Xuxiang Li (University of Utah) [HET Lunch Seminar] Geometrizing Effective Field Theories

Friday 12 Dec 2025, 12:00 → 14:00 US/Eastern

https://bnl.zoomgov.com/j/1610974905?pwd=RNUmaMcDbNYgeIBiawRl8bqdx0ICcI.1 (2-160)

Abstract: The redundancy introduced by field redefinitions poses a challenge in the Lagrangian formulation of effective field theories (EFTs), often obscuring the underlying physical content. The analogy between field redefinitions and coordinate transformations suggests that EFTs may admit a geometric reformulation that makes their physics more transparent. While non-derivative field redefinitions can be naturally accommodated within the field space geometry on the target manifold, this formalism breaks down once derivatives enter the transformations. In this talk, I will present an extension of the geometric framework—known as functional geometry—that incorporates derivative field redefinitions, and I will discuss its relation to the field space geometry, focusing on scattering amplitudes. This geometric perspective offers new insights into the structure of EFT amplitudes and paves the way toward a formulation of EFTs free from the redundancies of field redefinitions.