2019/08/12 by Joseph Hundley, Stephen D. Miller, Hundley, Joseph +1
Mathematics · #Advanced Algebra and Geometry #Advanced Operator Algebra Research #Finite Group Theory Research #math.NT #math.RT
paper · pdf · doi:10.48550/arxiv.1908.04363
openalex publication_date 2019/08/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Arthur's conjectures predict the existence of some very interesting unitary representations occurring in spaces of automorphic forms. We prove the unitarity of the "Langlands element" (i.e., the one specified by Arthur) of all unipotent Arthur packets for split real groups. The proof uses Eisenstein series, Langlands' constant term formula and square integrability criterion, analytic properties of intertwining operators, and some mild arithmetic input from the theory of Dirichlet L-functions, to reduce to a more combinatorial problem about intertwining operators. This updated arXiv posting also includes some comments (in blue) concerning statements about normalized intertwining operators we quoted from the literature in Section 9.