Irreversibility, QNEC and defects

We establish the irreversibility of renormalization group flows on planar d-dimensional defects embedded in D-dimensional conformal field theories by studying the behavior of relative entropy under null deformations. This proof completes and unifies all known irreversibility theorems for defect dimensions d≤4. The F theorem on defects d=3 is a new result that, so far, only has an information theory proof.