The Hilbert Modular Group and Orthogonal Groups

arXiv (Cornell University)

Abstract

We derive an explicit isomorphism between the Hilbert modular group and certain congruence subgroups on the one hand and particular subgroups of the special orthogonal group $SO(2, 2)$ on the other hand. The proof is based on an application of linear algebra adapted to number theoretical needs.

Authors 2

1. Adrian Hauffe-Waschbüsch Aachen Lehrstuhl A für Mathematik

   RWTH Aachen University

   Affiliation as printed

   Lehrstuhl A für Mathematik , RWTH Aachen University , D-52056 Aachen ,

2. Aloys Krieg Aachen Lehrstuhl A für Mathematik

   RWTH Aachen University

   Affiliation as printed

   Lehrstuhl A für Mathematik , RWTH Aachen University , D-52056 Aachen ,