Addendum to ‘Property (FA) and lattices in SU(2, 1)’

Two proofs in [10] contain errors and the statement of [10, Thm. 1] requires correction. The purpose of this note is to correct these. Fortunately, the corrections allow us to extend [10, Thm. 3] to higher dimensions. We now describe the organization of this addendum. The first section corrects the statement of [10, Thm. 1]. The second section corrects [10, Prop. 19], which applies to [10, Thm. 3] and [10, Cor. 4]. This correction requires an extra hypothesis that, conjecturally, is unnecessary. Finally, §3 gives a corrected proof of [10, Prop. 20]. The corrected proof also implies Theorem 3.1 below, which generalizes [10, Thm. 3] to SU(n, 1) for n ≥ 4 (independent from the corrections to [10, Thm. 3]).