Line Defects and Interfaces from Holography

In this dissertation, we discuss half-BPS solutions of gauged supergravity that are holographic realizations of conformal line defects and interfaces. These solutions are constructed by taking a suitable ansatz for the geometry, consisting of a warped product of an AdS spacetime and a sphere, if necessary, over a line, and solving the supersymmetry variations. Quantities such as one-point functions in the presence of the defect and the entanglement entropy are calculated holographically.In chapter 1, we review the AdS/CFT correspondence and holography. In chapter 2, we relate two different formulations of AdS6 solutions in type IIB supergravity. In chapter 3, we construct solutions in six-dimensional F(4) gauged supergravity that are dual to line defects. In chapter 4, we construct solutions in four-dimensional N = 2 gauged supergravity that are dual to line defects, obtained by a double-analytic continuation of BPS black hole solutions. In chapter 5, we construct Janus solutions in three-dimensional N = 8 gauged supergravity that are dual to interface CFTs