We revisit the paper [Automorphy lifting for residually reduciblel-adic Galois representations, J. Amer. Math. Soc. 28 (2015), 785–870] by the third author. We prove new automorphy lifting theorems for residually reducible Galois representations of unitary type in which the residual representation is permitted to have an arbitrary number of irreducible constituents.This work was partially conducted during the period that J.T. served as a Clay Research Fellow. J.T.’s work received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 714405). J.T. would like to thank Lue Pan for pointing out an error in [Tho15], which is addressed here in §3.1 below.
P.A. was supported by Simons Foundation Collaboration Grant 527275 and NSF grant DMS- 1902155