Analytic Bootstrap for $O(N)$ Boundary Conformal Field Theories with Interacting Boundaries (opens in new tab)

We investigate $O(N)$ boundary conformal field theories (BCFTs) with boundary interactions in $d=4-\epsilon$ and $d=3-\epsilon$ employing the analytic bootstrap. By deriving universal constraints on conformal data, we show that infinitely many operator expansions can be expressed in terms of a finite set of inputs. Complementing the analytic bootstrap with a perturbative renormalization-group analysis, we identify totally new boundary fixed po...