Book excerpt: Presents twenty-three selected survey articles on central topics of geometric analysis and general relativity, written by prominent experts in the fields. Topics of geometric analysis include the Yamabe problem, mean curvature flow, minimal surfaces, harmonic maps, collapsing of manifolds, and Kähler-Einstein metrics. General relativity topics include the positive mass theorem, the Penrose inequality, scalar curvature and Einstein's constraint equations, and the positive mass theorem for asymptotically hyperbolic manifolds.