The wavefront set over a maximal unramified field extension

Abstract: Let $(\pi,X)$ be a depth-$0$ admissible smooth complex representation of a $p$-adic reductive group that splits over an unramified extension. In this paper we develop the theory necessary to study the wavefront set of $X$ over a maximal unramified field extension of the base $p$-adic field. In the final section we then apply these methods to compute the geometric wavefront set of spherical Arthur representations of split $p$-adic reductive groups. In this case we see how the wavefront set over a maximal unramified extension can be computed using perverse sheaves on the Langlands dual group.