The results of [2] on the congruence of Ankeny-Artin-Chowla type modulo p² for real subfields of of a prime degree l is simplified. This is done on the basis of a congruence for the Gauss period (Theorem 1). The results are applied for the quadratic field ℚ(√p), p ≡ 5 (mod 8) (Corollary 1).
In this note we will determine the associated order of relative extensions of algebraic number fields, which are cyclic of prime order p, assuming that the ground field is linearly disjoint to the pth cyclotomic field, . For quadratic extensions we will furthermore characterize when the ring of integers of the extension field is free over the associated order. All our proofs are quite elementary. As an application, we will determine the Galois module structure of .
Let be a prime, let . Let be the norm of under , so that is a purely ramified extension of discrete valuation rings of degree . The minimal polynomial of over is an Eisenstein polynomial; we give lower bounds for its coefficient valuations at . The function field analogue, as introduced by Carlitz and Hayes, is studied as well.