WITT VECTORS AND A QUESTION OF KEATING AND RUDNICK 1 ...

• exposé

WITT VECTORS AND A QUESTION OF KEATING AND RUDNICK NICHOLAS M. KATZ 1. Introduction We work over a finite field k = Fq inside a fixed algebraic closure k, and fix an integer n ≥ 2. We form the k-algebra B := k[X]/(Xn+1). Following Keating and Rudnick, we say that a character Λ : B× → C× is “even” if it is trivial on the subgroup k×.

• bigwittn
• primn
• artin- schreier sheaf lψ
• lisse sheaf lλ
• witt vectors
• unitary group
• bigwitt
• r−1
• conjugacy classes
• ring