Signed fundamental domains for totally real number fields

Perfect Forms over Totally Real Number Fields

A rational positive-definite quadratic form is perfect if it can be reconstructed from the knowledge of its minimal nonzero value m and the finite set of integral vectors v such that f(v) = m. This concept was introduced by Voronöı and later generalized by Koecher to arbitrary number fields. One knows that up to a natural “change of variables” equivalence, there are only finitely many perfect f...

On Shintani’s ray class invariant for totally real number fields

We introduce a ray class invariant X(C) for a totally real field, following Shintani’s work in the real quadratic case. We prove a factorization formula X(C) = X1(C) · · ·Xn(C) where each Xi(C) corresponds to a real place (Theorem 3.5). Although this factorization depends a priori on some choices (especially on a cone decomposition), we can show that it is actually independent of these choices ...

Fundamental units in a parametric family of not totally real quintic number fields

In this article we compute fundamental units for a family of number fields generated by a parametric polynomial of degree 5 with signature (1, 2) and Galois group D5.

Gross–Stark units for totally real number fields

Signed Interval Logi on Totally Ordered Domains