We provide a new instance of singular relative Langlands duality, underlying a Rankin-Selberg integral on GSO(6) due to Bump-Friedberg-Ginzburg. We conclude that this integral represents an essentially self-dual object in the relative Langlands program, and we demonstrate that the Langlands dual automorphic integral computes a finite sum of L-functions, reflecting stacky structure on the spectral side.
This is joint work with Antonio Cauchi and Eric Yen-Yo Chen.
