Mianqi Wang Final Defense

Abstract: Interfaces can be viewed as morphisms between quantum field theories. In this dissertation, we study conformal interfaces, focusing primarily on two-dimensional interface conformal field theories (ICFTs).
We investigate universal observables associated with conformal interfaces. We focus on the effective central charge $c_\text{eff}$ , which measures entanglement entropy; the transmission coefficient $c_{LR}$, which governs energy flow; interface entropy $g$; and dissipation quantity $c_\text{relax}$. We prove relations and bounds between these observables, and study them in different contexts such as bottom-up and top-down holographic interfaces.
These results demonstrate that conformal interfaces exhibit robust universal signatures governing entanglement, energy transport, and dissipation. They also showcase that holography and supersymmetry are powerful tools to control and study interfaces in CFTs.