Ph.D. (1992) Princeton University
Algebraic number theory
My research is in Galois theory. This is the branch of mathematics concerned with symmetries of solutions of equations. There is an object that encodes all symmetries of solutions to all equations, the absolute Galois group of the rational numbers. I study this object and its relations with number theory. The study of these symmetries has gained an increasingly important role in number theory in recent years. In particular, Galois theory played an important role in the solution of Fermat's Last Theorem.
Deforming Galois representations and the conjectures of Serre and Fontaine-Mazur, Ann. of Math. (2) 156 no. 1 (2002), 115–154.
Deformations of certain reducible Galois representations, J. Ramanujan Math. Soc. 17 no. 1 (2002), 51–63.
Finitenss of Selmer groups and deformation rings, Invent. Math. 154 (2003), 179–198.
Transcendental $\ell$-adic Galois representations (with C. Khare and M. Larsen), Math Research Letters 12 (2005), 685–700.Constructing semisimple p-adic Galois representations with prescribed properties (with C. Khare and M. Larsen), American Journal of Mathematics 127 (2005), 709–734.