity—to constrain the direction of RG evolution in effective field theory that shares a similar spirit as the a-theorem in conformal field theory. This result can be understood as an infrared avatar of positivity bound. For phenomenological applications, I will discuss examples in chiral perturbation theory and the Standard Model Effective Field Theory. I will also discuss a similar behavior in the renormalization of the dynamical tidal Love numbers of Schwarzschild black holes. This talk is based on 2505.02910 and work in progress.
Join via zoom:
https://hu-berlin.zoom-x.de/j/62678657968?pwd=N0RKd3U2WWF0cnk0SG0wdEEwOExPZz09