Vinberg’s representations and arithmetic invariant theory

Arithmetic invariant theory

Arithmetic invariant theory II

2 Lifting results 4 2.1 Pure inner forms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.2 Twisting the representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.3 Rational orbits in the twisted representation . . . . . . . . . . . . . . . . . . . . . . . 5 2.4 A cohomological obstruction to lifting invariants . . . . . . . . . . . . . . . ...

Epipelagic representations and invariant theory

We introduce a new approach to the representation theory of reductive p-adic groups G, based on the Geometric Invariant Theory (GIT) of Moy-Prasad quotients. Stable functionals on these quotients are used to give a new construction of supercuspidal representations of G having small positive depth, called epipelagic. With some restrictions on p, we classify the stable and semistable functionals ...

On Bhargava’s representations and Vinberg’s invariant theory

Manjul Bhargava has recently made a great advance in the arithmetic theory of elliptic curves. Together with his student, Arul Shankar, he determines the average order of the Selmer group Sel(E,m) for an elliptic curve E over Q, when m = 2, 3, 4, 5. We recall that the Selmer group is a finite subgroup of H(Q, E[m]), which is defined by local conditions. Their result (cf. [1, 2]) is that the ave...

Arithmetic Teichmuller Theory

By Grothedieck's Anabelian conjectures, Galois representations landing in outer automorphism group of the algebraic fundamental group which are associated to hyperbolic smooth curves defined over number fields encode all arithmetic information of these curves. The goal of this paper is to develope and arithmetic teichmuller theory, by which we mean, introducing arithmetic objects summarizing th...