Arthur’s multiplicity formula for even orthogonal and unitary groups

Source abstract

Let F be a number field and G an even orthogonal or unitary group over a number field. Based on the method used by Gan and Ichino (2018), we prove Arthur’s multiplicity formula for the generic part of the automorphic discrete spectrum of G by using the theta lift. Enhancing this method, we also obtain a description of the full automorphic discrete spectrum of G of F -rank \le1 .