Tame cuspidal representations in non-defining characteristics

Abstract

Let F be a non-archimedean local field of odd residual characteristic p. Let G be a (connected) reductive group that splits over a tamely ramified field extension of F. We show that a construction analogous to Yu's construction of complex supercuspidal representations yields smooth, irreducible, cuspidal representations over an arbitrary algebraically closed field R of characteristic different from p. Moreover, we prove that this construction provides all smooth, irreducible, cuspidal R-representations if p does not divide the order of the Weyl group of G.

arXiv comment12 pages; the revised version focuses on modular coefficients (previously Sections 5 to 7); for the case of complex representations see arXiv:1908.09819