Causality and Effective Field Theories

Abstract:

Effective Field Theories (EFTs) are a useful low energy description where high-energy modes have been integrated out. While from an EFT point of view, every operator consistent with the symmetries is allowed, not every value of the Wilson coefficients of these operators lead to physical theories.

In this talk, I will show how requiring causal propagation in the IR one can bound the values of the Wilson coefficients in a manner consistent with positivity bounds which require assumptions if the UV.