Characterization of γ-factors: the Asai case
arXiv:0910.3128 · doi:10.1093/imrn/rns171
Abstract
Let be a separable quadratic extension of a locally compact field of positive characteristic. Asai γ-factors are defined for smooth irreducible representations πof . If σis the Weil-Deligne representation of corresponding to πunder the local Langlands correspondence, we show that the Asai γ-factor is the same as the Deligne-Langlands γ-factor of the Weil-Deligne representation of obtained from σunder tensor induction. This is achieved by proving that Asai γ-factors are characterized by their local properties together with their role in global functional equations for -functions. As an immediate application, we establish the stability property of γ-factors under twists by highly ramified characters.