Commutative algebraic groups and p-adic linear forms

Forms and Linear Algebraic Groups

Behavior of $R$-groups for $p$-adic inner forms of quasi-split special unitary groups

‎We study $R$-groups for $p$-adic inner forms of quasi-split special unitary groups‎. ‎We prove Arthur's conjecture‎, ‎the isomorphism between the Knapp-Stein $R$-group and the Langlands-Arthur $R$-group‎, ‎for quasi-split special unitary groups and their inner forms‎. ‎Furthermore‎, ‎we investigate the invariance of the Knapp-Stein $R$-group within $L$-packets and between inner forms‎. ‎This w...

Twisted signs for p-adic linear groups

Let G be a reductive p-adic group and let θ be an automorphism of G of order at most two. Let π be an irreducible smooth representation of G that is taken to its dual by θ. The space V of π then carries a non-zero bilinear form ( , ) ( unique up to scaling) with the invariance property (π(g)v, π(g)w) = (v, w), for g ∈ G and v, w ∈ V . The form is easily seen to be symmetric or skew-symmetric an...

Twisting Commutative Algebraic Groups

If V is a commutative algebraic group over a field k, O is a commutative ring that acts on V , and I is a finitely generated free O-module with a right action of the absolute Galois group of k, then there is a commutative algebraic group I ⊗O V over k, which is a twist of a power of V . These group varieties have applications to cryptography (in the cases of abelian varieties and algebraic tori...

THE abc THEOREM FOR COMMUTATIVE ALGEBRAIC GROUPS IN CHARACTERISTIC p

Buium proved what he called the abc theorem for abelian varieties over function fields in characteristic zero [3]. Using methods of algebraic model theory we prove an analog of his theorem for commutative algebraic groups in characteristic p. In what follows, k is an algebraically closed field of characteristic p, C is a smooth projective curve over k, and K = k(C) is the function field of C. I...