An R=T theorem for certain orthogonal Shimura varieties

Abstract

We prove an almost minimal R=T theorem for self-dual Galois representations with coefficients in a finite field satisfying a property called rigid. We also prove the rigidity property for a large family of residual Galois representations attached to regular algebraic self-dual representations. Our theorem is based on a Taylor--Wiles patching argument for G-valued Galois representation, where G equals GO(2m) or GSp(2m).