He was named to the 2021 class of fellows of the American Mathematical Society "for contributions to hyperbolic 3-manifolds, low-dimensional topology, geometric group theory and Teichmuller theory".[5] He was elected to the American Academy of Arts and Sciences in 2023.[6]
with Howard Masur: "Geometry of the complex of curves II: Hierarchical structure", Geometric and Functional Analysis, 10 (4), 902–974.
"The classification of Kleinian surface groups, I: Models and bounds", Annals of Mathematics, 171 (2010), 1–107.
with Jeffrey Brock, and Richard Canary: "The classification of Kleinian surface groups, II: The ending lamination conjecture", Annals of Mathematics, 176 (2012), 1–149.
with Jason Behrstock: "Dimension and rank for mapping class groups", Annals of Mathematics (2) 167 (2008), no. 3, 1055–1077.
"The classification of punctured-torus groups", Annals of Mathematics, 149 (1999), 559–626.
"When Thurston proposed it, the virtual Haken conjecture seemed like a small question, but it hung on stubbornly, shining a spotlight on how little we knew about the field."[7]