We define the p-adic trace of
certain rank-one local systems on the multiplicative group over p-adic numbers, using
Sekiguchi and Suwa’s unification of Kummer and Artin–Schreier–Witt theories. Our
main observation is that, for every nonnegative integer n, the p-adic trace defines an
isomorphism of abelian groups between local systems whose order divides (p − 1)pn
and ℓ-adic characters of the multiplicative group of p-adic integers of depth less than
or equal to n.
Keywords
geometrization, character sheaves, continuous
multiplicative characters of p-adic fields, p-adic trace function, continuous
characters of ℤp×