3 papers
hep-th2025
Geometric Building Blocks of Effective Field Theory Amplitudes
Timothy Cohen, Xu-Xiang Li, Zhengkang Zhang
On-shell amplitudes are invariant under field redefinitions. Nonderivative field redefinitions have a natural interpretation as coordinate transformations on the target manifold. G…
hep-th2025
Geometry of soft scalars at one loop
Timothy Cohen, Ipak Fadakar, Andreas Helset +1
We extend the soft theorems for scattering amplitudes of scalar effective field theories to one-loop order. Our analysis requires carefully accounting for the fact that the soft li…
hep-th2024
Field Redefinitions Can Be Nonlocal
Timothy Cohen, Matthew Forslund, Andreas Helset
We revisit the lore establishing the allowed space of field redefinitions and show that there are essentially no restrictions. Our conclusions hold to all orders in perturbation th…