Let $F$ be a non-Archimedean locally compact field‎. ‎Let $sigma$ and $tau$ be finite-dimensional representations of the Weil-Deligne group of $F$‎. ‎We give strong upper and lower bounds for the Artin and Swan exponents of $sigmaotimestau$ in terms of those of $sigma$ and $tau$‎. ‎We give a different lower bound in terms of $sigmaotimeschecksigma$ and $tauotimeschecktau$‎. ‎Using the Langlands...

In 1979, Lusztig proposed a cohomological construction of supercuspidal representations of reductive p-adic groups, analogous to Deligne–Lusztig theory for finite reductive groups. In this paper we establish a new instance of Lusztig’s program. Precisely, let X be the Deligne–Lusztig (ind-pro-)scheme associated to a division algebra D over a non-Archimedean local field K of positive characteris...

We prove a 1979 conjecture of Lusztig on the cohomology of semi-infinite Deligne– Lusztig varieties attached to division algebras over local fields. We also prove the two conjectures of Boyarchenko on these varieties. It is known that in this setting, the semi-infinite Deligne–Lusztig varieties are ind-schemes comprised of limits of certain finite-type schemes Xh. Boyarchenko’s two conjectures ...

We study the double cosets of a Lie group by a compact Lie subgroup. We show that a Weil formula holds for double coset Lie hypergroups and show that certain representations of the Lie group lift to representations of the double coset Lie hypergroup. We characterize smooth (analytic) vectors of these lifted representations.

An explicit expression for the ε-factor εK((V,N),ψ,dμ) of a representation (V,N) of the Weil-Deligne group WDK of a local field K is given in terms of the nonabelian local class field theory of K.

Abstract We show that an orthogonal root number of a tempered L -parameter $$\varphi $$ φ decomposes as the product two other numbers: principal parameter and value on central involution Langlands’s character for . The formula resolves conjecture Gross Reeder computes numbers Weil–Deligne representations aris...