On anti-tempered local Arthur packets and a lemma of Arthur

Abstract

In this paper, following Arthur’s ideas, we rework the process of constructing the anti-tempered local Arthur packets for quasi-split classical groups and their pure inner forms. In particular, we present explicit examples illustrating a gap in a consequential lemma of Arthur and provide a uniform modification, based on the work of Mœglin, Waldspurger, and Xu.