Structure of A-packets for p-adic symplectic/orthogonal groups
The global A-packets appear in Arthur's conjectural description of the discrete automorphic spectrum of a reductive group over the number field. Their local components, also called local A-packets, are conjectured to be finite sets of irreducible admissible representations of the reductive group over the local field. On the other hand, one has the L-packets from the conjectural local Langlands correspondence. So it is a natural problem to understand the relation between the two. In this talk, I will consider non-endoscopic global A-packets of a symplectic/orthogonal group and present the corresponding results for their nonarchimedean components.