One-point functions for doubly-holographic BCFTs and backreacting defects

We derive one-point functions in 4d $\mathcal N=4$ SYM with $\tfrac{1}{2}$-BPS boundaries, defects and interfaces which host large numbers of defect degrees of freedom. The theories are engineered by Gaiotto-Witten D3/D5/NS5 brane setups with large numbers of D5 and NS5 branes, and have holographic duals with fully backreacted 5-branes. They include BCFTs with 3d SCFTs on the boundary which allow for the notion of double holography, as well as D3/D5 defects and interfaces with large numbers of D5-branes. Through a combination of supersymmetric localization and holography we derive one-point functions for 4d chiral primary operators.